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PubMed1990

Effects of sodium iodate on experimental subretinal neovascularization in the primate.

We investigated the role of the retinal pigment epithelium (RPE) in the development of subretinal neovascularization (SRN) induced by bilateral laser photocoagulation of the retinas in monkeys. RPE function was affected by a unilateral carotid injection of sodium iodate, a selective RPE toxin, before laser photocoagulation. This caused severe RPE damage in the ipsilateral eye, but did not affect the contralateral eye. After laser photocoagulation no SRN was demonstrable clinically or histopathologically in the ipsilateral eye; in contrast, active SRN showing extensive fluorescein leakage was found in the contralateral eye. These results suggest that RPE may play a role in the development of laser-induced SRN.

Animals↗
PubMed2000

Localization of adenosine A2a receptor in retinal development and oxygen-induced retinopathy.

PURPOSE: To investigate the association of adenosine A2a receptors (A2aR) with retinal vasculogenesis and angiogenesis that occurs in the canine model of oxygen-induced retinopathy (OIR). METHODS: One-day-old dogs were exposed to 100/o oxygen for 4 days and killed in oxygen (5 days old) and at 3, 10, 17, and 23 days after exposure to hyperoxia. Room air control animals were killed at 1, 5, 8, 15, 22, and 28 days of age. Immunolocalization of A2aR was performed on frozen sections, and reaction product density was quantified using microdensitometry. Cell types were identified in serial sections using antibodies against von Willebrand factor (endothelial cells) and GFAP (astrocytes), and enzyme histochemistry for menadione-dependent a-glycerophosphate dehydrogenase (M-a-GPDH) (to label angioblasts and developing blood vessels). RESULTS: A2aR immunoreactivity was associated with forming blood vessels and angioblasts in the nerve fiber layer (NFL) of peripheral retina. As development progressed, vascular labeling decreased, whereas labeling of neuronal elements increased. In OIR, A2aR immunoreactivity in the NFL was reduced after exposure to hyperoxia and significantly elevated in the inner retina throughout vascularized retina and in advance of forming vasculature in all oxygen-treated animals returned to room air. A2aR immunoreactivity was also prominent in fronds of intravitreal neovascularization. CONCLUSIONS: A2aR immunoreactivity was associated with developing retinal vessels. As development progressed, vascular-associated A2aR labeling decreased and, concomitantly, labeling of neuronal elements increased. A2aR immunoreactivity was significantly elevated at the edge of forming vasculature in all animals returned to room air after hyperoxia and in intravitreal neovas cular formations. These results provide additional evidence for the importance of A2aR and its ligand adenosine in retinal vascular development and in the vasoproliferative stage of canine OIR.

Animals↗
PubMed1997

[Treatment of retinal venous occlusion with hemodilution and laser coagulation. Prevention of secondary glaucoma].

BACKGROUND: Neovascular glaucoma is similarly as other ocular neovascularizations, a complication of retinal venous occlusions. The objective of the present work was to assess whether it is possible to prevent this complication by isovolaemic haemodilution and laser coagulation of the retina. METHODS AND RESULTS: Between 1991 and 1996 we used in 10 patients with occlusion of the central retinal vein and in 25 patients with occlusion of the branch of the central retinal vein repeated haemodilution with reduction of the haematocrit to 0.36. In case of soft retinal exudates the retina was treated by laser coagulation. The whole group comprised 28 men and 7 women. The patients' age was 42 to 76 years, 14% of the patients were under 50 years. The mean follow-up period was 29.5 months. During the investigation period so far none of the patients developed neovascular glaucoma. After treatment venous collaterals developed in the retina in 48.5%, in the disc of the optic nerve in 16% of the patients. Improved visual acuity was recorded in 90% of the patients after occlusion of the trunk and in 44% patients after occlusion of the branch of the central retinal vein. CONCLUSIONS: Adjustment of rheological conditions by haemodilution improved for three months the haemodynamic conditions in the affected retina, promote recanalization of the occluded vessels and the development of a collateral circulation and prevented neovascularization. Based on their experience the authors assume that haemodilution combined with laser coagulation has a positive impact on the visual prognosis, but in particular on prevention of neovascular glaucoma, which so far did not develop in the thus treated patients.

Adult↗
PubMed2005

Complications of intravitreal steroid injections.

