Neurotrophic Keratopathy: Ophthalmology's Diabetic Foot Problem.

ABSTRACT: This article summarizes key elements of the 2020 Harold A. Stein Lecture presented at the Eye and Contact Lens Special Symposium "Healing the Ocular Surface: What's New for Neurotrophic Keratitis." The major point that I made in this talk is that we need to think about neurotrophic keratopathy as ophthalmology's diabetic foot problem; as a chronic condition that is, often best managed by prevention. Neurotrophic keratopathy is not primarily an inflammatory condition, as suggested by the term ?neurotrophic keratitis." The epitheliopathy in this condition is a consequence of the dysregulated epithelial cell migration, differentiation, and homeostasis that occurs with denervation of the ocular surface. Although this epitheliopathy may be complicated by poor lid closure, or rarely, aqueous tear deficiency, most of these eyes are not dry and do not require exogenous lubrication for comfort, prophylaxis, or healing. The use of topical agents in these eyes inevitably leads to unrecognized iatrogenic injury, with poor outcomes because of inherently poor wound healing and delays in seeking medical care. Tarsorrhaphy is a time-honored method of protecting the neurotrophic cornea, shielding the eye from iatrogenic injury. Alternative methods for protecting the ?at risk" surface of the neurotrophic cornea include patient education, minimizing topical agents, and the use of protective eyewear.

Factors Associated with Adherence to Screening Guidelines for Diabetic Retinopathy Among Low-Income Metropolitan Patients.

In this retrospective analysis of patients with diabetes in an academic primary care clinic in St. Louis, attendance at ophthalmic screening appointments was recorded over a two-year observation window. Factors associated with adherence were analyzed by multivariable regression. Among 974 total patients included, only 330 (33.9%) were adherent within a two-year period. Multivariate analyses identified older age, female gender, primary language other than English, and attendance at ancillary diabetes clinic visits as factors associated with improved diabetic retinopathy screening adherence. Factors not associated with adherence included race and insurance status.

Characterization of herpes simplex virus 2 primary microRNA Transcript regulation.

UNLABELLED: In order to understand factors that may influence latency-associated transcription and latency-associated transcript (LAT) phenotypes, we studied the expression of the herpes simplex virus 2 (HSV-2) LAT-associated microRNAs (miRNAs). We mapped the transcription initiation sites of all three primary miRNA transcripts and identified the ICP4-binding sequences at the transcription initiation sites of both HSV-2 LAT (pri-miRNA for miR-I and miR-II, which target ICP34.5, and miR-III, which targets ICP0) and L/ST (a pri-miRNA for miR-I and miR-II) but not at that of the primary miR-H6 (for which the target is unknown). We confirmed activity of the putative HSV-2 L/ST promoter and found that ICP4 trans-activates the L/ST promoter when the ICP4-binding site at its transcription initiation site is mutated, suggesting that ICP4 may play a dual role in regulating transcription of L/ST and, consequently, of miR-I and miR-II. LAT exon 1 (containing LAT enhancer sequences), together with the LAT promoter region, comprises a bidirectional promoter required for the expression of both LAT-encoded miRNAs and miR-H6 in latently infected mouse ganglia. The ability of ICP4 to suppress ICP34.5-targeting miRNAs and to activate lytic viral genes suggests that ICP4 could play a key role in the switch between latency and reactivation. IMPORTANCE: The HSV-2 LAT and viral miRNAs expressed in the LAT region are the most abundant viral transcripts during HSV latency. The balance between the expression of LAT and LAT-associated miRNAs and the expression of lytic viral transcripts from the opposite strand appears to influence whether individual HSV-infected neurons will be latently or productively infected. The outcome of neuronal infection may thus depend on regulation of gene expression of the corresponding primary miRNAs. In the present study, we characterize promoter sequences responsible for miRNA expression, including identification of the primary miRNA 5' ends and evaluation of ICP4 response. These findings provide further insight into the virus' strategy to tightly control expression of lytic cycle genes (especially the neurovirulence factor, ICP34.5) and suggest a mechanism (via ICP4) for the transition from latency to reactivated productive infection.

Different mechanisms regulate productive herpes simplex virus 1 (HSV-1) and HSV-2 infections in adult trigeminal neurons.

