Glen P. Johnston

Pseudophakic Retinal Detachments in the Presence of Various IOL Types

A series of 600 pseudophakic retinal detachments in 578 patients undergoing surgical repair between 1974 and 1984 was reviewed. Patients with previous retinal surgery of less than six months follow-up were excluded. The series included 395 iris-fixated (IF) lenses, 130 anterior chamber (AC) lenses, and 75 posterior chamber (PC) lenses. The overall success rate for retinal detachment was 88% but was significantly better in the PC lens group and significantly worse in the AC lens group. Forty-one percent of all cases achieved 20/40 visual acuity or better, although the AC lens group did worse (28%), while the PC lens group did significantly better (48%). Risk factors that were predictive of failure also were identified. Many of these factors occurred more frequently in the AC lens group and probably are related to the overall worse outcome in eyes with AC lens implants. The implications of these results for retinal and cataract surgeons are discussed.

New Retinal Detachment after Pneumatic Retinopexy

Thirteen cases of rhegmatogenous retinal detachment repaired by pneumatic retinopexy were reviewed retrospectively. All patients were followed for a minimum of 6 months after surgery. At the end of follow-up, retinal detachment repair by pneumatic retinopexy succeeded in nine cases (70%) and failed in four (30%). Within 2 days of pneumatic retinopexy, vitreous condensation and traction with new retinal tears and associated detachments in previously uninvolved quadrants developed in two patients. The occurrence of new retinal detachments in the early postoperative period after pneumatic retinopexy has not been previously observed.

Preoperative Antibiotic Soaking of Silicone Sponges: Does it Make a Difference?

A prospective randomized trial was carried out during the years 1974 to 1981 to determine whether preoperative antibiotic soaking of silicone sponges used in retinal detachment surgery would reduce the incidence of postoperative infection and extrusion. During this period 2972 consecutive primary scleral buckles were performed and in 921 (31%) of the cases an episcleral sponge was utilized either alone or in conjunction with a hard silicone encircling band. In alternate cases the sponge was soaked in an antibiotic solution for at least 30 minutes prior to insertion. In the remaining cases the sponge was not soaked. Overall, a statistically significant (P = 0.00018) seven-fold reduction in the rate of infection or extrusion was observed in cases where the silicone sponge was soaked preoperatively in antibiotics. An additional result of the study showed the rate of sponge removal was significantly increased by the use of multiple episcleral sponges (P = 0.00002).

Pregnancy and Diabetic Retinopathy

Diabetic retinopathy can be expected to progress during the term of pregnancy. A retrospective study indicated that photocoagulation was successful in preserving vision in 70 to 80% of 30 pregnant diabetic patients as well as in a similar group of nonpregnant patients with juvenile-onset diabetes. Proliferative diabetic retinopathy, in and of itself, is not an absolute indication for therapeutic abortion.

Transconjunctival Anterior Retinal Cryotherapy for Proliferative Diabetic Retinopathy

Transconjunctival anterior retinal cryotherapy (ARC) for proliferative diabetic retinopathy (PDR) in 408 eyes was reviewed retrospectively. Of 266 eyes available for analysis for treatment effect on neovascularization, 138 (52%) had reduced neovascularization at 6 months. Eighty (30%) had no change in neovascularization, and 48 (18%) had increased neovascularization at 6 months. Factors having a significant effect on reduction of neovascularization were duration of diabetes and severity of retinopathy. Of 238 eyes available for analysis for treatment effect on vitreous hemorrhage at 6 months, 118 (50%) had reduced vitreous hemorrhage, 80 (33%) had no change, and 40 (17%) had increased vitreous hemorrhage. Severity of vitreous hemorrhage significantly affected the outcome in the subgroup of eyes with both neovascularization and vitreous hemorrhage. Of the total 408 eyes in this series, at 6 months, 172 (44%) had improved visual acuity, 89 (23%) had no change, and 126 (33%) had decreased visual acuity. Retinal detachments developed in 17 eyes (4%) post-treatment, 68 eyes (17%) had significant recurrent vitreous hemorrhage, and 61 eyes (15%) eventually underwent vitrectomy.

The Lincoff Temporary Balloon Buckle

The Lincoff temporary balloon buckle is an equally effective alternative to more conventional techniques in the management of selected retinal detachments. We used this technique in the management of 45 selected primary retinal detachments operated on since Nov. 22, 1980. Initial complete retinal flattening was achieved in 42 eyes (93%). Two of the three eyes that initially did not show complete flattening ultimately went on to do well without further surgery. Redetachment occurred in three of the five aphakic eyes (60%) and in four of the 36 phakic eyes (11%). None of the retinas in the four eyes with intraocular lenses redetached. Conventional scleral buckling techniques were used in the one case of initial failure and in the seven cases of redetachment for a final success rate of 98% after an average follow-up of 13 months.

Xenon Arc Photocoagulation of Proliferative Diabetic Retinopathy: A review of 2688 Consecutive Eyes in the format of the Diabetic Retinopathy Study

In a retrospective study, 2688 eyes treated with xenon arc photocoagulation which would have qualified for inclusion in the Diabetic Retinopathy Study (DRS) were reviewed in the format of the DRS. When comparable risk groups were compared, the results of treatment were even more favorable than reported in the DRS without the severe complications attributed to xenon treatment in the DRS. A critical analysis of the DRS gives clues for the greater amount of visual loss found with xenon than argon in the DRS. Since these complications may be avoidable in some cases, and since xenon has been shown to be at least as effective as argon, it should continue to be used in the treatment of proliferative diabetic retinopathy.

Early photocoagulation treatment of active histoplasmic maculopathy.

Photocoagulation has proved to be an effective means of treating active presumed histoplasmic maculopathy. Xenon arc and argon laser light sources have proved equally effective when moderately intense, confluent burns are produced, and both are ineffective when mild lesions are produced. The membrane must be destroyed for the treatment to be effective; and, of course, the fovea must be preserved. In treating neovascular nets that are very close to the fovea, the argon laser offers the advantage of being capable of producing a sharper zone of delineation than the xenon arc (Fig. 6). When moderate amounts of subretinal fluid or hemoglobin overlie the neovascular membrane, it is very difficult to achieve the required degree of coagulation. Under these circumstances, it is best first to try to reduce the height of the sensory retinal detachment by means of systemic steroid treatment. If this is not successful, xenon photocoagulation has produced better coagulation effects than the argon laser. Analysis of our data indicates that resultant visual acuity can be correlated with pretreatment visual acuity (Fig. 5), with best results achieved before visual acuity deteriorates beyond the 20/40 level. The closer the edge of the neovascular membrane is to the fovea, the more risky it is to treat. However, these lesions are also those most apt to destroy central vision if left alone. It is encouraging to note that in only 3 of the 16 lesions in which the foveal edge was within 1 degree of the fovea did the visual acuity deteriorate to the 20/200 level, compared to 50 percent deterioration reported in the natural history of this disease [3].