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Pupillary and Iridovitreal Block in Pseudophakic Eyes
Pupillary and Iridovitreal Block in Pseudophakic Eyes C. ERIC SHRADER, MD, C. DAVIS BELCHER III, MD, JOHN V. THOMAS, MD, RICHARD J. SIMMONS, MD, EDWARD B. MURPHY, MD
Abstract: Twenty-six cases of pupillary and iridovitreal block in pseudophakic eyes are reported. Although ten patients presented with acute angle closure glaucoma, the majority were asymptomatic and had normal intraocular pressures. While cure was finally achieved in all cases, recurrence of block occurred in six eyes as late as two months after initial successful treatment. A variety of therapeutic modalities including argon laser iridectomy, argon laser gonioplasty (iridoplasty), surgical iridectomy, surgical vitrectomy, Q-switched Nd:YAG laser iridectomy and Nd:YAG laser photodisruption of the anterior vitreous face were needed. Despite successful relief of pupillary and iridovitreal block in these eyes with no evidence of glaucoma prior to cataract and lens implant surgery, four eyes developed eight or more clock hours of peripheral anterior synechiae, and nine eyes continue to require chronic medical therapy for glaucoma. [Key words: glaucoma, iridovitreal block, pseudophakos, pupillary block.] Ophthalmology 91 :831-837, 1984
Pupillary block is a well-known complication of cataract surgery with intraocular lens implantation. It was first noted by Ridleyl,2 and has been reported with nearly every known design of pseudophakos. 3-1 3 It is thought that the majority of such patients can be cured with argon laser iridectomy. In the largest previously reported series of seventeen pseudophakic eyes,14 sixteen were cured by argon laser iridectomy with no recurrence of pupillary block. In our series of 26 eyes, however, a significant number developed recurrence of block or failed to respond to argon laser iridectomy alone. Since this report illustrates the spectrum of the disease as seen in a glaucoma referral practice, it is possible that the referral process has preselected more difficult cases for inclusion. Cases of particular interest are those in which iris bombe occurred despite the presence of a full-thickness surgical iridectomy. In some of these cases, block was relieved transiently by argon laser iridectomy but required Nd:YAG laser photodisruption of the vitreous face for permanent relief. Prior to the availability ofthe Nd:YAG laser, such cases may have been misdiagnosed as having malignant glaucoma in aphakia. We hold the view that these cases demonstrate iridovitreal block which is conFrom the Glaucoma Consultation Service, Massachusetts Eye and Ear Infirmary, Harvard Medical School and the New England Glaucoma Research Foundation, Boston. Reprint requests to John V. Thomas, MD, 100 Charles River Plaza, Boston, MA 02114.
sidered to be a variant of pupillary block. This phenomenon of iridovitreal block has been previously described in aphakic patients without lens implants. ls - 17 Its etiology appears to be the lack of free access of aqueous humor from the posterior to the anterior chamber due to an anterior hyaloid face which is in apposition or adherent to the posterior iris surface, a mechanism that is supported by the fact that both laser iridectomy and Nd:YAG photodisruption of the vitreous face were necessary to relieve block. The pathophysiologic mechanism involved is distinctly different from malignant glaucoma in which communication from the posterior to the anterior chamber is present, posterior diversion to and entrapment of aqueous in the vitreous cavity is present, and simple iridectomy with incision of the hyaloid face does not relieve the condition. 18- 2o The following case reports are representative examples of the spectrum of presenting clinical features and methods of treatment of pupillary and iridovitreal block in this series of pseudophakic eyes.
CASE REPORTS Case 1. Pupillary block which recurred due to closure of multiple argon-laser iridectomies and was relieved by re-opening the iridectomies with the argon laser. A 71-year-old white man was referred after having undergone an intracapsular cataract extraction in the left eye with implantation of a Leiske style anterior chamber intraocular lens.
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An iridectomy was not performed. The patient did well for three weeks following surgery and achieved a corrected visual acuity of 20/25 in the left eye. Three weeks after surgery, iris bombe was noted and the intraocular pressure was said to be normal. Topical mydriatics failed to relieve the block and the patient was referred for treatment. On our initial examination, his corrected visual acuity was 20/50 in the right eye and 20/30 in the left eye. The applanation tensions were 18 mmHg in the right eye and 20 mmHg in the left eye. On slit-lamp examination of the left eye, the iris was noted to balloon forward with iridocorneal touch to the midperiphery. Vitreous bulged around the lens optic into the anterior chamber. No lens corneal touch was present. On gonioscopy, no angle structures were visible except superiorly and inferiorly in the region of the lens haptics where the scleral spur was seen. The same day, four argon laser iridectomies were done, one in each of four quadrants. The iris plane flattened immediately. Gonioscopy showed peripheral anterior synechiae (PAS) covering the trabecular meshwork for one clock hour temporally and three clock hours nasally. Thirty-six argon laser gonioplasty (iridoplasty) applications to the peripheral iris resulted in a retraction of all PAS from the angle structures. One day postoperatively, the applanation tension in the left eye was 10 mmHg and the C value was 0.25 on no glaucoma medications. Two weeks following treatment, the patient returned to his referring ophthalmologist with severe pain in the left eye. All four iridectomies were occluded with pigment. The iris bombe configuration had recurred. The applanation tension was 35 mmHg. Mydriasis with cyclopentolate I% and phenylephrine 10% relieved the pupillary block. The iris plane reflattened and the anterior chamber deepened. The following day, miosis was induced with pilocarpine 4% and the occluded iridectomies were reopened with the argon laser. Retraction of two clock hours of PAS was accomplished with argon laser gonioplasty. When last examined three months after the second laser treatment, his corrected visual acuity in the left eye was 20/25 and his iridectomies were patent. The applanation tension was 21 mmHg on pilocarpine 2% four times daily and Timolol 0.5% twice daily. The C value was 0.07. The angle was entirely open and the visual field was full. Case 2. Iridovitreal block which occurred in the presence of a full-thickness surgical iridectomy and was relieved by argon laser iridectomy. A 71-year-old white man underwent an intracapsular cataract extraction in the right eye with implantation of a Leiske-style anterior chamber intraocular lens. A single surgical iridectomy was performed and the procedure was reported to be uncomplicated. On the eighth postoperative day, iris bombe was noted in the right eye by the surgeon. The intraocular pressure at that time was said to have been 16 mmHg. Medical therapy consisting of cyclopentolate I % and phenylephrine 10% failed to relieve the block. The eye was observed over a period of three months. The intraocular pressure never rose above 21 mmHg, but the iris bombe configuration persisted. Fifteen weeks after surgery, the patient was referred for treatment. On our initial examination, the corrected visual acuity was 20/40 in the right eye and 20/30 in the left eye. The applanation tensions were 20 mmHg in the right eye and 16 mmHg in the left eye without medical therapy. On slit-lamp examination of the right eye, the iris was noted to balloon forward with iridocorneal touch in the far periphery. A full-thickness surgical iridectomy was noted between the lens haptics superiorly. An intact, anterior hyaloid face was bulging through the iridectomy. On gonioscopy, no angle structures were visible except in the
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region of the lens haptics. The optic nerve and macula appeared to be normal. Following treatment with pilocarpine 4%, argon laser iridectomies were done in the inferotemporal and superonasal quadrants. The iris flattened immediately. Despite relief of iridovitreal block, the angle remained closed with the exception of approximately 2 clock hours adjacent to the lens haptics where the trabecular meshwork could be seen. Fourteen months following relief of the block, the corrected visual acuity was 20/40 in the right eye. The applanation tension was 19 mmHg on timolol 0.5% twice daily. Gonioscopy was unchanged and the optic nerve showed no evidence of cupping. Case 3. Iridovitreal block which persisted despite full-thickness surgical and argon laser iridectomies. and required Nd:YAG laser photodisruption ofthe anterior vitreous face for resolution. A 71-year-old white man underwent an intracapsular cataract extraction in the right eye with placement of an Optiflex anterior chamber intraocular lens. A single surgical iridectomy was performed and the procedure was reported to be uncomplicated. Two days after surgery, the anterior chamber was noted to be deep and the applanation tension was 18 mmHg in the right eye. Five days after surgery, bulging of the iris was noted around the implant although no iridocorneal touch was present. The applanation tension was 13 mmHg. A surgical peripheral iridectomy was visible. The patient was then referred. On our initial examination eight days after surgery, his corrected visual acuity was 20/40 in the right eye and 20/20 in the left eye. The applanation tension was 35 mmHg in the right eye and 21 mmHg in the left eye on topical prednisolone 1% and cyclopentolate I %. On slit-lamp examination, the iris was noted to balloon forward. A full-thickness surgical peripheral iridectomy was visible superonasally. The anterior hyaloid face appeared to obstruct the full-thickness iridectomy, although it did not herniate through the iridectomy. Four argon laser iridectomies were made in the superior quadrants. Despite these full-thickness laser iridectomies, the iris bombe configuration persisted. The patient was given tropicamide 0.8% and phenylephrine 2.5% and the anterior chamber deepened slightly. Using a Q-switched Nd:YAG laser, photodisruption of the anterior hyaloid face which appeared to be obstructing the full-thickness argon laser and surgical iridectomies was done. The anterior chamber remained deep after the tropicamide and the phenylephrine were discontinued. It has maintained its depth for three months of follow-up. When last examined, his corrected visual acuity in the right eye was 20/15 and applanation tension was 17 mmHg without glaucoma medications.
