Retina

PURPOSE: To report a rare case of Birt-Hogg-Dubé Syndrome (BHD) with progressive chorioretinopathy. METHODS: Case report. RESULTS: A 55-year-old woman presented with longstanding nyctalopia attributed to a congenital retinal dystrophy, but no prior genetic testing. Her posterior pole examination demonstrated retinal pigment epithelium (RPE) mottling with extensive macular drusen and paracentral chorioretinal atrophy, consistent with a fleck retinopathy. Her past medical history was remarkable for nephrectomy for unilateral renal malignancy, parotid tumors and thyroid nodules. Dark adaptation time was prolonged, and electroretinography (ERG) revealed abnormal waveforms with depressed amplitudes. Genetic testing confirmed a deletion mutation in the folliculin (FLCN) gene and was negative for other relevant mutations, including EFEMP1 responsible for autosomal dominant macular and peripapillary drusen in Doyne honeycomb retinal dystrophy and TIMP3 responsible for Sorsby Fundus Dystrophy. CONCLUSION: BHD is a rare autosomal-dominant disorder with multi-systemic clinical manifestations caused by a mutation in the FLCN gene. Affected individuals are prone to renal and pulmonary cysts, renal cancer, and fibrofolliculomas. Reports on ocular manifestations of BHD include eyelid fibrofolliculomas, flecked chorioretinopathy, choroidal melanoma, choroidal melanoma with sector melanocytosis, and retinal pigment epithelial micro-detachments. In this case of BHD, we note a fleck retinopathy with bilateral chorioretinal atrophy, displaying a phenotype of extensive chorioretinopathy associated with impaired dark adaptation and ERG abnormalities. ABBREVIATIONS: BHD: Birt-Hogg-Dubé syndrome; FLCN: Folliculin. RPE: retinal pigment epithelium; OD: Oculus dexter (right eye); OS: Oculus sinister (left eye). OU: Oculus uterque (both eyes); ERG: electroretinogram; mfERG: multifocal electroretinography. ffERG: full-field electroretinography; FAF: fundus autofluorescence; OCT: optical coherence tomography; FA: fluorescein angiography; DA: dark-adapted; LA: light-adapted; mTOR: mammalian target of rapamycin; EFEMP1: epithelial growth factor-containing fibulin-like extracellular matrix protein 1; VPS13B: Vacuolar Protein Sorting 13 Homolog B; AGBL5: AATP/GTP-Binding Protein Like 5; ALMS1: Alstrom Syndrome 1; COL1BA1: Collagen Type I Beta, Alpha Chain 1; PDE6A: Rod Phosphodiesterase 6-alpha; USH2A: Usherin 2a; VCAN: Versican; RP: Retinitis pigmentosa; AR: Autosomal recessive.

PURPOSE: To describe two cases of catastrophic, bilateral retinal vascular occlusion after intravitreal (IVT) bevacizumab injection. METHODS: Case series. Main outcome measures included clinical and fluorescein angiography findings. RESULTS: Case 1-A 65-year-old woman with calcinosis, Raynaud phenomenon, esophageal dysfunction, sclerodactyly, and telangiectasis syndrome developed acute, severe, bilateral visual loss 2 weeks after bilateral IVT bevacizumab injection for proliferative diabetic retinopathy. Examination and fluorescein angiography revealed moderate anterior chamber inflammation, bilateral perivascular retinal hemorrhages, and near total retinal vascular occlusion. Extensive testing revealed moderately elevated anti-B2 glycoprotein (antiphospholipid) antibodies. Case 2-An 85-year-old man with polymyalgia rheumatica and left eye exudative age-related macular degeneration experienced severe, bilateral, sequential visual loss in the left eye and then right eye approximately 3 weeks after IVT bevacizumab left eye injection. Examination revealed bilateral panuveitis, diffuse perivascular exudates, and intraretinal hemorrhages. Fluorescein angiography showed diffuse venous leakage. Extensive testing revealed an elevated antinuclear antibody and mildly elevated anticardiolipin antibody. CONCLUSION: Patients with underlying retinal vascular vulnerabilities may be at increased risk of catastrophic, bilateral retinal vascular occlusion after treatment with IVT bevacizumab. The moderate-to-severe intraocular inflammation in both cases and the contralateral involvement after unilateral IVT injection in Case 2 suggest a possible delayed immune-mediated mechanism.

