Larry E. Magargal

Retinal arterial obstruction in children and young adults.

The records of 27 patients who developed retinal arterial obstruction (RAO) prior to the age of 30 years were studied to ascertain associated systemic and ocular findings as possible etiologic factors. A history of migraine was found in approximately one third of the patients, and coagulation abnormalities wer also common. Trauma, sickle cell hemoglobinopathies, cardiac disorders, use of oral contraceptives, pregnancy, systemic lupus erythematosus and intravenous drug abuse were less frequently encountered. Ocular abnormalities included increased intraocular pressure, subtle buried drusen of the optic nerve head and a congenital prepapillary arterial loop. In contrast to older patients with RAO, there was no clinical evidence of atheromatous disease. In most patients, one or more systemic or ocular etiologic factors could be discerned. Whereas etiologic relationships may be multifactorial and generally differ from those commonly found in older patients with RAO, the visual prognosis in younger and older patients appears to be similar.

Visual prognosis following treatment of acute central retinal artery obstruction.

The authors report the visual outcome in 34 consecutive cases of treated acute central retinal artery obstruction. Visual acuity equal to or better than 6/30 was recovered in 35% of the cases. The presenting visual acuity and duration of visual impairment appear to correlate with visual prognosis.

Central Retinal Artery Obstruction and Visual Acuity

The records of 72 patients (73 eyes) with acute central retinal arterial obstruction (CRAO) were reviewed. Three eyes (4%) were initially observed to have no light perception vision. However, two of these three were found to have concomitant posterior ciliary circulation defects on fluorescein angiography, and the third had electroretinographic evidence of both outer and inner retinal damage. Previous studies have indicated that a much higher percentage of patients with CRAO present with NLP vision. From the data presented it is the feeling of the authors that cases with obstruction of the central retinal artery alone and NLP acuity in the involved eye are most unusual. If true NLP vision is present, additional complicating factors should be suspected, particularly abnormalities of the choroidal circulation and the optic nerve.

Neovascular Glaucoma: Etiologic Considerations

A review of 208 patients with neovascular glaucoma (NVG) is presented. The most common primary etiologic associations included retinal venous obstructive disease (36.1%), diabetic retinopathy (32.2%), and carotid artery obstructive disease (12.9%). Systemic arterial hypertension was present in 51% and diabetes mellitus was noted in 46% of all patients. Among the 25 bilateral cases of NVG, 24 occurred in patients with diabetic retinopathy. Women comprised 65% of patients with NVG secondary to diabetes, and 57% of the venous obstruction group, while men accounted for 74% of cases in which NVG occurred secondary to carotid artery obstructive disease. Overall, 97% of eyes with NVG had a disease process that produced extensive retinal ischemia and preceded the onset of iris neovascularization. Patients with NVG, but without an obvious precipitating fundus condition, should be suspected of having severe carotid artery obstructive disease.

Neovascular Glaucoma Following Central Retinal Vein Obstruction

The results of a prospective clinical and fluorescein angiographic study of 155 patients with central retinal vein obstruction (CRVO) were analyzed to identify risk factors contributing to the subsequent development of iris neovascularization (NVI) and neovascular glaucoma (NVG). Of 144 untreated eyes, 20% developed NVG. The eyes were classified as having either an ischemic or a hyperpermeable type of CRVO according to the extent of retinal capillary nonperfusion demonstrated by the initial fluorescein angiogram. The risk of developing NVG was found to be approximately 60% in those eyes with extensive retinal ischemia. None of the 22 eyes with an ischemic CRVO treated with panretinal photocoagulation (PRP) prior to the onset of NVI developed NVG.