METHODS The records of 26 eyes of 26 patients who developed pupillary and iridovitreal block following cataract surgery with intraocular lens implantation were reviewed. All cases had been performed by other surgeons and referred to us over a four-year period (November 1979 to November 1983).
RESULTS The patients in this series ranged in age from 47 to 83 years (average, 69.2 years). There were 15 men and 11
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Table 1. Types of Cataract Surgery
=
Table 3. Known Intraoperative Complications
Type of Operation
No. of Eyes
Type of Complications
No. of Eyes
ICCE with AC IOL ICCE with iris-plane IOL ECCE with AC IOL Replacement of Subluxated AC IOL
18 1 6 1
Rupture of vitreous face Rupture of posterior capsule with vitreous loss
1 2
Table 4. Status of Surgical Peripheral Iridectomies on Initial Slit-lamp Examination
ICCE = intracapsular cataract extraction; AC = anterior chamber; IOL intraocular lens; ECCE = extracapsular cataract extraction.
Status
women. Twenty-five were white and one was black. The average length of follow-up after treatment was 10.6 months (range, 4 weeks-42 months). In 10 of 26 eyes, presenting symptoms were those of acute angle closure glaucoma with pain, congestion, and blurred vision. The average intraocular pressure in these ~yes was 47 mmHg (range, 32-70 mmHg). The average intraocular pressure of the remaining 16 patients was 16 mmHg (range, 2-20 mmHg). Among these 16 patients, only two had significantly decreased visual acuity. The remaining 14 patients were essentially asymptomatic when seen. Types of cataract surgery performed and intraocular lenses implanted are listed in Tables 1 and 2 respectively. Table 3 notes the intraoperative complications known to have occurred. Table 4 lists the status of the surgical peripheral iridectomies observed on initial slit-lamp examination. Medical treatment with topical mydriatic and cycloplegic agents to relieve pupillary block was attempted by referring physicians in 14 eyes. Temporary relief of block occurred in only 4 eyes. All 26 eyes were treated with laser therapy and/or conventional surgery with eventual relief of pupillary and iridovitreal block in all cases. The initial treatment modalities used are listed in Table 5. The effectiveness of argon laser iridectomy in relieving block is noted in Table 6. Among eyes in which block was initially relieved by argon laser iridectomy alone, recurrence of block occurred in six eyes as late as two months after initial successful treatment. In three of these six eyes, the recurrence was the result of closure of previously full thickness laser iri-
Table 2. Types of Intraocular Lenses Lens Types Anterior chamber IOL Azar Flex Azar Rigid Choyce Leiske Optiffex Pannu AC Tennant Iris-plane IOL
No. of Eyes
Visible and full-thickness, but occluded by vitreous face Visible and full-thickness, but occluded by haptic of IOL . Not visible (but said to be done at time of surgery) Not done at time of surgery Imperforate iridectomy Tucked and occluded by superior haptiC of IOL Three surgical iridectomies done of which two were occluded by vitreous face and one by haptiC of IOL IOL
=
7 6 4 4 3 1
intraocular lens.
dectomies. In the remaining three eyes, full thickness laser iridectomies were present but were functionally occluded by an adherent anterior hyaloid face. Among the six eyes with recurrence, five were permanently cured with repeat argon laser iridectomy. Table 7 lists the treatment modalities used in eyes in which argon laser iridectomy was ineffective. Gonioscopy was done following final resolution of pupillary and iridovitreal block in 23 of 26 eyes and the findings are noted in Table 8. The average length of time between clinical recognition of block to definitive laser and/or surgical treatment was 33 days in eyes with 8 or more clock hours of PAS versus five days in eyes with less than two clock hours of PAS.
Table 5. Initial Treatment Modalities Used Treatment Modality
No. of Eyes
Argon laser iridectomy Nd:YAG laser iridectomy
25 1
No. of Eyes Table 6. Effectiveness of Argon Laser Iridectomy (ALI)*
3 2 5 6
1 4 4 1
Result
No. of Eyes
Cured by ALI alone initial ALI repeat ALI Not cured by ALI
20
15 5 5
* ALI performed on 25 eyes.
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Fig 1. Top left. pupillary block in eye in which no iridectomy was done. Fig 2. Top right. eye with full-thickness surgical iridectomy occluded by haptic of intraocular lens. Fig 3. Second row left. retroilluminated view of eye with full-thickness surgical iridectomy occluded by haptic of intraocular lens. Fig 4. Second row right. gonioscopic view of a full-thickness surgical iridectomy occluded by haptic of intraocular lens. Fig 5. Bottom left. iridovitreal block in eye with two full-thickness surgical iridectomies.
