Argon Laser Destruction of Anterior Chamber Implantation Cysts

Five patients with anterior chamber implantation cysts underwent argon laser therapy. Three cysts were eradicated and one shrunk to a small stable remnant within 1 to 5 treatment sessions. One cyst re-formed repeatedly, prompting iridocyclectomy. Follow-up ranged from 3 to 38 months.

Effect of primary capsulotomy with extracapsular surgery on the incidence of pseudophakic cystoid macular edema

We performed a prospective randomized study of 288 patients to assess the effect of primary capsulotomy on the angiographic incidence of cystoid macular edema in patients undergoing extracapsular surgery with implantation of an intraocular lens. Patients either had a primary capsulotomy or the posterior capsule remained intact immediately following uneventful posterior chamber intraocular lens implantation. Of the 288 patients, 183 (63%) underwent fluorescein angiography. Angiographically confirmed cystoid macular edema occurred significantly more often in the primary capsulotomy group (20 of 93 patients) than in the intact capsule group (four of 71 patients), for an incidence of 21.5% vs 5.6% (P = .003). The cystoid macular edema appeared milder in the intact capsule group; all the patients with angiographically confirmed cystoid macular edema achieved visual acuities of 20/50 or better. The presence of cystoid macular edema made no difference on visual outcome in the intact capsule group. In contrast, the patients with angiographically confirmed cystoid macular edema in the primary capsulotomy group had significantly worse vision than those who did not have cystoid macular edema (P less than .02).

Management of loose Choyce-style anterior chamber lenses

Loose Choyce-style anterior chamber intraocular lens implants were removed from four patients. We offer general and specific guidelines for the management of patients with mobile Choyce-style anterior chamber lens, with discussion of corneal decompensation, cystoid macular edema, and iritis in these patients, and for prevention of the problem.

Multiple evanescent white dot syndrome. I. Clinical findings

We examined 11 young patients with unilateral ocular findings that included multiple white dots at the level of the retinal pigment epithelium (RPE) or the deep retina, vitreal cells, RPE granularity in the macula, reduced visual acuity, electroretinogram (ERG) and early receptor potential (ERP) amplitudes, and fluorescein leakage from disc capillaries and late staining of the RPE. Recovery of visual function included a dramatic improvement in ERG and ERP amplitudes over several weeks. The etiology of this syndrome remains uncertain; there is no definite evidence of systemic involvement.

Prophylaxis and therapy of aphakic cystoid macular edema

Aphakic cystoid macular edema (ACME) can be a visually significant complication of modern cataract surgery. Prophylaxis of ACME is preferable to therapy of established ACME. Selection of the appropriate cataract operation, control of systemic factors, avoidance of topical catecholamines, control of intraocular inflammation and use of topical or systemic pharmacologic agents may play a role in the prevention of ACME. If it is proven that light toxicity influences the development of ACME, filters in operating microscopes or in intraocular lenses, cataract glasses, or contact lenses may be helpful. Once ACME is present, antiinflammatory therapy has been the main intervention, although its longterm value remains uncertain. Surgical approaches of unproven value have included photocoagulation, vitrectomy, and removal of an intraocular lens.

Multiple evanescent white dot syndrome. II. Electrophysiology of the photoreceptors during retinal pigment epithelial disease

We performed electrophysiologic studies of photoreceptor function in three patients with multiple evanescent white dot syndrome. During the acute stage, while the visual acuity was impaired, the electroretinogram (ERG) a-wave and the early receptor potential (ERP) amplitudes were profoundly decreased. The ERP regeneration times, determined for one subject, were prolonged. These findings suggest that photoreceptor function was impaired (abnormal a-wave), the effective visual pigment optical density of the outer segments was markedly reduced (ERP amplitude), and visual pigment regeneration was abnormal (ERP regeneration kinetics). During the recovery stage, the ERG and ERP amplitudes and visual acuity returned to normal. Our patients' disease seemed to be primarily of the retinal pigment epithelium (RPE). The decreased visual pigment density and prolonged regeneration kinetics emphasize the physiologic dependence of the sensory retina on the RPE.

