Michael A. Novak

COMPLICATIONS OF ACUTE SYMPTOMATIC POSTERIOR VITREOUS DETACHMENT

During a ten-year period, 172 eyes of 155 patients developed acute symptomatic posterior vitreous detachments. The study included only patients examined within three months of the onset of symptoms. The patients ranged in age from 22 to 82 years, with an average age of 60 years. Of the 172 eyes, 118 (69%) developed no retinal or vitreous complications. Retinal tears occurred in 14 eyes (8%) and vitreous or retinal hemorrhages occurred in 36 eyes (21%). Seventeen patients (11%) who had acute symptomatic posterior vitreous detachment in one eye later developed acute symptomatic posterior vitreous detachment in the fellow eye. The second posterior vitreous detachment developed within two years of the first one in 15 eyes (88%). In 13 patients (76%), the second eye responded in the same manner to the posterior vitreous detachment as had the first, that is, ten pairs of eyes had no further complications, two pairs had retinal or vitreous hemorrhages, and one pair had retinal breaks.

Vitreous Hemorrhage after Vitrectomy for Diabetic Retinopathy

The records of 596 consecutive vitrectomy cases performed for complications of diabetic retinopathy were reviewed to determine the incidence of intraoperative and postoperative vitreous hemorrhage and to determine if blood cleared more rapidly in aphakic compared to phakic eyes. Uncontrollable intraocular bleeding occurred in two eyes (0.5%). Vitreous hemorrhage was present on the first postoperative day in 278 eyes (63%). This early hemorrhage cleared in an average of 9.1 weeks in phakic eyes and 3.4 weeks in aphakic eyes. Further vitreous hemorrhage occurred in 88 eyes (23%). Sixty-four percent of later hemorrhages occurred in 88 eyes (23%). Sixty-four percent of later hemorrhages occurred within six months of the operation and 80% occurred within one year. Later vitreous hemorrhage cleared in an average of 16.2 weeks in phakic eyes and 5.3 weeks in aphakic eyes. Of the 311 eyes with vitreous hemorrhage at some time during the postoperative course, twenty-nine eyes (9%) underwent reoperation to remove nonclearing blood. Nonclearing vitreous hemorrhage was the main cause of final visual loss in only 15 (3.4%) of 438 eyes with adequate follow-up, and 6 of these 15 eyes had final vision of 5/200 or better.

The Crystalline Lens after Vitrectomy for Diabetic Retinopathy

We reviewed the records of 596 consecutive cases of vitrectomy performed for complications of diabetic retinopathy at the Wilmer Eye Institute. Accidental lens damage occurred during surgery in three eyes. Fourteen (8%) of 180 phakic eyes underwent later cataract removal. Follow-up of at least six months and detailed description of the lens at final examination were available in 151 eyes. Of these, visually significant opacities occurred in 32 eyes (21%), and the lens opacities accounted for substantial loss of final vision in 6 (19%) of these 32 eyes. Moderate or severe lens opacities that developed postoperatively were as follows: anterior subcapsular or cortical changes in 2 eyes (1%), nuclear sclerosis in 11 eyes (7%), posterior subcapsular changes in 25 eyes (17%). One hundred twenty-five preoperative, operative and postoperative factors were analyzed for each patient to detect correlations with postoperative lens changes. Nuclear sclerotic changes correlated with older patient age. Posterior subcapsular changes correlated with three intraoperative factors: longer duration of the operation, use of intravitreal gas, and use of a gas bubble filling more than 50% of the vitreous cavity. Posterior subcapsular changes were progressive with longer follow-up.

Laser treatment in fellow eyes with large drusen: Updated findings from a pilot randomized clinical trial

PURPOSE To update the findings from the Choroidal Neovascularization Prevention Trial (CNVPT) with respect to resolution of drusen, incidence of choroidal neovascularization, and visual function. DESIGN A multicenter, randomized, controlled, pilot clinical trial. PARTICIPANTS The 120 patients enrolled in the CNVPT. Patients had signs of choroidal neovascularization or retinal pigment epithelial detachment in 1 eye and had >/=10 large (>63- micro m) drusen in the contralateral, or fellow, eye. INTERVENTION The fellow eye of 59 patients was assigned randomly to argon green laser treatment consisting of multiple 100- micro m spots at least 750 micro m from the center of the fovea. The fellow eye of the remaining 61 patients was assigned randomly to observation. MAIN OUTCOME MEASURES Change in visual acuity was the primary outcome measure. Incidence of choroidal neovascularization, resolution of drusen, change in contrast threshold, change in critical print size for reading, and incidence of geographic atrophy were secondary outcome measures. RESULTS Throughout 4 years of follow-up, there were no statistically significant differences in change in visual acuity, contrast threshold, critical print size, or incidence of geographic atrophy. With additional follow-up, the large increase in the incidence of choroidal neovascularization observed within 18 months of treatment was maintained; however, by 30 months, the incidence in the two treatment groups was the same. Most drusen resolution in treated eyes occurred within 24 months of the initial treatment. Treated eyes that received higher-intensity laser burns had an increased risk of choroidal neovascularization. Among eyes developing choroidal neovascularization in each treatment group, most lesions (two thirds or more) were composed of occult neovascularization only. CONCLUSIONS Laser treatment as applied in the CNVPT caused an excess risk of choroidal neovascularization in the first year or so after treatment. The increased early incidence of choroidal neovascularization was not associated with either a harmful or beneficial effect in this pilot study.

Calcium oxalate retinopathy associated with methoxyflurane abuse.

A 34-year-old woman developed a crystalline retinopathy after 2 years of inhalational abuse of methoxyflurane. After the woman developed renal failure, a renal biopsy showed multiple birefringent crystals in the renal tubular lumens, epithelial cells, and interstitium compatible with calcium oxalate. Multiple bright yellow-white crystals were deposited throughout the retina and at the level of the retinal pigment epithelium with a retinal arterial and periarterial predilection. This is the first reported case of methoxyflurane abuse with secondary hyperoxaluria in which there was a widespread retinal distribution of crystalline deposits, especially along the retinal arteries and arterioles.

Vitrectomy in Patients With Decreased Visual Acuity Secondary to Asteroid Hyalosis

PURPOSE To evaluate the role of vitrectomy in patients with decreased visual acuity solely attributable to asteroid hyalosis. METHOD We retrospectively reviewed the records of patients with asteroid hyalosis and identified those who underwent vitrectomy for symptomatic asteroid hyalosis alone. RESULTS After vitrectomy, nine of 10 eyes (10 patients) had at least 1 line of improvement in nonstandardized best-corrected visual acuity. In one eye, vision was unchanged postoperatively. The average gain was 3.44 lines. CONCLUSIONS A small percentage of patients with asteroid hyalosis have decreased visual acuity caused solely or primarily by the asteroid hyalosis. Vitrectomy in these patients may alleviate symptoms and improve visual acuity.

Krypton and argon laser photocoagulation for central serous chorioretinopathy.

Based on medical records, the authors divided 86 eyes of 84 patients with central serous chorioretinopathy with serous detachment of the macula and retinal pigment epithelial leakage on fluorescein angiography into three groups; no laser treatment (45 eyes), argon laser treatment (26 eyes), and krypton laser treatment (15 eyes). One or more episodes of recurrence developed during the follow-up period in 10 untreated eyes (22%), 9 argon-treated eyes (35%), and 0 krypton-treated eyes. The difference in recurrence rate between argon- and krypton-treated eyes was statistically significant. The findings suggest that whenever laser treatment is indicated, krypton red laser photocoagulation may reduce the incidence of recurrence in eyes with central serous chorioretinopathy.