Publications

2021

Greenwald S, Brown E, Scandura M, Hennessey E, Farmer R, Du J, Wang Y, Pierce E. Mutant Nmnat1 leads to a retina-specific decrease of NAD+ accompanied by increased poly(ADP-ribose) in a mouse model of NMNAT1-associated retinal degeneration. Hum Mol Genet. 2021;30(8):644–657.
Nicotinamide mononucleotide adenylyltransferase 1 (NMNAT1) is required for nuclear nicotinamide adenine mononucleotide (NAD+) biosynthesis in all nucleated cells, and despite its functional ubiquity, mutations in this gene lead to an isolated retinal degeneration. The mechanisms underlying how mutant NMNAT1 causes disease are not well understood, nor is the reason why the pathology is confined to the retina. Using a mouse model of NMNAT1-associated retinal degeneration that harbors the p.Val9Met mutation, we tested the hypothesis that decreased function of mutant NMNAT1 has a greater effect on the levels of NAD+ in the retina than elsewhere in the body. Measurements by liquid chromatography with tandem mass spectrometry showed an early and sustained decrease of NAD+ in mutant retinas that was not observed in other tissues. To understand how consumers of nuclear NAD+ are affected by the reduced availability of NAD+ in mutant retinas, poly(ADP-ribose) polymerase (PARP) and nuclear sirtuin activity were evaluated. PARP activity was elevated during disease progression, as evidenced by overproduction of poly(ADP-ribose) (PAR) in photoreceptors, whereas histone deacetylation activity of nuclear sirtuins was not altered. We hypothesized that PARP could be activated because of elevated levels of oxidative stress; however, we did not observe oxidative DNA damage, lipid peroxidation, or a low glutathione to oxidized glutathione ratio. Terminal deoxynucleotidyl transferase dUTP nick end labeling staining revealed that photoreceptors appear to ultimately die by apoptosis, although the low NAD+ levels and overproduction of PAR suggest that cell death may include aspects of the parthanatos cell death pathway.
The goal of personalized diabetes eye care is to accurately predict in real-time the risk of diabetic retinopathy (DR) progression and visual loss. The use of electronic health records (EHR) provides a platform for artificial intelligence (AI) algorithms that predict DR progression to be incorporated into clinical decision-making. By implementing an algorithm on data points from each patient, their risk for retinopathy progression and visual loss can be modeled, allowing them to receive timely treatment. Data can guide algorithms to create models for disease and treatment that may pave the way for more personalized care. Currently, there exist numerous challenges that need to be addressed before reliably building and deploying AI algorithms, including issues with data quality, privacy, intellectual property, and informed consent.
Retinal imaging remains the mainstay for monitoring and grading diabetic retinopathy. The gold standard for detecting proliferative diabetic retinopathy (PDR) requiring treatment has long been the seven-field stereoscopic fundus photography and fluorescein angiography. In the past decade, ultra-wide field fluorescein angiography (UWF-FA) has become more commonly used in clinical practice for the evaluation of more advanced diabetic retinopathy. Since its invention, optical coherence tomography (OCT) has been an important tool for the assessment of diabetic macular edema; however, OCT offered little in the assessment of neovascular changes associated with PDR until OCT-A became available. More recently, swept source OCT allowed larger field of view scans to assess a variety of DR lesions with wide field swept source optical coherence tomography (WF-SS-OCTA). This paper reviews the role of WF-SS-OCTA in detecting neovascularization of the disc (NVD), and elsewhere (NVE), microaneurysms, changes of the foveal avascular zone (FAZ), intraretinal microvascular abnormalities (IRMA), and capillary non-perfusion, as well as limitations of this evolving technology.
Shanbhag S, Shih G, Bispo P, Chodosh J, Jacobs D, Saeed H. Diphtheroids as Corneal Pathogens in Chronic Ocular Surface Disease in Stevens-Johnson Syndrome/Toxic Epidermal Necrolysis. Cornea. 2021;40(6):774–779.