The eye in accelerated hypertension. II. Localized serous detachments of the retina in patients

Hypertensive choroidopathy was noted in seven patients with accelerated or malignant hypertension. The acute lesion consisted of white areas of retinal pigment epithelial necrosis with overlying serous detachments of the retina. The detachments varied in size. Fluorescein staining of the damaged pigment epithelium and leakage into the subretinal space were demonstrated in several of these patients. Medical control of the BP resulted in a rapid disappearance of the detachment with minimal permanent ophthalmoscopic changes. Reperfusion of the choriocapillaris was suggested by the fluorescein angiogram. Patients with poor control of BP demonstrated at old sites of serous detachments more extensive retinal pigment epithelial pigmentary changes. Some lesions show a central hyperpigmented core surrounded by pigment atrophy (chronic Elschnig's spots). We suspect that choroidal vascular changes predominate when acute elevation of BP is present, whereas a more gradual onset of hypertension results in retinal vascular changes.

Retinal damage from a Q-switched YAG laser

A 42-year-old woman with sickle cell anemia and proliferative retinopathy underwent neodymium-YAG laser therapy for a taut posterior hyaloid membrane causing peripapillary and peripheral traction detachment of the retina. Vitrectomy was not done because the patient required anticoagulation. A Q-switched YAG laser was capable of cutting holes in the taut membrane, but treatment 2 to 3 mm from the retina resulted in microperforation of a retinal vein and focal areas of damage to the retinal pigment epithelium. The damage to the retinal pigment epithelium was not immediately apparent, and ophthalmoscopically visible lesions were seen only when the patient was reexamined 48 hours later.

Aminocaproic acid decreases secondary hemorrhage after traumatic hyphema

Forty-eight patients (49 eyes) had nonperforating traumatic hyphema. Twenty-eight patients (28 eyes with hyphema) received oral aminocaproic acid, an antifibrinolytic agent, in a dosage of 100 mg/kg every four hours for five days, up to a maximum daily dose of 30 g. Twenty patients (21 eyes with hyphema) received placebo in an identical regimen. One eye treated with aminocaproic acid rebled; seven eyes receiving the placebo rebled. The results of this study show a statistically significant reduction in the incidence of secondary hemorrhage in the patients receiving aminocaproic acid.

Vitreous fluorophotometry in patients with hypertension

Vitreous fluorophotometry performed on 22 patients with moderate to severe hypertension showed that patients with active retinopathy, as manifested by retinal hemorrhages, cotton-wool spots, retinal exudates and edema, or disc edema, generally had elevated values (20/28 eyes). Control of the BP resulted in a decrease in the values toward the normal range. Patients with only arteriolar sclerosis, even some with particularly high BP, generally had normal fluorophotometric values (14/16 eyes). The two exceptions showed minimal elevations. Vitreous fluorophotometry is a useful tool to quantitate the blood-retinal barrier in patients with moderate to severe hypertension and may be a sensitive indicator of treatment efficacy.

A randomized clinical trial of feeder vessel photocoagulation of proliferative sickle cell retinopathy. I. Preliminary results

A randomized prospective clinical trial of feeder vessel photocoagulation for proliferative sickle cell retinopathy was performed. In Chicago there were 34 argon laser-treated eyes and 30 control eyes. In Kingston there were 53 xenon arc treated eyes and 50 control eyes. Prolonged loss of visual acuity was rare in both photocoagulated and control eyes. Argon laser and xenon arc feeder vessel photocoagulation reduced the incidence of vitreous hemorrhage and visual loss from vitreous hemorrhage. However, photocoagulation was associated with an increased risk of choroidal neovascularization (xenon arc greater than argon laser) and retinal detachment (argon laser), although visual loss from these complications has not been seen in these patients so far.

Arteriolar occlusive diseases of the macula

Occlusion of retinal precapillary arterioles may be related to vascular endothelial damage, embolization, vasculitis, and other factors. Following acute retinal precapillary arteriolar occlusion in the macular area, inhibition of axoplasmic transport results in the formation of cotton-wool patches. A variable loss of retinal function occurs. During the subacute phase, reperfusion of the vascular bed is usually seen with a gradual fading of the cotton-wool patch. In the chronic phase, the only sign of the infarction may be a loss of inner retinal substance with an irregularity of the light reflex from the internal limiting membrane, the retinal depression sign. The characteristics of retinal precapillary arteriolar occlusions are reviewed and specific features of hypertensive retinopathy, talc retinopathy, and sickle cell retinopathy are discussed.