PURPOSE: To determine the cumulative incidence of retinal detachment (RD) repair following pediatric cataract surgery and identify the associated risk factors. DESIGN: US population-based insurance claims retrospective cohort study. PARTICIPANTS: Patients ≤ 18 years old who underwent cataract surgery in 2 large databases: Optum Clinformatics (2003-2021) and IBM MarketScan (2007-2016). METHODS: Individuals with ≥ 6 months of prior enrollment were included, and those with a history of RD, RD repair, traumatic cataract, spherophakia, or ectopia lentis were excluded. The primary outcome was time between initial cataract surgery and RD repair. The risk factors investigated included age, sex, persistent fetal vasculature (PFV), prematurity, intraocular lens (IOL) placement, and pars plana lensectomy approach. MAIN OUTCOME MEASURES: Kaplan-Meier estimated cumulative incidence of RD repair 5 years after cataract surgery and hazard ratios (HRs) with 95% confidence intervals (CIs) from multivariable Cox proportional hazards regression models. RESULTS: Retinal detachment repair was performed on 47 of 3289 children included in this study. The cumulative incidence of RD repair within 5 years of cataract surgery was 2.0% (95% CI, 1.3%-2.6%). Children requiring RD repair were more likely to have a history of prematurity or PFV and less likely to have an IOL placed (all P < 0.001). Factors associated with RD repair in the multivariable analysis included a history of prematurity (HR, 6.89; 95% CI, 3.26-14.56; P < 0.001), PFV diagnosis (HR, 8.20; 95% CI, 4.11-16.37; P < 0.001), and IOL placement (HR, 0.44; 95% CI, 0.21-0.91; P = 0.03). Age at surgery, sex, and pars plana lensectomy approach were not significantly associated with RD repair after adjusting for all other covariates. CONCLUSIONS: Approximately 2% of patients will undergo RD repair within 5 years of pediatric cataract surgery. Children with a history of PFV and prematurity undergoing cataract surgery without IOL placement are at the greatest risk.

Ultraviolet light A (UVA) is the only UV light that reaches the retina and can cause indirect damage to DNA via absorption of photons by non-DNA chromophores. Previous studies demonstrate that UVA generates reactive oxygen species (ROS) and leads to programmed cell death. Programmed cell death (PCD) has been implicated in numerous ophthalmologic diseases. Here, we investigated receptor interacting protein 1 and 3 (RIPK1 and RIPK3) kinases, key signaling molecules of PCD, in UVA-induced photoreceptor injury using in vitro and ex vivo models. UVA irradiation activated RIPK3 but not RIPK1 and mediated necroptosis through MLKL that lie downstream of RIPK3 and induced apoptosis through increased oxidative stress. Moreover, RIPK3 but not RIPK1 inhibition suppresses UVA-induced cell death along with the downregulation of MLKL and attenuates the levels of oxidative stress and DNA fragmentation. In conclusion, these results identify RIPK3, not RIPK1, as a critical regulator of UVA-induced necroptosis cell death in photoreceptors and highlight RIPK3 potential as a neuroprotective target.

Amino acid (AA) metabolism in vascular endothelium is important for sprouting angiogenesis. SLC38A5 (solute carrier family 38 member 5), an AA transporter, shuttles neutral AAs across cell membrane, including glutamine, which may serve as metabolic fuel for proliferating endothelial cells (ECs) to promote angiogenesis. Here, we found that Slc38a5 is highly enriched in normal retinal vascular endothelium, and more specifically, in pathological sprouting neovessels. Slc38a5 is suppressed in retinal blood vessels from Lrp5-/- and Ndpy/- mice, both genetic models of defective retinal vascular development with Wnt signaling mutations. Additionally, Slc38a5 transcription is regulated by Wnt/β-catenin signaling. Genetic deficiency of Slc38a5 in mice substantially delays retinal vascular development and suppresses pathological neovascularization in oxygen-induced retinopathy modeling ischemic proliferative retinopathies. Inhibition of SLC38A5 in human retinal vascular ECs impairs EC proliferation and angiogenic function, suppresses glutamine uptake, and dampens vascular endothelial growth factor receptor 2. Together these findings suggest that SLC38A5 is a new metabolic regulator of retinal angiogenesis by controlling AA nutrient uptake and homeostasis in ECs.

