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Laser photomydriasis in pseudophakic pupillary block
laser photomydriasis in pseudophakic pupillary block Stephen A. Obstbaum, M.D. Kenneth R. Barasch, M.D. Miles A. Galin, M.D. Irving Baras, M.D. New York, New York ABSTRACT Pupillary block glaucoma is a potential complication of implantation. Early recognition and prompt medical therapy will generally successfully treat the condition. In some instances surgical treatment is required if medical therapy is inadequate. Laser iridectomy and laser photomydriasis are other alternatives to surgical therapy. This case reports successful treatment of pseudophakic pupillary block glaucoma using laser photomydriasis. Key words: pupillary block glaucoma, pupil-supported intraocular lens, mydriasis, peripheral iridectomy, laser iridectomy, laser photomydriasis.
Pupillary block is one of the early complications of iris-supported intraocular lenses (IOLs). Any lens that resides within the pupillary space and relies on the sphincter for support may hamper anterior aqueous flow. Accurate recognition of this condition and prompt medical management frequently produce a favorable outcome. When the block mechanism cannot be broken by medical means surgical therapy is initiated. We will report a case that was unresponsive to conventional medical therapy, but which responded to laser photomydriasis thereby obviating the need for surgical intervention.
CASE REPORT A 75-year-old woman was initially evaluated for cataract surgery OS in November 1978. During the intervening year her visual acuity gradually diminished to 20/200 and a planned extracapsular cataract extraction with insertion of a Fyodorov sputnik implant (Coburn) was performed on December 10, 1979. On the first postoperative visit visual acuity was 20/40 and intraocular pressure was 12 mm Hg. The anterior chamber was deep and a mild reaction present. The pupil was dilated with 0.5% tropicamide and topical steroids were prescribed q. i. d. The anterior chamber remained deep centrally on the second postoperative day, but was shallower temporally and inferiorly than on the previous visit. The implant was properly situated and lOP remained normal. The change in chamber depth was considered to be secondary to retained cortical material. The pupil was again dilated and topical steroids continued. The appearance on the following day was unchanged. One week postoperatively visual acuity was 20/40, lOP was 16 mm Hg, the central chamber was deep with trace reaction, and the peripheral chamber was
shallow in the areas previously noted. The posterior capsule was intact centrally. On the ninth postoperative day the patient telephoned complaining of severe pain. On examination the cornea was mildly edematous. The anterior chamber was almost totally flat with only a slit-like central area. There was no evidence of wound leakage, but there was a greater inflammatory reaction in the anterior chamber. Pigmented cells were deposited on the surface of the implant. The sphincter was tight around the implant and synechiae to the supporting elements had formed. lOP was 50 mm Hg. A solution of 1% tropicamide and 2.5% phenylephrine (Neo-Synephrine) hydrochloride was instilled, but only one sector of the pupil dilated. The anterior chamber remained shallow centrally (Fig. 1). A 1 % solution of cyclopentolate and 10% phenylephrine, and
Fig. 1 (Obstbaum et all. Shallow anterior chamber characterizing pupil block early in the course of medical therapy.
From the Department of Ophthalmology, Mount Sinai School of Medicine, New York, New York (Drs. Obstbaum, Barasch, and Baras); and the New York Medical College, Valhalla, New York (Dr. Galin). Reprint requests to Dr. Obstbaum, 115 East 39th Street, New York, NY 10016. 28
AM INTRA-OCULAR IMPLANT SOC J-VOL. 7, JANUARY 1981
Fig. 2 (Obstbaum et all. Maximal dilation achieved by medical therapy. Dense synechiae are evident.
Fig. 3 (Obstbaum et all. Laser bums applied in area of greatest "pupil dilation. Note that synechiae in this area have been lysed.
Fig. 4 (Obstbaum et al) . Immediate deepening of the an terior chamber after laser photomydriasis.
Fig. 5 (Obstbaum et all. Eye has remained stable for at least eight months after laser photomydriasis.
oral osmotics were added to the regimen with minimal effect. lOP remained elevated and the patient still complained of pain. Dense synechiae were evident between the iris and posterior posts of th e implant (Fig. 2). Argon laser photomydriasis was performed under topical anesthesia, using the antireflective coated Goldmann contact lens. Several rows of laser burns (200 microns, 0.2 seconds, 400-500 mW) were delivered to the superior nasal iris in the area of greatest pharmacologic pupillary dilation (Fig. 3). The anterior chamber deepened immediately after laser treatment and lOP fell 20 mm Hg within minutes (Fig. 4). Iris tissue shrinkage occurred circumferentially and also posteriorly relative to the implant, creating a channel through which aqueous could flow. Synechiae to the posterior supporting elements were separated by this treatment.
