Thomas A. Rice

Idiopathic Epiretinal Membranes: Ultrastructural Characteristics and Clinicopathologic Correlation+

Current theories of idiopathic epiretinal membrane (ERM) pathogenesis, based mainly on clinical and autopsy studies, emphasize a glial tissue origin. The clinical and ultrastructural features of 101 cases of idiopathic ERMs removed from the macular area during vitrectomy were studied. The predominant cell type was retinal pigment epithelium (RPE) in 51 cases, fibrous astrocytes in 29 cases, fibrocytes in 14 cases, and myofibroblasts in 7 cases. Features of myofibroblastic differentiation were present in 64 cases. Myofibrocytes were more common in younger patients with shorter duration of symptoms. Fibrous astrocytes were more common in females. The high incidence of RPE cells in this series raises new questions regarding the pathogenesis of idiopathic ERMs.

Complications of Vitreous Surgery for Diabetic Retinopathy: I. Intraoperative Complications

One hundred seventy-nine eyes were analyzed to determine the incidence of intraoperative complications during vitrectomy for proliferative diabetic retinopathy. Inadvertent corneal epithelial defects occurred in 51 eyes (28%). The lens was removed in 42 (25%) of 170 phakic eyes. This was done through a pars plana approach. Accidental mechanical lens damage occurred in one eye, and mild pharmacologic lens damage occurred in two eyes. Some bleeding from fibrovascular tissue occurred in nearly every case, but this was controlled with diathermy except in seven eyes (4%) in which severe bleeding required premature termination of the operation. Latrogenic retinal tears occurred in 36 (20%) of the 179 eyes. Fifteen (34%) of the total of 44 retinal tears were anterior to the equator, and 11 (73%) of the 15 anterior tears were located posterior to the sclerotomy through which the vitrectomy probe was introduced. Twenty-nine (66%) of the 44 retinal tears were posterior to the equator, and 19 of the 29 occurred within 15 degrees radius of the fovea.

The effect of lensectomy on the incidence of iris neovascularization and neovascular glaucoma after vitrectomy for diabetic retinopathy.

We analyzed a consecutive series of 596 eyes that underwent vitrectomy for complications of diabetic retinopathy to determine the postoperative incidence of iris neovascularization and neovascular glaucoma. Survival curves for various factors were plotted, showing the cumulative incidence of these complications at various postoperative times up to one year. Eyes in which the lens was removed during vitrectomy had a statistically significant (P < .001 by log-rank test) increase in the postoperative incidence of both iris neovascularization and neovascular glaucoma compared to eyes in which the lens was not removed. Lens removal at vitrectomy increased the risk of postoperative iris neovascularization by a factor of more than three and the risk of neovascular glaucoma by a factor of more than four. Other factors associated with a significantly increased incidence of postoperative iris neovascularization were severe preoperative retinal neovascularization and the absence of preoperative scatter retinal photocoagulation. Neither of these two factors nor postoperative retinal detachment invalidated or reduced the effect of lensectomy on increased postoperative iris neovascularization when all factors were considered simultaneously. This study showed a statistically significant increase in the postoperative incidence of neovascular glaucoma in eyes undergoing combined lensectomy and vitrectomy compared to eyes in which the lens was not removed.

Idiopathic retinal vasculitis, aneurysms, and neuro-retinitis

Purpose: The authors describe the clinical feature of ten patients with a new syndrome characterized by the presence of retinal vasculitis, multiple macroaneurysms, neuro-retinitis, and peripheral capillary nonperfusion. Methods: The authors evaluated ten patients identified to have clinical features compatible with the syndrome of idiopathic retinal vasculitis, aneurysms and neuroretinitis (IRVAN). Clinical examination findings, sequential fundus photographs (when available), fluorescein angiograms, systemic investigations, response to therapy, and visual outcomes were reviewed. Results: Seven eyes of four patients sustained a marked decrease in visual acuity of 20/200 or worse. Visual loss was due to a combination of an exudative maculopathy and sequelae of retinal ischemia. Capillary nonperfusion was seen in all ten patients and was severe enough to warrant panretinal laser photocoagulation in six patients. Systemic investigations were uniformly noncontributory. Oral prednisone appears to have little beneficial effects on patients with this disorder. Conclusions: Patients with IRVAN have characteristic retinal features that readily identify this syndrome. An increased awareness of this rare syndrome may help to identify sight-threatening complications at an earlier stage. The authors caution against extensive medical investigations. Ophthalmology 1995;102:1089-1097