PURPOSE: The intravitreal injection volume is known to vary with plunger alignment and the speed of injection. We investigated the role that syringe stopper deformation plays in allowing excess volumes to be injected into the eye and the potential for the vitreous humor to become incarcerated when excess force is released within the eye. DESIGN: Experimental study. METHODS: Aflibercept prefilled syringes (PFSs), ranibizumab PFSs, and 1-ml tuberculin (TB) syringes were subjected to increasing injection force to assess the extent to which each design allowed for excess volumes to be expelled after the stopper reached the bottom of the syringe barrel (i.e., after the 50-μl dose was expelled). MAIN OUTCOME MEASURES: Additional volume expelled with stopper deformation. RESULTS: Syringe stoppers are capable of deformation into the dead space when additional force is applied. This allows for progressively greater medication doses to be administered. At an additional force of 3.92 N after the syringe stopper came in contact with the bottom of the syringe barrel, the aflibercept PFSs, ranibizumab PFSs, and 1-ml TB syringes dispensed an additional 17.2%, 11.4%, and 0.8% higher volume than the intended volume of 50 μl, respectively. Upon release of this force, a proportional volume was observed to be drawn back into the needle. CONCLUSIONS: The intravitreal injection volume varies with the force applied to fully depressed syringes because of syringe stopper deformation. We advise that performing forceful intravitreal injections be avoided to prevent excessive dosing of medication. We also caution that pressure applied to the plunger during intravitreal injections not be released while the needle is in the vitreous cavity to guard against vitreous incarceration, which could lead to retinal tear formation or detachment.

Inherited retinal diseases (IRDs) are a genetically and phenotypically heterogeneous group of genetic eye disorders. There are more than 300 disease entities, and together this group of disorders affects millions of people globally and is a frequent cause of blindness or low-vision certification. However, each type is rare or ultra-rare. Characteristically, the impaired vision in IRDs is due to retinal photoreceptor dysfunction and loss resulting from mutation in a gene that codes for a retinal protein. Historically, IRDs have been considered incurable and individuals living with these blinding conditions could be offered only supportive care. However, the treatment landscape for IRDs is beginning to evolve. Progress is being made, driven by improvements in understanding of genotype-phenotype relationships, through advances in molecular genetic testing and retinal imaging. Alongside this expanding knowledge of IRDs, the current era of precision medicine is fueling a growth in targeted therapies. This has resulted in the first treatment for an IRD being approved. Several other therapies are currently in development in the IRD space, including RNA-based therapies, gene-based therapies (such as augmentation therapy and gene editing), cell therapy, visual prosthetics, and optogenetics. RNA-based therapies are a novel approach within precision medicine that have demonstrated success, particularly in rare diseases. Three antisense oligonucleotides (AONs) are currently in development for the treatment of specific IRD subtypes. These RNA-based therapies bring several key advantages in the setting of IRDs, and the potential to bring meaningful vision benefit to individuals living with inherited blinding disorders. This review will examine the increasing breadth and relevance of RNA-based therapies in clinical medicine, explore the key features that make AONs suitable for treating genetic eye diseases, and provide an overview of the three-leading investigational AONs in clinical trials.

Chemotherapy is often used to treat retinoblastoma; however, this treatment method has severe systemic adverse effects and inadequate therapeutic effectiveness. Extracellular vesicles (EVs) are important biological information carriers that mediate local and systemic cell-to-cell communication under healthy and pathological settings. These endogenous vesicles have been identified as important drug delivery vehicles for a variety of therapeutic payloads, including doxorubicin (Dox), with significant benefits over traditional techniques. In this work, EVs were employed as natural drug delivery nanoparticles to load Dox for targeted delivery to retinoblastoma human cell lines (Y-79). Two sub-types of EVs were produced from distinct breast cancer cell lines (4T1 and SKBR3) that express a marker that selectively interacts with retinoblastoma cells and were loaded with Dox, utilizing the cells' endogenous loading machinery. In vitro, we observed that delivering Dox with both EVs increased cytotoxicity while dramatically lowering the dosage of the drug. Dox-loaded EVs, on the other hand, inhibited cancer cell growth by activating caspase-3/7. Direct interaction of EV membrane moieties with retinoblastoma cell surface receptors resulted in an effective drug delivery to cancer cells. Our findings emphasize the intriguing potential of EVs as optimum methods for delivering Dox to retinoblastoma.

At preterm birth, the retina is incompletely vascularized. Retinopathy of prematurity (ROP) is initiated by the postnatal suppression of physiological retinal vascular development that would normally occur in utero. As the neural retina slowly matures, increasing metabolic demand including in the peripheral avascular retina, leads to signals for compensatory but pathological neovascularization. Currently, only late neovascular ROP is treated. ROP could be prevented by promoting normal vascular growth. Early perinatal metabolic dysregulation is a strong but understudied risk factor for ROP and other long-term sequelae of preterm birth. We will discuss the metabolic and oxygen needs of retina, current treatments, and potential interventions to promote normal vessel growth including control of postnatal hyperglycemia, dyslipidemia and hyperoxia-induced retinal metabolic alterations. Early supplementation of missing nutrients and growth factors and control of supplemental oxygen promotes physiological retinal development. We will discuss the current knowledge gap in retinal metabolism after preterm birth.