Although none of the eyes in this series had glaucoma prior to cataract and lens implant surgery, 9 of 26 eyes have continued to require chronic medical therapy to control intraocular pressure. Table 9 lists the types of glaucoma medications being used. No patient has yet required additional glaucoma surgery although two patients with essentially total angle closure may be candidates in the near future. Visual acuity data after definitive treatment with laser and/or conventional surgical therapy are presented in Table 10. 834
DISCUSSION The initial step towards the recognition of pupillary and iridovitreal block in pseudophakic eyes is careful slitlamp evaluation. Since the majority of these patients are asymptomatic and have normal intraocular pressures, the clinical condition may not be diagnosed in the early stages. If examination reveals even the suggestion of an iris bombe configuration, one should assess the integrity of the cataract incision, measure the intraocular pressure,
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Table 7. Treatment Modalities in Eyes in Which Argon Laser Iridectomy Was Ineffective Modality
No. of Eyes
Nd:YAG photodisruption of vitreous face Surgical peripheral iridectomy Pars plana closed vitrectomy Non-automated vitreous aspiration
2 1
1 1
determine the presence or absence of full thickness surgical iridectomies, and note the location of the haptics of the intraocular lens in relation to the iridectomy sites. If a full thickness iridectomy is present, one should carefully assess the position of the anterior vitreous face in relation to its opening. Gonioscopy is helpful in more accurately determining the location of the haptics relative to the iridectomY 'sites and in assessing angle structures. If the eye is hypotonous, the diagnoses of wound leak or inativertent cyclodialysis cleft with secondary choroidal detachment should be considered. Sodium fluorescein 2% is helpful in assessing the presence of a wound leak. Ophthalmoscopic and ultrasonographic examinations are helpful in detecting the presence of a secondary choroidal detachment. If the intraocular pressure is greater than 10 mmHg and if the possibility of a wound leak and choroidal detachment have been excluded, the diagnoses of pupillary block, iridovitreal block, and true aphakic malignant glaucoma have to be considered. The causes of pupillary block in pseudophakic eyes include omission of an iridectomy at the time of cataract surgery (Fig 1), an imperforate iridectomy and obstruction of a full thickness iridectomy by the haptic of an anterior chamber intraocular lens which may have rotated postoperatively (Figs 2-4). Iridovitreal block is caused by ap anterior movement of the hyaloid face causing apposition and sometimes, in the presence of postoperative inflammation, adherence to the posterior surface of the iris at the iridectomy thereby functionally occluding the full thickness surgical or laser iridectomy (Fig 5). The diagnosis of iridovitreal block may be made by careful evaluation of the iridectomy site with high-power slit-lamp magnification giving particular attention to the position of the anterior hyaloid. At present, argon-laser iridectomy is considered to be tpe initial treatment of choice for pupillary and iridovitreal Table 8. Final Status of Angle after Relief of Block
Table 9. Chronic Glaucoma Therapy Required After Relief of Block Medication
No. of Eyes
Timolol 0.5% b.i.d. Timolol 0.5% b.i.d. and dipivefrin 0.1% b.i.d. Timolol 0.5% b.i.d. and pilocarpine 2% Q.i.d. Timolol 0.5% b.i.d. and pilocarpine 4% b.i.d. Timolol 0.5% b.i.d., pilocarpine 4% b.i.d. and methazdamide 50 mg PO b.i.d. Timolol 0.5% b.i.d., pilocarpine 4% Q.i.d. and acetazolamide 250 mg PO Q.i.d.
3 2 1 1
b.i.d. = twice daily; Q.i.d. = four times daily; PO = by mouth.
block in pseudophakic eyes. However, it may be necessary in certain cases to initiate medical therapy prior to definitive laser therapy. If the intraocular pressure is markedly elevated, treatment with timolol, carbonic anhydrase inhibitors and oral hyperosmotics may be necessary. If laser therapy must be delayed, mydriatic drops will occasionally relieve the block by enlarging the pupil to a size larger than the optic of the intraocular lens. Ainong the 14 eyes in this series treated with mydriasis, only four eyes were temporarily relieved of block. Ifmydriatics are to be used, short acting drugs (eg. tropicamide and/or phenylephrine) are used since it is advantageous to constrict the pupil with miotics immediately prior to laser iridectomy. If laser therapy is to be delayed, miotics are not used since they may tend to increase block and further shallow the anterior chamber. It is important to note that achieving a full-thickness argon laser iridectomy in postoperative eyes is frequently difficult. Lack of adequate visualization of the iris due to a hazy, edematous cornea and an extremely shallow anterior chamber with large areas of iridocorneal touch can make performing an iridectomy difficult. Lowering the intraocular pressure with medical glaucoma therapy and using topical glycerin immediately prior to the laser procedure are helpful in improving visibility. Medical therapy may also, in certain cases, produce a slight deepening of the anterior chamber by lowering the relative pressure difference between the anterior and posterior chambers. Sinf:,;e these eyes are frequently quite sensitive to any manipulatIon, topical 10% cocaine is used as an adjunct to proparacaine hydrochloride 0.5% just prior to laser therapy. After it is determined that iris visibility and anterior chamber depth have improved as much as possible, a Table 10. Visual Acuity After Relief of Block
Gonioscopy
No. of Eyes
PAS for 360 0 except in region of lens haptics Eight clock hours PAS Two to four One to one and one-half Open without PAS
2
Visual Status
No. of Eyes
7 4 8
Worse after Treatment Same or One Line Better Two or Three Lines Better Four or More Lines Better
14 6 6
PAS
=
peripheral anterior synechiae.
2
o
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laser iridectomy is attempted. If a surgical iridectomy is not visible or if a full-thickness surgical iridectomy appears to be obstructed by the haptic of an intraocular lens, a primary iridectomy is performed. Corneal burns may be avoided by making the initial iridectomy where the anterior chamber is deepest. In pseudophakiceyes with anterior chamber implants, the chamber is usually deepest centrally and adjacent to the lens haptics. If an imperforate surgical iridectomy is present with an intact sheet of posterior pigment epithelium remaining, block is easily relieved by disrupting this sheet of pigment epithelium with low levels of laser energy. . After a full-thickness laser iridectomy is achieved, the anterior chamber will deepen in almost every case. Occasionally, this will occur abruptly, but more commonly, it may require 15 minutes to one hour. The entire anterior chamber may deepen or only the portion in which the iridectomy was done deepens. After the anterior chamber has deepened, intense miotics (1 drop of pilocarpine 4% q5minutes X 6) are administered. As the pupil becomes miotic, the initial laser iridectomy may migrate behind the intraocular lens·. Multiple laser iridectomies, generally one in each quadrant of the iris are then done. Intensive topical steroids (Pred-Forte® 1% q 1h X 2 days while awake, followed by four times daily X 5 days) are prescribed and the patient is reexamined the next day. Other laser modalities are available if a full thickness argon laser iridectomy cannot be achieved initially. If the pupillary margin is behind the intraocular lens optic, argon laser pupilloplasty may relieve the block. 21 ,22 If pupilloplasty fails, gonioplasty (iridoplasty) can be considered. 23 - 25 Occasionally, unsuccessful iridectomy or pupilloplasty will put the iris on stretch and segmentally open the angle. Although this may lower the intraocular pressure, it does not relieve the block and definitive therapy is still necessary. The ultrashort pulse Nd:YAG laser can be used to make an iridectomy when the argon laser fails. 26 - 28 The capability of the Nd:YAG laser to make iridectomies and to produce photodisruption of the anterior hyaloid face by a non-thermal mechanism, may in the future make it the treatment modality of choice in pseudophakic eyes with pupillary and iridovitreal block. The argon laser relieved block in 20 eyes (Table 6). However, before permanent success was obtained, six eyes had recurrence of block due to closure of the iridectomy sites and occlusion of full thickness . laser iridectomies by the vitreous face. It is known that 34% of argon laser iridectomies in phakic eyes tend to become at least partially occluded by pigment epithelium within the first six weeks. 29 The incidence of recurrent block in our series (6 of 20 eyes) is similar. This is of concern because it occurred despite frequent examinations and multiple retreatments with the argon laser when the iridectomy sites showed any sign of narrowing or impending closure. If a full-thickness surgical peripheral iridectomy is present and not obviously occluded by the vitreous face, an argon laser iridectomy is attempted. Full thickness argon laser iridectomies in such eyes in our series failed