Vitrectomy for Diabetic Traction Retinal Detachment Involving the Macula

We analyzed the surgical results for 197 eyes that underwent vitrectomy for diabetic traction detachment of the macula. The retina was successfully reattached in 130 of the 197 cases (66%), although the final level of vision depended on the amount of permanent macular damage from the previous detachment and on the effects of the retinal vascular disease. At the final examinations, 112 eyes (57%) had improved visual acuities, 68 eyes (35%) were worse, and 17 eyes (9%) were unchanged. Thirteen eyes (7%) had final visual acuities of 20/40 or better, 103 eyes (52%) had final visual acuities of 20/50 to 20/800, and 81 eyes (41%) had final visual acuities worse than 20/800. Two preoperative factors were associated with a worse prognosis for achieving a final visual acuity of 20/800 or better: preoperative vitreous hemorrhage (P < .01) and the absence of preoperative scatter retinal photocoagulation (P < .01). Additionally, two surgical factors, lens removal and the creation of iatrogenic retinal breaks, were associated with a poorer visual prognosis (P < .002 and P < .01, respectively). The group of eyes that underwent lens removal during vitrectomy also had a significantly higher incidence of postoperative iris neovascularization compared to eyes in which the lenses were not removed (P < .05).

Vitrectomy for Prevention of Macular Holes: Results of a Randomized Multicenter Clinical Trial

PURPOSE: The purpose of this study is to assess the benefit of vitreous surgery in preventing full-thickness macular holes in patients with impending (stage 1) macular holes. METHODS: A prospective randomized multicenter clinical trial was conducted on patients with full-thickness macular holes in their first eye (stage 3 or 4) and signs and symptoms of stage 1 macular holes in their fellow eye (study eye). The study eye was randomized to vitreous surgery or observation. Outcome was assessed by standardized measurement of visual acuity, detailed clinical examination, fundus photographs, and fluorescein angiography. RESULTS: A full-thickness macular hole developed in 10 (37%) of 27 patients in the vitrectomy group compared with 14 (40%) of 35 patients randomized to observation (P = 0.81). This difference of 3% has a 95% confidence interval of (-21%, 27%). CONCLUSION: The study was terminated because of low recruitment. The authors were unable to prove (or disprove) the benefit of vitreous surgery in patients with stage 1 macular holes. The authors can state, however, that should a beneficial effect from vitrectomy exist, it would probably be minimal. Considering the cost and morbidity of vitreous surgery, a conservative approach for stage 1 macular hole might be appropriate.Purpose: The purpose of this study is to assess the benefit of vitreous surgery in preventing full-thickness macular holes in patients with impending (stage 1) macular holes. Methods: A prospective randomized multicenter clinical trial was conducted on patients with full-thickness macular holes in their first eye (stage 3 or 4) and signs and symptoms of stage 1 macular holes in their fellow eye (study eye). The study eye was randomized to vitreous surgery or observation. Outcome was assessed by standardized measurement of visual acuity, detailed clinical examination, fundus photographs, and fluorescein angiography. Results: A full-thickness macular hole developed in 10 (37%) of 27 patients in the vitrectomy group compared with 14 (40%) of 35 patients randomized to observation ( P = 0.81). This difference of 3% has a 95% confidence interval of (-21%,27%). Conclusion: The study was terminated because of low recruitment. The authors were unable to prove (or disprove) the benefit of vitreous surgery in patients with stage 1 macular holes. The authors can state, however, that should a beneficial effect from vitrectomy exist, it would probably be minimal. Considering the cost and morbidity of vitreous surgery, a conservative approach for stage 1 macular hole might be appropriate.

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.

Central Retinal Artery Occlusion without Retrobulbar Hemorrhage after Retrobulbar Anesthesia

Four patients had central retinal artery occlusions after retrobulbar anesthesia with lidocaine HCl was administered before photocoagulation. One of these four had two separate episodes of closure. Only one had permanent visual loss, and none had evidence of retrobulbar hemorrhage. Each patient had a severe hematologic or vascular disorder. We think that direct trauma to the central retinal artery behind the globe, the pharmacologic or compressive effects of the injected solution, or both caused the occlusions in these patients.

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.

Long-Term Anatomic and Functional Results of Vitrectomy for Diabetic Retinopathy

Summary A long-term follow-up study of 130 eyes that had had initially successful vitrectomies for complications of proliferative diabetic retinopathy showed that only ten (8%) eyes had significant worsening of visual acuity at final examination (18 to 68 months after surgery), compared to the best visual acuity recorded during the first six months after surgery. Active flat retinal neovascularization was present at final examination in only three eyes (2%), and in no case did elevated fibrovascular proliferation occur. The type and incidence of important complications during the early and later postoperative periods indicated a low rate of late complications.