Etiology of choroidal neovascularization in young patients.

BACKGROUND: Choroidal neovascularization (CNV) is a common cause of legal blindness in developed countries. In patients younger than 50 years of age, CNV can be due to various causes, but to the authors' knowledge there has been no large epidemiologic study to compare the relative incidence of the various causes of CNV in this younger-aged group. METHODS: A retrospective study was performed of patients seen over a 30-month period to precisely define the relative incidence of the various etiologies of CNV in patients younger than 50 years of age who had been referred to a tertiary care ophthalmology department in western Europe. RESULTS: Clinical charts and angiograms of 363 patients were reviewed. The etiology of CNV was high myopia in 225 (62%) patients, pseudo-presumed ocular histoplasmosis syndrome in 42 (12%), angioid streaks in 17 (5%), and miscellaneous hereditary or traumatic or inflammatory disorders in 16 (4%). Choroidal neovascularization could not be related to any etiology in 63 (17%) patients, and was considered to be idiopathic lesions. Choroidal neovascularization was subfoveal in 62% of the patients due to myopia versus 30% to 36% in patients due to other etiologies. Laser photocoagulation was applied in the majority of patients due to all etiologies except myopia. CONCLUSION: These data provide the relative incidence of the various etiologies of CNV in young patients and emphasize the importance of myopia as an etiology of CNV in such patients. In addition, an apparent preferential localization of CNV to the subfoveal region in myopic eyes precludes its treatment with photocoagulation.

Retinitis punctata albescens associated with the Arg135Trp mutation in the rhodopsin gene.

PURPOSE: To screen for mutations in the rhodopsin, peripherin/RDS, and ROM1 genes in a family affected with retinitis punctata albescens. Because clinical heterogeneity was observed in this family, with some members affected with retinitis punctata albescens and one member affected with features typical of retinitis pigmentosa, we analyzed the apolipoprotein E gene to elucidate this unusual intrafamilial heterogeneity. METHODS: The coding sequences of these genes were analyzed with a combination of single-strand conformation polymorphism and direct sequence analysis. Haplotypes of the apolipoprotein E gene were analyzed by polymerase chain reaction and enzymatic digestion. RESULTS: The Arg135Trp mutation in the rhodopsin gene was observed in all affected members of this family, but no mutation was detected in the peripherin/RDS or ROM1 genes. The e4 allele of the apolipoprotein E gene apparently cosegregated with the albescens phenotype in this family. CONCLUSIONS: The albescent phenotype in retinal dystrophy appears to not be caused exclusively by a peripherin/RDS gene mutation, and we suggest that the apolipoprotein E gene may play a role in the albescent phenotype.

Indocyanine green videoangiography of angioid streaks.

PURPOSE: The fluorescein angiographic features of angioid streaks are variable, and angioid streaks and their main complication, choroidal neovascularization, can sometimes be difficult to visualize in the presence of diffuse pigment migration, diffuse atrophy of the retinal pigment epithelium, or hemorrhage. The objective of the present investigation was to define the indocyanine green angiographic features of angioid streaks and to compare them with findings on fluorescein angiography. METHODS: For this prospective study, we recruited 22 consecutive patients, 21 of whom had angioid streaks and one who had typical peau d'orange appearance of the fundus. Complete ophthalmologic examination, fluorescein angiography, and indocyanine green videoangiography by the means of scanning laser ophthalmoscope were performed on all patients. RESULTS: In 21 patients with angioid streaks and in one patient with peau d'orange appearance of the fundus, indocyanine green videoangiography showed angioid streaks in the form of hyperfluorescent lines with numerous associated hyperfluorescent foci. The angioid streaks were more clearly visualized and were seen to be more numerous and larger by indocyanine green videoangiography than with red-free images or fluorescein angiography. Choroidal neovascularization was suspected in six eyes but could be precisely localized by fluorescein angiography in only three eyes. Indocyanine green angiography allowed precise localization of choroidal neovascularization in all six of these eyes. CONCLUSIONS: These findings indicate that indocyanine green videoangiography provides different information than fluorescein angiography in the evaluation of angioid streaks and can more precisely localize their neovascular complications.

Visual function and course of basal laminar drusen combined with vitelliform macular detachment.

Basal laminar drusen (BLD) are small round yellow drusen that are more easily visualised angiographically than biomicroscopically, with a 'stars in the sky' pattern. Patients with BLD are predisposed to macular vitelliform detachment. Little is known about the course of the disease, but the prognosis for retention of useful central vision for patients with BLD is thought to be better than for patients with typical drusen. A retrospective analysis of clinical and angiographic charts of 19 patients with BLD combined with a vitelliform macular detachment was performed to precisely describe their course. In addition, nine patients were re-examined to allow an analysis of their visual function--that is, central visual field, contrast sensitivity, and colour vision. Eyes without choroidal new vessels retained a fair visual acuity (mean final visual acuity 0.5; follow up 4 to 69 months, mean 24 months). In 11 of these eyes visual function assessment disclosed a reduction of contrast sensitivity in high and medium spatial frequencies in nine eyes (81%), a blue-yellow dyschromatopsia in nine eyes (81%), and a mild reduction of foveal threshold in seven eyes (63%). Choroidal neovascularisation (CNV) was observed in 12 eyes (31%) with a poor final outcome (mean final visual acuity 0.1). Two thirds of cases of CNV were observed at the time of presentation; thus this finding may be a bias of a referring centre. However, the high prevalence of CNV suggests the need for a close follow up of patients with BLD.