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to relieve the block in only one case. However, if the initial diagnosis is vitreous occlusion of a full-thickness surgical iridectomy, recurrence of block secondary to vitreous occlusion of full thickness argon laser iridectomies frequently occurs. Therefore, in such cases, Nd:YAG laser photodisruption of the anterior hyaloid face within the iridectomy site is the treatment of choice. In the past, this has been done with invasive surgical techniques in aphakic eyes without lens implants. 3D,31 The xenon arc photocoagulator has also been used with infrequent success in an attempt to produce photodisruption of the hyaloid face in eyes in which pigment was present for energy absorption. 32 Nd:YAG laser vitrotomy is also recommended for initial recurrences if the argon laser iridectomies are visibly patent. The Nd:YAG laser is aimed at the base of the laser iridectomies as well as any patent surgical iridectomies. This enlarges the argon laser iridectomies as well as ruptures the anterior hyaloid face. If necessary, the vitreous face may be ruptured in the pupil although this is less desirable. Using these techniques, surgical vitrectomy has not been necessary since the YAG laser became available. Permanent glaucoma due to PAS is the most serious sequel of pupillary block in pseudophakic eyes. Early recognition of pupillary block and rapid, definitive laser therapy are essential in helping prevent the formation of peripheral anterior synechiae. In our series, a dfrect correlation was noted between the time that elapsed petween clinical recognition of block and definitive laser and/or surgical therapy and the number of clock hours of PAS noted on gonioscopy after relief of block. It is important to prevent this complication since the prognosis for successful filtration surgery is poor due to conjunctival scarring, inflammation, and the aphakic state. Since most of these eyes have the potential for good vision, cyclocryotherapy is perhaps best avoided since in some cases a reduction of vision due to chronic vitreous haze and macular changes may occur as a result of the treatment. The prognosis for cyclodialysis in pseudophakic eyes is not known. Gonioscopy is performed as soon as pupillary block is relieved. If more than one clock hour of peripheral anterior synechiae is present, argon laser gonioplasty (iridoplasty) is attempted. 24,25 If the PAS are relatively recent, this technique is frequently successful in producing a retraction of synechiae from ;lngle structures. If argon laser gonioplasty fails and if four or more clock hours of PAS are present, Nd:YAG laser synechiolysis is attempted. 33 If despite these forms of laser therapy, six or more clock hours of PAS remain, surgical synechiolysis is considered. 34•35 Attention to intraoperative details are helpful in avoiding pupillary iridovitreal block in pseudophakic eyes. Regardless of the type of cataract surgery, surgical peripheral iridectomies should be performed when implanting any anterior chamber or pupillary plane intraocular lens. If an anterior chamber lens implant is used, at least two iridectomies should be made far enough apart so that the
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lens haptics cannot simultaneously obstruct both. It is possible that a basal iridectomy may be more likely to prevent iridovitreal block than one which is more centrally located. It is important to be certain the anterior chamber is well formed at the end of the procedure. If the anterior chamber should shallow while the speculum is removed, the peripheral iridectomy may become apposed to the cornea with an ensuing pupillary block. Adequate postoperative topical steroid therapy helps decrease the ocular inflammatory response and thereby perhaps the tendency of the anterior hyaloid to become adherent to the posterior iris surface. In addition, if block does occur, topical steroid may help prevent or reduce the extent of permanent synechial closure of the angle.
17. Weiss DI, Shaffer RN. Ciliary block (malignant) glaucoma. Trans Am Acad Ophthalmol Otolaryngol 1972; 76:450-61. 18. Simmons RJ, Thomas JV. Malignant glaucoma. In: Ritch R, Shields MB, eds. The Secondary Glaucomas. St. Louis: CV Mosby, 1982; 331-44. 19. Chandler PA, Simmons RJ, Grant WM. Malignant glaucoma: medical and surgical treatment. Am J Ophthalmol 1968; 66:495-502. 20. Simmons RJ, Dallow RL. Primary angle-closure glaucoma. In: Duane TD, ed. Clinical Ophthalmology. Philadelphia: Harper & Row, 1983; Vol. 3, Chapter 53. 21. Obstbaum SA, Barasch KR, Galin MA, et al. Laser photomydriasis in pseudophakic pupillary block. Am Intraocul Implant Soc J 1981; 7:28-30. 22. Shin DH. Argon laser iris photocoagulation to relieve acute angleclosure glaucoma. Am J Ophthalmol 1982; 93:348-50. 23. Ritch R. Argon laser treatment for medically unresponsive attacks of angle-closure glaucoma. Am J Ophthalmol 1982; 94: 197-204.
REFERENCES
24. Simmons RJ, Kimbrough RL, Belcher CD, et al. Laser gonioplasty for special problems in angle closure glaucoma. In: Symposium on Glaucoma; Transactions of the New Orleans Academy of Ophthalmology. St. Louis: CV Mosby, 1981; 220-35. 25. Simmons RJ, Simmons RB. Gonioplasty. In: Belcher CD III, Thomas JV, Simmons RJ, eds. Photocoagulation in Glaucoma and Anterior Segment Disease. Baltimore: Williams and Wilkins, 1984; 122-140.
1. Ridley H. Intra·ocular acrylic lenses. 10 years' development. Br J Ophthalmol 1960; 44:705-12. 2. Ri~:ey H. Intra·ocular acrylic lenses-past, present and future. Trans Ophthalmol Soc UK 1964; 84:5-14. 3. Boberg-Ans J. Experience with twelve cases of intra-ocular anterior chamber implants for aphakia. Br J Ophthalmol 1961; 45:37-43. 4. Boberg-Ans J. Complications from intraocular lenses in aphakia. Int Ophthalmol Clin 1965; 5(1):107-22. 5. Bresnick GH. Eyes containing anterior chamber acrylic implants, pathological complications. Arch Ophthalmol 1969; 82:726-37. 6. Feldman F, Stein H. Delayed glaucoma after implantation of a Choyce intraocular lens. Can J Ophthalmol 1979; 14: 190-1. 7. Kielar RA. Stambaugh JL. Pupillary block glaucoma following intraocular lens implantation. Ophthalmic Surg 1982; 13:647-50. 8. Kokoris N, Macy JI. Laser iridectomy treatment of acute pseudophakic pupillary block glaucoma. Am Intraocul Implant Soc J 1982; 8:33-4. 9. Layden WE. Pseudophakia and glaucoma. Ophthalmology 1982; 89:875-9. 10. Moses L. Pupillary-block glaucoma after Choyce lens implantation. Am Intraocullmplant Soc J 1978; 4:50. 11. Reese WS. Results in 39 bilateral Ridley intra-ocular implants. Br J Ophthalmol1960; 44:713-7. 12. Werner D, Kaback M. Pseudophakic pupillary-block glaucoma. Br J Ophthalmol 1977; 61 :329-33. 13. Aron-Rosa DS. Posterior capsulotomy and picosecond pulsed YAG laser influence on eye pressure. Cataract 1983; 1: 13-7. 14. Van Buskirk EM. Pupillary block after intraocular lens implantation. Am J Ophthalmol 1983; 95:55-9. 15. Anderson DR, Forster RK, Lewis ML. Laser iridotomy for aphakic pupillary block. Arch Ophthalmol 1975; 93:343-6. 16. Gillman AM. Pathogenesis of complications following cataract surgery. In: Theodore FH, ed. Complications After Cataract Surgery. Boston: Little, Brown and Co., 1965; 533-82.