Efficacy of Panretinal Photocoagulation in Preventing Neovascular Glaucoma Following Ischemic Central Retinal Vein Obstruction

Ninety-three percent of eyes that develop neovascular glaucoma (NVG) following central retinal vein obstruction (CRVO) have an ischemic index greater than 50%. An ischemic index (percentage of retinal capillary nonperfusion) of 50% represents approximately 10 disc areas of retinal ischemia as determined by computer analysis of standard 30 degrees fluorescein angiograms. The difficulties of following patients clinically and angiographically at frequent intervals over extended periods of time, and the tendency for iris neovascularization (NVI) to develop and to progress rapidly to NVG with painful loss of vision emphasizes the importance of early recognition and treatment of high-risk eyes. In this prospective study (1976--81), 100 consecutive eyes with an ischemic CRVO pattern (average ischemic index 82%) received early argon laser panretinal photocoagulation (PRP) and none developed NVG unless another ischemic event occurred following treatment. Prophylactic PRP in high-risk ischemic CRVO eyes appears to eliminate virtually the devastating complications of NVG.

Arterial Obstruction and Ocular Neovascularization

A series of 12 patients (13 eyes) with neovascular glaucoma in association with arterial obstructive disease is presented. Appropriately characterized as having an ocular ischemic syndrome, the anterior segment findings in each included aqueous flare and rubeosis iridis. Posterior segment manifestations included midperipheral intraretinal hemorrhages (venous stasis retinopathy), narrowed retinal arteries, often a cherry red spot, and neovascularization of the disc and/or retina. Most eyes with the ocular ischemic syndrome have either ipsilateral common carotid artery obstruction or severe bilateral obstruction of the internal carotid arteries.

The ocular ischemic syndrome. III. Visual prognosis and the effect of treatment

SummaryThe records of fifty-two consecutive patients with the ocular ischemic syndrome seen between 1978 and 1985 were reviewed with the purpose of investigating the visual prognosis and effects of treatment. On initial presentation, 43% of affected eyes had a visual acuity of 20/20–20/50, whereas 37% were counting fingers or worse. By the end of one year, only 24% remained in the 20/20–20/50 group, while 58% were counting fingers or worse. The presence of rubeosis iridis was an indicator of poor visual prognosis. Ninety-seven percent of eyes with rubeosis had vision of counting fingers or worse at the end of one year. We were unable to demonstrate convincingly that carotid endarterectomy and superficial temporal artery to middle cerebral artery bypass were of benefit in stabilizing or improving vision in persons with the ocular ischemic syndrome.

Retinal Ischemia and Risk of Neovascularization Following Central Retinal Vein Obstruction

The predominant risk factor for the development of neovascular complications involving the retina (NVR), the optic disc (NVD), and iris (NVI) following central retinal vein obstruction (CRVO) is the extent, location, and duration of retinal ischemia (ischemic drive). The extent of retinal capillary nonperfusion (ischemic index) was quantitated by microcomputer analysis of 200 standard fundus-iris fluorescein angiograms. The results were correlated with the development of neovascularization in eyes not receiving prophylactic argon laser panretinal photocoagulation (PRP). Of the 85 eyes with intact capillary perfusion (hyperpermeable group), none developed NVR/NVD and only one eye (1%) developed neovascular glaucoma (NVG). Twenty-nine eyes exhibited moderate degrees of retinal ischemia (indeterminate group), and three eyes (10%) developed NVR/NVD, with two eyes (7%) developing NVG. Of the 86 eyes with extensive retinal capillary nonperfusion (ischemic group), 28 eyes (33%) developed NVR/NVD and NVG occurred in 39 eyes (45%). The inherent difficulties in following high risk patients clinically and angiographically at frequent intervals over extended periods of time, the tendency for rapid progression of early NVI to NVG, and the relatively poor results following treatment in advanced cases make the early recognition of eyes at high risk to develop NVG essential and the initiation of prophylactic PRP as the treatment of choice in this disorder.

Acute Obstruction of the Retinal and Choroidal Circulations

The cases of eight patients (10 eyes) with the equivalent of an acute ophthalmic artery obstruction (simultaneous impairment of both the retinal and choroidal circulations) are described. Ophthalmoscopic features included intense opacification of the retina in the posterior pole; variable absence of a cherry red spot, and the subsequent development of optic atrophy and pigment epithelial changes. Fluorescein angiographic signs encompassed delayed retinal and choroid filling, as well as leakage at the level of the retinal pigment epithelium (RPE). Electroretinography (ERG) disclosed absence of both the a- and b-waves. The entity carries a grim visual prognosis, as all ten eyes initially had no perception of light; improvement to light perception occurred in one instance.