High Dynamic Range Image Processing for Retinal Color Fundus Photography.

BACKGROUND AND OBJECTIVE: Color fundus photography is an important imaging modality that is currently limited by a narrow dynamic range. We describe a post-image processing technique to generate high dynamic range (HDR) retinal images with enhanced detail. PATIENTS AND METHODS: This was a retrospective, observational case series evaluating fundus photographs of patients with macular pathology. Photographs were acquired with three or more exposure values using a commercially available camera (Topcon 50-DX). Images were aligned and imported into HDR processing software (Photomatix Pro). Fundus detail was compared between HDR and raw photographs. RESULTS: Sixteen eyes from 10 patients (5 male, 5 female; mean age 59.4 years) were analyzed. Clinician graders preferred the HDR image 91.7% of the time (44/48 image comparisons), with good grader agreement (81.3%, 13/16 eyes). CONCLUSIONS: HDR fundus imaging is feasible using images from existing fundus cameras and may be useful for enhanced visualization of retinal detail in a variety of pathologic states. [Ophthalmic Surg Lasers Imaging Retina 2024;55:XX-XX.].

Surgical Management of Full-Thickness Macular Holes in Macular Telangiectasia Type 2: A Global Multicenter Study.

PURPOSE: To report on macular hole repair in macular telangiectasia type 2 (MacTel2). DESIGN: Global, multicenter, retrospective case series. PARTICIPANTS: Patients undergoing surgery for MacTel2-associated full-thickness macular hole (MTMH). METHODS: Standardized data collection sheet distributed to all surgeons. MAIN OUTCOME MEASURES: Anatomic closure and visual outcomes of MTMH. RESULTS: Sixty-three surgeries in 47 patients with MTMH were included from 30 surgeons. Mean age was 68.1 years, with 62% female, 72% White, 21% East or South Asian, 2% African American, and 2% Hispanic or Latino. Procedures included 34 internal limiting membrane (ILM) peeling alone, 22 ILM flaps, 5 autologous retinal transplantations (ARTs), 1 retinotomy, and 1 subretinal bleb. For ILM peeling, preoperative visual acuity (VA) was 0.667 ± 0.423 logarithm of the minimum angle of resolution (logMAR). Minimum hole diameter (MHD) was 305.5 ± 159.4 µm (range, 34-573 µm). Sixteen of 34 ILM peels (47%) resulted in MTMH closure. At postoperative month 6, VA was stable at 0.602 ± 0.516 logMAR (P = 0.65). VA improved by at least 2 lines in 43% and at least 4 lines in 24%. For ILM flaps, preoperative VA was 0.878 ± 0.552 logMAR. MHD was 440.8 ± 175.5 µm (range, 97-697 µm), which was significantly larger than for ILM peels (P < 0.01). Twenty of 22 ILM flaps (90%) resulted in MTMH closure, which was significantly higher than for ILM peels (P < 0.01). At postoperative month 6, VA improved to 0.555 ± 0.405 logMAR (P < 0.05). VA improved by at least 2 lines in 56% and at least 4 lines in 28%. For ARTs, preoperative VA was 1.460 ± 0.391 logMAR. MHD was 390.2 ± 203.7 µm (range, 132-687 µm). All 5 ARTs (100%) resulted in MTMH closure. At postoperative month 6, VA was stable at 1.000 ± 0.246 logMAR (P = 0.08). Visual acuity improved at least 2 lines in 25%. CONCLUSIONS: Surgical closure of macular holes improved VA in 57% of MTMHs. Internal limiting membrane flaps achieved better anatomic and functional outcomes than ILM peeling alone. Autologous retinal transplantation may be an option for refractory MTMHs. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Modeling rod and cone photoreceptor cell survival in vivo using optical coherence tomography.

