Pars Plana Vitrectomy in the Management of Retinal Detachments Associated with Degenerative Retinoschisis

Pars Plana Vitrectomy in the Management of Retinal Detachments Associated with Degenerative Retinoschisis SCOTI R. SNEED, MD, CHRISTOPHER F. BLODI, MD, JAMES C. FOLK, MD, THOMAS A.. WEINGEIST, MD, PhD, JOSE S. PULIDO, MD

Abstract: Pars plana vitrectomy and gas-fluid exchange were used to successfully reattach eyes of 12 patients who had symptomatic retinoschisis retinal detachments (RDs) associated with large or posterior outer-layer holes. Visual acuity improved postoperatively in seven (58%) eyes, was unchanged in two (17%) eyes, and decreased in three (25%) eyes. Loss of vision was secondary to a mild posterior subcapsular cataract in one eye and to epiretinal membranes in the other two. In two other eyes, cataracts developed that subsequently required an extracapsular cataract extraction (ECCE) and posterior chamber intraocular lens (PC IOL) implantation with 20/20 visual acuity in both eyes after cataract surgery. All eyes with a macula-involved RD stabilized or improved in visual acuity . Surgical indications, techniques, and results in the management of these retinoschisis RDs are discussed. Ophthalmology 1990; 97:470-474

Senile retinoschisis is a relatively common degenerative disorder of the peripheral retina in patients 50 years of age or older. Outer-layer breaks have been found in 10%1 to 27%2 of eyes with senile retinoschisis. Byer! found that 56% of eyes with outer-layer breaks had a non progressive schisis detachment. Some patients, however, do have progressive detachments and schisis. Several authors have reported the surgical treatment of these retinal detachments (RDs).3-9The use of pars plana vitrectomy has been described in the management of only two cases of schisis detachments." We report 12 additional cases of symptomatic schisis RDs that were managed mainl y with pars plana vitrectomy. Originally received : March 8, 1989. Revision accepted: September 15, 1989. From the Department of Ophthalmology, University of Iowa Hospitals and Clinics, Iowa City. Dr. Sneed is currently affiliatedwith the W. K. Kellogg Eye Center. University of Michigan , Ann Arbor. Supported in part by the Retina Research Fund of the University of Iowa and an unrestricted grant from Research to Prevent Blindness , New York, New York. Reprint requests to Christopher F. Blodi, MD, Department of Ophthalmology, University of Iowa Hospitals and Clinics, Iowa City, IA 52242.

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MATERIALS AND METHODS The medical records of 16 patients who were operated on for retinoschisis RDs at the University of Iowa Hospitals and Clinics from January 1984 to December 1988 were retrospectively analyzed. Four of these patients had small to moderately sized peripheral outer retinal breaks and were treated successfully with traditional scleral buckling procedures alone. When larger and more posterior outer-layer breaks were present, a pars plana vitrectomy was included as an integral part of the operative procedure. There were 12 patients in this group (Table 1). All patients were initially examined for symptomatic RDs. Ten patients had macular involvement causing visualloss. The remaining two patients with macula-spared detachments had noted visual field loss and had detachments well posterior to the equator. One to seven large posterior outer-layer holes were identified in all instances and inner-layer holes were found in 8 of the 12 eyes. No patients had tractional detachments, nor was focal vitreoretinal traction present at the site of any inner retinal holes. However, the vitreous was usually attached over the schisis cavity. Because ofthe size and location ofthese holes, they were treated with the following technique: first,

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Table 1. Summary of Retinoschisis/Retinal Detachment Cases Treated with Pars Plana Vitrectomy Visual Acuity

Case No.

Age (yrs)/Sex

Preoperative

Postoperative

FOllow-up (rnos)

1 2

50/F 41 /M

20/100 20/25

20/20 20/30

23 30

3 4 5 6

79/F 69/M 58/F 67/F

HM 20/750 20/20 CF

20/400 20/200 20/40 CF

10 26 54 29

7

8

20/25 20/50 HM

20/60 20/25 20/200

6

9

70/F 51 /M 77/M

8

10

74/M

20/300

20/50

37

11 12

54/F 67/M

HM 20/500

20/20 20/500

6

6 6

Type of Surgery PPV. laser, A FX~ 1) Pneumatic retinopexy 2) PPV, PPL, laser, AFX~ PPV, SSP, AFX~ PPV, SSP. AFX~ , ED PPV, SSP, AFX~, ED (1) SSP (2) PPV. SSP, AFX~ PPV, SSP, AFX~ PPV. SSP. laser, A FX~ (1) PPV. SSP, AFX~ (2) PPL. PPV. MX. SSP. laser. A FX~ . ED (1) SEP (2) PPV. SSP. laser. AFX~ , ED PPV, SSP, AFX~ . ED PPV, SSP, AFX~

