Pigment epithelium-Bruch's Membrane Research Articles

Temporal Changes in the Retinal Pigment Epithelium-Bruch's Membrane Complex Thickness After Autologous Retinal Transplantation in Myopic Eyes.

To investigate the association between the thickness of the retinal pigment epithelium (RPE)-Bruch's membrane (BM) complex and the development of retinal autograft edema as a postoperative complication following autologous retinal transplantation (ART). This retrospective study examined data from 28 eyes of 28 patients (14 males, 14 females; mean age, 61.5 ± 19.8 years) who underwent ART and were followed for 1 year. The RPE-BM complex thickness was measured 2000 µm from the fovea using Image J software. Additionally, the graft blood flow was also evaluated by optical coherence tomography angiography and fluorescein angiography. Macular hole (MH) diameters ranged from 711.2 ± 251.9 µm to 1299.9 ± 333.0 µm, with MH closure achieved in all patients. RPE-BM complex thickness decreased by 4.17 µm at 6 months and 4.34 µm at 1 year, showing significant differences from preoperative measurements (29.88 ± 4.99 µm; 6 months: 95% confidence interval [CI], 1.62-6.71, P = 0.0018; 1 year: 95% CI, 2.03-6.65 µm, P = 0.00044). The decrease was significantly greater in the edema-positive group (95% CI, -8.33 to -0.82, P = 0.020). Furthermore, the rates of ellipsoid zone (EZ) recovery, alignment of neurosensory layers (ANL), and graft reperfusion were lower in the edema-positive group (EZ, P = 0.017; ANL, P = 0.0098; reperfusion, P = 0.039). After ART, RPE-BM complex thickness decreases, particularly in cases with postoperative edema, suggesting a potential relationship between RPE function and postoperative outcomes, highlighting the importance of monitoring RPE-BM complex thickness after surgery.

OCT Changes Observed during the Progression of Early Age-Related Macular Degeneration

Automated retinal cell layer segmentation empowers OCT as a precise tool for characterizing morphologic features of retinal health throughout age-related macular degeneration (AMD) progression, particularly in advance of more visible biomarkers such as drusen and macular pigmentary changes. Few studies have examined OCT changes in eyes progressing from early to intermediate disease, or combined examinations of cell layer thickness, reflectivity, and heterogeneity. Therefore, this study analyzed OCTs from eyes progressing from early to intermediate AMD to identify changes in retinal morphology and reflectivity that may serve as biomarkers of early progression. Retrospective cohort study. Patients ≥50 years with a diagnosis of AMD and with high-quality ipsilateral OCTs in both early and intermediate stage disease. Fifty OCTs from 25 patients were automatically segmented using a previously validated artificial intelligence-driven algorithm. Changes in the mean and standard deviation of cell layer thickness and reflectivity with progression through stages were calculated for 90 retinal volumes with the help of a novel Python-based analysis tool. The primary outcomes were significant changes to cell layer thickness, reflectivity, and heterogeneity with progression of AMD. With progression from early to intermediate disease, photoreceptor outer segments diffusely thinned. Within the ellipsoid zone, the fovea and parafovea were thinned with a simultaneous increase in thickness variability and a decrease in parafoveal reflectivity. The retinal pigment epithelium-Bruch's membrane complex underwent diffuse thickening and increased thickness variability alongside a decrease in foveal and parafoveal reflectivity. These findings correlate with the known histopathology of early AMD and identify measurable OCT trends through the earliest stages of disease. Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Outer Retinal Thickness Is Associated With Cognitive Function in Normal Aging to Intermediate Age-Related Macular Degeneration.