Disseminated herpes simplex infection with retinitis in a renal allograft recipient

An immunosuppressed recipient of a renal allograft developed bilateral necrotizing retinitis. Disseminated herpes simplex infection was documented by clinical findings and serologic and viral culture studies. Cultures and serologic tests for cytomegalovirus were negative. The evidence strongly favored the diagnosis of herpes simplex retinitis. Tapering of immunosuppressive drugs and administration of adenine arabinoside appeared to halt temporarily the progression of the disease in one eye and resulted in healing of the retinitis in the other eye. Subsequent progression of the more severely involved right eye resulted in an exudative retinal detachment and loss of vision prior to the patient's death from meningoencephalitis. Herpes simplex retinitis must be considered in the differential diagnosis of necrotizing retinitis in an immunosuppressed patient.

Spontaneous peripheral chorioretinal neovascularisation in association with sickle cell anaemia

Chorioretinal neovascularisation was noted in the midperipheral fundus of a young black girl with sickle cell anaemia. Rapid-sequence fluorescein angiography showed choroidally fed neovascularisation in the centre of a large black sunburst (chorioretinal scar). We suspect that a massive midperipheral retinal haemorrhage from the sickle cell disease caused the sunburst and altered Bruch's membrane, thus allowing the ingrowth of choroidally fed vessels.

Talc retinopathy in primates: a model of ischemic retinopathy. III. An electron microscopic study

Electron microscopic study of experimental talc retinopathy provides an opportunity to study the basic cytologic response of retinal and choroidal vessels to small, relatively inert emboli. Occlusion of the retinal and choroidal capillaries resulted primarily from the cellular reaction to, rather than directly from, the emboli. Mitotic figures in pericytes were observed. Even though we failed to produce retinal neovascularization (as is sometimes seen in human talc retinopathy) in this experimental model, our observations suggest that proliferation of pericytes may be an initial step in the process of retinal neovascularization.

Pathophysiology of hypertensive retinopathy

The effects of systemic hypertension on the posterior segment of the eye are discussed under the headings of hypertensive choroidopathy, hypertensive retinopathy, and hypertensive optic disc edema. The sympathetic nervous control and autoregulatory mechanisms of the retinal and choroidal vasculatures are briefly reviewed. In hypertensive choroidopathy focal occlusion of choriocapillaris leads to necrosis of retinal pigment epithelium (Elschnig spots). Hypertensive retinopathy is described in vasoconstrictive, exudative, and sclerotic phases, followed by complications of the sclerotic phase. Hypertensive optic disc edema is influenced by the blood supply and extracellular tissue fluid pressure of the optic nervehead. In baboons with hypertensive disc edema, accumulation of axoplasmic components is observed in the optic nervehead.

Talc retinopathy in primates: a model of ischemic retinopathy. II. A histopathologic study

Experiment talc retinopathy was produced in four adult rhesus monkeys by biweekly intravenous injections of talc for 31/2 to ten months and was studied by retinal vascular flat preparations and by light microscopy. Talc particles were lodged in the walls of the precapillary arterioles and capillaries, producing focal occlusion of retinal and choroidal capillaries. The pericyte-endothelial cell ratio was 1:0.77 in the posterior pole and 1:0.53 in the retinal periphery. The horseradish peroxidase study showed leakage of tracer from the retinal vasculature into the extracellular interstitial space, but the barrier of the retinal pigment epithelium was intact. Microinfarcts produced small cystoid spaces in the outer plexiform layer, inner nuclear layer, and ganglion cell layer of the macula. Cytoid bodies and macrophages were scattered in the retina. No retinal or vitreal neovascularization was observed.

Pharmacologic therapy of aphakic cystoid macular edema. A review

Pharmacologic therapy of aphakic cystoid macular edema (ACME) in the past has included the use of topical, periocular, and systemic corticosteroids as well as inhibitors of prostaglandin synthesis. Preliminary studies have suggested a beneficial effect of systemic corticosteroids on ACME, although it has been said that this effect is temporary and that recurrences are common. To date, no adequate therapeutic or prophylactic trial of topical, periocular, or systemic corticosteroids for ACME has been performed. Several elegant clinical trials have been done to study the effects of indomethacin, a prostaglandin (PG) synthesis inhibitor, on the incidence of ACME. It seems likely that topical, and perhaps systemic, indomethacin is effective in reducing the incidence of angiographically proved ACME. To date, however, no trial has demonstrated a sustained effect of topical or systemic PG synthesis inhibitors on ACME or visual acuity. Further studies of the role of PG synthesis inhibitors (especially topical agents) in the therapy of ACME are necessary. In addition, further efforts should be made to determine the efficacy of the use of PG synthesis inhibitors in combination with corticosteroids.