PURPOSE: To characterize diphtheroid corneal infections in eyes in the chronic phase of Stevens-Johnson syndrome/toxic epidermal necrolysis (SJS/TEN). METHODS: Observational case series. RESULTS: Four eyes of 3 patients were included in this review. Each eye presented with persistent corneal epithelial defect with corneal thinning in the chronic phase of SJS/TEN. None of the epithelial defects were associated with stromal infiltration. The corneas were cultured at the time of workup of persistent epithelial defect (3 eyes) or at time of tectonic penetrating keratoplasty after perforation (1 eye). Cultures yielded abundant growth of Corynebacterium spp., including Corynebacterium jeikeium (n = 2), Corynebacterium glucuronolyticum (n = 1), and a multidrug-resistant Corynebacterium striatum isolate (n = 1). The ocular surface was stabilized with surgical intervention (1 eye) or with introduction of fortified topical antibiotic based on laboratory identification and susceptibility testing of the isolated organisms (3 eyes). Numerous risk factors for microbial keratitis were present in all 4 eyes. CONCLUSIONS: In eyes with a persistent corneal epithelial defect in the chronic phase of SJS/TEN, even in the absence of an infiltrate, corneal culture should be undertaken. Recognition and treatment of Corynebacterium spp. as opportunistic pathogens may lead to favorable outcomes in cases of clinically sterile ulceration during the chronic phase of SJS/TEN.
Brill D, Papaliodis G. Uveitis Specialists Harnessing Disruptive Technology during the COVID-19 Pandemic and Beyond. Semin Ophthalmol. 2021;36(4):296–303.
Spurred by the coronavirus disease pandemic and shortage of eye care providers, telemedicine is transforming the way ophthalmologists care for their patients. Video conferencing, ophthalmic imaging, hybrid visits, intraocular inflammation quantification, and portable technology are evolving areas that may allow more uveitis patients to be evaluated via telemedicine. Despite these promising disruptive technologies, there remain significant technological limitations, legal barriers, variable insurance coverage for virtual visits, and lack of clinical trials for uveitis specialists to embrace telemedicine.
Nguyen QD, Anesi S, Chexal S, Chu D, Dayani P, Leng T, Meleth A, Sallam A, Sheppard J, Silverstein S, Toyos M, Wang R, Foster CS. Management of repository corticotropin injection therapy for non-infectious uveitis: a Delphi study. Acta Ophthalmol. 2021;99(6):669–678.
PURPOSE: Diagnosis and management of non-infectious uveitis (NIU), a major cause of blindness worldwide, are challenging. Corticosteroids, the cornerstone of therapy, are not appropriate for long-term use, and while non-biologic and biologic immunomodulators may be used for some patients, data on their efficacy and safety in this population are limited. Repository corticotropin injection (RCI), believed to affect uveitis by multiple mechanisms, has received regulatory approval for treatment of ophthalmic diseases including posterior uveitis, but is not widely used or discussed in guidelines for the management of uveitis and ocular inflammatory diseases. METHODS: The index study employed a modified Delphi process with a panel of 14 US-based ophthalmologists. Consensus recommendations were developed through a series of three questionnaires. Panellists rated statements on a Likert scale from -5 (strongly disagree) to +5 (strongly agree). RESULTS: The Delphi panel provided consensus recommendations on examinations and testing needed for diagnosis, treatment goals, and the use of corticosteroids, as well as the use of non-biologic and biologic immunomodulators. The panel reached consensus that RCI may be considered for posterior and pan-uveitis, and dosing should be individualized for each patient. Dose reduction/discontinuation should be considered for excessive RCI-related toxicity, hyperglycaemia and/or diabetic complications, excessive costs, or remission ≥ 2 years. Patients should be weaned from RCI if uveitis is stable and well controlled. Adverse events during RCI therapy can be managed by appropriate interventions, with dose reduction/discontinuation considered if events are severe or recurrent. CONCLUSIONS: Expert consensus suggests RCI may be an appropriate treatment option for some patients with uveitis when other therapies are ineffective or intolerable.