Research on Alzheimer's disease (AD) and precursor states demonstrates a thinner retinal nerve fiber layer (NFL) compared to age-similar controls. Because AD and age-related macular degeneration (AMD) both impact older adults and share risk factors, we asked if retinal layer thicknesses, including NFL, are associated with cognition in AMD. Adults ≥ 70 years with normal retinal aging, early AMD, or intermediate AMD per Age-Related Eye Disease Study (AREDS) nine-step grading of color fundus photography were enrolled in a cross-sectional study. Optical coherence tomography (OCT) volumes underwent 11-line segmentation and adjustments by a trained operator. Evaluated thicknesses reflect the vertical organization of retinal neurons and two vascular watersheds: NFL, ganglion cell layer-inner plexiform layer complex (GCL-IPL), inner retina, outer retina (including retinal pigment epithelium-Bruch's membrane), and total retina. Thicknesses were area weighted to achieve mean thickness across the 6-mm-diameter Early Treatment of Diabetic Retinopathy Study (ETDRS) grid. Cognitive status was assessed by the National Institutes of Health Toolbox cognitive battery for fluid and crystallized cognition. Correlations estimated associations between cognition and thicknesses, adjusting for age. Based on 63 subjects (21 per group), thinning of the outer retina was significantly correlated with lower cognition scores (P < 0.05). No other retinal thickness variables were associated with cognition. Only the outer retina (photoreceptors, supporting glia, retinal pigment epithelium, Bruch's membrane) is associated with cognition in aging to intermediate AMD; NFL was not associated with cognition, contrary to AD-associated condition reports. Early and intermediate AMD constitute a retinal disease whose earliest, primary impact is in the outer retina. Our findings hint at a unique impact on the brain from the outer retina in persons with AMD.

Quantification of choroidal hyperreflective layer: A swept-source optical coherence tomography study.

To investigate variation in reflectivity of choroidal layers in normal eyes. From the swept-source optical coherence tomography database, we retrospectively included eyes with a normal fundus. Choroidal reflectivity was measured on the horizontal and vertical B-scan optical coherence tomography images. The optical barrier of the choroid was defined as the first hill in the middle of the reflectance graph from the retinal pigment epithelium-Bruch's membrane complex to the chorioscleral junction. The optical barrier of the choroid was identified in 91 eyes of 91 individuals. The amplitude of peak reflectivity of the optical barrier of the choroid at macular center (142.85 ± 15.04) was greater than those in superior (136.12 ± 14.08) or inferior macula (135.30 ± 16.13) (P = 0.028, P = 0.008, respectively). Latency between the peak of the retinal pigment epithelium-Bruch's membrane complex and the optical barrier of the choroid at macular center (48.11 ± 13.78 μm) was shorter than those in nasal macula (55.58 ± 19.21 μm) (P = 0.021). The amplitude of the peak reflectivity of the optical barrier of the choroid in the center negatively correlated with the latency between the retinal pigment epithelium-Bruch's membrane complex and the optical barrier of the choroid (P < 0.001). An optical barrier exists in the inner choroid of the normal eye. Its depth depends on the location within the macula. Further studies are mandatory to evaluate variations in the barrier in the eyes with chorioretinal disease.

Retinal pigment epithelium-Bruch's membrane volume in grading of age-related macular degeneration.

To assess the agreement of optical coherence tomography (OCT) algorithm-based retinal pigment epithelium -Bruch's membrane complex volume (RBV) with fundus photograph-based age-related macular degeneration (AMD) grading. Digital color fundus photographs (CFPs) and spectral domain OCT images were acquired from 96 elderly subjects. CFPs were graded according to Age-Related Eye Disease Study (AREDS) classification. OCT image segmentation and RBV data calculation were done with Orion™ software. Univariate and multivariate analyses were performed to find out whether AMD lesion features associated with higher RBVs. RBV correlated with AMD grading (rs=0.338, P=0.001), the correlation was slightly stronger in early AMD (n=52; rs=0.432, P=0.001). RBV was higher in subjects with early AMD compared with those with no AMD lesions evident in fundus photographs (1.05±0.20 vs 0.96±0.13 mm3, P=0.023). In multivariate analysis higher RBVs were associated significantly with higher total drusen (β=0.388, P=0.027) and pigmentation areas (β=0.319, P=0.020) in fundus photographs, whereas depigmentation area (β=-0.295, P=0.015) associated with lower RBV. RBV correlate with AMD grading status, with a stronger association in patients with moderate, non-late AMD grades. This effect is driven mostly by lesions with drusen or pigmentation. Lesions with depigmentation tend to have lower values. RBV is more comprehensive measurement of the key area of AMD pathogenesis, compared to sole drusen volume analysis. RBV measurements are independent on grader variations and offer a possibility to quantify early and middle grade AMD lesions in a research setting, but may not substitute fundus photograph-based grading in the whole range of AMD spectrum.