Surgical Result A A A A A A A A A A A A

PPV = pars plana vitrectomy; AFX~ = air-fluid exchange; PPL = pars plana lensectomy; HM = hand motions; SSP = scleral buckling procedure; CF = counting fingers; ED = external drainage of subretinal fluid; A = attached; MX = posterior membranectomy.

Fig 1. Case I. Inferotemporal macula-involved schisis retinal detachment, left eye.

the schisis cavity were drained and collapsed. If the RD was completely flattened, endolaser was applied around the outer layer hole(s). Alternatively, transscleral cryopexy was administered if a small amount of subretinal fluid persisted. A long-acting gas (perfluoropropane or SF6 ) was injected into the vitreous cavity before closing the sclerotomies. A scleral buckle was used to relieve peripheral vitreous traction or to support more peripheral outer-layer holes. In many eyes, this buckle was an anterio r encircling element prophylactically placed without any attempt to support the outer-layer holes. Ten of 12 eyes had a scleral buckle placed during th e course oftreatment. In five eyes, we drained subretinal fluid by an external approach; however, we now think this is more cumbersome and less controlled than draining fluid under direct observation internally, either through a preexisting hole or through a surgical retinotomy.

CASE REPORTS a standard three -port pars plana vitrectomy was performed. As much as possible, attached vitreous over the schisis cavity was removed. A plan ned retino tomy was created, usually with intraocular diathermy, in the inner schisis layer over a conveniently located outer-layer hole. If a large inner-layer break was already present, this was used instead of creating a retinotomy. A soft-tipped 10 or conventional extrusion needle was placed through the inner-layer hole and also through or at least into the outerlayer hole. The cannula was inserted through the outerlayer hole to ensure drainage of both the RD and schisis cavity rathe r than the schisis cavity alone. A gas-fluid exchange was then performed and the subretinal fluid and

Case 1. A 50-year-old white woma n noticed that her vision was decreased in the left eye when she took a driver's license examination. She was seen I month later at the University of Iowa (April 15, 1987). Visual acuity at that time was 20/20 in the right eye and 20/70 in the left. Slit-lamp examination findings were unremarkable. Dilated ophthalmoscopic examination findings of the right eye were significant only for a peripheral area ofinferotemporal retinoschisis. An inferotemporal maculainvolved RD was present in the left eye (Fig I). There were several large posterior outer-layer holes below the macula (Fig 2) and several small inner-layer holes. Argon laser photocoagulation was initially placed around the outer-layer hole in an attempt to increase subretinal fluid resorption and to seal the

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Fig 2. Case I. Large outer-layer holes in retinoschisis inferotemporal to the macula with associated retinal detachment, left eye.

hole. This was unsuccessful and the retina remained detached with a visual acuity of 20/100 (May 27, 1987). On May 28, 1987, a pars plana vitrectomy was performed. A retinotomy was created in the inner layer of the schisis cavity. A gas-fluid exchange was performed and the RD and schisis cavity were flattened using an extrusion needle placed through the retinotomy. Argon endolaser photocoagulation was placed around the outerlayer hole and a 20% mixture of perfluoropropane was injected into the eye. The retina remained attached (Fig 3) although shallow peripheral retinoschisis persisted inferotemporally. A posterior subcapsular cataract developed postoperatively and by November 1988 visual acuity had diminished to 20/200. An extracapsular cataract extraction (ECCE) with posterior chamber intraocular lens (PC IOL) implantation was performed on November 9, 1988, and in January 1989 visual acuity was 20/20 and the retina was attached. Case 2. A 40-year-old white man was initially seen at the University ofIowa in October 1984. At that time, visual acuity was 20/20 in the right eye and 20/15 in the left eye. Slit-lamp examination findings were unremarkable. Retinoschisis was noted bilaterally on dilated ophthalmoscopic examination (Fig 4). Several large outer-layer holes were noted inferotemporally in the right eye. No inner-layer or outer-layer holes were identified in the left eye. No RD was present in either eye. The patient was next seen on September 30, 1986. He had a 5-day history of metamorphopsia and a nasal visual field defect in the left eye. Visual acuity was 20/20 in the right eye and 20/25 in the left. Dilated ophthalmoscopic examination findings of the right eye were unchanged. In the left eye, a large posterior outer-layer hole was present temporal to the macula with multiple tiny innerlayer holes and an associated temporal RD (Fig 5). A pneumatic retinopexy was performed and laser was used to surround the outer-layer hole. Despite this procedure, the RD continued to progress. On October 7, 1986, a pars plana vitrectomy was performed. Intraoperative cataractous lens changes required a pars plana lensectomy. A retinotomy was created in the inner layer and subretinal fluid and schisis fluid were removed with an extrusion needle during a gas-fluid exchange. The retina flattened and endolaser was used to surround the outer-layer hole. A prophylactic encircling band was placed anteriorly. The postoperative course was unremarkable and when last seen 15 months later, the patient had visual acuity of 20/40 in the left eye with contact lens correction. The retina was completely attached (Fig 6). 472