Many retinal diseases involve the loss of light-sensing photoreceptor cells (rods and cones) over time. The severity and distribution of photoreceptor loss varies widely across diseases and affected individuals, so characterizing the degree and pattern of photoreceptor loss can clarify pathophysiology and prognosis. Currently, in vivo visualization of individual photoreceptors requires technology such as adaptive optics, which has numerous limitations and is not widely used. By contrast, optical coherence tomography (OCT) is nearly ubiquitous in daily clinical practice given its ease of image acquisition and detailed visualization of retinal structure. However, OCT cannot resolve individual photoreceptors, and no OCT-based method exists to distinguish between the loss of rods versus cones. Here, we present a computational model that quantitatively estimates rod versus cone photoreceptor loss from OCT. Using histologic data of human photoreceptor topography, we constructed an OCT-based reference model to simulate outer nuclear layer thinning caused by differential loss of rods and cones. The model was able to estimate rod and cone loss using in vivo OCT data from patients with Stargardt disease and healthy controls. Our model provides a powerful new tool to quantify photoreceptor loss using OCT data alone, with potentially broad applications for research and clinical care.

Xp11.3 microdeletion causing Norrie disease and X-linked Kabuki syndrome.

Purpose: To describe a novel case of Norrie disease and X-linked Kabuki syndrome caused by a microdeletion encompassing multiple genes on the X chromosome. Observations: A 3-day-old boy born at full term had bilateral retrolental fibrovascular plaques. Surgery with lensectomy and vitrectomy revealed bilateral, closed funnel retinal detachments consistent with a clinical diagnosis of Norrie disease. In addition, the baby had congenital heart defects, hearing loss, and dysmorphic facies. His mother carried a clinical diagnosis of Kabuki syndrome. Genetic testing of the baby revealed an Xp11.3 microdeletion that included the NDP and KDM6A genes, confirming the baby had both Norrie disease and X-linked Kabuki syndrome. The mother was found via ultrawide-field fluorescein angiography to have asymptomatic peripheral retinal vascular anomalies, consistent with NDP-associated familial exudative vitreoretinopathy (FEVR). Conclusions and importance: This is the first reported case of Norrie disease together with X-linked Kabuki syndrome. Contiguous gene deletions may explain some of the variable systemic involvement in Norrie disease.

Choroidal Neovascularization Is Common in Best Vitelliform Macular Dystrophy and Plays a Role in Vitelliform Lesion Evolution.

OBJECTIVE: Choroidal neovascularization (CNV) is usually considered to be a late-stage complication in Best vitelliform macular dystrophy (BVMD) and can be difficult to diagnose with fluorescein angiography. This study used swept-source (SS) OCT angiography (OCTA) to evaluate the prevalence of CNV in BVMD, identify structural features associated with CNV, and provide insight into the role of CNV in vitelliform lesion evolution. DESIGN: Institutional review board-approved, retrospective, cross-sectional, and longitudinal study. PARTICIPANTS: Patients with molecularly confirmed BVMD. METHODS: Charts from consecutive patients with BVMD imaged with SS-OCTA (PLEX Elite 9000, Carl-Zeiss Meditec Inc) at the University of Iowa from September 2017 to October 2021 were reviewed. Clinical data, including age, gender, best-corrected visual acuity (BCVA), and treatment with intravitreal anti-VEGF injections were recorded. The presence of CNV on SS-OCTA was determined by expert graders and correlated with structural features, such as interstitial fluid, subretinal fluid, nodular subretinal pillar, focal choroidal excavation (FCE), and subfoveal choroidal thickness, with a P value of < 0.05 considered statistically significant. MAIN OUTCOME MEASURES: Presence of CNV on SS-OCTA and correlation with structural features on SS-OCT. RESULTS: A total of 53 eyes from 27 patients (13 women; 48.1%) were included. The mean age was 45 years (range, 8-79 years), and the mean logarithm of the minimum angle of resolution BCVA was 0.38 (range, 0-1). Choroidal neovascularization was identified on SS-OCTA in 27 eyes (50.9%), of which 63.0% had a vitelliform (Gass stage 2) lesion. In 40.7% (11 of 27) of eyes, there was no prior clinical diagnosis of CNV. Other structural features associated with CNV included FCEs (15.1%, 8 of 53 eyes) and nodular pillars (15.1%, 8 of 53 eyes) (P < 0.01). Seven patients had available longitudinal imaging, and most of these patients had CNV visible on SS-OCTA (71.4%; 10 of 14 eyes). CONCLUSION: Choroidal neovascularization is common in BVMD, including in the early stages of the disease. The presence of FCEs or nodular pillars should heighten the clinical suspicion of CNV, which may accelerate vitelliform lesion evolution. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found after the references.