Review of Retinal Imaging Modalities for Hydroxychloroquine Retinopathy.

This review provides an overview of conventional and novel retinal imaging modalities for hydroxychloroquine (HCQ) retinopathy. HCQ retinopathy is a form of toxic retinopathy resulting from HCQ use for a variety of autoimmune diseases, such as rheumatoid arthritis and systemic lupus erythematosus. Each imaging modality detects a different aspect of HCQ retinopathy and shows a unique complement of structural changes. Conventionally, spectral-domain optical coherence tomography (SD-OCT), which shows loss or attenuation of the outer retina and/or retinal pigment epithelium-Bruch's membrane complex, and fundus autofluorescence (FAF), which shows parafoveal or pericentral abnormalities, are used to assess HCQ retinopathy. Additionally, several variations of OCT (retinal and choroidal thickness measurements, choroidal vascularity index, widefield OCT, en face imaging, minimum intensity analysis, and artificial intelligence techniques) and FAF techniques (quantitative FAF, near-infrared FAF, fluorescence lifetime imaging ophthalmoscopy, and widefield FAF) have been applied to assess HCQ retinopathy. Other novel retinal imaging techniques that are being studied for early detection of HCQ retinopathy include OCT angiography, multicolour imaging, adaptive optics, and retromode imaging, although further testing is required for validation.

CLINICAL CHARACTERISTICS OF STREAKY MULTIFOCAL CHOROIDITIS: A Subtype of Multifocal Choroiditis.

To describe and analyze clinical characteristics of multifocal choroiditis with linear streaks (LSs). Eight cases of multifocal choroiditis with LSs were retrospectively studied. Multimodal imaging was performed. Demographic data and spherical equivalent were collected. Axial length was measured. All cases are young myopic women with a mean age of 17.13 ± 3.64 years (range, 13-23 years), presenting with vision loss and distortion. Nine eyes with LSs were high myopia of -8.97 ± 2.69 D (range, -6.00 to 12.5 D; growing by 1.88 ± 0.61 D annually since wearing glasses), with mean axial length of 26.36 ± 1.71 mm. Vitreous cells were noted in seven eyes. LSs were located in the equator (eight eyes), around the optic disk (three eyes), and at the edge of the posterior pole (one eye). Angio-optical coherence tomography showed choroidal neovascularization in eight eyes, especially 2 to 3 choroidal neovascularizations in three eyes. The location of choroidal neovascularization were in subfovea (three eyes), parafovea (six eyes), and perifovea (two eyes). Swept source optical coherence tomography showed punched-out disruption of retinal pigment epithelium‒Bruch's membrane‒choriocapillaris complex at the LSs' sites. LSs showed fluorescence staining on late FA but hypofluorescence throughout all phases on ICGA. Multifocal choroiditis with LSs mostly occurs in young women with high myopia, especially occurring in eyes with rapid progression of myopia. LSs are mainly located in the midperiphery near the equator, being prone to concur with choroidal neovascularization. Based on our findings, we propose a new term called "streaky multifocal choroiditis" as a subtype of multifocal choroiditis.

Clinical Evaluation of an Instrument-Integrated OCT-Based Distance Sensor for Robotic Vitreoretinal Surgery

