Reassessment of arterial versus venous perfusion of diabetic retinal neovascularization using ultrawide-field fluorescein angiography.

PURPOSE: The purpose of this study was to assess whether diabetic NV is perfused by the arterial or the venous circulation. METHODS: This is a retrospective, consecutive case series evaluating patients with proliferative diabetic retinopathy (PDR) imaged with ultrawide-field (UWF) fluorescein angiography (FA). Areas of neovascularization elsewhere (NVE) and neovascularization of the disc (NVD) were assessed. Perfusion was defined as arterial, arteriovenous, or venous if the area of diabetic neovascularization (NV) began to hyperfluoresce either prior, during, or after laminar venous flow, respectively. RESULTS: A total of 180 eyes from 176 patients with 928 NV were identified (830 NVE, 98 NVD). Of those, 5.1% of NVE were classified as arterial and 58.2% of NVD were classified as arterial. The remaining NV were classified as arteriovenous except for a small subset (6.1%) which were indeterminate. None of the NV were classified as venous. Noteworthy examples demonstrated NV that nearly fully perfused prior to any detectable fluorescence within nearby veins as well as clear shunting of blood from a feeding artery to a draining vein. CONCLUSIONS: UWF FA images suggest that some NV is perfused by retinal arteries. This may be useful in devising strategies for early detection and treatment of NV precursors. KEY MESSAGES: What is known • Diabetic retinal neovascularization has long been thought to be perfused by the retinal venous circulation. • Vascular endothelial growth factor has been shown to play key roles in both angiogenesis and arteriogenesis. What is new • Ultrawide-field fluorescein angiography demonstrates that at least some diabetic neovascularization is perfused by the retinal arterial circulation. • This supports the hypothesis that diabetic neovascularization may arise from arterially-perfused intraretinal microvascular abnormalities in the capillary bed.

Coats-Like Presentation of Familial Exudative Vitreoretinopathy Associated With a Novel LRP5 Variant.

This report describes a unique case of a Coats-like presentation of familial exudative vitreoretinopathy in an 11-year-old girl. The patient was originally referred for evaluation of presumed Coats disease and presented with telangiectatic vessels, perivascular exudates, diffuse peripheral exudation, and intraretinal hemorrhages. Clinical and angiographical findings were consistent with familial exudative vitreoretinopathy, while genetic testing identified variants of uncertain significance in two associated genes, LRP5 and ZNF408. In silico analysis predicts the LRP5 variant to be pathogenic. Retinal vasculopathies often have phenotypic overlap, warranting angiographic examination of both eyes and genetic testing to uncover the correct diagnosis and guide proper treatment. [Ophthalmic Surg Lasers Imaging Retina 2024;55:462-466.].

Self-Reported Perceptions of Preparedness among Incoming Ophthalmology Residents.

Purpose The purpose of this study was to assess the self-perceived preparedness of incoming postgraduate year 1 (PGY1) and postgraduate year 2 (PGY2) ophthalmology interns/residents to carry out core competencies in ophthalmology. Methods An online survey was created using the Survey Monkey survey platform and distributed to all ophthalmology resident applicants to the Bascom Palmer Eye Institute from the 2021 to 2022 and 2022 to 2023 application cycles. The survey contained questions pertaining to demographics, prior ophthalmic experience, online resources that were used to prepare for ophthalmology, and self-perceived preparedness to carry out key clinical skills in ophthalmology. Results A total of 170 responses were obtained (16.1% response rate). Of those, 119 (70%) were incoming PGY1 interns and 51 (30%) were incoming PGY2 residents for the 2022 to 2023 academic year. Most respondents (90.6%, n = 154) reported that their ophthalmology residency was affiliated with an integrated ophthalmology intern year. Incoming PGY2s moderately agreed with the statement that they felt as prepared to see patients in ophthalmology as they do in other surgical subspecialties, whereas incoming PGY1s only mildly agreed with that statement ( p = 0.003). Both incoming PGY1s and PGY2s felt most prepared to obtain histories relating to basic ophthalmic complaints and felt least prepared to read and interpret ophthalmic imaging studies. The most popular online resources used by respondents in order of popularity were EyeGuru (35.2%, n = 60), EyeWiki (32.9%, n = 56), Tim Root/OphthoBook (26.5%, n = 45), American Academy of Ophthalmology (13.5%, n = 23), and EyeRounds/University of Iowa (13.5%, n = 23). Conclusion A major challenge in integrating ophthalmic education into the medical school curricula is the gradual shift toward shorter preclinical curricula. However, having a core foundation of ophthalmic knowledge is critical for incoming ophthalmology residents to be able to maximize their specialty-specific training. Integrated ophthalmology intern years likely play a significant role in the increased self-efficacy of incoming PGY2s compared with incoming PGY1s. Adopting nontraditional teaching methods like flipped classroom learning, utilizing online medical education resources, and continuing to increase ophthalmology exposure during PGY1 year may better prepare incoming PGY2s to operate independently in ophthalmology settings.