The patient's condition has remained stable for eight months following this episode. Visual acuity is 20/40 + and lOP is 16 mm Hg. The chamber is deep and all residual cortex has resorbed (Fig. 5).
DISCUSSION Pupillary block may occur in phakic, aphakic, and pseudophakic conditions. Therapy of pupillary block is directed at alleviating the obstruction to aqueous flow through the pupil by overcoming the resistance in this area or by shunting aqueous from the posterior to anterior chambers. Pupillary block in the pseudophakic eye generally is accompanied by pain, corneal edema, a shallow to flat anterior chamber, a sphincter tightly positioned around th e implant's supporting e leme nts , and synechial formation. lOP is invariab"ly elevated.
AM INTRA-OCULAR IMPLANT SOC J-VOL. 7, JANUARY 1981
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Medical therapy should be instituted as soon as the diagnosis is made. Controlled mydriasis is the treatment of choice. Usually a short-acting cycloplegic mydriatic agent is used so that pupil dilation is not great enough to produce loop dislocation . If these agents are ineffective , weak adrenergics can be cautiously administered. Adrenergic agents act by directly stimulating the dilator pupillae muscle and can cause rapid and uncontrolled dilation , especially if the sphincter has been previously blocked by parasympatholytics. In the present instance we were unable to effect pupil dilation even using stronger mydriatic agents. If the pupil does not respond to medical management surgical intervention is mandated . Peripheral iridectomy is the classical operation for pupillary block. Iridectomy can be performed through the previous corneoscleral incision or preferably by using a clear corneal approach. In either event, once the attack is broken the chamber deepens and lOP returns to normal levels. Delay in either making the diagnosis or starting therapy can result in endothelial-implant contact with the possibility of corneal decompensation in the future or of secondary angle closure following formation of peripheral anterior synechiae, especially in the inflamed eye. Laser therapy provides an alternative method to the surgical treatment of pupillary block. Laser iridectomy or laser photomydriasis are viable modes of treatment. Of these procedures the latter is easier to perform. In classical pupillary block angle closure glaucoma the iris lies in close proximity to the corneal endothelium. The energy required to achieve through-and-through iris pen e tration may be absorbed by the cornea, producing corneal burns which damage the cornea and prohibit adequate delivery of laser energy to the desired areas on the iris. However, excellent results with varied techniques have been reported by others using laser iridectomy in acute angle closure. 1,2 Pupillary block produced by a pupil-
30
supported IOL mimics the anatomic condition of acute angle closure glaucoma, and laser iridectomy in this situation can introduce similar technical problems. During laser iridectomy for subacute angle closure for the fellow eye in angle closure, the pupil peaks towards the area of laser applications. In even some of the unsuccessful cases of laser iridectomy in acute angle closure the pupil dilates asymmetrically , permitting aqueous to flow anteriorly and abort the angle closure attack. Sphincter ischemia with segmen tal iris shortening can spontaneously break an attack of pupillary block angle closure. 3 The xenon arc and laser photocoagulators have been used to produce photomydriasis for a variety of conditions, generally to enlarge the pupil for visual considerations. 4 ,5 In this report we used argon laser photomydriasis to treat pupillary block in the pseudophakic state. This procedure does not have the same energy requirements as laser iridectomy and is a rapid, efficient means to alter the course of pupillary block. The effect is lasting and precludes the immediate use of conventional surgical procedures.