BACKGROUND: Intravitreal corticosteroid injections are a new therapeutic procedure used to treat various retinal edematous and neovascular conditions. They have been used in the treatment of diabetic macular edema, exudative macular degeneration, pseudophakic cystoid macular edema, macular edema associated with retinal vein occlusion, and chronic uveitis as well as other conditions. Because the use of this therapeutic technique is becoming increasingly more common, adverse effects are now being seen. The most common adverse effects associated with intravitreal steroid injection are elevation of intraocular pressure and progression of cataract. Endophthalmitis, pseudoendophthalmitis, and retinal detachment have also been reported. CASE REPORTS: This report describes 2 patients who were followed up at the VA Connecticut Healthcare System Newington Campus Optometry Clinic for steroid-induced elevation of intraocular pressure after intravitreal corticosteroid injection. One patient exhibited elevation of intraocular pressure after his first intravitreal steroid injection for treatment of clinically significant macular edema secondary to diabetes. The second patient did not exhibit a steroid response to the first intravitreal steroid injection utilized as treatment for choroidal neovascularization from age-related macular degeneration. However, he did show a rise in intraocular pressure after a second intravitreal corticosteroid injection. Intraocular pressures, treatment, and frequency of follow-up in both patients pre- and postinjection are discussed. CONCLUSION: Elevation of intraocular pressure after intravitreal steroid injection can commonly be controlled with topical glaucoma medications. Cataract progression is common in patients after intravitreal injection of corticosteroid; however, findings show these patients are at no additional risk for cataract surgery complications. Therefore, these do not appear to be major contraindications. However, because 30% to 50% of patients experience intraocular pressure rise up to a few months postinjection, and patients are at higher risk for complications such as endophthalmitis, optometrists should be aware of appropriate management after this increasingly utilized therapeutic procedure.

Aged↗
PubMed1995

Imaging of chorioretinal anastomoses in vascularized retinal pigment epithelium detachments.

OBJECTIVE: To identify specific features of pigment epithelium detachments with limited hyperfluorescent lesions (hot spots). DESIGN: One hundred eighty-two consecutive patients (186 eyes) who had vascularized pigment epithelium detachments and recent onset of symptoms were examined with indocyanine green and fluorescein videoangiography using the scanning laser ophthalmoscope. The choroidal neovascularization complex and macular retinal vessels were studied. The natural history and the effect of laser treatment were evaluated. RESULTS: Fifty-four eyes had hot spots on indocyanine green angiography. In 50 of these 54 eyes, the video analysis showed an anastomosis of one or more retinal vessels, with the choroidal neovascularization within the hot spot. One or two retinal veins or arteries or both filled with both dyes and were seen to enter into the hot spot. Results of indocyanine green-guided photocoagulation of the hot spot in 28 eyes were disappointing. CONCLUSION: Continuous recording of the early phases of fluorescein and indocyanine green angiography allowed identification of chorioretinal anastomoses in vascularized pigment epithelium detachments with hot spots at an early exudative stage of age-related macular degeneration in 50 (26.8%) of 186 eyes. The poor outcome of laser photocoagulation could be related not only to the development of an overlying pigment epithelium detachment, but also to the retinal and choroidal vascularization of the lesion.

Aged↗
PubMed2004

Aggressive retinal astrocytomas in four patients with tuberous sclerosis complex.

OBJECTIVE: To report the clinical and histopathologic findings of retinal astrocytic tumors that showed progressive growth in four patients with tuberous sclerosis complex (TSC). METHODS: Four young children each developed an enlarging retinal neoplasm that eventually necessitated enucleation of the affected eye. The systemic findings, clinical course, and histopathologic findings were reviewed. RESULTS: Each patient had a progressively enlarging retinal mass associated with a total exudative retinal detachment and neovascular glaucoma. Enucleation was necessary in each case because the affected eye became blind and painful. The mean patient age at enucleation was 7 years, and the median age was 3 years. At the time of enucleation the tumors ranged from 10 to 20 mm in basal diameter and from 10 to 25 mm in thickness. Histopathologic studies of each eye revealed a giant cell astrocytoma that had produced a total exudative retinal detachment. The tumor cells showed positive immunoreactivity to neuron-specific enolase and glial fibrillary acidic protein. The retinal neoplasms in these cases were identical histopathologically to the subependymal giant cell astrocytoma that typifies TSC in the brain. One tumor filled the entire eye and perforated the globe. Although the lesions simulated retinoblastoma clinically, each patient had ocular and systemic findings of TSC, supporting the diagnosis of astrocytic hamartoma. CONCLUSIONS: Although retinal astrocytic lesions of TSC generally are stationary, they can sometimes grow relentlessly and cause severe ocular complications. Patients with retinal astrocytic hamartomas should have serial ophthalmic evaluations because of this possibility.