Adult central nervous system (CNS) axons fail to regenerate after injury, and master regulators of the regenerative program remain to be identified. We analyzed the transcriptomes of retinal ganglion cells (RGCs) at 1 and 5 days after optic nerve injury with and without a cocktail of strongly pro-regenerative factors to discover genes that regulate survival and regeneration. We used advanced bioinformatic analysis to identify the top transcriptional regulators of upstream genes and cross-referenced these with the regulators upstream of genes differentially expressed between embryonic RGCs that exhibit robust axon growth vs. postnatal RGCs where this potential has been lost. We established the transcriptional activator Elk-1 as the top regulator of RGC gene expression associated with axon outgrowth in both models. We demonstrate that Elk-1 is necessary and sufficient to promote RGC neuroprotection and regeneration in vivo, and is enhanced by manipulating specific phosphorylation sites. Finally, we co-manipulated Elk-1, PTEN, and REST, another transcription factor discovered in our analysis, and found Elk-1 to be downstream of PTEN and inhibited by REST in the survival and axon regenerative pathway in RGCs. These results uncover the basic mechanisms of regulation of survival and axon growth and reveal a novel, potent therapeutic strategy to promote neuroprotection and regeneration in the adult CNS.

PURPOSE: Low-dose and very low-dose intravitreal bevacizumab (IVB) have been reported to be successful in short-term treatment of type 1 retinopathy of prematurity (ROP), down to an initial dose of 0.004 mg. We now report 12-month outcomes for these infants. DESIGN: Masked, multicenter, dose de-escalation study. PARTICIPANTS: One hundred twenty prematurely born infants with type 1 ROP. METHODS: A cohort of 120 infants with type 1 ROP in at least 1 eye from 2 sequential dose de-escalation studies of low-dose IVB (0.25 mg, 0.125 mg, 0.063 mg, and 0.031 mg) or very low-dose IVB (0.016 mg, 0.008 mg, 0.004 mg, and 0.002 mg) to the study eye; the fellow eye (if also type 1) received 1 dose level higher of IVB. After primary success or failure at 4 weeks, clinical management was at investigator discretion, including all additional treatment. MAIN OUTCOME MEASURES: Reactivation of severe ROP by 6 months corrected age, additional treatments, retinal and other ocular structural outcomes, and refractive error at 12 months corrected age. RESULTS: Sixty-two of 113 study eyes (55%) and 55 of 98 fellow eyes (56%) received additional treatment. Of the study eyes, 31 (27%) received additional ROP treatment, and 31 (27%) received prophylactic laser therapy for persistent avascular retina. No trend toward a higher risk of additional ROP treatment related to initial IVB doses was found. However, time to reactivation among study eyes was shorter in eyes that received very low-dose IVB (mean, 76.4 days) than in those that received low-dose IVB (mean, 85.7 days). At 12 months, poor retinal outcomes and anterior segment abnormalities both were uncommon (3% and 5%, respectively), optic atrophy was noted in 10%, median refraction was mildly myopic (-0.31 diopter), and strabismus was present in 29% of infants. CONCLUSIONS: Retinal structural outcomes were very good after low- and very low-dose IVB as initial treatment for type 1 ROP, although many eyes received additional treatment. The rate of reactivation of severe ROP was not associated with dose; however, a post hoc data-driven analysis suggested that reactivation was sooner with very low doses.

