A comparison of stereoscopic fluorescein angiography with indocyanine green videoangiography in age-related macular degeneration.

PURPOSE: To correlate features of indocyanine green (ICG) videoangiography with stereo film fluorescein angiography (FA) in the analysis of age-related macular degeneration (AMD). DESIGN: A retrospective study with concurrent comparison of two methods of assessment on one set of patients with AMD undergoing sequential FA-ICG videoangiography. METHODS: One hundred four patients with AMD who had undergone immediately sequential FA-ICG videoangiography were selected in a consecutive fashion from the photographic files of the Casey Eye Institute. Three interpreters independently graded in an unbiased fashion the FA features of AMD. These were compared with ICG videoangiography features of hypocyanescence (ICG videoangiography hypofluorescence), moderate or intense hypercyanescence (ICG videoangiography hyperfluorescence), or absence of fluorescence over background (ICG videoangiography isocyanescence). We also assessed ICG videoangiography features in the opposite eye of those with choroidal neovascularization (CNV) by FA in one eye by examining an additional 96 FA-ICG videoangiography scans. MAIN OUTCOME MEASURES: Outcomes were the ICG videoangiography characteristics of classic and occult CNV, serous pigment epithelial detachments (SPEDs) both with and without CNV, macular hemorrhage, and the comparative size of these features. RESULTS: There were 25 eyes that had significant macular hemorrhage by FA. Of these, the FA revealed CNV in its entirety under or near the hemorrhage in 11. The ICG examination revealed all 11 plus an additional 12 hypercyanescent features that were not visible by FA. Although 26 of 32 SPEDs had CNV by FA analysis, 31 of 32 had well-defined hypercyanescence under or at the SPED edge by ICG videoangiography. Eighty-seven percent of eyes with classic choroidal neovascular membranes (CCNV; 20 of 23) and 93% of eyes with fibrovascular pigment epithelial detachments (FVPED; 66 of 71) were hypercyanescent with distinct edges. Fifty percent of eyes with only late leakage of undetermined source (LLUS) were hypercyanescent, whereas 50% were isocyanescent on ICG videoangiography. There were four of 104 eyes in which ICG videoangiography revealed poorly defined hypercyanescent areas when, by FA, there were only drusen or elevated blocked fluorescence. Indocyanine green videoangiography revealed only three eyes with poorly defined hypercyanescence of 200 fellow eyes in patients with unilateral AMD. CONCLUSIONS: Indocyanine green videoangiography correlated fairly well with stereoscopic FA for the presence of CCNV or FVPED, but correlated poorly when LLUS was present. In certain cases where CNV was associated with SPED or macular hemorrhage, ICG videoangiography demonstrated features not apparent on FA.

Histoplasmosis-like choroiditis in a nonendemic area: the northwest United States.

PURPOSE: Histoplasmosis is not endemic in the U.S. northwest, but a type of multifocal choroiditis resembling ocular histoplasmosis occurs there. This study was designed to find a group of affected patients and study their clinical characteristics and immunologic responses to Histoplasma antigens. METHOD: Ten patients were found in the authors' files whose geographic histories made it unlikely that they had ever been exposed to Histoplasma capsulatum and yet they had features of ocular histoplasmosis. They were recalled for examination and testing by lymphocyte-stimulation assay for previous exposure to histoplasmosis. RESULTS: The clinical features of these patients resembled those of patients with ocular histoplasmosis, but their histories and the results of the assay did not support H. capsulatum as the cause of the ocular disease. CONCLUSION: This study confirmed that there is a type of choroiditis that resembles ocular histoplasmosis but is due to another agent or agents.

Natural course of perfused central retinal vein occlusion.

OBJECTIVE: To investigate the visual prognosis in perfused (nonischemic) central retinal vein occlusion (CRVO), to determine the frequency of conversion from perfused to nonperfused CRVO, and to identify risk factors for poor visual outcome. DESIGN: Case series. SETTING: Retina referral centre in Portland, Ore. PATIENTS: Fifty-eight patients (59 eyes) with perfused CRVO followed for at least 1 year (average 2.5 years). MAIN OUTCOME MEASURES: Visual acuity, progression to nonperfused CRVO. RESULTS: At the final follow-up visit the visual acuity had improved by two or more lines in 9 eyes (15%), remained the same in 33 eyes (56%) and decreased by two or more lines in 17 eyes (29%). Factors significantly related to visual outcome were initial visual acuity (p = 0.0001) and age, older patients having a worse visual outcome (p = 0.0029). Nine eyes (15%) progressed to nonperfused CRVO. None of the factors analysed, including age, sex, duration of symptoms and initial visual acuity, were predictive of progression. CONCLUSIONS: Perfused CRVO frequently results in significant, permanent visual loss, and a poor visual outcome is most likely in older patients and those with poor initial visual acuity.