Prophylaxis of pseudophakic cystoid macular edema with topical indomethacin

A prospective double-masked study of 500 patients was performed to assess the effect of topical indomethacin on the angiographic incidence of cystoid macular edema (CME) in patients undergoing intraocular lens implant surgery. All patients received either topical indomethacin or placebo before surgery and for nine months after surgery. All patients underwent planned extracapsular extraction (PEC) or posterior chamber phacoemulsification (PC-KPE). Implantation of a posterior chamber lens and a primary capsulotomy were performed in all cases. All cases received postoperative topical corticosteroids. Of the 500 cases, 390 (78%) underwent fluorescein angiography; most were performed between 2 1/2 and 5 months after surgery. The incidence of angiographically confirmed CME was significantly higher in the placebo-treated patients as compared to those treated with indomethacin (18.5% vs 9.6%; P = 0.04). Patients 60 years of age or older had a significantly higher incidence of CME than younger individuals (15% vs. 3.4%; P = 0.03). When corrected for the effects of drug regimen and age, by means of multiple logistic regression, there was no significant correlation between procedure (PEC vs. PC-KPE) and CME rate (P = 0.62). There was no significant difference in postoperative visual acuity between the indomethacin- and placebo-treated patients (P = 0.65).

Spontaneous regression of retinal lesions in Coats' disease

Coats' disease is characterized by vascular anomalies in the retina that are usually associated with exudates. In the absence of treatment the disease almost always progresses toward loss of vision and, often, loss of the eye. This report describes three patients in whom some of the retinal lesions apparently regressed spontaneously; only two other such patients are mentioned in the literature. These patients may have had a form of Coats' disease that has a better prognosis than usual for the eye.

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.

Scatter retinal photocoagulation for proliferative sickle cell retinopathy

We treated sea-fan neovascularization in 19 patients (21 eyes) who had proliferative sickle cell retinopathy with localized scatter photocoagulation. We placed burns of light to moderate intensity adjacent to 45 sea fans in a scatter fashion. In general, treatment extended from 1.5 mm posterior to 1.5 mm anterior to the sea fan and one clock hour to each side of each lesion. Flat sea fans responded dramatically to treatment, with complete regression in 24 of 28 lesions. Elevated sea fans (especially large ones) responded less rapidly, with complete regression in only four of 17 lesions. Localized scatter photocoagulation is valuable in treating patients with early proliferative sickle cell retinopathy.

Computed tomography in the management of orbital infections associated with dental disease

Two patients developed orbital infection secondary to dental infections. In one patient the infection spread from maxillary premolar and molar teeth to the infratemporal and pterygopalatine fossa and then through the inferior orbital fissure to the subperiosteal space. A subperiosteal abscess in the posterior orbital wall developed, which subsequently spread within the muscle cone. In the second patient infection of an anterior maxillary tooth caused a pansinusitis and unilateral orbital cellulitis. In both patients computed tomographic scanning of the orbit proved valuable in localising the infection and, in one case, planning a surgical approach to the orbit. The infection in both patients responded to treatment, with no permanent visual impairment. Appropriate antibiotics and prompt identification and surgical drainage of orbital abscesses are essential for the preservation of vision in cases of orbital infection.

An update on vitrectomy surgery and retinal detachment repair in sickle cell disease

Eighteen patients (19 eyes) with sickling hemoglobinopathies underwent vitrectomy or scleral buckling operations. The indications for surgery were tractional or rhegmatogenous retinal detachment or vitreous hemorrhage. The retina was reattached in all four patients with rhegmatogenous detachments requiring scleral buckling surgery but no vitrectomy. All had excellent visual acuity postoperatively. Four of the five patients with vitreous hemorrhage requiring vitrectomy without buckling had substantial improvement in visual acuity. In ten patients with vitreous hemorrhage with either preexisting or iatrogenic retinal breaks, rhegmatogenous detachment, or tractional detachment, the rate of improvement in visual acuity was only 50%. Problems associated with vitreous or retinal surgery in patients with sickling hemoglobinopathies include iatrogenic retinal breaks, intraocular bleeding and secondary glaucoma, anterior segment ischemia, and systemic sickling.

