Arnall Patz

Photocoagulation Treatment of Proliferative Diabetic Retinopathy: The Second Report of Diabetic Retinopathy Study Findings

Data from the Diabetic Retinopathy Study (DRS) show that photocoagulad inhibited the progression of retinopathy. These beneficial effects were noted to some degree in all those stages of diabetic retinopathy which were included in the Study. Some deleterious effects of treatment were also found, including losses of visual acuity and constriction of peripheral visual field. The risk of these harmful effects was considered acceptable in eyes with retinopathy in the moderate or severe retinopathy in the moderate or severe proliferative stage when the risk of severe visual loss without treatment was great. In early proliferative or severe nonproliferative retinopathy, when the risk of severe visual loss without treatment was less, the risks of harmful treatment effects assumed greater importance. In these earlier stages, DRS findings have not led to a clear choice between prompt treatment and deferral of treatment unless and until progression to a more severe stage occurs.

Macular edema. A complication of diabetic retinopathy

Diabetic macular edema is the leading cause of decreased vision from diabetic retinopathy. This decreased vision is caused by an increase in extracellular fluid within the retina distorting the retinal architecture and frequently taking on a pattern of cystoid macular edema. This fluid accumulates within the retina because of the breakdown of the barriers within the retinal blood vessels and possibly the pigment epithelium. Diabetic macular edema tends to be a chronic disorder. Although spontaneous recovery is not an uncommon occurrence, over one-half of diabetics with macular edema will lose two or more lines of visual acuity within two years. The most promising treatment for diabetic macular edema has been photocoagulation. It is recommended that in all patients with diabetic macular edema attempts be made to normalize elevated blood glucose, decrease elevated blood pressure, and improve cardiac or renal status. Reduction of serum lipids by diet or pharmacologic means is an unproven treatment at this time. The Early Treatment Diabetic Retinopathy Study hopefully will provide more definitive information as to whether photocoagulation is effective in various subgroups of patients with diabetic macular edema.

Natural Course of Choroidal Neovascular Membranes Within the Foveal Avascular Zone in Senile Macular Degeneration

We divided 96 eyes (93 patients) with senile macular degeneration and choroidal neovascular membranes into two groups--those with juxtafoveal membranes (1 to 250 mu from the center of the foveal avascular zone) and those with subfoveal membranes (0 mu from the center of the zone). After an average follow-up period of 21 months, one of 38 eyes in the juxtafoveal group (3%) had improved two or more lines on the Snellen chart, three eyes (8%) had remained the same, and 34 eyes (89%) had lost two or more lines on the Snellen chart. Although 35 of the 38 eyes (92%) had had initial visual acuities of 6/30 (20/100) or better, 27 eyes (71%) had become legally blind. Of the 58 eyes in the subfoveal group, 18 (31%) had remained the same or improved and 40 (69%) had lost two or more lines on the Snellen chart; 41 (70%) had final visual acuities of 6/60 (20/20) or worse. Of the 26 eyes in the subfoveal group that had had initial visual acuities of 6/60 (20/100) or better (45%). four (15%) had stayed the same and 22 (85%) had lost two or more lines on the Snellen chart. Fourteen of the 26 eyes (54%) had final visual acuities of 6/60 (20/200) or worse. Exudative maculopathy developed in the second eye in 13% of patients who initially had unilateral choroidal neovascularization after 12 months, in 22% after 24 months, and in 29% after 36 months, using life table analysis.

Clinical and experimental studies on retinal neovascularization. XXXIX Edward Jackson Memorial Lecture.

Retinal neovascularization is a serious complication of the retinopathy associated with diabetes, branch vein occlusion, sickle cell anemia, and retrolental fibroplasia. Retinal capillary nonperfusion, demonstrated on fluorescein angiography, precedes the development of neovascularization in each of these conditions. Our working hypothesis is that the nonperfused (ischemic or hypoxic) retina liberates a vasoproliferative or angiogenic substance. Although I have delineated the clinical and experimental observations relating to the hypothesis of an ischemic-mediated angiogenesis substance, other postulated mechanisms for the development of retinal neovascularization may be involved. Recent observations on the experimental model of retrolental fibroplasia have demonstrated the markedly abnormal persistence and apparent proliferation of the hyaloid vessels in mice following oxygen-induced retinal vascular closure.

Retinal branch vein occlusion

Obstruction of a major temporal branch vein, or one of its macular tributaries, presents a significant threat to vision. Visual acuity may be reduced by macular edema or the consequences of retinal neovascularization, and these afflictions frequently become irreversible. Since the complicating macular edema and retinal neovascularization respond, at least in part, to argon laser therapy in some other conditions, some investigators have begun to treat branch vein occlusions with this modality. However, since the pathogenesis and natural history of the disorder have not yet been elucidated by prospective studies, it is not clear whether such treatment is indicated. Clinical and experimental studies are reviewed, and treatment rationale and techniques are discussed. The authors emphasize the need for well-controlled randomized studies to evaluate the natural history of branch vein occlusion and the efficacy of photocoagulation in its treatment.