The ophthalmology residency match: a new era.

PURPOSE OF REVIEW: The average number of applications per ophthalmology residency applicant continues to rise. The present article reviews the history and negative impacts of this trend, the dearth of effective solutions and the potential promise of preference signalling as an alternative strategy to address this and potentially improve match outcomes. RECENT FINDINGS: Application inflation adversely impacts applicants and programmes and undermines holistic review. Most recommendations to limit volume have been largely unsuccessful or undesirable. Preference signalling does not restrict applications. Early results from initial pilots in other specialties are promising. Signalling has the potential to facilitate holistic review, reduce interview hoarding and promote equitable distribution of interviews. SUMMARY: Preliminary data suggest preference signalling could be a useful strategy to address current issues with the Match. Building upon the blueprints and experiences of our colleagues, Ophthalmology should conduct its own investigation and consider a pilot project.

Endophthalmitis Associated With XEN Stent Implantation.

PURPOSE: The aim of this study is to report the clinical characteristics, causative organisms, and treatment outcomes in patients presenting with endophthalmitis related to XEN stent implants. DESIGN: Retrospective, noncomparative consecutive case series. METHODS: Clinical and microbiologic review was performed for 8 patients presenting to the Bascom Palmer Eye Institute Emergency Room between 2021 and 2022 with XEN stent-related endophthalmitis. Data collected included clinical characteristics of patients at presentation, organisms identified in ocular cultures, treatments received, and visual acuity at last follow-up. RESULTS: The current study included 8 eyes from 8 patients. All cases of endophthalmitis occurred >30 days after implantation of the XEN stent. At the time of presentation, there were external exposures of the XEN stent in 4 of 8 patients. Five of the 8 patients had positive intraocular cultures, all of which were variants of staphylococcus and streptococcus species. Management included intravitreal antibiotics in all patients, explantation of the XEN stent in 5 patients (62.5%), and pars plana vitrectomy in 6 patients (75%). At last follow-up, 6 of the 8 patients (75%) had a visual acuity of hand motion or worse. CONCLUSIONS: Endophthalmitis in the setting of XEN stents results in poor visual outcomes. The most common causative organisms are staphylococcus or streptococcus species. At time of diagnosis, prompt treatment with broad-spectrum intravitreal antibiotics is recommended. Consideration can be made to explant the XEN stent and perform early pars plana vitrectomy.

Smith-Lemli-Optiz syndrome: importance of ophthalmology referral and follow-up.

Smith-Lemli-Opitz syndrome (SLOS) is an autosomal recessive disorder caused by mutations in the 7-dehydrocholesterol reductase (DHCR7) gene, located on chromosomal region 11q13. This results in reduced cholesterol and increased 7-dehydrocholesterol (7DHC) levels. Accumulation of 7DHC in patients with SLOS can affect multiple organs and display a broad phenotypic expression. Ophthalmic abnormalities related to SLOS are variable but the most common is blepharoptosis. Over 50% of these patients present with self-injurious behavior, such as head banging, which can result in ocular complications and blindness. We report the first case of peripheral avascularity of the retina in a patient with SLOS. Physicians should be aware of the potential ocular complications associated with SLOS and confounding factors, such as prematurity, given that referral is usually delayed due to the lack of awareness of these potentially blinding associations. This case highlights the importance of early referral and continuous ophthalmologic follow-up in preventing further deterioration of visual development and complications that can lead to blindness.