Exudative retinal detachment in hemoglobin SC disease

A 21-year-old black man with hemoglobin SC disease had a unilateral exudative retinal detachment. A large area of sea fan neovascularization was identified in this eye at the superotemporal border of the detachment; no retinal holes were present. Following closure of the neovascularization by argon laser photocoagulation using feeder vessel technique, the retina flattened and the exudation cleared. However, multiple holes developed in thin ischemic retina at foci of vitreoretinal traction. Although many retinal vascular diseases may cause exudative detachments, to the authors' knowledge, this is the first definite case of exudative retinal detachment in a patient with a sickling hemoglobinopathy.

Talc retinopathy in primates. A model of ischemic retinopathy: I. Clinical studies

Four rhesus monkeys received intravenous injections of talc twice weekly for 3 1/2 to ten months. Within one month, talc particles were visible in fine perifoveal retinal vessels in the posterior pole. Continued deposition of talc could then be seen after subsequent injections. Hemorrhages in the nerve fiber layer, cotton-wool patches, and whitish plaques in the choroid were visible ophthalmoscopically. Fluorescein angiography revealed precapillary arteriolar occlusions, capillary nonperfusion, an abnormal foveal avascular zone, and retinal vascular leakage. Vitreous fluorophotometric findings were abnormal in all five eyes tested, while electroretinograms were normal in two eyes with advanced talc retinopathy. Talc retinopathy in the primate is similar to ischemic retinopathies in humans, including human talc retinopathy, sickle cell retinopathy, and hypertensive retinopathy. Subsequent reports will describe the light microscopic and ultrastructural changes in these eyes using tracer studies with in these eyes using tracer studies with horseradish peroxidase.

Chorioretinal and choriovitreal neovascularization. Their presence after photocoagulation of proliferative sickle cell retinopathy

Delayed development of choroidally fed neovascularization represents a potentially serious complication of feeder vessel photocoagulation of proliferative sickle cell retinopathy (PSR). Of the 53 photocoagulated eyes, choroidally fed neovascularization developed in 21 within one month to seven years (mean, 32.8 months). This complication appeared in eyes treated with argon laser and xenon arc. In 11, neovascular tissue remained flat in the chorioretinal scar (chorioretinal neovascularization), but in ten, the vessels grew into the vitreous (choriovitreal neovascularization). In many cases of chorioretinal neovascularization, the only subsequent complication was local vitreous hemorrhage. Visual acuities remained near normal. The development of choriovitreal neovascularization was associated with vitreous hemorrhages or retinal detachment in six of ten cases. Final visual acuities, however, were 20/50 or better in nine. Photocoagulation in some cases converted chorioretinal neovascularization to choriovitreal neovascularization or seemed to stimulate further growth of choriovitreal neovascularization. We now recommend no treatment for most cases of choroidally fed neovascularization. Photocoagulation techniques for PSR should attempt to minimize the development of choroidally fed neovascularization.

Choroidal neovascularisation induced by photocoagulation in sickle cell disease

Choroidal neovascularisation occurred in 35 out of 57 (61%) patients during a trial of xenon are photocoagulation in proliferative sickle retinopathy. Nineteen patients manifested abnormal vessel systems in the plane of the retina which tended to be benign, not enlarging, and without complications (choroidoretinal neovascularisation). In 16 patients the abnormal vessel systems grew into the vitreous, tended to increase in size, and to be associated with vitreous haemorrhage and retinal traction (choroidovitreal neovascularisation). Both forms of neovascularisation were significantly more common at younger ages. Treatment was generally unsatisfactory, frequently resulting in further enlargement of the lesions. Although the natural history of choroidal neovascularisation and its ultimate effect on visual function remains to be recorded, these lesions constitute a common and potentially serious complication of xenon are photocoagulation in proliferative sickle retinopathy as currently performed.

Laser therapy for open angle glaucoma

Fort-five phakic eyes with open angle glaucoma received argon laser therapy to the trabecular meshwork (laser goniotherapy). The average IOP dropped from 27.5 to 20.3 mm Hg in 22 eyes that were followed up for seven to fourteen months. Tonographic data obtained from 13 eyes prior to and approximately one month after laser treatment demonstrated a 50% increase in the facility of aqueous outflow. Several eyes experienced hypertensive episodes following treatment, in which the IOP increased as high as 60 mm Hg on one occasion. Two eyes developed prolonged uveitis with peripheral anterior synechiae formation. Laser goniotherapy appears to be a beneficial mode of therapy for open angle glaucoma in many patients. Longer follow-up is needed, however, and its role in secondary and aphakic glaucomas needs to be defined.