26. Fankhauser F, U:irtscher H, van der Zypen E. Clinical studies on high and low power laser radiation upon some structures of the anterior and posterior segments of the eye. Int Ophthalmol1982; 5:15-32. 27. Cohn HC, Whalen W. The picosecond YAG laser in glaucoma treatment. In: Aron-Rosa D, ed. Pulsed YAG Laser Surgery. Thorofare: Slack, 1983; 33-6. 28. Birngruber R, Gabel BP, Boergen KP, et al. The German experience in YAG laser surgery side effects using ultrashort, pulsed, Neodynium YAG lasers in intraocular microsurgery. In: Aron-Rosa D, ed. Pulsed YAG Laser Surgery. Thorofare: Slack, 1983; 45-48. 29. Pollack IP. Use of argon laser energy to produce iridotomies. Ophthalmic Surg 1980; 11 :506-15. 30. Peyman GA, Sanders DR, Minatoya H. Pars plana vitrectomy in the management of pupillary block glaucoma following irrigation and aspiration. Br J Ophthalmol 1978; 62:336-9. 31. Cotlier E. Anterior vitriotomy for aphakic flat anterior chamber. Br J Ophthalmol 1972; 56:347-52. 32. Patti JC, Cinotti AA. Iris photocoagulation therapy of aphakic pupillary block. Arch Ophthalmol1975; 93:347-8. 33. Fankhauser F, Roussel P, Steffen J, et aI. Clinical studies on the efficiency of high power laser radiation upon some structures of the anterior segment of the eye. Int Ophthalmol 1981; 3: 129-39. 34. Simmons RJ. Angle-closure glaucoma after scleral buckling operations for separated retina. In: Chandler PA, Grant WM, eds. Glaucoma, 2d ed. Philadelphia: Lea and Febiger, 1979; 183-6. 35. Campbell DG, Vela A. Synechialysis for the treatment of synechial angle closure in glaucoma. Read before the 69th Annual Clinical Congress of the American College of Surgeons, Atlanta, Georgia, October 17, 1983.
837
Abstract: Twenty-six cases of pupillary and iridovitreal block in pseudophakic eyes are reported. Although ten patients presented with acute angle closure glaucoma, the majority were asymptomatic and had normal intraocular pressures. While cure was finally achieved in all cases, recurrence of block occurred in six eyes as late as two months after initial successful treatment. A variety of therapeutic modalities including argon laser iridectomy, argon laser gonioplasty (iridoplasty), surgical iridectomy, surgical vitrectomy, Q-switched Nd:YAG laser iridectomy and Nd:YAG laser photodisruption of the anterior vitreous face were needed. Despite successful relief of pupillary and iridovitreal block in these eyes with no evidence of glaucoma prior to cataract and lens implant surgery, four eyes developed eight or more clock hours of peripheral anterior synechiae, and nine eyes continue to require chronic medical therapy for glaucoma. [Key words: glaucoma, iridovitreal block, pseudophakos, pupillary block.] Ophthalmology 91 :831-837, 1984
Pupillary block is a well-known complication of cataract surgery with intraocular lens implantation. It was first noted by Ridleyl,2 and has been reported with nearly every known design of pseudophakos. 3-1 3 It is thought that the majority of such patients can be cured with argon laser iridectomy. In the largest previously reported series of seventeen pseudophakic eyes,14 sixteen were cured by argon laser iridectomy with no recurrence of pupillary block. In our series of 26 eyes, however, a significant number developed recurrence of block or failed to respond to argon laser iridectomy alone. Since this report illustrates the spectrum of the disease as seen in a glaucoma referral practice, it is possible that the referral process has preselected more difficult cases for inclusion. Cases of particular interest are those in which iris bombe occurred despite the presence of a full-thickness surgical iridectomy. In some of these cases, block was relieved transiently by argon laser iridectomy but required Nd:YAG laser photodisruption of the vitreous face for permanent relief. Prior to the availability ofthe Nd:YAG laser, such cases may have been misdiagnosed as having malignant glaucoma in aphakia. We hold the view that these cases demonstrate iridovitreal block which is conFrom the Glaucoma Consultation Service, Massachusetts Eye and Ear Infirmary, Harvard Medical School and the New England Glaucoma Research Foundation, Boston. Reprint requests to John V. Thomas, MD, 100 Charles River Plaza, Boston, MA 02114.
sidered to be a variant of pupillary block. This phenomenon of iridovitreal block has been previously described in aphakic patients without lens implants. ls - 17 Its etiology appears to be the lack of free access of aqueous humor from the posterior to the anterior chamber due to an anterior hyaloid face which is in apposition or adherent to the posterior iris surface, a mechanism that is supported by the fact that both laser iridectomy and Nd:YAG photodisruption of the vitreous face were necessary to relieve block. The pathophysiologic mechanism involved is distinctly different from malignant glaucoma in which communication from the posterior to the anterior chamber is present, posterior diversion to and entrapment of aqueous in the vitreous cavity is present, and simple iridectomy with incision of the hyaloid face does not relieve the condition. 18- 2o The following case reports are representative examples of the spectrum of presenting clinical features and methods of treatment of pupillary and iridovitreal block in this series of pseudophakic eyes.
CASE REPORTS Case 1. Pupillary block which recurred due to closure of multiple argon-laser iridectomies and was relieved by re-opening the iridectomies with the argon laser. A 71-year-old white man was referred after having undergone an intracapsular cataract extraction in the left eye with implantation of a Leiske style anterior chamber intraocular lens.
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An iridectomy was not performed. The patient did well for three weeks following surgery and achieved a corrected visual acuity of 20/25 in the left eye. Three weeks after surgery, iris bombe was noted and the intraocular pressure was said to be normal. Topical mydriatics failed to relieve the block and the patient was referred for treatment. On our initial examination, his corrected visual acuity was 20/50 in the right eye and 20/30 in the left eye. The applanation tensions were 18 mmHg in the right eye and 20 mmHg in the left eye. On slit-lamp examination of the left eye, the iris was noted to balloon forward with iridocorneal touch to the midperiphery. Vitreous bulged around the lens optic into the anterior chamber. No lens corneal touch was present. On gonioscopy, no angle structures were visible except superiorly and inferiorly in the region of the lens haptics where the scleral spur was seen. The same day, four argon laser iridectomies were done, one in each of four quadrants. The iris plane flattened immediately. Gonioscopy showed peripheral anterior synechiae (PAS) covering the trabecular meshwork for one clock hour temporally and three clock hours nasally. Thirty-six argon laser gonioplasty (iridoplasty) applications to the peripheral iris resulted in a retraction of all PAS from the angle structures. One day postoperatively, the applanation tension in the left eye was 10 mmHg and the C value was 0.25 on no glaucoma medications. Two weeks following treatment, the patient returned to his referring ophthalmologist with severe pain in the left eye. All four iridectomies were occluded with pigment. The iris bombe configuration had recurred. The applanation tension was 35 mmHg. Mydriasis with cyclopentolate I% and phenylephrine 10% relieved the pupillary block. The iris plane reflattened and the anterior chamber deepened. The following day, miosis was induced with pilocarpine 4% and the occluded iridectomies were reopened with the argon laser. Retraction of two clock hours of PAS was accomplished with argon laser gonioplasty. When last examined three months after the second laser treatment, his corrected visual acuity in the left eye was 20/25 and his iridectomies were patent. The applanation tension was 21 mmHg on pilocarpine 2% four times daily and Timolol 0.5% twice daily. The C value was 0.07. The angle was entirely open and the visual field was full. Case 2. Iridovitreal block which occurred in the presence of a full-thickness surgical iridectomy and was relieved by argon laser iridectomy. A 71-year-old white man underwent an intracapsular cataract extraction in the right eye with implantation of a Leiske-style anterior chamber intraocular lens. A single surgical iridectomy was performed and the procedure was reported to be uncomplicated. On the eighth postoperative day, iris bombe was noted in the right eye by the surgeon. The intraocular pressure at that time was said to have been 16 mmHg. Medical therapy consisting of cyclopentolate I % and phenylephrine 10% failed to relieve the block. The eye was observed over a period of three months. The intraocular pressure never rose above 21 mmHg, but the iris bombe configuration persisted. Fifteen weeks after surgery, the patient was referred for treatment. On our initial examination, the corrected visual acuity was 20/40 in the right eye and 20/30 in the left eye. The applanation tensions were 20 mmHg in the right eye and 16 mmHg in the left eye without medical therapy. On slit-lamp examination of the right eye, the iris was noted to balloon forward with iridocorneal touch in the far periphery. A full-thickness surgical iridectomy was noted between the lens haptics superiorly. An intact, anterior hyaloid face was bulging through the iridectomy. On gonioscopy, no angle structures were visible except in the