REFERENCES 1. Abraham RK, Miller GL: Outpatient argon laser iridectomy for angle closure glaucoma: a two year study. Trans Am Acad Ophthalmol Otolaryngol 79:529, 1975 2. Podos SM , Kels BK , Moss AP e t al: Continuous wave argon laser iridectomy in angle closure glaucoma. Am ] Ophthalmol 88:836, 1979 3. Phillips CI, Woodhouse DF: Self-limiting acute closed angle glaucoma with segmental iris shortening. BrJ Ophthalmol 47:547, 1963 4. Straatsma BR, Allen RA, Pettit TH: Subluxation of the lens treated with iris photocoagulation. Am] Ophthalmol 61: 1312, 1966 5. L'Esperance FA, James WA: Argon laser photocoagulation of iris abnormalities. Trans Am Acad Ophthalmol Otolaryngol 79:321, 1975
AM INTRA-OCULAR IMPLANT SOC J-VOL. 7, JANUARY 1981
Pupillary block is one of the early complications of iris-supported intraocular lenses (IOLs). Any lens that resides within the pupillary space and relies on the sphincter for support may hamper anterior aqueous flow. Accurate recognition of this condition and prompt medical management frequently produce a favorable outcome. When the block mechanism cannot be broken by medical means surgical therapy is initiated. We will report a case that was unresponsive to conventional medical therapy, but which responded to laser photomydriasis thereby obviating the need for surgical intervention.
CASE REPORT A 75-year-old woman was initially evaluated for cataract surgery OS in November 1978. During the intervening year her visual acuity gradually diminished to 20/200 and a planned extracapsular cataract extraction with insertion of a Fyodorov sputnik implant (Coburn) was performed on December 10, 1979. On the first postoperative visit visual acuity was 20/40 and intraocular pressure was 12 mm Hg. The anterior chamber was deep and a mild reaction present. The pupil was dilated with 0.5% tropicamide and topical steroids were prescribed q. i. d. The anterior chamber remained deep centrally on the second postoperative day, but was shallower temporally and inferiorly than on the previous visit. The implant was properly situated and lOP remained normal. The change in chamber depth was considered to be secondary to retained cortical material. The pupil was again dilated and topical steroids continued. The appearance on the following day was unchanged. One week postoperatively visual acuity was 20/40, lOP was 16 mm Hg, the central chamber was deep with trace reaction, and the peripheral chamber was
shallow in the areas previously noted. The posterior capsule was intact centrally. On the ninth postoperative day the patient telephoned complaining of severe pain. On examination the cornea was mildly edematous. The anterior chamber was almost totally flat with only a slit-like central area. There was no evidence of wound leakage, but there was a greater inflammatory reaction in the anterior chamber. Pigmented cells were deposited on the surface of the implant. The sphincter was tight around the implant and synechiae to the supporting elements had formed. lOP was 50 mm Hg. A solution of 1% tropicamide and 2.5% phenylephrine (Neo-Synephrine) hydrochloride was instilled, but only one sector of the pupil dilated. The anterior chamber remained shallow centrally (Fig. 1). A 1 % solution of cyclopentolate and 10% phenylephrine, and
Fig. 1 (Obstbaum et all. Shallow anterior chamber characterizing pupil block early in the course of medical therapy.
From the Department of Ophthalmology, Mount Sinai School of Medicine, New York, New York (Drs. Obstbaum, Barasch, and Baras); and the New York Medical College, Valhalla, New York (Dr. Galin). Reprint requests to Dr. Obstbaum, 115 East 39th Street, New York, NY 10016. 28
AM INTRA-OCULAR IMPLANT SOC J-VOL. 7, JANUARY 1981
Fig. 2 (Obstbaum et all. Maximal dilation achieved by medical therapy. Dense synechiae are evident.
Fig. 3 (Obstbaum et all. Laser bums applied in area of greatest "pupil dilation. Note that synechiae in this area have been lysed.
Fig. 4 (Obstbaum et al) . Immediate deepening of the an terior chamber after laser photomydriasis.
Fig. 5 (Obstbaum et all. Eye has remained stable for at least eight months after laser photomydriasis.
oral osmotics were added to the regimen with minimal effect. lOP remained elevated and the patient still complained of pain. Dense synechiae were evident between the iris and posterior posts of th e implant (Fig. 2). Argon laser photomydriasis was performed under topical anesthesia, using the antireflective coated Goldmann contact lens. Several rows of laser burns (200 microns, 0.2 seconds, 400-500 mW) were delivered to the superior nasal iris in the area of greatest pharmacologic pupillary dilation (Fig. 3). The anterior chamber deepened immediately after laser treatment and lOP fell 20 mm Hg within minutes (Fig. 4). Iris tissue shrinkage occurred circumferentially and also posteriorly relative to the implant, creating a channel through which aqueous could flow. Synechiae to the posterior supporting elements were separated by this treatment.