PurposeTo assess the efficacy of an instrument-integrated OCT (iiOCT)-based distance sensor during robotic vitreoretinal surgery using the Preceyes Surgical System (PSS; Preceyes B.V.).DesignSingle-center interventional study.ParticipantsPatients requiring vitreoretinal surgery.MethodsFive patients were enrolled. Standard preoperative OCT images were obtained. After vitrectomy, a predefined set of actions was performed using the iiOCT-based sensor. Images then were processed to assess the signal-to-noise ratio (SNR) at various angles to the retina and at different distances between the instrument tip and the retinal surface. Preoperative and intraoperative OCT images were compared qualitatively and quantitatively.Main Outcomes MeasuresThe feasibility in performing surgical tasks using the iiOCT-based sensor during vitreoretinal surgery, the SNR when imaging the retina, differences among intraoperative and preoperative OCT images, and characteristics of intraoperative retinal movements detected with the iiOCT-based probe.ResultsSurgeons were able to perform all the tasks but one. The PSS was able to maintain a fixed distance. The SNR of the iiOCT-based sensor signal was adequate to determine the distance to the retina and to control the PSS. Analysis of iiOCT-based sensor A-scans identified 3 clearly distinguishable retinal layers, including the inner retinal boundary and the interface at the retinal pigment epithelium–Bruch’s membrane. Thickness values differed by less than 5% from that measured by preoperative OCT, indicating its accuracy. The Fourier analysis of iiOCT-based sensor recordings identified anteroposterior retinal movements attributed to heartbeat and respiration.ConclusionsThis iiOCT-based sensor was tested successfully and promises reliable use during robot-assisted surgery. An iiOCT-based sensor is a promising step toward OCT-guided robotic retinal surgery.

Inflammatory retinal and choroidal neovascularization in a case of post-fever immune retinitis

The development of retinal and choroidal neovascularization in posterior uveitis is attributed to the angio-inflammatory drive with/without ruptures in the retinal pigment epithelium-Bruch's membrane complex. We report a unique case of a 15-year-old Asian-Indian female who developed immune retinitis post-typhoid fever along with simultaneous retinal and choroidal neovascularization. After ruling out infectious etiologies, she was initiated on a course of systemic steroids considering that the retinitis had immune-mediated pathogenesis. Subsequently, the retinitis lesion and choroidal neovascular membrane healed with scarring while the retinal neovascular complex showed fibrotic regression.

Presumed Natural History of Combined Hamartoma of the Retina and Retinal Pigment Epithelium

To correlate structural changes of combined hamartoma of the retina and retinal pigment epithelium (CHRRPE) with patient age. Retrospective study. Fifty eyes of 49 patients (age range, 1-74 years) with CHRRPE studied at 9 tertiary vitreoretinal institutions. We analyzed the clinical findings with respect to lesion topography and pigmentation as well as investigated the OCT findings regarding the thickness, vitreoretinal interface, outer plexiform layer distortion, ellipsoid zone disruption, and retinal pigment epithelium-Bruch's membrane complex involvement of CHRRPE. Clinical and imaging findings of CHRRPE at different ages. Analysis of 50 CHRRPE patients revealed that younger patients were more likely to demonstrate partial thickness involvement of the retina (P= 0.009) with predominantly inner retinal layer involvement (P=0.04). The inverse was true for older patients with CHRRPE. In addition, older patients more commonly showed pigmentary changes. Eyes with CHRRPE were more likely to show an increase in central macular thickness independently of tumor location. Based on these findings, we believe that CHRRPE typically begins in the inner retina and continues toward the outer retina over time, with increase in central macular thickness, despite the location of the tumor.

Multimodal Imaging for Differential Diagnosis of Bietti Crystalline Dystrophy

To evaluate the diagnostic usefulness of multimodal imaging in patients with Bietti crystalline dystrophy (BCD). Retrospective cross-sectional study. Patients with chorioretinal dystrophy accompanied by crystalline-like deposits. The right eyes of the patients were analyzed. Fundus photograph, near-infrared reflectance (NIR), fundus autofluorescence (FAF), and OCT images were evaluated. Presence of hyperreflectivity on NIR, well-demarcated areas of decreased FAF, hyperreflective material at or on the retinal pigment epithelium-Bruch's membrane complex, and outer retinal tubulation were graded for each patient. All exons and franking introns of CYP4V2 were screened using Sanger sequencing. Sensitivity and specificity of the findings to discriminate patients with and without CYP4V2 mutation. In total, 33 patients were included in the study. Sanger sequencing revealed homozygous or compound heterozygous CYP4V2 mutations in 20 patients and heterozygous mutations in 2 patients. Among the investigated factors, hyperreflective appearance on NIR imaging yielded 100% sensitivity and 100% specificity in this cohort. The presence of outer retinal tubulation also was sensitive (95%), but specificity was moderate (45%). The revised diagnoses of patients without CYP4V2 mutations included retinitis pigmentosa, late-onset macular dystrophy, and central areolar choroidal dystrophy. Multimodal imaging, especially NIR imaging, is useful to differentiate BCD patients with CYP4V2 mutations from patients with other chorioretinal dystrophies accompanied by crystalline-like retinal deposits.