Astrocytoma↗
PubMed1980

Unusual presentation of acute ocular toxoplasmosis.

Two unusual cases of ocular toxoplasmosis are presented. A 24 year old woman developed retinal and optic nerve neovascularization in conjunction with acute ocular toxoplasmosis. The neovascularization regressed with resolution of the inflammation. The possibility of retinal ischemia or inflammation alone as an etiology are discussed. A 19 year old woman developed optic nerve edema and a marked decrease in vision associated with a nasal toxoplasma lesion and a macular star. With resolution of the process, optic atrophy developed but visual acuity returned to normal. Optic nerve edema and atrophy were felt to result from diffuse inflammation, but not from focal involvement in the nerve itself with the organism.

Adult↗
PubMed1994

Long-term outcomes after the surgical removal of advanced subfoveal neovascular membranes in age-related macular degeneration.

BACKGROUND: The poor results of laser photocoagulation in patients with age-related macular degeneration who have subfoveal neovascular membranes, as reported by the Macular Photocoagulation Study Group, have posed the question as to whether the surgical removal of the neovascular membranes by subfoveal surgery might provide superior functional results, possibly in subgroups of patients. METHODS: The authors' first ten patients treated by subfoveal surgery were followed prospectively. Follow-up of a mean duration of 2 years is presented, with particular emphasis on visual and anatomic outcomes. Preoperative subfoveal choroidal neovascular membranes and postoperative retinal pigment epithelial defects were measured using digitized planimetry. RESULTS: Initial visual acuities were equal to or less than 20/400, with a mean duration of visual loss of 8 months. The mean choroidal neovascular membrane size was 7 disc areas. Eight of ten patients improved one to two lines of Snellen visual acuity postoperatively. One patient achieved visual acuity of 20/60 at 15 months before declining because of recurrent neovascularization. Surgically induced retinal pigment epithelial defects were invariable; the mean defect was 14 standard disc areas in size. Choriocapillaris atrophy and focal losses of deeper choroidal tissue also occurred. Surgical complications were frequent but responded to routine management. The authors observe a 2-year recurrence rate of 40%. Recurrences often are atypical, fibrous, and poorly vascularized. CONCLUSIONS: Although substantial visual improvements are common, long-term reading vision has not been achieved. Retinal pigment epithelial incorporation into late subfoveal membranes remains a major limiting factor. The role of early surgery and the role of surgery for patient subgroups need to be compared directly with the results of foveal laser treatment, using several visual outcomes.

Aged↗
PubMed2005

Vitreous leptin levels in retinal disease.

BACKGROUND/AIMS: The purpose of this study was to investigate the relationship between vitreous leptin levels and retinal diseases. METHODS: Levels of vitreous leptin were evaluated in proliferative diabetic retinopathy (PDR) and a variety of other retinopathies including: macular disease, neovascular maculopathies, primary retinal detachments, and vascular occlusive disease. RESULTS: In patients with PDR (N=7), the average vitreous level of leptin (37.4 ng/ml) was significantly higher than that in patients with PVR (<1.0 ng/ml, P<0.05). Vitreous leptin level in patients with PVR or macular disease (N=18), with or without diabetes, was not significantly different from the control subjects who had retinal detachment only (N=7). CONCLUSION: The results show that the leptin level in vitreous taps is elevated in PDR. We suggest that leptin plays an active role in PDR.

Adult↗
PubMed1985

The visual outcome in cases of neovascular glaucoma.

The visual outcome of cases of neovascular glaucoma treated by draining implants has improved from 12% to 32% of eyes achieving a vision of 6/60 or better. The main factor responsible for this improvement has been the recognition that, in neovascular glaucoma, the retinal blood vessels are not capable of autoregulation of calibre in response to changes in intraocular pressure and ophthalmic artery perfusion pressure. The consequences of this situation are discussed and the importance of early treatment of neovascular glaucoma by a combination of photocoagulation, insertion of a draining implant and medical measures to improve the circulation where possible is emphasized.

Adult↗
PubMed2005

[Fundus flavimaculatus and subretinal neovascularization--case report].

Fundus flavimaculatus is a progressive, bilateral, hereditary retinal dystrophy characterized by ill-defined, yellowish, pisiform flecks at the level of the retinal pigment epithelium. Since the disease process is at level of the retinal pigment epithelium, it is not surprising that subretinal macular neovascularizations might occur. Nevertheless, they have been rarely reported as complications of the disease. The following report describes a case of fundus flavimaculatus that progressed with blurred vision by a subretinal macular neovascularization.