Salmon-patch hemorrhages after central retinal artery occlusion in sickle cell disease

In two patients with sickle cell disease (one hemoglobin SC and one hemoglobin SS), central retinal artery occlusions developed. In one case, the occlusion followed a retrobulbar injection of lidocaine hydrochloride. Although the central retinal artery reperfused in each patient, many secondary peripheral retinal arteriolar occlusions remained. During the subsequent days, multiple salmon-patch hemorrhages developed in the distribution of these occluded arterioles. In one patient, the salmon-patch hemorrhages evolved into atrophic schisis cavities. These unusual cases allowed us to document the origin of salmon-patch hemorrhages after peripheral retinal arteriolar occlusions. The development of the hemorrhages was a delayed phenomenon that occurred hours to days after the initial vascular occlusion. Reperfusion of the damaged ischemic vessels with a blowout of the wall of the vessels seems the most likely explanation for this phenomenon.

Large capillary aneurysms secondary to retinal venous obstruction

Three patients had unusually large capillary aneurysms. Two of the patients had had previous branch vein occlusions, while a third had had a central retinal vein occlusion. The large capillary aneurysms were located in areas of ischaemic retina that were drained by the previously obstructed veins. Retinal ischaemia and, possibly, increased hydrostatic pressure following vein occlusion were postulated to result in the development of these atypical capillary aneurysms. They are similar in size to arterial macroaneurysms, but originate from the venous side of the capillary bed. Like typical capillary microaneurysms and arterial macroaneurysms, these large capillary aneurysms may result in visual loss from macular oedema, serous elevation of the macula, and circinate lipid exudation. Argon laser obliteration of the aneurysms appears to be effective therapy.

Uveal melanoma in association with multiple malignancies. A case report and review

A 66-year-old man had a pigmented choroidal lesion in his right eye. Over a subsequent period of 8 1/2 years, the lesion showed slight growth. At autopsy, the diagnosis was spindle B melanoma of the choroid without evidence of systemic metastasis. A very unusual feature of this case was the presence in this patient of seven primary malignant tumors and five benign neoplasms. In addition to the choroidal melanoma, these included three distinct pulmonary carcinomas, leiomyosarcoma of the stomach, adenocarcinoma of the sigmoid colon, and basal cell carcinoma. The literature on multiple malignancies in association with uveal melanoma is reviewed.

Peripheral proliferative retinopathy without oxygen therapy in a full-term infant

A 2,948-g full-term male infant, the product of an uncomplicated pregnancy, developed fundus changes consistent with retrolental fibroplasia in the absence of supplemental oxygen therapy. He had no associated illnesses or congenital anomalies, and had not received exchange transfusions. There was no family history of ocular disease. Changes similar to those of retrolental fibroplasia do occasionally occur in fullterm infants who have had no supplemental oxygen therapy. A relative hyperoxia caused by the increase in arterial oxygen saturation occurring at birth is one possible explanation for these events. This rise, plus susceptibility factors apart from prematurity, may account for these unusual cases. Additionally, these cases may represent sporadic examples of familial exudative vitreoretinopathy.

Peripheral proliferative retinopathies

Peripheral retinal neovascularization (i.e., new vessel growth peripheral to the major vascular arcades) may be secondary to a wide variety of ocular and systemic diseases. Vascular and inflammatory diseases in particular may cause peripheral neovascularization. Following a brief review of ocular angiogenesis, the various clinical entities that can cause peripheral retinal neovascularization are described. The diagnostic workup of a patient with peripheral proliferative retinopathy is outlined and techniques of treatment of the neovascularization (including feeder vessel technique, cryopexy, and panretinal photocoagulation) are discussed.

Retinal breaks after photocoagulation of proliferative sickle cell retinopathy

Retinal breaks developed in four eyes of four patients with hemoglobin SC disease and advanced proliferative sickle cell retinopathy (PSR) after argon laser photocoagulation of feeder vessels. These cases represented 8.7% of the 46 eyes with PSR treated with the argon laser at our institution in 1977 and 1978. In three patients, the retinal breaks were immediately adjacent to the site of photocoagulation. A scleral buckling procedure was necessary in only one of the four eyes; the breaks were successfully managed in the other three cases by encirclement with further laser treatment. None of the four eyes lost vision. In patients with vitreous traction in association with seafan neovascularization, argon laser photocoagulation may result in retinal breaks and retinal detachment.