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Fig 3. Case I. Postoperative retinal reattachment and collapse of schisis cavity with inferior scarring secondary to laser photocoagulation, left eye.

Fig 4. Case 2. Top and bottom, temporal retinoschisis, left eye, October

1984.

Case 3. A 79-year-old white woman was initially seen at the University of Iowa in July 1984. Visual acuity at that time was 20/40 in the right eye and 20/30 in the left. Nuclear sclerotic cataracts were present bilaterally. Retinoschisis was noted in-

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RESULTS

Fig 5. Case 2. Temporal retinal detachment with large outer-layer hole, left eye, September 1986.

All retinas were successfully reattached using pars plana vitrectomy as part of the surgical procedure. Data on surgical technique and results are listed in Table 1. Before the vitrectomy, scleral buckling alone was unsuccessful in two eyes (cases 6 and 10) and a pneumatic retinopexy was unsuccessful in an eye with multiple inner-layer holes (case 2). One eye that initially had 0-2 proliferative vitreoretinopathy!' required two surgical procedures before successful retinal reattachment (case 9). Final postoperative visual acuity improved in seven (58%) eyes, was unchanged in two (17%) eyes and decreased in three (25%) eyes. Loss of vision was caused by a mild posterior subcapsular cataract in one eye (case 7) and an epiretinal membrane in two eyes (cases 2 and 5). All eyes with a macula-involved retinal detachment showed improvement or stabilization of visual acuity after surgery.

DISCUSSION

Fig 6. Case 2. Postoperative retinal reattachment with temporal chorioretinal changes from laser photocoagulation, left eye.

ferotemporally in the dilated right eye on ophthalmoscopic examination. Peripheral lattice degeneration was present in the left eye. The patient was examined again on April 16, 1988. She had a 4-day history of decreased vision in the right eye. Visual acuity was limited to hand motions in the right eye and was 20/ 50 in the left eye. Results of slit-lamp examination detected 2 + nuclear sclerosis in both eyes. Results of ophthalmoscopic examination of the dilated right eye showed a bullous RD involving the inferotemporal periphery and macula. A large outer-layer hole was present temporally with an overlying inner-layer hole. A pars plana vitrectomy was performed on April 25, 1988. Internal drainage was performed through the preexisting innerlayer hole and the outer-layer hole with a cannulated extrusion needle during a gas-fluid exchange. Cryopexy was used to surround the outer-layer hole and an encircling scleral buckle was placed to support the outer-layer hole. The patient was last seen 7 months later with a visual acuity of 20/400 and a totally attached retina. Mild surface-wrinkling retinopathy was present in the macula and there was a 2 to 3+ brunescent nuclear sclerotic cataract.