Morphometric analysis of human retinal pigment epithelium: correlation with age and location.

Flat bleached preparations of retinal pigment epithelial (RPE) cells from foveal, temporal posterior pole, and temporal equatorial fundus locations of 20 normal human eyes from donors age ranked from 13 to 96 years were analyzed for density, and 10 were analyzed for area, hexagonality and polymegathism. These factors were related to fundus locations and age. Foveal RPE cells were significantly more dense and more hexagonal in eyes from younger donors. Loss of hexagonality in the fovea, but not elsewhere, was correlated with increasing age. As the eye ages, foveal RPE cells selectively lose unique morphologic characteristics and resemble nonfoveal cells. These morphologic changes resemble other pathologic features of age-related degeneration in their proclivity for the fovea and posterior pole.

A model for the apparent decrease in optical transmittance of the diabetic eye.

This paper compares observed changes of ocular transmittance at short and long wavelengths in diabetic patients with values predicted by a model based on the Rayleigh light scattering properties of albumin. Selective chromatic adaptation was used to obtain critical flicker fusion (CFF) frequency thresholds from 21 subjects and 18 patients with insulin-dependent diabetes. The Ferry-Porter characteristic of each color-sensitive mechanism of each patient was compared to age-specific control values. For those eyes without an indication of neural injury, changes in optical density associated with the red- and blue-sensitive mechanisms were calculated and adjusted to reflect accelerated yellowing of the lens produced by increased duration of diabetes. The range of concentration of glycosylated albumin required to fit the model to the adjusted short-wavelength changes in optical density was determined and used to calculate the theoretical long-wavelength changes in optical density. The experimentally derived long-wavelength changes in optical density fell within the 95% confidence level of the values described by the model. These results support the premise that the apparent decrease in optical transmittance observed in patients with diabetes mellitus is caused by light scattering produced by dilute increase of plasma proteins within the retina.

Acute idiopathic blind spot enlargement. A spectrum of disease.

The authors present a report on their experience with 10 patients with acute idiopathic blind spot enlargement. All had enlarged steep-margined blind spots without accompanying changes in optic disc appearance, significantly diminished visual acuity or color vision. Fluorescein angiography was obtained in eight patients. Five patients had retinal appearance that was either normal or could not be attributed to a known disease entity. Three patients had the multiple evanescent white dot syndrome, one had acute macular neuroretinopathy, and at least one had presumed ocular histoplasmosis. It has been proposed that acute idiopathic blind spot enlargement is a subset of multiple evanescent white dot syndrome. The authors' findings suggest that multiple evanescent white dot syndrome and other retinal diseases, some not yet identified, are subsets of acute idiopathic blind spot enlargement.

Retinal vasculitis--a primer.

Retinal vasculitis is a diagnosis that is generally suggested by an ophthalmologist. Frequently patients with the disorder are referred to nonophthalmologists for further diagnostic evaluation or treatment. The criteria for defining vasculitis differ greatly between ophthalmologists and other physicians. To facilitate collaboration between ophthalmologists and their colleagues, we have sought to clarify the term "retinal vasculitis" by discussing its subcategories, the potential role of antiphospholipid antibodies, and the etiology of retinal vasculitis. We offer guidelines for evaluating the disorder and treating patients.

Photographic grading in the retinopathy of prematurity cryotherapy trial.

We report a system for photographic grading of the posterior fundus features of retinopathy of prematurity and correlation of such features with potential future visual function. The severity of temporal vessel traction, retinal fold, macular ectopia, retinal detachment, retrolental mass, blood vessel attenuation, retinal pigment epithelial scarring, and cataract was assessed by review of photographs at the Fundus Photograph Reading Center, Portland, Ore, according to a scheme designed to avoid bias or knowledge of treatment status. Reliability for all features was in the fair to excellent range (kappa greater than .40), except for blood vessel attenuation (kappa = .18), which was not a factor in the final outcome determination. The grading scheme provided the basis for the 3-month conclusions of the multicenter trial of cryotherapy for retinopathy of prematurity. This system will have further application in the 12-month Cryotherapy for Retinopathy of Prematurity Study conclusions and in future long-term correlation with visual acuity as the trial patients mature.

Growth features of choroidal neovascular membranes in age-related macular degeneration.

The authors studied 80 eyes of patients with choroidal neovascular membranes (CNVMs) associated with age-related macular degeneration between 1982 and 1988. In each case, fluorescein angiography was done on two occasions separated by an interval of 2 days to 11 weeks (average, 13 days) without intervening photocoagulation. Forty-three CNVMs (54%) grew toward the fovea during the interval between fluorescein angiograms, with growth rates ranging from 1 to 24 microns daily (average, 10 microns daily). The CNVM growth was related to the time interval between angiograms (P less than 0.0001), but was not associated with morphologic features of the CNVM. These results reinforce the need for early detection and prompt evaluation of elderly patients with symptoms of CNVMs.