Outcomes in Patients with Suprachoroidal Hemorrhage After Anterior Segment Surgery.

Objective: The purpose of the current study is to report outcomes of suprachoroidal hemorrhage (SCH) after anterior segment surgery at a single institution, and to identify clinical features associated with visual prognosis. Methods and Analysis: Retrospective consecutive case series of patients with SCH occurring after anterior segment surgery. Results: The study includes 112 eyes of 112 patients between 2014 and 2020. There were 76 cases of non-appositional SCH versus 36 cases of appositional SCH. The mean presenting visual acuity for patients with non-appositional versus appositional SCH was 2.03 logMAR (SD 0.78) versus 2.39 logMAR (SD 0.43), respectively. Visual acuity outcomes generally remained poor at last follow-up: 64 (58%) patients had a visual acuity (VA) of ≤ 20/200, including 19 (17%) with light perception (LP), and 11 (10%) with no light perception (NLP). Regarding management of non-appositional versus appositional SCH, observation was selected in 46 (61%) vs 12 (33%), delayed drainage in 14 (18%) vs 15 (42%), delayed pars plana vitrectomy in 16 (21%) vs 13 (36%), and VA at last follow-up was 1.2 versus 1.86 logMAR (p=0.002). In patients that were observed, both appositional SCH (p=0.01) and duration of apposition (p=0.04) were correlated with worse outcome. Conclusion: Appositional SCH was associated with poorer visual outcomes compared to non-appositional SCH. Observation remains a reasonable management strategy for non-appositional SCH.

Relative Postpartum Retinal Vasoconstriction Detected With Optical Coherence Tomography Angiography.

Purpose: To characterize changes in retinal perfusion during pregnancy and the postpartum period using optical coherence tomography angiography (OCTA). Methods: A nonmydriatic OCTA camera was used to image healthy women who were pregnant or in the postpartum period along with nonpregnant controls. Perfusion density (PD) and vessel length density (VLD) in the superficial capillary plexus (SCP), intermediate capillary plexus (ICP), and deep capillary plexus (DCP) were evaluated. Results: A total of 16, 15, and 13 eyes from nonpregnant, pregnant, and healthy postpartum subjects, respectively, were evaluated. When compared to controls, there were significant increases in ICP PD during the second and third trimester of pregnancy, along with significant decreases in both PD and VLD in SCP, ICP, and DCP up to 14 weeks postpartum. Conclusions: During pregnancy, vascular changes consistent with retinal vasodilation were noted in the ICP. During the postpartum period, changes in retinal vasculature suggest relative vasoconstriction involving all three layers when compared to both the pregnant and nonpregnant states. Translational Relevance: Detecting postpartum changes in retinal vasculature could offer important insights into postpartum physiology throughout the body.

Maternal Optical Coherence Tomography Angiography Changes Related to Small for Gestational Age Pregnancies.

Purpose: To study maternal retinal changes in pregnancies that resulted in a small for gestational age (SGA) infant. Methods: Pregnant women with SGA infants at birth and age-matched pregnant women with appropriate for gestational age (AGA) infants at birth (controls) were enrolled. All subjects underwent spectral domain optical coherent tomography angiography (OCTA) imaging using a 10° × 10° scan pattern centered on the fovea. Vessel density (VD) and vessel length density (VLD) of the superficial capillary plexus (SCP), intermediate capillary plexus (ICP), and deep capillary plexus (DCP) were analyzed and compared between the two groups. Results: Twelve eyes of eight subjects with SGA infants and 64 eyes of 44 age-matched subjects with AGA infants were included in this study. There was no significant difference in chronic hypertension (P = 1.0), gestational hypertension (P = 1.0), type 1/2 diabetes (P = 1.0), gestational diabetes (P = 0.97), or preeclampsia (P = 0.50) between the SGA group and AGA group. There were significant increases in both VD and VLD in the SCP and ICP layers when comparing the SGA group with the AGA group (P < 0.05). Conclusions: In this pilot study, subjects with SGA infants had increases in selective retinal vasculature layers that may represent systemic perfusion changes compensating for placental insufficiency. Translational Relevance: Additional assessment of maternal retinal changes in pregnancy using OCTA could prove the technology useful as a biomarker of fetal morbidity.