Aged↗
PubMed1998

Advanced glycation end products increase retinal vascular endothelial growth factor expression.

Advanced glycation end products (AGEs) are linked with the development of diabetic retinopathy; however, the pathogenic mechanisms are poorly defined. Vascular endothelial growth factor (VEGF) levels are increased in ischemic and nonischemic diabetic retina, and VEGF is required for the development of retinal and iris neovascularization. Moreover, VEGF alone can induce much of the concomitant pathology of diabetic retinopathy. In this study, we found that AGEs increased VEGF mRNA levels in the ganglion, inner nuclear, and retinal pigment epithelial (RPE) cell layers of the rat retina. In vitro, AGEs increased VEGF mRNA and secreted protein in human RPE and bovine vascular smooth muscle cells. The AGE-induced increases in VEGF expression were dose- and time-dependent, inhibited by antioxidants, and additive with hypoxia. Use of an anti-VEGF antibody blocked the capillary endothelial cell proliferation induced by the conditioned media of AGE-treated cells. AGEs may participate in the pathogenesis of diabetic retinopathy through their ability to increase retinal VEGF gene expression.

Animals↗
PubMed2006

Choroidal neovascular membrane in radiation retinopathy.

Radiation retinopathy can occur years after the initial radiotherapy of the cancers of head and neck. It generally has a fulminant course, and can cause a variety of severe retinal abnormalities. Choroidal neovascularization has been rarely reported in radiation retinopathy. In this case report, a 21-year-old boy is presented who developed fulminant radiation retinopathy and choroidal neovascular membrane 4 years after receiving radiotherapy for his nasopharyngeal carcinoma.

Adult↗
PubMed1993

The appearance of stippled retinal pigment epithelial detachments. A sign of occult choroidal neovascularization in age-related macular degeneration.

The clinical source of 62 eyes that had been coded for macular degeneration and fibrovascular retinal pigment epithelial (RPE) detachment on fluorescein angiography was reviewed; 17 eyes had signs of a choroidal neovascular membrane (CNVM) at initial examination, and 30 eyes developed a definite CNVM during follow-up examination. Thus, 47 of the 62 eyes (76%) developed a CNVM in association with fibrovascular RPE detachments. Features of fibrovascular RPE detachments include: 1) focal, tiny hyperfluorescent spots at the level of the RPE arising in the mid and late frames of the angiogram, which do not correspond to drusen or foci of depigmentation (stippled hyperfluorescence); 2) intensification of these spots in the later stages of the angiogram; 3) slight enlargement of the spots in the late frames of the angiogram; 4) occasional presence of scant overlying subretinal fluid; and 5) minimal elevation of the RPE. Fibrovascular RPE detachments appear to be a distinct form of an RPE detachment. It is concluded that this sign is associated with a high risk of developing a frank CNVM and is thus a reliable indicator of occult neovascularization.

Aged↗
PubMed1996

Central serous chorioretinopathy in younger and older adults.

PURPOSE: The purpose of the study is to investigate the demographic characteristics and clinical findings of central serous chorioretinopathy (CSC). METHODS: This study examined a consecutive series of 130 patients with CSC seen over an 18-month period. RESULTS: The mean age of the patients when examined was 51 years, and the male-to-female ratio was 2.6:1.0. A total of 62 patients were older than 50 years of age when first examined. Although the patients shared some clinical and angiographic similarities, the older patients had a lower mean visual acuity and were more likely to have diffuse retinal pigment epitheliopathy, bilateral involvement, and secondary choroidal neovascularization than were the younger patients. With ophthalmoscopic and angiographic examination results, it was possible to differentiate CSC in older adults from choroidal neovascularization. CONCLUSION: This study expands the clinical concept of CSC. The male-to-female ratio was much lower, and the range of ages of the patients was much greater than in previous studies. Disease manifestations in older adults differed somewhat from those seen in younger adults. In older patients, CSC can be distinguished from other exudative maculopathies, particularly that of choroidal neovascularization secondary to age-related macular degeneration.

Adult↗
PubMedDate not supplied

Ophthalmologic findings as predictors of carotid artery disease.