Idiopathic Preretinal Gliosis

Of 89 patients with idiopathic preretinal gliosis examined between 1970 and 1978, 52 were examined within six months of the onset of symptoms. Forty-seven patients were men and 42 were women; 83 (93%) were more than 50 years old. Initial visual acuities were 6/12 (20/40) or better in 60 of 98 eyes (61%). Nine patients had initial bilateral involvement, and the second eye became involved in one other patient during the follow-up period. Posterior vitreous detachment was present in 59 of the 64 eyes (92%) for which the state of the vitreous had been recorded; 16 of 74 eyes (21%) had fluorescein leakage into the macula. During a mean follow-up period of 31.1 months, the appearance of the fundus remained unchanged in 65 of 72 eyes (90%). Fifty-one of the 72 eyes (71%) had final visual acuities within one line of those recorded at the first examination. Spontaneous improvement of two lines or more occurred in only two patients, accompanied in both cases by an apparent decrease in the severity of the retinal wrinkling. Although these data indicated that idiopathic preretinal gliosis is generally a nonprogressive condition that does not cause serious visual loss, those patients followed up for more than three years did have a small overall decline in visual acuity.

Vaso-occlusive Retinopathy Associated with Anti-phospholipid Antibodies (lupus anticoagulant retinopathy)

The authors observed three cases (6 eyes) of vaso-occlusive retinopathy associated with the lupus anticoagulant and the related antiphospholipid antibody anticardiolipin. The disease occurred in patients who had no definable autoimmune disease such as systemic lupus erythematosus (SLE) and was characterized by severe bilateral retinal vascular occlusion. There was profound visual loss from intraretinal ischemia as well as vitreous hemorrhage from preretinal neovascularization. Results of laboratory testing showed a prolonged partial thromboplastin time (PTT) in two patients, and the presence of the lupus anticoagulant in all. Treatment with panretinal photocoagulation appeared to stabilize the neovascularization. The role of systemic anticoagulation and immunosuppressive therapy is uncertain.

The Demonstration of Angiogenic Activity from Ocular Tissues: Preliminary Report

Human, bovine, and rabbit retinal extracts are shown to be capable of stimulating (1) proliferation and thymidine uptake of bovine vascular endothelial cells in cultures and (2) neovascularization of the chick chorioallantoic membrane (CAM). Extracts of skeletal muscle, heart, and liver lack similar stimulatory activity. Vitreous aspirates from patients with proliferative diabetic retinopathy, in a preliminary study, were able to stimulate vascular endothelial cell thymidine uptake. Most vitreous samples from patients without intraocular neovascularization lacked similar stimulatory activity. Indirect evidence suggests the liberation of an angiogenic factor from the retina in several ocular disorders. The data contained in this report represent the first direct evidence of angiogenic activity from mammalian retina.

The natural history of serous retinal pigment epithelium detachment in patients with age-related macular degeneration

One hundred ten patients with serous detachment of the retinal pigment epithelium (RPE) were reexamined to enhance our knowledge of the natural course of this condition. All patients were greater than 50 years of age, had age-related macular degeneration, and had neither blood, lipid, nor angiographic evidence of a definite choroidal neovascular membrane (NVM) at the time of the initial examination. All patients were followed up for at least six months except for two patients who had developed a choroidal NVM within the first six months of the initial exam. Forty-five of 140 eyes (32%) developed a choroidal NVM within an average of 19.6 months (median, 12 months). This was associated with a final visual acuity of 20/200 or worse (P less than 0.0001). Ophthalmoscopic and angiographic features present at the initial visit which were associated with the development of NVM and poor final visual acuity were: sensory retinal detachment; increased size of PED; hot spot; late filling; notching; and irregular filling. At the most recent examination, 39% of the eyes had a final visual acuity of 20/20 to 20/40, while 24% of the eyes had a final visual acuity of less than or equal to 20/200.

Acute retinal necrosis syndrome.

Six patients with the acute retinal necrosis (ARN) syndrome are described. Ophthalmoscopic examination demonstrated occlusion of peripheral retinal vessels and patchy areas of peripheral retinal whitening spreading rapidly over a period of weeks to markedly decreased vision. In four patients, the disease was bilateral. Histologic examination of vitrectomy specimens from three cases and one enucleated eye revealed chronic granulomatous inflammation. Extensive medical evaluations were noncontributory, with no evidence of compromised immune systems. No patient demonstrated a response to any form of therapy. The etiology is unknown.