Herpes simplex virus 1 (HSV-1) and HSV-2 establish latency in different neuronal subtypes (A5+ and KH10+) in murine trigeminal ganglia, results which correlate with restricted productive infection in these neurons in vitro. HSV-2 latency-associated transcript (LAT) contains a cis-acting regulatory element near the transcription start site that promotes productive infection in A5+ neurons and a second element in exon 1 that inhibits productive infection in KH10+ neurons. HSV-1 contains no such regulatory sequences, demonstrating different mechanisms for regulating productive HSV infection in neurons.

High prevalence of anelloviruses in vitreous fluid of children with seasonal hyperacute panuveitis.

Seasonal hyperacute panuveitis (SHAPU) is a potentially blinding ocular disease occurring in Nepal that principally affects young children. Random amplification of partially purified vitreous fluid (VF)-derived nucleic acid revealed the presence of human anelloviruses in VF of SHAPU patients. In a comparative study of patients with different ocular pathologies, SHAPU patients were at highest risk of harboring anelloviruses in their eyes. The majority of SHAPU patients had multiple anelloviruses in their VF. The ocular anellovirus load in SHAPU and non-SHAPU patients did not differ and no SHAPU-specific anellovirus variant was detected. Analysis of paired serum and VF samples from SHAPU and non-SHAPU patients showed that the anellovirus detected in VF samples most likely originated from the systemic viral pool during viremia, potentially through breakdown of the blood-ocular barrier. The detection of anelloviruses in VF samples of uveitis patients, profoundly so in SHAPU patients, is imperative and warrants elucidation of its clinical significance.

Quality of Life Outcomes Among Patients Being Screened for Cytomegalovirus Retinitis in Thailand.

PURPOSE: Cytomegalovirus (CMV) retinitis can have debilitating impacts on quality of life (QOL), but few contemporary studies have characterized these ramifications. This study assessed the impact of CMV retinitis on vision-related QOL for those living with HIV/AIDS in Thailand. METHODS: QOL was assessed as part of a prospective interventional cohort study of patients referred to a tertiary hospital in Thailand for CMV retinitis screening. A validated vision-related QOL questionnaire was administered at the baseline screening visit and at the 6-month study visit. Multivariable linear regression models were performed to determine the effect of CMV retinitis diagnosis on QOL score. RESULTS: A total of 152 participants completed the QOL questionnaire at their initial clinic visit. At baseline, a diagnosis of CMV retinitis diagnosis was significantly associated with decreased QOL score: unilateral retinitis was associated with a 0.11 (95% CI: -0.26-0.03) decrement in QOL, and bilateral retinitis was associated with a 0.33 (95% CI: -0.51-0.16) decrement (joint P-value = 0.0009). For the 78 participants with a 6-month visit, changes in QOL from baseline were small and not significant. A diagnosis of CMV retinitis was still associated with decreased QOL score at 6 months (joint P-value = 0.03). CONCLUSIONS: This study found that vision-related QOL was lower in those with CMV retinitis, especially with bilateral involvement, and did not improve after treatment among those with follow-up. These findings reinforce the debilitating clinical manifestations of this disease, and support efforts for earlier screening to detect CMV retinitis before impacts on QOL have occurred.

Herpes simplex virus 2 microRNA miR-H6 is a novel latency-associated transcript-associated microRNA, but reduction of its expression does not influence the establishment of viral latency or the recurrence phenotype.

The herpes simplex virus 2 (HSV-2) viral microRNA (miRNA) designated miR-H6 is located upstream of the latency-associated transcript (LAT) promoter region on the strand opposite the LAT. Deletion of the LAT promoter and part of LAT exon 1 abolished HSV-2 miR-H6 expression in acutely and latently infected guinea pig dorsal root ganglia (DRG), suggesting that this region is needed both for the expression of LAT-encoded miRNAs and for miR-H6 expression in vivo. Relative to cells infected with a viral rescuant, miR-H6 expression was significantly reduced in cells infected with a mutant HSV-2 virus, NotPolyA, with an insertion of a simian virus (SV40) polyadenylation signal sequence between the LAT promoter and miR-H6 sequences. In addition, expression of miR-H6, but not LAT or viral DNA, was significantly reduced in both mouse trigeminal ganglia (TG) and guinea pig DRG latently infected with the NotPolyA mutant. Guinea pigs infected with NotPolyA experienced reduced neurological complications of acute infection relative to those infected with the rescuant, but the recurrence phenotype of the NotPolyA mutant was similar to those of its rescuant and wild-type HSV-2, indicating that reduction of miR-H6 expression is not by itself able to alter the establishment of latency for the wild-type virus or the recurrence phenotype. Furthermore, the mutation in NotPolyA did not affect the propensity of wild-type HSV-2 to establish latency in neurons positive for subtype marker KH10. In contrast to published reports regarding its HSV-1 homolog, HSV-2 miR-H6 did not affect ICP4 expression in transfected or infected cells. We hypothesize that viral miRNAs associated with LAT expression are likely to work collectively, contributing to the phenotype attributed to the LAT.