Vascular events that occur in the brain also occur in the eye, giving rise to different ophthalmologic manifestations that range from amaurosis fugax to complete blindness due to central retinal artery occlusion. The objective of this study was to ascertain the relative frequency and predictive value of ocular findings suggestive of carotid occlusive disease in patients being investigated for carotid endarterectomy. The charts of 366 patients undergoing carotid angiography for evaluation of cerebrovascular or visual symptoms over a 5-year period were reviewed. The presence of eye symptoms, neurologic symptoms, cervical bruits, and ophthalmologic findings on admission was recorded and correlated with the presence of significant carotid artery stenosis (>or=50%). Positive eye findings included retinal plaques, rubeosis iridis, neovascular glaucoma, venous stasis retinopathy, central and branch retinal artery occlusion, ischemic optic neuropathy, and asymmetric hypertensive retinopathy. Seventy-five patients (21%) presented with amaurosis fugax; 41 patients (11%) were found to have one or more ocular findings consistent with carotid artery disease. All patients with positive eye findings were diagnosed by ophthalmologists, who were consulted in 94 cases. Of these 41 patients, 29 (70.3%) were subsequently shown to have greater than 50% stenosis of the common or internal carotid artery. Ten patients had amaurosis fugax, a carotid bruit, and positive eye findings. All were shown to have a significant carotid stenosis. This study shows that ocular pathology, if diagnosed, is correlated with carotid stenosis, especially if other contributing history and physical findings are also considered.

Adult↗
PubMed2004

Effect of bicarbonate on retinal vasculature and acidosis-induced retinopathy in the neonatal rat.

BACKGROUND: Systemic acidosis induces preretinal neovascularization (NV) analogous to retinopathy of prematurity (ROP) in the neonatal rat. Sodium bicarbonate is used in human neonates to treat acidosis. The effects of alkali administration on the developing retinal vasculature and on acidosis-induced retinopathy (AIR) are unknown. We investigated the effect of sodium bicarbonate gavage on the retinal vasculature of normal and acidotic neonatal rats to determine (1) whether bicarbonate treatment is associated with preretinal NV and (2) whether AIR can be prevented with systemic bicarbonate treatment. METHODS: The extent of acidosis and alkalosis were initially determined from carotid arterial blood samples. In the bicarbonate-alone study, newborn rats were randomized into litters of 25 and received bicarbonate doses of 15 mmol/kg twice daily and 20 mmol/kg once daily from days 2 to 7. Control animals received saline gavage. In the AIR treatment study, acidosis was induced in neonatal rats by intraperitoneal injection of acetazolamide 200 mg/kg from days 2 to 7. Acetazolamide-treated rats received either additional bicarbonate gavage or no additional treatment. Eyes were enucleated on day 13, and the retinal vasculature was assessed for NV using ADPase staining techniques and light microscopy. RESULTS: Systemic alkalosis (peak pH 7.55+/-0.02; mean +/- SD) was confirmed with bicarbonate gavage, and partial reversal of acidosis was confirmed when acetazolamide-treated rats received bicarbonate. Surviving rats receiving bicarbonate 15 mmol/kg twice daily (28% survival) and 20 mmol/kg bicarbonate once daily (45% survival) had an incidence of preretinal NV of 9% and 8%, respectively. No NV was seen in saline-control rats. In the acetazolamide-treated rats, the incidence of preretinal NV in surviving rats was numerically lower in bicarbonate-treated rats than acetazolamide-only controls (8% versus 24%, p=0.065) but with only 19% survival in the bicarbonate-treated rats. CONCLUSIONS: In the neonatal rat, alkalosis induced by bicarbonate gavage is associated with a low incidence of mild, preretinal NV similar to ROP. Although treating acidotic rats with bicarbonate may reduce the incidence of preretinal NV, treatment was associated with an unacceptable mortality rate.

Acetazolamide↗
PubMed2000

[Hereditary occlusive cerebroretinal vasculopathy in two sisters].

BACKGROUND: Retinal microvascular abnormalities associated with multiorgan disease may be observed in a number of systemic illnesses and syndromes. PATIENTS: Two sisters with identical signs of a hereditary cerebroretinal vasculopathy (occlusive retinal angiopathy--cerebral vasculopathy--microcephalus) were treated at the University Hospital of Saarland. COURSE: Photocoagulation for treatment of neovascular complications secondary to retinal ischemia was performed. In one eye a vitrectomy became necessary because of persistent vitreal hemorrhage. One sister died because of non treatable intracranial hypertension at the age of 22 years. CONCLUSIONS: Interdisciplinary work-up is important in patients with cerebroretinal disease. Neuropathologic evaluation including brain biopsy and neuroimaging plus ophthalmoscopy and pedriatic findings lead to the diagnosis of this rare hereditary, in this case most likely autosomal recessive condition. Photocoagulation may limit neovascular complications secondary to retinal ischemia. A specific form of treatment has, however, not yet been found.

Adult↗