Characterization of Retinal Lesions Secondary to Hemophagocytic Lymphohistiocytosis With OCTA.

Hemophagocytic lymphohistiocytosis (HLH) is a high-mortality primary immunologic or genetic disorder that rarely presents with ocular symptoms. This is a case report of a 30-year-old Asian female with quiescent HLH in whom retinal lesions were identified during the third trimester of pregnancy. Multimodal imaging, including the first use of optical coherence tomography angiography (OCTA) in HLH, was used to characterize these lesions. OCTA was useful for distinguishing chronic ocular HLH from other uveitic syndromes affecting the retina. [Ophthalmic Surg Lasers Imaging Retina. 2019;50:653-655.].

Student-Written Multiple-Choice Questions-a Practical and Educational Approach.

The purpose of our student-led project was to fulfill junior medical students' demand for instructive, curriculum-specific practice questions while providing a learning experience and teaching opportunity for participating senior students. Eleven second-year students were taught how to write high-quality multiple-choice questions through an interactive workshop. Subsequently, they were instructed to write questions with detailed explanations for their assigned lecture topics. Thirty-four student-written and faculty-reviewed questions were combined with 16 purely faculty-written questions to create a 50-question exam. No significant difference was found in question difficulty between the student-written (79.5%) and faculty-written (84.0%) questions (p = 0.37). The discrimination index and point biserial correlation were higher for student-written (0.29, 0.32) vs. faculty-written (0.17, 0.25) questions (p < .01, < .05). The test-takers learned key course topics, while the test-writers reviewed key first-year objectives and refined their test-taking strategies. The project provided a model for feasibly developing comprehensive, high-quality, and curriculum-specific questions.

Elucidating the molecular basis of PPCD: Effects of decreased ZEB1 expression on corneal endothelial cell function.

PURPOSE: To investigate the functional role that the zinc e-box binding homeobox 1 (ZEB1) gene, which underlies the genetic basis of posterior polymorphous corneal dystrophy 3 (PPCD3), plays in corneal endothelial cell proliferation, apoptosis, migration, and barrier function. METHODS: A human corneal endothelial cell line (HCEnC-21T) was transfected with siRNA targeting ZEB1 mRNA. Cell proliferation, apoptosis, migration, and barrier assays were performed: Cell proliferation was assessed with cell counting using a hemocytometer; cell apoptosis, induced by either ultraviolet C (UVC) radiation or doxorubicin treatment, was quantified by measuring cleaved caspase 3 (cCASP3) protein levels; and cell migration and barrier function were monitored with electric cell-substrate impedance sensing (ECIS). RESULTS: ZEB1 knockdown in HCEnC-21T cells transfected with siRNA targeting ZEB1 did not result in a significant difference in cell proliferation when compared with control. Although knockdown of ZEB1 in HCEnC-21T cells sensitized the cells to UV-induced apoptosis, ZEB1 knockdown did not alter the cells' susceptibility to doxorubicin-induced apoptosis, as measured with cCASP3 protein levels, compared with controls. Similarly, no difference was observed in cell migration following ZEB1 knockdown. However, cell barrier function increased significantly following ZEB1 knockdown. CONCLUSIONS: The corneal endothelium in PPCD3 is characterized by morphologic, anatomic, and molecular features that are more consistent with an epithelial-like rather than an endothelial-like phenotype. Although these characteristics have been well documented, we demonstrate for the first time that susceptibility to UV-induced apoptosis and cell barrier function are significantly altered in the setting of reduced ZEB1. The significance of an altered cellular response to apoptotic stimuli and increased cell barrier function in the pathobiology of PPCD remains to be fully elucidated.

Transcriptomic Profiling of Posterior Polymorphous Corneal Dystrophy.