Results and complications of pneumatic retinopexy.

Fifty-one patients with primary rhegmatogenous retinal detachment (RD) were treated by pneumatic retinopexy. The overall success rate for reattachment with one operation was 63%. Of the 34 phakic eyes, 25 (74%) were reattached; of the 17 aphakic or pseudophakic eyes, seven (41%) were reattached (P less than 0.05). Postoperative complications included the development of new tears (22%), inadequate closure of the original tear, shifting and delayed absorption of subretinal fluid, and opening of previously closed tears. Pneumatic retinopexy is a valuable new technique; however, careful patient selection and postoperative management is required.

Early loss of blue-sensitive color vision in patients with type I diabetes.

Existing methods for early detection of ocular injury from diabetes have serious limitations. We describe a new method, measuring visual flicker discrimination of the blue-sensitive mechanism of vision. This method is noninvasive, quantitative, and capable of distinguishing two types of impairment. Blue-flicker discrimination was measured in 10 adults with type I (insulin-dependent) diabetes for less than 5 yr. Although no evidence of diabetic changes was detected by careful ophthalmic examination by an experienced ophthalmologist, 12 of 19 eyes (63%) had flicker discrimination scores considered abnormal in comparison with those of a control group, and 8 of 10 subjects (80%) had at least 1 eye with abnormal performance. In all but 2 abnormal eyes the deficit of blue-flicker discrimination was of the "absorptive" type, suggesting increased absorbance or scattering of blue light in the optical media. These data show that a functional impairment of vision can be measured very early in the course of type I diabetes, before visible retinopathy is present, and suggest this test procedure may have both investigative and clinical applications.

Abnormal glucose metabolism and parafoveal telangiectasia.

Parafoveal telangiectasia is a microvascular abnormality of the macula that may be developmental or acquired. Twenty-eight patients with this condition and normal fasting blood glucose levels underwent ophthalmologic evaluation and glucose tolerance testing. Bilateral telangiectasia was more frequently associated with laboratory evidence of abnormal glucose metabolism than unilateral disease (five of eight cases vs six of 17 cases). In five of our patients, results of glucose tolerance testing were consistent with diabetes even though fasting blood glucose levels were normal. Right-angle venules, which have been reported to be an important sign of bilateral disease, were also found in unilateral telangiectasia. Unilateral telangiectasia occurs in females as well as males. Glucose tolerance testing should be performed in all patients who have bilateral parafoveal telangiectasia.

Punctate inner choroidopathy.

Ten moderately myopic women had blurred vision, light flashes, or paracentral scotomas associated with small yellow-white lesions of the inner choroid and pigment epithelium. Most lesions had an overlying serous detachment, were hyperfluorescent, and leaked fluorescein during the acute phase. The lesions healed into atrophic scars and became progressively more pigmented with time. Subretinal neovascular membranes later developed from scars in six patients. Vision was usually only minimally affected unless the lesions were subfoveal or unless choroidal neovascular membranes subsequently occurred. Extensive laboratory studies were noncontributory.

Toxocara canis infection of the eye. Correlation of clinical observations with developing pathology in the primate model.

A primate model for the study of Toxocara canis infection was created by intravitreal, periocular, systemic, and intracarotid injection of viable larvae in cynomolgus monkeys. The results were as follows: (1) Intravitreal larvae caused retinal hemorrhages, perivasculitis, mild vitritis, and retinal nodules. (2) Apparently viable larvae without inflammatory reaction were found in the vitreous, retina, and optic nerves up to nine months after intravitreal inoculation. (3) Other larvae were surrounded by an acute inflammatory granuloma or a chronic fibrotic granuloma, but they did not appear to be necrotic. (4) Toxocara canis larvae apparently had the ability to move through ocular tissue, to leave the site of tissue reaction, and to exit via the optic nerve. Viable larvae were found in the retina up to 15 months after inoculation. (5) Culture fluid containing Toxocara proteins stimulated a severe retinal vasculitis. Dead larvae caused little reaction. (6) Positive aqueous and vitreous enzyme-linked immunosorbent assay titers were found in the most severely inflamed eyes, which often harbored live larvae.

Scleral patch graft for exposed episcleral implants.

A method of covering exposed noninfected episcleral implants after retinal detachment surgery using a graft of preserved sclera is described. Four of seven eyes have had the dehiscence covered for six months or more. In three eyes the dehiscence recurred. The procedure is simple and effective in eyes in which removal of the implant might cause redetachment of the retina.