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region of the lens haptics. The optic nerve and macula appeared to be normal. Following treatment with pilocarpine 4%, argon laser iridectomies were done in the inferotemporal and superonasal quadrants. The iris flattened immediately. Despite relief of iridovitreal block, the angle remained closed with the exception of approximately 2 clock hours adjacent to the lens haptics where the trabecular meshwork could be seen. Fourteen months following relief of the block, the corrected visual acuity was 20/40 in the right eye. The applanation tension was 19 mmHg on timolol 0.5% twice daily. Gonioscopy was unchanged and the optic nerve showed no evidence of cupping. Case 3. Iridovitreal block which persisted despite full-thickness surgical and argon laser iridectomies. and required Nd:YAG laser photodisruption ofthe anterior vitreous face for resolution. A 71-year-old white man underwent an intracapsular cataract extraction in the right eye with placement of an Optiflex anterior chamber intraocular lens. A single surgical iridectomy was performed and the procedure was reported to be uncomplicated. Two days after surgery, the anterior chamber was noted to be deep and the applanation tension was 18 mmHg in the right eye. Five days after surgery, bulging of the iris was noted around the implant although no iridocorneal touch was present. The applanation tension was 13 mmHg. A surgical peripheral iridectomy was visible. The patient was then referred. On our initial examination eight days after surgery, his corrected visual acuity was 20/40 in the right eye and 20/20 in the left eye. The applanation tension was 35 mmHg in the right eye and 21 mmHg in the left eye on topical prednisolone 1% and cyclopentolate I %. On slit-lamp examination, the iris was noted to balloon forward. A full-thickness surgical peripheral iridectomy was visible superonasally. The anterior hyaloid face appeared to obstruct the full-thickness iridectomy, although it did not herniate through the iridectomy. Four argon laser iridectomies were made in the superior quadrants. Despite these full-thickness laser iridectomies, the iris bombe configuration persisted. The patient was given tropicamide 0.8% and phenylephrine 2.5% and the anterior chamber deepened slightly. Using a Q-switched Nd:YAG laser, photodisruption of the anterior hyaloid face which appeared to be obstructing the full-thickness argon laser and surgical iridectomies was done. The anterior chamber remained deep after the tropicamide and the phenylephrine were discontinued. It has maintained its depth for three months of follow-up. When last examined, his corrected visual acuity in the right eye was 20/15 and applanation tension was 17 mmHg without glaucoma medications.
METHODS The records of 26 eyes of 26 patients who developed pupillary and iridovitreal block following cataract surgery with intraocular lens implantation were reviewed. All cases had been performed by other surgeons and referred to us over a four-year period (November 1979 to November 1983).
RESULTS The patients in this series ranged in age from 47 to 83 years (average, 69.2 years). There were 15 men and 11
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Table 1. Types of Cataract Surgery
=
Table 3. Known Intraoperative Complications
Type of Operation
No. of Eyes
Type of Complications
No. of Eyes
ICCE with AC IOL ICCE with iris-plane IOL ECCE with AC IOL Replacement of Subluxated AC IOL
18 1 6 1
Rupture of vitreous face Rupture of posterior capsule with vitreous loss
1 2
Table 4. Status of Surgical Peripheral Iridectomies on Initial Slit-lamp Examination
ICCE = intracapsular cataract extraction; AC = anterior chamber; IOL intraocular lens; ECCE = extracapsular cataract extraction.
Status
women. Twenty-five were white and one was black. The average length of follow-up after treatment was 10.6 months (range, 4 weeks-42 months). In 10 of 26 eyes, presenting symptoms were those of acute angle closure glaucoma with pain, congestion, and blurred vision. The average intraocular pressure in these ~yes was 47 mmHg (range, 32-70 mmHg). The average intraocular pressure of the remaining 16 patients was 16 mmHg (range, 2-20 mmHg). Among these 16 patients, only two had significantly decreased visual acuity. The remaining 14 patients were essentially asymptomatic when seen. Types of cataract surgery performed and intraocular lenses implanted are listed in Tables 1 and 2 respectively. Table 3 notes the intraoperative complications known to have occurred. Table 4 lists the status of the surgical peripheral iridectomies observed on initial slit-lamp examination. Medical treatment with topical mydriatic and cycloplegic agents to relieve pupillary block was attempted by referring physicians in 14 eyes. Temporary relief of block occurred in only 4 eyes. All 26 eyes were treated with laser therapy and/or conventional surgery with eventual relief of pupillary and iridovitreal block in all cases. The initial treatment modalities used are listed in Table 5. The effectiveness of argon laser iridectomy in relieving block is noted in Table 6. Among eyes in which block was initially relieved by argon laser iridectomy alone, recurrence of block occurred in six eyes as late as two months after initial successful treatment. In three of these six eyes, the recurrence was the result of closure of previously full thickness laser iri-
Table 2. Types of Intraocular Lenses Lens Types Anterior chamber IOL Azar Flex Azar Rigid Choyce Leiske Optiffex Pannu AC Tennant Iris-plane IOL
No. of Eyes
Visible and full-thickness, but occluded by vitreous face Visible and full-thickness, but occluded by haptic of IOL . Not visible (but said to be done at time of surgery) Not done at time of surgery Imperforate iridectomy Tucked and occluded by superior haptiC of IOL Three surgical iridectomies done of which two were occluded by vitreous face and one by haptiC of IOL IOL
=
7 6 4 4 3 1
intraocular lens.
dectomies. In the remaining three eyes, full thickness laser iridectomies were present but were functionally occluded by an adherent anterior hyaloid face. Among the six eyes with recurrence, five were permanently cured with repeat argon laser iridectomy. Table 7 lists the treatment modalities used in eyes in which argon laser iridectomy was ineffective. Gonioscopy was done following final resolution of pupillary and iridovitreal block in 23 of 26 eyes and the findings are noted in Table 8. The average length of time between clinical recognition of block to definitive laser and/or surgical treatment was 33 days in eyes with 8 or more clock hours of PAS versus five days in eyes with less than two clock hours of PAS.
Table 5. Initial Treatment Modalities Used Treatment Modality
No. of Eyes
Argon laser iridectomy Nd:YAG laser iridectomy
25 1
No. of Eyes Table 6. Effectiveness of Argon Laser Iridectomy (ALI)*
3 2 5 6
1 4 4 1
Result
No. of Eyes
Cured by ALI alone initial ALI repeat ALI Not cured by ALI
20
15 5 5
* ALI performed on 25 eyes.
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Fig 1. Top left. pupillary block in eye in which no iridectomy was done. Fig 2. Top right. eye with full-thickness surgical iridectomy occluded by haptic of intraocular lens. Fig 3. Second row left. retroilluminated view of eye with full-thickness surgical iridectomy occluded by haptic of intraocular lens. Fig 4. Second row right. gonioscopic view of a full-thickness surgical iridectomy occluded by haptic of intraocular lens. Fig 5. Bottom left. iridovitreal block in eye with two full-thickness surgical iridectomies.