A5-positive primary sensory neurons are nonpermissive for productive infection with herpes simplex virus 1 in vitro.

Herpes simplex viruses 1 and 2 (HSV-1 and HSV-2) establish latency and express the latency-associated transcript (LAT) preferentially in different murine sensory neuron populations, with most HSV-1 LAT expression in A5(+) neurons and most HSV-2 LAT expression in KH10(+) neurons. To study the mechanisms regulating the establishment of HSV latency in specific subtypes of neurons, cultured dissociated adult murine trigeminal ganglion (TG) neurons were assessed for relative permissiveness for productive infection. In contrast to that for neonatal TG, the relative distribution of A5(+) and KH10(+) neurons in cultured adult TG was similar to that seen in vivo. Productive infection with HSV was restricted, and only 45% of cultured neurons could be productively infected with either HSV-1 or HSV-2. A5(+) neurons supported productive infection with HSV-2 but were selectively nonpermissive for productive infection with HSV-1, a phenomenon that was not due to restricted viral entry or DNA uncoating, since HSV-1 expressing ß-galactosidase under the control of the neurofilament promoter was detected in ∼90% of cultured neurons, with no preference for any neuronal subtype. Infection with HSV-1 reporter viruses expressing enhanced green fluorescent protein (EGFP) from immediate early (IE), early, and late gene promoters indicated that the block to productive infection occurred before IE gene expression. Trichostatin A treatment of quiescently infected neurons induced productive infection preferentially from non-A5(+) neurons, demonstrating that the nonpermissive neuronal subtype is also nonpermissive for reactivation. Thus, HSV-1 is capable of entering the majority of sensory neurons in vitro; productive infection occurs within a subset of these neurons; and this differential distribution of productive infection is determined at or before the expression of the viral IE genes.

A "shining" example of interstitial keratitis.

We present a case of interstitial keratitis, presumed to be herpetic, with a striking clinical appearance. A 67-year-old woman was initially diagnosed with viral conjunctivitis and ocular hypertension OD with conjunctival injection and elevated intraocular pressure (IOP). She later presented with a 'spot on my right eye' and, after referral, was diagnosed with presumed herpetic keratitis. She was treated with oral valacyclovir and topical prednisolone acetate. The cornea improved, leaving radiating lines in the corneal stroma. This case illustrates an unusual appearance of presumed herpetic stromal keratitis.

Tofacitinib for refractory ocular mucous membrane pemphigoid.

PURPOSE: To report the successful use of tofacitinib in the treatment of refractory ocular mucous membrane pemphigoid (MMP). OBSERVATIONS: Two patients with ocular MMP presented with refractory disease after failure of multiple therapies. Treatment with tofacitinib led to durable control of conjunctival inflammation within 8 weeks and no apparent progression of sub-conjunctival fibrosis. One patient maintained absence of apparent disease activity over 16 months of follow-up. Cessation of tofacitinib in the other patient led to disease relapse which was reversed by re-initiation of therapy. CONCLUSIONS AND IMPORTANCE: Small molecule inhibitors of Janus kinases, such as tofacitinib, may offer an effective treatment option for refractory ocular MMP.

Contralateral Eye Involvement and Retinal Detachment in Patients with Cytomegalovirus Retinitis Treated with Intravitreous Ganciclovir.