Purpose: To investigate the molecular basis of posterior polymorphous corneal dystrophy (PPCD) by examining the PPCD transcriptome and the effect of decreased ZEB1 expression on corneal endothelial cell (CEnC) gene expression. Methods: Next-generation RNA sequencing (RNA-seq) analyses of corneal endothelium from two PPCD-affected individuals (one with PPCD3 and one of unknown genetic cause) compared with two age-matched controls, and primary human CEnC (pHCEnC) transfected with siRNA-mediated ZEB1 knockdown. The expression of selected differentially expressed genes was validated by quantitative polymerase chain reaction (qPCR) and/or assessed by in situ hybridization in the corneal endothelium of four independent cases of PPCD (one with PPCD3 and three of unknown genetic cause). Results: Expression of 16% and 46% of the 104 protein-coding genes specific to ex vivo corneal endothelium was lost in the endothelium of two individuals with PPCD. Thirty-two genes associated with ZEB1 and 3 genes (BMP4, CCND1, ZEB1) associated with OVOL2 were differentially expressed in the same direction in both individuals with PPCD. Immunohistochemistry staining and RNA-seq analyses demonstrated variable expression of type IV collagens in PPCD corneas. Decreasing ZEB1 expression in pHCEnC altered expression of 711 protein-coding genes, many of which are associated with canonical pathways regulating various cellular processes. Conclusions: Identification of the altered transcriptome in PPCD and in a cell-based model of PPCD provided insight into the molecular alterations characterizing PPCD. Further study of the differentially expressed genes associated with ZEB1 and OVOL2 is expected to identify candidate genes for individuals with PPCD and without a ZEB1 or OVOL2 mutation.

Investigating the Molecular Basis of PPCD3: Characterization of ZEB1 Regulation of COL4A3 Expression.

PURPOSE: To investigate the role of the zinc finger e-box binding homeobox 1 (ZEB1) transcription factor in posterior polymorphous corneal dystrophy 3 by demonstrating its ability to regulate type IV collagen gene transcription via binding to putative E2 box motifs. METHODS: Putative E2 box motifs were identified by in silico analysis within the promoter region of collagen, type IV, alpha3 (COL4A3) and collagen, type IV, alpha4 (COL4A4). To test the ability of ZEB1 to bind to each identified E2 box, electrophoretic mobility shift assays were performed by incubating ZEB1-enriched nuclear extracts with DIG-labeled probes containing one of each of the identified E2 box motifs. Dual-luciferase reporter assays were performed to test the effects of ZEB1 on the luciferase activity of COL4A3 and cadherin 1 (CDH1) promoter constructs, and to determine the effect of a ZEB1 truncating mutation on CDH1 promoter activity. RESULTS: ZEB1 exhibited binding to six of the nine COL4A3 E2 box probes, whereas no binding was observed for either of the two COL4A4 E2 box probes. ZEB1 overexpression resulted in reduced activity of the COL4A3 promoter construct containing all identified E2 box motifs, whereas a truncating ZEB1 mutation led to the loss of ZEB1-dependent repression of the CDH1 promoter. CONCLUSIONS: COL4A3 gene expression is negatively regulated by ZEB1 binding to E2 box motifs in the COL4A3 promoter region. Therefore, the altered expression of type IV collagens, particularly COL4A3, in the corneal endothelium in individuals with PPCD3 is likely due to reduced transcriptional repression in the setting of a single functional ZEB1 allele.

Identification of the First De Novo UBIAD1 Gene Mutation Associated with Schnyder Corneal Dystrophy.

Purpose. To report the identification of the first de novo UBIAD1 missense mutation in an individual with Schnyder corneal dystrophy (SCD). Methods. A slit lamp examination was performed on a 47-year-old woman without a family history of corneal disorders. The proband's parents, two sisters, and son were also examined and genomic DNA from all six individuals was collected. The exons and exon-intron boundaries of UBIAD1 were screened using Sanger sequencing. Identified mutations were screened for in 200 control chromosomes. In silico analysis predicted the impact of identified mutations on protein function and structure. Results. Slit lamp examination of the proband revealed findings consistent with SCD. Corneas of the family members appeared unaffected. Screening of UBIAD1 in the proband identified a novel heterozygous c.308C>T mutation, predicted to encode the missense amino acid substitution p.(Thr103Ile). This mutation was not identified in any of the family members or in 200 control chromosomes and was predicted to be damaging to normal protein function and structure. Conclusions. We present a novel heterozygous de novo missense mutation in UBIAD1, p.(Thr103Ile), identified in a patient with classic clinical features of SCD. This highlights the value of genetic testing in clinical diagnostic settings, even in the absence of a positive family history.