Although none of the eyes in this series had glaucoma prior to cataract and lens implant surgery, 9 of 26 eyes have continued to require chronic medical therapy to control intraocular pressure. Table 9 lists the types of glaucoma medications being used. No patient has yet required additional glaucoma surgery although two patients with essentially total angle closure may be candidates in the near future. Visual acuity data after definitive treatment with laser and/or conventional surgical therapy are presented in Table 10. 834
DISCUSSION The initial step towards the recognition of pupillary and iridovitreal block in pseudophakic eyes is careful slitlamp evaluation. Since the majority of these patients are asymptomatic and have normal intraocular pressures, the clinical condition may not be diagnosed in the early stages. If examination reveals even the suggestion of an iris bombe configuration, one should assess the integrity of the cataract incision, measure the intraocular pressure,
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Table 7. Treatment Modalities in Eyes in Which Argon Laser Iridectomy Was Ineffective Modality
No. of Eyes
Nd:YAG photodisruption of vitreous face Surgical peripheral iridectomy Pars plana closed vitrectomy Non-automated vitreous aspiration
2 1
1 1
determine the presence or absence of full thickness surgical iridectomies, and note the location of the haptics of the intraocular lens in relation to the iridectomy sites. If a full thickness iridectomy is present, one should carefully assess the position of the anterior vitreous face in relation to its opening. Gonioscopy is helpful in more accurately determining the location of the haptics relative to the iridectomY 'sites and in assessing angle structures. If the eye is hypotonous, the diagnoses of wound leak or inativertent cyclodialysis cleft with secondary choroidal detachment should be considered. Sodium fluorescein 2% is helpful in assessing the presence of a wound leak. Ophthalmoscopic and ultrasonographic examinations are helpful in detecting the presence of a secondary choroidal detachment. If the intraocular pressure is greater than 10 mmHg and if the possibility of a wound leak and choroidal detachment have been excluded, the diagnoses of pupillary block, iridovitreal block, and true aphakic malignant glaucoma have to be considered. The causes of pupillary block in pseudophakic eyes include omission of an iridectomy at the time of cataract surgery (Fig 1), an imperforate iridectomy and obstruction of a full thickness iridectomy by the haptic of an anterior chamber intraocular lens which may have rotated postoperatively (Figs 2-4). Iridovitreal block is caused by ap anterior movement of the hyaloid face causing apposition and sometimes, in the presence of postoperative inflammation, adherence to the posterior surface of the iris at the iridectomy thereby functionally occluding the full thickness surgical or laser iridectomy (Fig 5). The diagnosis of iridovitreal block may be made by careful evaluation of the iridectomy site with high-power slit-lamp magnification giving particular attention to the position of the anterior hyaloid. At present, argon-laser iridectomy is considered to be tpe initial treatment of choice for pupillary and iridovitreal Table 8. Final Status of Angle after Relief of Block
Table 9. Chronic Glaucoma Therapy Required After Relief of Block Medication
No. of Eyes
Timolol 0.5% b.i.d. Timolol 0.5% b.i.d. and dipivefrin 0.1% b.i.d. Timolol 0.5% b.i.d. and pilocarpine 2% Q.i.d. Timolol 0.5% b.i.d. and pilocarpine 4% b.i.d. Timolol 0.5% b.i.d., pilocarpine 4% b.i.d. and methazdamide 50 mg PO b.i.d. Timolol 0.5% b.i.d., pilocarpine 4% Q.i.d. and acetazolamide 250 mg PO Q.i.d.
3 2 1 1
b.i.d. = twice daily; Q.i.d. = four times daily; PO = by mouth.
block in pseudophakic eyes. However, it may be necessary in certain cases to initiate medical therapy prior to definitive laser therapy. If the intraocular pressure is markedly elevated, treatment with timolol, carbonic anhydrase inhibitors and oral hyperosmotics may be necessary. If laser therapy must be delayed, mydriatic drops will occasionally relieve the block by enlarging the pupil to a size larger than the optic of the intraocular lens. Ainong the 14 eyes in this series treated with mydriasis, only four eyes were temporarily relieved of block. Ifmydriatics are to be used, short acting drugs (eg. tropicamide and/or phenylephrine) are used since it is advantageous to constrict the pupil with miotics immediately prior to laser iridectomy. If laser therapy is to be delayed, miotics are not used since they may tend to increase block and further shallow the anterior chamber. It is important to note that achieving a full-thickness argon laser iridectomy in postoperative eyes is frequently difficult. Lack of adequate visualization of the iris due to a hazy, edematous cornea and an extremely shallow anterior chamber with large areas of iridocorneal touch can make performing an iridectomy difficult. Lowering the intraocular pressure with medical glaucoma therapy and using topical glycerin immediately prior to the laser procedure are helpful in improving visibility. Medical therapy may also, in certain cases, produce a slight deepening of the anterior chamber by lowering the relative pressure difference between the anterior and posterior chambers. Sinf:,;e these eyes are frequently quite sensitive to any manipulatIon, topical 10% cocaine is used as an adjunct to proparacaine hydrochloride 0.5% just prior to laser therapy. After it is determined that iris visibility and anterior chamber depth have improved as much as possible, a Table 10. Visual Acuity After Relief of Block
Gonioscopy
No. of Eyes
PAS for 360 0 except in region of lens haptics Eight clock hours PAS Two to four One to one and one-half Open without PAS
2
Visual Status
No. of Eyes
7 4 8
Worse after Treatment Same or One Line Better Two or Three Lines Better Four or More Lines Better
14 6 6
PAS
=
peripheral anterior synechiae.
2
o
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laser iridectomy is attempted. If a surgical iridectomy is not visible or if a full-thickness surgical iridectomy appears to be obstructed by the haptic of an intraocular lens, a primary iridectomy is performed. Corneal burns may be avoided by making the initial iridectomy where the anterior chamber is deepest. In pseudophakiceyes with anterior chamber implants, the chamber is usually deepest centrally and adjacent to the lens haptics. If an imperforate surgical iridectomy is present with an intact sheet of posterior pigment epithelium remaining, block is easily relieved by disrupting this sheet of pigment epithelium with low levels of laser energy. . After a full-thickness laser iridectomy is achieved, the anterior chamber will deepen in almost every case. Occasionally, this will occur abruptly, but more commonly, it may require 15 minutes to one hour. The entire anterior chamber may deepen or only the portion in which the iridectomy was done deepens. After the anterior chamber has deepened, intense miotics (1 drop of pilocarpine 4% q5minutes X 6) are administered. As the pupil becomes miotic, the initial laser iridectomy may migrate behind the intraocular lens·. Multiple laser iridectomies, generally one in each quadrant of the iris are then done. Intensive topical steroids (Pred-Forte® 1% q 1h X 2 days while awake, followed by four times daily X 5 days) are prescribed and the patient is reexamined the next day. Other laser modalities are available if a full thickness argon laser iridectomy cannot be achieved initially. If the pupillary margin is behind the intraocular lens optic, argon laser pupilloplasty may relieve the block. 21 ,22 If pupilloplasty fails, gonioplasty (iridoplasty) can be considered. 23 - 25 Occasionally, unsuccessful iridectomy or pupilloplasty will put the iris on stretch and segmentally open the angle. Although this may lower the intraocular pressure, it does not relieve the block and definitive therapy is still necessary. The ultrashort pulse Nd:YAG laser can be used to make an iridectomy when the argon laser fails. 26 - 28 The capability of the Nd:YAG laser to make iridectomies and to produce photodisruption of the anterior hyaloid face by a non-thermal mechanism, may in the future make it the treatment modality of choice in pseudophakic eyes with pupillary and iridovitreal block. The argon laser relieved block in 20 eyes (Table 6). However, before permanent success was obtained, six eyes had recurrence of block due to closure of the iridectomy sites and occlusion of full thickness . laser iridectomies by the vitreous face. It is known that 34% of argon laser iridectomies in phakic eyes tend to become at least partially occluded by pigment epithelium within the first six weeks. 29 The incidence of recurrent block in our series (6 of 20 eyes) is similar. This is of concern because it occurred despite frequent examinations and multiple retreatments with the argon laser when the iridectomy sites showed any sign of narrowing or impending closure. If a full-thickness surgical peripheral iridectomy is present and not obviously occluded by the vitreous face, an argon laser iridectomy is attempted. Full thickness argon laser iridectomies in such eyes in our series failed