Schisis detachments may be associated with large posterior outer-layer holes that are technically difficult to approach with a standard scleral buckling procedure. Even if a scleral buckling procedure can be performed, posterior scleral buckles may cause significant macular distortion and some may need to be removed' Sulonen and others" described two cases ofschisis detachments with large posterior outer-layer holes that were successfully treated with a pars plana vitrectomy approach. Recently, Ambler et al" have had good results with a technique simply using drainage of the subretinal fluid externally with simultaneous insufflation of an expansile gas. One of the six eyes in their series had failed a scleral buckling procedure before undergoing external subretinal fluid drainage and insufflation of an expansile gas, and one patient failed the initial procedure after 9 months and required a scleral buckling procedure for successful reattachment. External drainage of subretinal fluid with insufflation of an expansile gas alone was successful in four of their six cases and appears to be an alternative approach to the treatment of these detachments. From schematic drawings in Ambler's article, it appears that most of their patients had outer-layer holes that were smaller and more peripheral than those seen in our patients. From the experience with our 12 patients, we feel most comfortable approaching eyes with schisis detachments and large or posterior outer-layer holes with a pars plana vitrectomy technique. Although external drainage is possible, we prefer the more controlled internal drain using the cannulated extrusion needle that can be positioned through a preexisting inner-layer hole or intentional retinotomy and then through the outer-layer hole to drain the schisis cavity and the subretinal fluid. A vitrectomy with internal drainage reduces the chance of sequential retinal tear development that has been described after

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pneumatic retinopexy and eliminates the complications of external subretinal fluid drainage. Expansile gases are commonly needed to maintain larger gas bubbles necessary to tamponade posterior or inferior retinal breaks. The only complication we have encountered with this surgical technique was the intraoperative formation of a cataract necessitating its removal in one instance (case 2). A posterior subcapsular cataract developed postoperatively in one patient (case 7), which dropped visual acuity from 20/25 preoperatively to 20/60 postoperatively. In two eyes (cases 1 and 5), postoperative cataracts developed that subsequently required ECCE and PC IOL implantation. Postoperative visual acuity in these two eyes was 20/20. An epiretinal membrane developed in two patients (cases 2 and 5) postoperatively, perhaps from the surgical procedure. Other, more severe, complications of pars plana vitrectomy and internal drainage were not noted. These include new retinal breaks, endophthalmitis, intraocular hemorrhage, and gas-related intraocular pressure elevation. Schisis detachments, although uncommon, should be treated if the patient has symptoms. Asymptomatic RDs associated with degenerative retinoschisis have been observed to be nonprogressive over years and do not warrant treatment. 1 Standard scleral buckling procedures may be successful in eyes that have peripheral outer-layer holes. Pars plana vitrectomy should be considered for treating symptomatic schisis detachments, especially in eyes that have large or posterior outer-layer holes.

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REFERENCES 1, Byer NE, Long-term natural history study of senile retinoschisis with implications for management. Ophthalmology 1986; 93:1127-37, 2, Dobbie JG, Cryotherapy in the management of senile retlnoschisls. Trans Am Acad Ophthai Otolaryng 1969; 73:1047-60, 3, Cox MS Jr, Gutow RF, The treatment of breaks and detachment of the outer layer in degenerative retmoschisis. In: Pruett RC, Regan CDJ, eds. Retina Congress: 25th Anniversary Meeting of the Retina Service, Massachusetts Eye and Ear Infirmary, New York: AppletonCentury-Crofts, 1972; 505-10, 4, Wilson RS, Dodson J, Giant tear dialysis in the outer layer of retinoschisis, Arch Ophthalmol 1972; 88:336-40, 5, Belkin M, Oliver M, Aviel E, David R. Surgical treatment of retinoschisis: anatomical and functional results, Ann Ophthalmoi 1973; 5:498-501, 6, Hagler WS, Woldoff HS, Retinal detachment in relation to senile retinoschisis. Trans Am Acad Ophthal Otolaryng 1973; 77:0P99-113, 7, Steahly LP, Comell FM. An unusual case of retinoschisis and retinal detachment. Ann Ophthalmol1982; 14:593-4, 8, Sulonen JM, Wells CG, Barricks ME, et al. Degenerative retinoschisis with giant outer layer breaks and retinal detachment. Am J Ophthalmol 1985; 99:114-21, 9, Ambler JS, Meyers SM, Zegarra H, Gutman FA. The management of retinal detachment complicating degenerative retinoschists, Am J Ophthalmol1989; 107:171-6, 10, Flynn HW Jr, Blumenkranz MS, Parel JM, Lee WG, Cannulated subretinal fluid aspirator for vitreoretinal microsurgery [Letter]. Am J Ophthalmol1987; 106-8, 11, The Retina Society Terminology Committee, The classification of retinal detachment with proliferative vitreoretinopathy, Ophthalmology 1983; 90:121-5,