Spontaneous separation of epiretinal membranes

Three patients had spontaneous separation of an epiretinal membrane from the macular region. Two of the patients had had argon laser photocoagulation of peripheral retinal lesions three to four months earlier. Vitreous contraction, which had led to the fundus conditions that required photocoagulation, may have created alterations in the vitreous or in the membrane itself, which enhanced the peeling of the membranes. Although photocoagulation may sometimes worsen macular puckers, the presence of an epiretinal membrane near the macula should not be considered an absolute contraindication to peripheral fundus photocoagulation when the pathologic process that is to be coagulated has a substantially worse prognosis if left untreated.

Macular lesions in blacks with the presumed ocular histoplasmosis syndrome

Six black patients had fundus lesions diagnostic of the presumed ocular histoplasmosis syndrome. All patients had peripapillary changes or peripheral punched-out chorioretinal lesions, or both. Five of the six had macular subretinal neovascularization, disciform scarring, or an atrophic macular lesion, and one patient had a macular hole; four of five patients tested had a positive histoplasmin skin test. The macular involvement was bilateral in three of the six cases. HLA B-7 was present in one of four patients who had HLA typing. Macular involvement can occur in blacks with the presumed ocular histoplasmosis syndrome.

Subretinal neovascularization with geographic (serpiginous) choroiditis

Three patients with geographic choroiditis developed subretinal neovascular membranes associated with subretinal hemorrhage and serous elevation of the retina. Proximity of the membrane to the foveal avascular zone prevented photocoagulation of the neovascular membrane in one patient. Central visual acuity remained 6/60 (20/200) despite systemic corticosteroid therapy. The neovascular membranes in the other two patients were obliterated by argon laser photocoagulation with preservation of central vision. The inflammatory process of geographic choroiditis can disrupt Bruch's membrane, allowing occasional choroidal vascular growth. Concomitant destruction of choroidal vessels may account for rarity of subretinal neovascularization in geographic choroiditis.

Vascular opacification and leakage in X-linked (juvenile) retinoschisis

A 22-year-old man had X-linked retinoschisis with extensive vascular sheathing in the posterior pole and dendritic opacified retinal vessels in the periphery. Detailed fluorescein angiographic studies were performed. In the far periphery areas of capillary nonperfusion were seen. Sluggish circulation was present in the majority of dendritic opacified vessels in the areas of schisis. Late staining of the disc and posterior arteries and veins was noted. Scattered intraretinal fluorescein leakage was present even in clinically nonschitic retina, which suggests that the vascular changes may precede the retinoschisis. The patient's half-brother also had X-linked retinoschisis, but the schisis and the vascular changes were much less prominent. Although the retinal vascular changes with X-linked retinoschisis are similar to those seen with the Favre-Goldmann syndrome, a differentiation of the two diseases can be made by family studies, the presence or absence of nyctalopia, examination of the macular areas, measurement of dark adaptation, and electroretinogram determinations.

Sickled erythrocytes, hyphema, and secondary glaucoma: III. Effects of sicle cell and normal human blood samples in rabbit anterior chambers

When injected into rabbit anterior chambers, human sickle cell erythrocytes cause more intense and prolonged effects than do nonsickling erythrocytes. The consequences of injected sickle cell trait erythrocytes are not less severe than those of injected SC, SS, and Sthal erythrocytes. Regardless of hemoglobin composition, blood with a higher hematocrit value causes more severe complications than blood with a lower hematocrit value.

Choroidal occlusive disease in sickle cell hemoglobinopathies

Two distinct episodes of posterior ciliary artery occlusion were studied in a 32-year-old man with hemoglobin SS disease and multiple episodes of amaurosis fugax. Although posterior ciliary artery occlusions have been observed following photocoagulation of sickle cell retinopathy, their spontaneous evolution in patients with sickling hemoglobinopathies has received little attention. The manifestations of posterior ciliar artery occlusion seen in this case and in other clinical and experimental situations are reviewed. Histopathologic examination of three additional eyes of patients with sickle hemoglobinopathies revealed changes which may have been the result of previous small posterior ciliary artery occlusions or small vessel occlusive disease related to the sickling hemoglobinopathies; these cases are also reported.