IMPORTANCE: Literature and anecdotal evidence suggest a relationship between male sex and retinopathy of prematurity (ROP). It is not known whether a difference, if present, is sex-related pathophysiologic predisposition or sex difference in meeting ROP screening criteria. OBJECTIVE: To evaluate the association of sex with the development of treatment-warranted ROP. DATA SOURCES: PubMed, Embase, and Web of Science databases were searched from 2000 to 2022. The search strategy used keywords including retinopathy of prematurity or ROP or retrolental fibroplasia and treatment or anti-VEGF or bevacizumab or ranibizumab or aflibercept or conbercept or laser or cryotherapy and gender or sex or male or female and medical subject headings terms. STUDY SELECTION: All studies reporting on treatment with anti-vascular endothelial growth factor, laser photocoagulation, and/or cryotherapy for ROP were identified. Studies reporting sex distribution in the treatment group were included in the meta-analysis. Exclusion criteria included case reports, case series of fewer than 10 treated patients, systematic reviews, conference abstracts, letters to the editor, animal studies, and non-English records. DATA EXTRACTION AND SYNTHESIS: Two reviewers independently screened and extracted the data following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The proportions of treated male and female infants were combined using random-effects meta-analysis. MAIN OUTCOMES AND MEASURES: Numbers and percentages of male and female infants treated for ROP. RESULTS: Of 11 368 identified studies, 316 met inclusion criteria, yielding a total of 31 026 treated patients. A higher percentage of male infants were treated for ROP (55% [95% CI, 0.54%-0.55%]), with low heterogeneity between studies (I2 = 34%; P < .001). Thirty-eight studies reported sex distribution in the screened population (170 053 patients; 92 612 [53%] male vs 77 441 [47%] female). There was no significant difference in the odds of receiving treatment between screened male and female infants (pooled odds ratio, 1.04 [95% CI, 0.91-1.18]; P = .67). CONCLUSIONS AND RELEVANCE: More male infants are treated for ROP than female infants. This could be due to a known relative pathophysiological fragility of preterm male infants in addition to a difference in ROP screening rates, with more male infants meeting the criteria than female infants. These findings have implications for future studies and may prompt more careful clinical monitoring of male neonates.

PURPOSE: To identify prognostic factors for poor visual outcomes in patients with isolated retinal vasculitis and to elucidate the outcome of immunosuppressive treatment without the use of antituberculosis drugs for patients with retinal vasculitis associated with a positive QuantiFERON-TB Gold In-Tube (QFT) test. METHODS: A retrospective chart review was performed of patients presenting with retinal vasculitis. After the diagnosis of active retinal vasculitis had been confirmed by fluorescein angiography and other possible causes of retinal vasculitis had been excluded, patients were categorized into two groups by their QFT result. Potential associated factors between the poor and good visual outcome groups were statistically analyzed by the chi-square test and logistic regression model with generalized estimating equations. RESULTS: Seventy-three eyes (48 patients) were enrolled in this study. After univariate analysis, multivariate logistic regression analysis was performed and revealed that logMAR visual acuity at the initial visit ( P = 0.01) and outer retinal disruption ( P = 0.03) were the two factors significantly associated with poor visual outcomes. Systemic corticosteroids were administered without the use of antituberculosis drugs to all 16 cases of presumed tuberculous retinal vasculitis associated with positive QFT (26 eyes), 10 (63%) of whom were given nonsteroidal immunosuppressive drugs and achieved inflammatory control and treatment success. CONCLUSION: Risk factors leading to poor visual outcome in patients with isolated retinal vasculitis have been identified. Immunosuppressive treatment without antituberculosis drugs seems to be a promising regimen for selected patients with presumed tuberculous retinal vasculitis under vigilant care.

Background: Retinal vascular abnormality is an important part of ocular systemic sclerosis (SSc), and long-term use of chloroquine can lead to retinal toxicity. This study was conducted to evaluate retinal microvascular changes using optical coherence tomography angiography (OCTA) in patients with SSc and SSc patients on long-term chloroquine treatment. Methods: Fifteen SSc patients without chloroquine (30 eyes), 15 SSc patients taking long-term chloroquine (30 eyes) and 15 healthy controls (30 eyes) were recruited to this cross-sectional study. OCTA was used to examine the superficial and deep retinal capillary plexus in the macular retina of each eye. The densities of microvessels (MIR), macrovessels (MAR) and total microvessels (TMI) in the superficial and deep retina of the three groups were calculated and compared. We used the hemisphere segmentation method [superior right (SR), superior left (SL), inferior left (IL), and inferior right (IR)] and Early Treatment Diabetic Retinopathy Study (ETDRS) method [right (R), superior (S), left (L), and inferior (I)] to analyze changes in retinal microvascular density. Results: The superficial and deep retinal MIR density in SSc patients decreased (P<0.05) compared with the healthy control group. This significant difference was found in both superficial and deep layers in S, L, SR, SL and IL regions (P<0.05), and additionally in the R and I regions in the superficial layer (P<0.05). Similarly, compared with SSc patients who did not take chloroquine, the superficial and deep retinal MIR density of SSc patients on long-term chloroquine also decreased (P<0.05). This significant difference was found in both superficial and deep layers in R, I and IL regions (P<0.05), and additionally in the IR region in the superficial layer (P<0.05). Conclusions: The OCTA results suggest that retinal MIR density is decreased in SSc patients, and that long-term use of chloroquine will aggravate this damage, resulting in a further decrease in retinal MIR density.