The patient's condition has remained stable for eight months following this episode. Visual acuity is 20/40 + and lOP is 16 mm Hg. The chamber is deep and all residual cortex has resorbed (Fig. 5).
DISCUSSION Pupillary block may occur in phakic, aphakic, and pseudophakic conditions. Therapy of pupillary block is directed at alleviating the obstruction to aqueous flow through the pupil by overcoming the resistance in this area or by shunting aqueous from the posterior to anterior chambers. Pupillary block in the pseudophakic eye generally is accompanied by pain, corneal edema, a shallow to flat anterior chamber, a sphincter tightly positioned around th e implant's supporting e leme nts , and synechial formation. lOP is invariab"ly elevated.
AM INTRA-OCULAR IMPLANT SOC J-VOL. 7, JANUARY 1981
29
Medical therapy should be instituted as soon as the diagnosis is made. Controlled mydriasis is the treatment of choice. Usually a short-acting cycloplegic mydriatic agent is used so that pupil dilation is not great enough to produce loop dislocation . If these agents are ineffective , weak adrenergics can be cautiously administered. Adrenergic agents act by directly stimulating the dilator pupillae muscle and can cause rapid and uncontrolled dilation , especially if the sphincter has been previously blocked by parasympatholytics. In the present instance we were unable to effect pupil dilation even using stronger mydriatic agents. If the pupil does not respond to medical management surgical intervention is mandated . Peripheral iridectomy is the classical operation for pupillary block. Iridectomy can be performed through the previous corneoscleral incision or preferably by using a clear corneal approach. In either event, once the attack is broken the chamber deepens and lOP returns to normal levels. Delay in either making the diagnosis or starting therapy can result in endothelial-implant contact with the possibility of corneal decompensation in the future or of secondary angle closure following formation of peripheral anterior synechiae, especially in the inflamed eye. Laser therapy provides an alternative method to the surgical treatment of pupillary block. Laser iridectomy or laser photomydriasis are viable modes of treatment. Of these procedures the latter is easier to perform. In classical pupillary block angle closure glaucoma the iris lies in close proximity to the corneal endothelium. The energy required to achieve through-and-through iris pen e tration may be absorbed by the cornea, producing corneal burns which damage the cornea and prohibit adequate delivery of laser energy to the desired areas on the iris. However, excellent results with varied techniques have been reported by others using laser iridectomy in acute angle closure. 1,2 Pupillary block produced by a pupil-
30
supported IOL mimics the anatomic condition of acute angle closure glaucoma, and laser iridectomy in this situation can introduce similar technical problems. During laser iridectomy for subacute angle closure for the fellow eye in angle closure, the pupil peaks towards the area of laser applications. In even some of the unsuccessful cases of laser iridectomy in acute angle closure the pupil dilates asymmetrically , permitting aqueous to flow anteriorly and abort the angle closure attack. Sphincter ischemia with segmen tal iris shortening can spontaneously break an attack of pupillary block angle closure. 3 The xenon arc and laser photocoagulators have been used to produce photomydriasis for a variety of conditions, generally to enlarge the pupil for visual considerations. 4 ,5 In this report we used argon laser photomydriasis to treat pupillary block in the pseudophakic state. This procedure does not have the same energy requirements as laser iridectomy and is a rapid, efficient means to alter the course of pupillary block. The effect is lasting and precludes the immediate use of conventional surgical procedures.
REFERENCES 1. Abraham RK, Miller GL: Outpatient argon laser iridectomy for angle closure glaucoma: a two year study. Trans Am Acad Ophthalmol Otolaryngol 79:529, 1975 2. Podos SM , Kels BK , Moss AP e t al: Continuous wave argon laser iridectomy in angle closure glaucoma. Am ] Ophthalmol 88:836, 1979 3. Phillips CI, Woodhouse DF: Self-limiting acute closed angle glaucoma with segmental iris shortening. BrJ Ophthalmol 47:547, 1963 4. Straatsma BR, Allen RA, Pettit TH: Subluxation of the lens treated with iris photocoagulation. Am] Ophthalmol 61: 1312, 1966 5. L'Esperance FA, James WA: Argon laser photocoagulation of iris abnormalities. Trans Am Acad Ophthalmol Otolaryngol 79:321, 1975
AM INTRA-OCULAR IMPLANT SOC J-VOL. 7, JANUARY 1981