Quantitative autofluorescence and cell density maps of the human retinal pigment epithelium.

Lipofuscin (LF) accumulation within RPE cells is considered pathogenic in AMD. To test whether LF contributes to RPE cell loss in aging and to provide a cellular basis for fundus autofluorescence (AF) we created maps of human RPE cell number and histologic AF. Retinal pigment epithelium-Bruch's membrane flat mounts were prepared from 20 donor eyes (10 ≤ 51 and 10 > 80 years; postmortem: ≤4.2 hours; no retinal pathologies), preserving foveal position. Phalloidin-binding RPE cytoskeleton and LF-AF (488-nm excitation) were imaged at up to 90 predefined positions. Maps were assembled from 83,330 cells in 1470 locations. From Voronoi regions representing each cell, the number of neighbors, cell area, and total AF intensity normalized to an AF standard was determined. Highly variable between individuals, RPE-AF increases significantly with age. A perifoveal ring of high AF mirrors rod photoreceptor topography and fundus-AF. Retinal pigment epithelium cell density peaks at the fovea, independent of age, yet no net RPE cell loss is detectable. The RPE monolayer undergoes considerable lifelong re-modeling. The relationship of cell size and AF, a surrogate for LF concentration, is orderly and linear in both groups. Autofluorescence topography differs distinctly from the topography of age-related rod loss. Digital maps of quantitative AF, cell density, and packing geometry provide metrics for cellular-resolution clinical imaging and model systems. The uncoupling of RPE LF content, cell number, and photoreceptor topography in aging challenges LF's role in AMD.

Optical Coherence Tomography Shape Analysis of the Peripapillary Retinal Pigment Epithelium Layer in Presumed Optic Nerve Sheath Meningiomas

Geometric morphometrics (GM) was used to compare the shape of the peripapillary retinal pigment epithelium-Bruch's membrane (ppRPE) layer imaged on spectral domain optical coherence tomography (SD-OCT) of patients with presumed optic nerve sheath meningiomas (pONSM) and normal subjects. We compared 2 groups: 30 normals to 10 patients (11 eyes) with pONSM. We digitized 20 equidistant semi-landmarks on OCT images of the ppRPE-layer, spanning 2500 μm on each side of the neural canal opening (NCO). Data were analyzed using standard GM techniques including a generalized least squares Procrustes superimposition, principal component analysis (PCA), thin-plate spline, and permutation statistical analysis to evaluate differences in shape. We also analyzed other variables with respect to shape including tumor size-proximity to the globe, age, retinal nerve fiber layer, and optic disc height. All pONSM patients were female (age 37-66 years); 10 had unilateral and 1 had bilateral optic nerve involvement. Ten of the eyes had optic disc edema at presentation, 4 went on to develop shunt vessels, and 4 had optic atrophy. The ppRPE-layer bordering the NCO in normals is V-shaped pointing away from the vitreous; the ppRPE-layer in pONSM is indented causing an inverted-U shaped deformation skewed nasally toward the vitreous. PCA showed a significant difference between normals and pONSM (permutation, n = 10,000, P = 0.001). The size and proximity of the tumor to the globe correlates with the shape of the ppRPE-layer (r = 0.75, P = 0.04). Correlation between shape variables and RNFL thickening (r = 0.51), optic disc height (r = 0.67), and age (r = 0.67) were not statistically significant. The shape of the RPE layer in pONSM is characterized by an inverted-U shape or indentation that differs significantly from normals. It is indistinguishable from the shape we previously reported in papilledema and is not caused by disc edema. The mechanism in pONSM is unknown but may involve a change in the compliance of the nerve and/or localized sequestration of cerebrospinal fluid in the distal optic nerve sheath.