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to relieve the block in only one case. However, if the initial diagnosis is vitreous occlusion of a full-thickness surgical iridectomy, recurrence of block secondary to vitreous occlusion of full thickness argon laser iridectomies frequently occurs. Therefore, in such cases, Nd:YAG laser photodisruption of the anterior hyaloid face within the iridectomy site is the treatment of choice. In the past, this has been done with invasive surgical techniques in aphakic eyes without lens implants. 3D,31 The xenon arc photocoagulator has also been used with infrequent success in an attempt to produce photodisruption of the hyaloid face in eyes in which pigment was present for energy absorption. 32 Nd:YAG laser vitrotomy is also recommended for initial recurrences if the argon laser iridectomies are visibly patent. The Nd:YAG laser is aimed at the base of the laser iridectomies as well as any patent surgical iridectomies. This enlarges the argon laser iridectomies as well as ruptures the anterior hyaloid face. If necessary, the vitreous face may be ruptured in the pupil although this is less desirable. Using these techniques, surgical vitrectomy has not been necessary since the YAG laser became available. Permanent glaucoma due to PAS is the most serious sequel of pupillary block in pseudophakic eyes. Early recognition of pupillary block and rapid, definitive laser therapy are essential in helping prevent the formation of peripheral anterior synechiae. In our series, a dfrect correlation was noted between the time that elapsed petween clinical recognition of block and definitive laser and/or surgical therapy and the number of clock hours of PAS noted on gonioscopy after relief of block. It is important to prevent this complication since the prognosis for successful filtration surgery is poor due to conjunctival scarring, inflammation, and the aphakic state. Since most of these eyes have the potential for good vision, cyclocryotherapy is perhaps best avoided since in some cases a reduction of vision due to chronic vitreous haze and macular changes may occur as a result of the treatment. The prognosis for cyclodialysis in pseudophakic eyes is not known. Gonioscopy is performed as soon as pupillary block is relieved. If more than one clock hour of peripheral anterior synechiae is present, argon laser gonioplasty (iridoplasty) is attempted. 24,25 If the PAS are relatively recent, this technique is frequently successful in producing a retraction of synechiae from ;lngle structures. If argon laser gonioplasty fails and if four or more clock hours of PAS are present, Nd:YAG laser synechiolysis is attempted. 33 If despite these forms of laser therapy, six or more clock hours of PAS remain, surgical synechiolysis is considered. 34•35 Attention to intraoperative details are helpful in avoiding pupillary iridovitreal block in pseudophakic eyes. Regardless of the type of cataract surgery, surgical peripheral iridectomies should be performed when implanting any anterior chamber or pupillary plane intraocular lens. If an anterior chamber lens implant is used, at least two iridectomies should be made far enough apart so that the
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BLOCK IN PSEUDOPHAKIC EYES
lens haptics cannot simultaneously obstruct both. It is possible that a basal iridectomy may be more likely to prevent iridovitreal block than one which is more centrally located. It is important to be certain the anterior chamber is well formed at the end of the procedure. If the anterior chamber should shallow while the speculum is removed, the peripheral iridectomy may become apposed to the cornea with an ensuing pupillary block. Adequate postoperative topical steroid therapy helps decrease the ocular inflammatory response and thereby perhaps the tendency of the anterior hyaloid to become adherent to the posterior iris surface. In addition, if block does occur, topical steroid may help prevent or reduce the extent of permanent synechial closure of the angle.
17. Weiss DI, Shaffer RN. Ciliary block (malignant) glaucoma. Trans Am Acad Ophthalmol Otolaryngol 1972; 76:450-61. 18. Simmons RJ, Thomas JV. Malignant glaucoma. In: Ritch R, Shields MB, eds. The Secondary Glaucomas. St. Louis: CV Mosby, 1982; 331-44. 19. Chandler PA, Simmons RJ, Grant WM. Malignant glaucoma: medical and surgical treatment. Am J Ophthalmol 1968; 66:495-502. 20. Simmons RJ, Dallow RL. Primary angle-closure glaucoma. In: Duane TD, ed. Clinical Ophthalmology. Philadelphia: Harper & Row, 1983; Vol. 3, Chapter 53. 21. Obstbaum SA, Barasch KR, Galin MA, et al. Laser photomydriasis in pseudophakic pupillary block. Am Intraocul Implant Soc J 1981; 7:28-30. 22. Shin DH. Argon laser iris photocoagulation to relieve acute angleclosure glaucoma. Am J Ophthalmol 1982; 93:348-50. 23. Ritch R. Argon laser treatment for medically unresponsive attacks of angle-closure glaucoma. Am J Ophthalmol 1982; 94: 197-204.
REFERENCES
24. Simmons RJ, Kimbrough RL, Belcher CD, et al. Laser gonioplasty for special problems in angle closure glaucoma. In: Symposium on Glaucoma; Transactions of the New Orleans Academy of Ophthalmology. St. Louis: CV Mosby, 1981; 220-35. 25. Simmons RJ, Simmons RB. Gonioplasty. In: Belcher CD III, Thomas JV, Simmons RJ, eds. Photocoagulation in Glaucoma and Anterior Segment Disease. Baltimore: Williams and Wilkins, 1984; 122-140.
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26. Fankhauser F, U:irtscher H, van der Zypen E. Clinical studies on high and low power laser radiation upon some structures of the anterior and posterior segments of the eye. Int Ophthalmol1982; 5:15-32. 27. Cohn HC, Whalen W. The picosecond YAG laser in glaucoma treatment. In: Aron-Rosa D, ed. Pulsed YAG Laser Surgery. Thorofare: Slack, 1983; 33-6. 28. Birngruber R, Gabel BP, Boergen KP, et al. The German experience in YAG laser surgery side effects using ultrashort, pulsed, Neodynium YAG lasers in intraocular microsurgery. In: Aron-Rosa D, ed. Pulsed YAG Laser Surgery. Thorofare: Slack, 1983; 45-48. 29. Pollack IP. Use of argon laser energy to produce iridotomies. Ophthalmic Surg 1980; 11 :506-15. 30. Peyman GA, Sanders DR, Minatoya H. Pars plana vitrectomy in the management of pupillary block glaucoma following irrigation and aspiration. Br J Ophthalmol 1978; 62:336-9. 31. Cotlier E. Anterior vitriotomy for aphakic flat anterior chamber. Br J Ophthalmol 1972; 56:347-52. 32. Patti JC, Cinotti AA. Iris photocoagulation therapy of aphakic pupillary block. Arch Ophthalmol1975; 93:347-8. 33. Fankhauser F, Roussel P, Steffen J, et aI. Clinical studies on the efficiency of high power laser radiation upon some structures of the anterior segment of the eye. Int Ophthalmol 1981; 3: 129-39. 34. Simmons RJ. Angle-closure glaucoma after scleral buckling operations for separated retina. In: Chandler PA, Grant WM, eds. Glaucoma, 2d ed. Philadelphia: Lea and Febiger, 1979; 183-6. 35. Campbell DG, Vela A. Synechialysis for the treatment of synechial angle closure in glaucoma. Read before the 69th Annual Clinical Congress of the American College of Surgeons, Atlanta, Georgia, October 17, 1983.
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