Basic fibroblast growth factor experimentally induced choroidal angiogenesis in the minipig.

Basic fibroblast growth factor (bFGF), a soluble mitogen, has been isolated and purified from various organs, including the retina. In vivo angiogenic activity of bFGF has been demonstrated with several assays. An experimental model of choroidal neovascularization was developed in the mini pig by perfusion of recombinant human bFGF through an osmotic minipump. Endogenous bFGF and bFGF receptors were localized in the normal pig retina by immunohistochemistry and autoradiography after binding. The perfusion of exogenous bFGF induced well-organized new vessels along the last 3 mm of the catheter in the suprachoroidal space. This neovascularization did not penetrate the normal Bruch's membrane. Vascular cells (identified by von Willebrand factor antibody staining) increased in number and in surface from the proximal part to the end of the intraocular catheter in all bFGF perfused eyes. In eyes perfused with phosphate buffered saline (controls), but not in the bFGF perfused eyes, an inflammatory response occurred (identified by a macrophage specific antibody). These results demonstrate that choroidal angiogenesis can be achieved without an inflammatory response by perfusing an excess of bFGF in the suprachoroidal space.

Focal visual evoked potentials generated by scanning laser ophthalmoscope in patients with age-related macular degeneration treated by perifoveal photocoagulation.

Perifoveal laser photocoagulation has been proposed for the treatment of subfoveal neovascular membranes in age-related macular degeneration. We evaluated residual function in seven eyes of six treated patients by means of transient focal visual potentials evoked with a scanning laser ophthalmoscope. The site of the preferred retinal locus was determined. The modulation of the helium-neon laser beam generated three tests (a homogeneous 6 x 6 degrees square--offset and onset--and two alternating pattern checkerboards 6 x 6 degrees and 2.5 x 2.5 degrees 60', 2 Hz) projected onto the preferred retinal locus. The focal visual evoked potentials were recorded. One eye had an unstable fixation with no discernible focal visual evoked potentials. The other six eyes had a stable fixation located in the superior retina, temporally for the right eyes and nasally for the left eyes. The homogeneous 6 x 6 degrees square evoked discernible responses in all six patients. The two checkerboards evoked discernible responses in five of six patients. These results were compared with those recorded in four controls in whom the three tests were projected onto the same retinal areas as in the patients. Evoked responses were more often recorded in the preferred retinal locus of the treated patients with age-related macular degeneration than in the corresponding retinal areas of the controls. The scanning laser ophthalmoscope allowed us to control the site of stimulation in the patients' and controls' retinas. These preliminary results suggest that there may be a functional plasticity of the visual system after therapeutic laser-induced central scotoma.

Retinal vascular changes in congenital hypertrophy of the retinal pigment epithelium.

BACKGROUND: Congenital hypertrophy of the retinal pigment epithelium (CHRPE) is a well-defined clinical entity with usually well-delineated, pigmented oval or round lesion with smooth or scalloped margins. Occasional retinal vascular changes have been reported previously. PURPOSE AND METHOD: To assess the prevalence of these changes, the authors performed a retrospective analysis of 12 patients with CHRPE, for whom fluorescein angiography allowed visualization of the entire lesion and of the retinal vascular capillary bed. RESULTS: Retinal vascular changes were found in 11 (91%) of these 12 patients. The changes consisted of capillary rarefaction in all 11 patients, with areas of capillary nonperfusion exceeding 1 disc diameter (DD) in three patients (25%), micro-aneurysmal capillary dilatations in three (25%), and chorioretinal anastomosis in one. CONCLUSION: These results suggest that the above changes could constitute clinical and angiographic characteristics of CHRPE and allow easy corroboration of its diagnosis, thus avoiding the need for further clinical investigations.

The dark choroid in systemic argyrosis.

Argyrosis is a cutaneous discoloration caused by silver. Ocular involvement, including conjunctival and corneal discoloration, has been previously reported. To our knowledge, a retinal involvement was never reported and no data is available about fluorescein angiography patterns of patients with argyrosis. Fluorescein angiography was performed in six consecutive patients with iatrogenic systemic argyrosis. A dark choroid was observed in each case. Red light monochromatic pictures disclosed a leopard spot pattern on the fundus, which was more clearly revealed in one patient by infrared light pictures. These findings suggest that the silver deposit in Bruch's membrane may be responsible for the obscuration of choroidal fluorescence during dye transit and for the visualization of choriocapillary units in pictures using long-wavelength light. The dark choroid is not only present in central retinal dystrophies, but may be observed in other conditions, such as systemic argyrosis.