Evaluation of retinal pigment epithelium–Bruch's membrane complex thickness in dry age-related macular degeneration using optical coherence tomography

AimTo compare retinal pigment epithelium–Bruch's membrane (RPE–BM) complex thickness in patients with early and intermediate dry age-related macular degeneration (AMD) and age-matched controls using spectral domain optical coherence tomography (SD-OCT).MethodsIn...

Shape Analysis of the Peripapillary RPE Layer in Papilledema and Ischemic Optic Neuropathy

Geometric morphometrics (GM) was used to analyze the shape of the peripapillary retinal pigment epithelium-Bruch's membrane (RPE/BM) layer imaged on the SD-OCT 5-line raster in normal subjects and in patients with papilledema and ischemic optic neuropathy. Three groups of subjects were compared: 30 normals, 20 with anterior ischemic optic neuropathy (AION), and 25 with papilledema and intracranial hypertension. Twenty equidistant semilandmarks were digitized on OCT images of the RPE/BM layer spanning 2500 μm on each side of the neural canal opening (NCO). The data were analyzed using standard GM techniques, including a generalized least-squares Procrustes superimposition, principal component analysis, thin-plate spline (to visualize deformations), and permutation statistical analysis to evaluate differences in shape variables. The RPE/BM layer in normals and AION have a characteristic V shape pointing away from the vitreous; the RPE/BM layer in papilledema has an inverted U shape, skewed nasally inward toward the vitreous. The differences were statistically significant. There was no significant difference in shapes between normals and AION. Pre- and posttreatment OCTs, in select cases of papilledema, showed that the inverted U-shaped RPE/BM moved posteriorly into a normal V shape as the papilledema resolved with weight loss or shunting. The shape difference in papilledema, absent in AION, cannot be explained by disc edema alone. The difference is a consequence of both the translaminar pressure gradient and the material properties of the peripapillary sclera. GM offers a novel way of statistically assessing shape differences of the peripapillary optic nerve head.

Choroidal neovascularization in a patient with blunt trauma-caused traumatic retinopathy without choroidal rupture

To report a case of choroidal neovascularization (CNV) following blunt trauma without choroidal rupture, with past history of central serous chorioretinopathy (CSC). A 43-year-old man with a nonperforating injury caused by a baseball that hit his right eye exhibited traumatic retinopathy. The damage was localized to the outer layer of the retina at the macula and there was no choroidal rupture. Five years prior to the accident, the patient suffered from a CSC attack with retinal pigment epithelium detachment. Two weeks after the blunt trauma, fundus examination revealed CNV extending into the subfoveal space, which led to an abrupt development of retinal hemorrhage and serous retinal detachment at the macula. Intravitreal injection of bevacizumab led to the resolution of retinal detachment 15 days later, with complete absorption of retinal hemorrhage 41 days later. Fluorescein angiography performed 2 months later revealed hyperfluorescent points with no leakage. CNV following blunt trauma in this case occurred in traumatic retinopathy, with the damage localized in the outer layer of the retina. This suggests that the retinal pigment epithelium-Bruch's membrane complex developed susceptibility to anteroposterior forces, which is subsequent to the spontaneous healing of CSC. Bevacizumab treatment also reduced exudation from CNV.