Whole Exome Sequencing and Segregation Analysis Confirms That a Mutation in COL17A1 Is the Cause of Epithelial Recurrent Erosion Dystrophy in a Large Dominant Pedigree Previously Mapped to Chromosome 10q23-q24.

PURPOSE: To report identification of a COL17A1 mutation in a family with a corneal dystrophy previously mapped to chromosome 10q23-q24. METHODS: Whole-exome sequencing was performed on DNA samples from five affected family members and two unrelated, unaffected individuals. Identified variants were filtered for those that were: located in the linked interval on chromosome 10q23-q24; novel or rare (minor allele frequency ≤0.01); heterozygous; present in all affected individuals and not in controls; and present in genes that encode proteins expressed in human corneal epithelial cells (reads per kilobase per million ≥1). Sanger sequencing of identified variants (SNVs) was performed in additional family members. In silico analysis was used to predict the functional impact of non-synonymous variants. RESULTS: Three SNVs located in two genes were identified that met the filtering criteria: one rare synonymous c.3156C>T variant in the collagen, type XVII, alpha I (COL17A1) gene; and two rare variants, one synonymous and one missense, in the dynamin binding protein (DNMBP) gene. Sanger sequencing of additional family members determined that only the COL17A1 variant segregates with the affected phenotype. In silico analysis predicts that the missense variant in DNMBP would be tolerated. CONCLUSIONS: The corneal dystrophy mapped to chromosome 10q23-q24 is associated with the c.3156C>T variant in COL17A1. As this variant has recently been identified in five other families with early onset recurrent corneal erosions, and has been shown in vitro to introduce a cryptic splice donor site, this dystrophy is likely caused by aberrant splicing of COL17A1 and should be classified as epithelial recurrent erosion dystrophy.

Identification of presumed pathogenic KRT3 and KRT12 gene mutations associated with Meesmann corneal dystrophy.

PURPOSE: To report potentially pathogenic mutations in the keratin 3 (KRT3) and keratin 12 (KRT12) genes in two individuals with clinically diagnosed Meesmann corneal dystrophy (MECD). METHODS: Slit-lamp examination was performed on the probands and available family members to identify characteristic features of MECD. After informed consent was obtained, saliva samples were obtained as a source of genomic DNA, and screening of KRT3 and KRT12 was performed. Potentially pathogenic variants were screened for in 200 control chromosomes. PolyPhen-2, SIFT, and PANTHER were used to predict the functional impact of identified variants. Short tandem repeat genotyping was performed to confirm paternity. RESULTS: Slit-lamp examination of the first proband demonstrated bilateral, diffusely distributed, clear epithelial microcysts, consistent with MECD. Screening of KRT3 revealed a heterozygous missense variant in exon 1, c.250C>T (p.(Arg84Trp)), which has a minor allele frequency of 0.0076 and was not identified in 200 control chromosomes. In silico analysis with PolyPhen-2 and PANTHER predicted the variant to be damaging to protein function; however, SIFT analysis predicted tolerance of the variant. The second proband demonstrated bilateral, diffusely distributed epithelial opacities that appeared gray-white on direct illumination and translucent on retroillumination. Neither parent demonstrated corneal opacities. Screening of KRT12 revealed a novel heterozygous insertion/deletion variant in exon 6, c.1288_1293delinsAGCCCT (p.(Arg430_Arg431delinsSerPro)). This variant was not present in either of the proband's parents or in 200 control chromosomes and was predicted to be damaging by PolyPhen-2, PANTHER, and SIFT. Haplotype analysis confirmed paternity of the second proband, indicating that the variant arose de novo. CONCLUSIONS: We present a novel KRT12 mutation, representing the first de novo mutation and the first indel in KRT12 associated with MECD. In addition, we report a variant of uncertain significance in KRT3 in an individual with MECD. Although the potential pathogenicity of this variant is unknown, it is the first variant affecting the head domain of K3 to be reported in an individual with MECD and suggests that disease-causing variants associated with MECD may not be restricted to primary sequence alterations of either the helix-initiation or helix-termination motifs of K3 and K12.