Aphakic and phakic retinal detachment. I. Preoperative findings

Lattice degeneration of the retina

Lattice degeneration of the retina is the most important of all clinically distinct entities that effect the peripheral fundus and are related to retinal detachment. The purpose of this review is to survey the extensive literature, to evaluate the many diverse opinions on this subject, and to correlate and summarize all the known facts regarding this disease entity. The disease is fully defined and described, both clinically and histologically. Some aspects of the disease are still poorly understood, and some remain controversial, especially in the area of management. For this reason, the indications for treatment are discussed under eight subsections, with a view toward providing practical guidelines for recommendations in management.

Vitreous findings in fellow eyes of aphakic retinal detachment

One hundred patients had bilateral aphakia, primary rhegmatogenous retinal detachment, and adequate visualization of the retinal and vitreous in the fellow eye. Of 43 patients with posterior vitreous separation and no retinal tear in the fellow eye, only one (2%) subsequently developed retinal detachment. Of 40 patients without posterior vitreous separation in the fellow eye, eight (20%) later developed retinal detachment following posterior vitreous separation. The remaining 17 patients had posterior vitreous separation and retinal tear or detachment at the time of initial examination. Thus, if posterior vitreous separation occurs without forming retinal tear, the risk of developing retinal detachment is significantly lowered.

Retinal detachment following phacoemulsification

In a consecutive series of 1,500 eyes in which phacoemulsification had been performed, the incidence of subsequent retinal detachment was 3.6%. Vitreous loss occurred in 4.2% (63) of the 1,500 cases, and in this group of eyes the incidence of retinal detachment was 14% (9). The characteristics of retinal breaks and the configurations of retinal detachments following phacoemulsification were in general similar to cases following intracapsular surgery. The surgical reattachment rates in these eyes compared favorably to previous reports on the repair of retinal detachments.

Prophylactic therapy of retinal breaks

Prophylaxis of selected retinal breaks is effective in preventing detachment. Most retinal breaks, however, will not cause detachment and can be safely followed without treatment. This paper reviews the evidence for and against prophylactic treatment of commonly encountered retinal breaks in an effort to arrive at typological guidelines for treatment. Education of patients with high risk of detachment is probably of equal value to cryotherapy or photocoagulation in preserving visual acuity.

On the molecular biology of the vitreous in the aphakic eye

The vitreous of aphakic and phakic eyes was assayed for hyaluronic acid. Intracapsular cataract extraction was regularly followed by decreased hyaluronic acid concentration and studies on the distribution of hyaluronic acid within the vitreous cavity showed that removal of the lens facilitates diffusion of hyaluronic acid into the anterior chamber. Based on these studies certain postoperative features of the aphakic eye are discussed. The instability of the vitreous gel, as reflected by rupture of the anterior vitreous face and an increased incidence of vitreous detachment supports the hypothesis of hyaluronic acid as a stabilizer of the gel. The decreased adhesion of the neural retina in the aphakic eye might be caused by the loss of hyaluronic acid. Normally the high concentration of hyaluronic acid adjacent to the retina contributes to the resistance of bulk flow of fluid into the subretinal space making it possible for the active transport system of the pigment epithelium to maintain a pressure drop across the neural retina. It is anticipated that saccades create currents in the fluid vitreous close to the eye wall after vitreous detachment. Model experiments showed that these currents were greatly enhanced, when the concentration of hyaluronic acid was lowered.

Retinal detachment in aphakia

In a prospective study five hundred consecutive cases of cataract operations were followed during ten years. Nine cases of retinal detachment were observed. In a retrospective study 77 cases with aphakic retinal detachment were studied according to type of cataract operation, interval between this operation and the onset of retinal detachment, refraction, area of detachment and results of treatment. About fifty percent of the cases of retinal detachment are observed during the first year after the cataract operation. At the first examination the detached area is usually larger in aphakic eyes than in phakic eyes. The anatomical and functional cure after detachment operation is probably less in aphakic than phakic eyes.

External buckling without drainage for selected detachments in aphakic eyes

Of 325 patients with retinal detachments, 110 patients (34%) had aphakic eyes. These detachments were subdivided into three types based on their clinical appearance during indirect ophthalmoscopy and slit-lamp biomicroscopy. Fifty-two patients (47%) had aphakic detachments (Type 3), categorized by small tears due to traction along a prominent posterior or vitreous base and the absence of visible retinal degeneration. Fifty of the 52 patients in this group were operated on by using a modification of the nondrainage procedure developed by Custodis, and employing cryosurgical coagulation and an external encircling buckle using a 3-mm silicone sponge. The sponge was secured beneath the retinal tear, and its length was shortened to produce a moderately elevated buckle. Although 50% of retinal tears were open at the end of the operation, 60% of all eyes operated on without drainage reattached in 16 hours, 90% in one week, and the remainder in two weeks. Visual acuity of 70% of these patients was 6/15 (20/50) or better when tested six months after surgery. The operation did not wall away peripheral fluid, but closed retinal tears completely, reduced circumferential vitreous traction, and avoided drainage of subretinal fluid.

Treatment of rhegmatogenous retinal detachment secondary to proliferative diabetic retinopathy

Fifty eyes with rhegmatogenous retinal detachment associated with proliferative diabetic retinopathy were treated surgically. Follow-up examination was from six months to 14 years with an average of 33 months. Successful reattachment of the retina was achieved in 74% of the cases, and visual acuity was preserved or improved in 60%.

Myopia-aphakia. I. Prevalence of retinal detachment

Retinal detachment after cataract extraction occurred in nine out of 136 eyes with myopia of 6 or more dioptress (6-7 per cent), during a follow-up period of 1 1/2-9 1/2 years. Five of the nine detachments occurred within 3 months of cataract extraction. All patients with retinal detachment were under the age of 63 years. Relatively young patients with high myopia bear a special risk of developing retinal detachment after lens extraction. The possible reason for this is discussed.

Giant retinal tears

Of 94 patients (100 eyes) with giant retinal tears, 71.4% of eyes with nontraumatic breaks were myopic and severe retinal pathologic findings were present in 57.3% of fellow eyes. Fifty-five (58%) of 95 treated eyes were successfully reattached; retinal incarceration, attempted in 19 cases, was successful in five. Serious surgical complications were responsible for failure in nine cases (22.5%). The worst prognostic factor were extension of the tear for over two quadrants, myopia of -10 diopters or more, and the presence of aphakia.