SPECTRAL DOMAIN OPTICAL COHERENCE TOMOGRAPHY CHARACTERISTICS OF CUTICULAR DRUSEN

To evaluate the appearance of cuticular drusen with spectral domain optical coherence tomography. Eyes of patients with cuticular drusen were imaged using a prototype spectral domain optical coherence tomography instrument with 5-microm axial resolution. Thickness maps were obtained after automated segmentation of the internal limiting membrane and retinal pigment epithelium layers using a proprietary algorithm. The volume of subretinal fluid (SRF) was calculated using a manual segmentation technique that involved drawing boundaries around the SRF. The repeatability of these measurements was tested by comparing the volume measurements from multiple scans performed on the same day in four eyes of three patients. Sixteen eyes from eight patients with cuticular drusen were scanned. Areas of decreased retinal thickness overlying drusen were best visualized using the three-dimensional retinal thickness map. The distribution and sawtooth pattern of cuticular drusen were best visualized using three-dimensional retinal pigment epithelium segmentation. Of the 16 eyes, 13 had SRF within the macula. In the eyes with macular SRF, characteristic excrescences were present along the outer retina and attenuation of the photoreceptor inner and outer segment boundary were observed in many areas. In areas where the retina was detached, the retinal pigment epithelium-Bruch's membrane complex appeared nodular or attenuated. The volumetric measurements of the SRF were performed using a manual segmentation with a 1.11% mean difference between repeated measurements on the same day (range, 0.47-1.68%; standard deviation, 0.55%). The sawtooth pattern of drusen and the presence of excrescences along the detached outer retina are characteristic features of cuticular drusen that should be helpful in confirming the diagnosis of this condition. The volumetric analysis of the SRF is repeatable and may be useful in following the clinical course of these patients.

Visual Results after Surgical Removal of Subfoveal Choroidal Neovascular Membranes

The authors report their experience with the surgical removal of subfoveal choroidal neovascularization. Correlations between preoperative characteristics and final postoperative visual acuity are explored. A retrospective study of 159 consecutive patients was performed between February 1990 and August 1993. Follow-up of 2 or more months was available for 147 eyes: presumed ocular histoplasmosis syndrome, 67 eyes; age-related macular degeneration, 41 eyes; myopia, 10 eyes; multifocal choroiditis, 9 eyes; idiopathic, 8 eyes; angioid streaks, 4 eyes; and miscellaneous, 8 eyes. Sixty-seven eyes had presumed ocular histoplasmosis syndrome: mean follow-up was 10.5 months. Visual acuity was stable or improved in 56 (83%) eyes and 20/40 or greater in 21 (31%) eyes. Mean interval to best visual acuity was 3 months. A recurrence rate of 37% had no significant effect on final visual outcome (P = 0.952). Forty-one eyes had age-related macular degeneration: mean follow-up was 15 months. Visual acuity was improved in only five (12%) eyes and was 20/40 or greater in only two (5%) eyes. The interval to best visual acuity was 5 months. A recurrence rate of 27% had not significant effect on final visual outcome (P = 0.31). The visual results and recurrence rates for eyes with less common disorders are presented. The surgical excision of subfoveal choroidal neovascularization may stabilize or improve visual acuity in selected cases. Patients with focal disorders of the retinal pigment epithelium-Bruch's membrane complex appear to have a better surgical outcome than those with diffuse disease.

Subretinal Endophotocoagulation in the Treatment of Choroidal Neovascularization

The development of subfoveal choroidal neovascularization is a major cause of visual loss in age-related macular degeneration and other disorders of the retinal pigment epithelium-Bruch's membrane complex. We designed a new subretinal laser delivery system and used it to treat subfoveal neovascular membranes in three eyes with age-related macular degeneration. Preoperative visual acuities were 20/200, 20/80, and 20/300, respectively. With a mean follow-up of seven months, postoperative visual acuities were 20/80, 20/400, and 20/300, respectively. One eye developed recurrent neovascularization, which was adequately treated with slit lamp-delivered laser photocoagulation. Another eye continued to lose visual acuity because of progressive atrophy of the retinal pigment epithelium. Although ablation of choroidal neovascular membranes was possible with this technique, visual results were disappointing, probably because of damage of the underlying retinal pigment epithelium and choriocapillaris.

Phenotypic similarities between Stargardt's flavimaculatus and pattern dystrophies.

Some heredomacular diseases share ophthalmoscopic and morphologic similarities despite being nosologically distinct. In part, this may arise from pathologic reaction patterns such as lipopigment accumulation and drusen deposition which are common to a variety of disorders of the photoreceptor--retinal pigment epithelium--Bruch's membrane complex. Two of these disorders, Stargardt's flavimaculatus and the pattern dystrophies of the retinal pigment epithelium may be especially difficult to differentiate clinically since they are characterised by both a similar ophthalmoscopic appearance and considerable inter and intrafamilial variation in their expression. Stargardt's flavimaculatus may, however, be distinguished from the retinal pigment epithelial pattern dystrophies by certain clinical and morphological features that are outlined below.