Purpose: To determine the incidence of contralateral eye involvement and retinal detachment in HIV-infected patients with cytomegalovirus retinitis treated with repeated intravitreous ganciclovir.Methods: In a prospective cohort study in Northern Thailand, HIV-infected patients with cytomegalovirus retinitis were treated with antiretroviral therapy and intravitreous ganciclovir injections and followed for 3 months for contralateral cytomegalovirus retinitis and retinal detachment.Results: Of 49 participants with unilateral cytomegalovirus retinitis at enrollment, 7 developed contralateral eye involvement (4.8/100 person-months, 95% CI 1.9-9.8). Of 105 eyes without a retinal detachment at enrollment, 6 developed a retinal detachment (2.0/100 eye-months, 95% CI 0.7-4.3). Baseline clinical factors were not associated with the development of either outcome.Conclusion: Eyes treated with intravitreous ganciclovir experienced retinal detachment at a rate similar to other populations treated with systemic antivirals. The risk of contralateral eye involvement was relatively high during the first 3 months after initial diagnosis despite the institution of antiretroviral therapy.

Comparison of automated and expert human grading of diabetic retinopathy using smartphone-based retinal photography.

PURPOSE: The aim of this study is to investigate the efficacy of a mobile platform that combines smartphone-based retinal imaging with automated grading for determining the presence of referral-warranted diabetic retinopathy (RWDR). METHODS: A smartphone-based camera (RetinaScope) was used by non-ophthalmic personnel to image the retina of patients with diabetes. Images were analyzed with the Eyenuk EyeArt® system, which generated referral recommendations based on presence of diabetic retinopathy (DR) and/or markers for clinically significant macular oedema. Images were independently evaluated by two masked readers and categorized as refer/no refer. The accuracies of the graders and automated interpretation were determined by comparing results to gold standard clinical diagnoses. RESULTS: A total of 119 eyes from 69 patients were included. RWDR was present in 88 eyes (73.9%) and in 54 patients (78.3%). At the patient-level, automated interpretation had a sensitivity of 87.0% and specificity of 78.6%; grader 1 had a sensitivity of 96.3% and specificity of 42.9%; grader 2 had a sensitivity of 92.5% and specificity of 50.0%. At the eye-level, automated interpretation had a sensitivity of 77.8% and specificity of 71.5%; grader 1 had a sensitivity of 94.0% and specificity of 52.2%; grader 2 had a sensitivity of 89.5% and specificity of 66.9%. DISCUSSION: Retinal photography with RetinaScope combined with automated interpretation by EyeArt achieved a lower sensitivity but higher specificity than trained expert graders. Feasibility testing was performed using non-ophthalmic personnel in a retina clinic with high disease burden. Additional studies are needed to assess efficacy of screening diabetic patients from general population.

Diabetic Retinopathy Screening with Automated Retinal Image Analysis in a Primary Care Setting Improves Adherence to Ophthalmic Care.

PURPOSE: Retinal screening examinations can prevent vision loss resulting from diabetes but are costly and highly underused. We hypothesized that artificial intelligence-assisted nonmydriatic point-of-care screening administered during primary care visits would increase the adherence to recommendations for follow-up eye care in patients with diabetes. DESIGN: Prospective cohort study. PARTICIPANTS: Adults 18 years of age or older with a clinical diagnosis of diabetes being cared for in a metropolitan primary care practice for low-income patients. METHODS: All participants underwent nonmydriatic fundus photography followed by automated retinal image analysis with human supervision. Patients with positive or inconclusive screening results were referred for comprehensive ophthalmic evaluation. Adherence to referral recommendations was recorded and compared with the historical adherence rate from the same clinic. MAIN OUTCOME MEASURE: Rate of adherence to eye screening recommendations. RESULTS: By automated screening, 8.3% of the 180 study participants had referable diabetic eye disease, 13.3% had vision-threatening disease, and 29.4% showed inconclusive results. The remaining 48.9% showed negative screening results, confirmed by human overread, and were not referred for follow-up ophthalmic evaluation. Overall, the automated platform showed a sensitivity of 100% (confidence interval, 92.3%-100%) in detecting an abnormal screening results, whereas its specificity was 65.7% (confidence interval, 57.0%-73.7%). Among patients referred for follow-up ophthalmic evaluation, the adherence rate was 55.4% at 1 year compared with the historical adherence rate of 18.7% (P < 0.0001, Fisher exact test). CONCLUSIONS: Implementation of an automated diabetic retinopathy screening system in a primary care clinic serving a low-income metropolitan patient population improved adherence to follow-up eye care recommendations while reducing referrals for patients with low-risk features.