Purpose of Review: Corneal neuropathic pain can be difficult to treat, particularly due to its lack of response to standard dry eye therapies. We describe a variety of topical therapeutic options that are available to treat corneal neuropathic pain with a significant or primary peripheral component. We also describe possible mechanisms of action for such topical therapies. Recent Findings: Topical corticosteroids and blood-derived tear preparations can be helpful. Newer therapies, including topical lacosamide and low-dose naltrexone are emerging therapeutic options that may also be considered. Summary: Corneal neuropathic pain with a significant peripheral component may be managed with a variety of topical therapeutic options.

Purpose of review

Given the impact that society as a whole, and medicine specifically, has experienced as a result of the COVID-19 pandemic, an examination of clinical care changes enacted in the field of ophthalmology is of interest to the specialty.

Recent findings

In order to adapt to the reality of the COVID-19 pandemic, measures, such as broadening telehealth capabilities, adopting universal masking, careful sanitation procedures, applying virtual teaching in academic environments, and deferring elective surgeries were put in place. These were aimed at reducing person-to-person spread of SARS-CoV-2. Though best efforts were made at triaging ophthalmic emergencies during these times, unfortunate delays in care were observed in some circumstances. Finally, a prospective study interrogating the risk of spread at slit lamp distances for short periods of time was encouraging, suggesting low risk of transmissibility, though limited by a small case-positive sample size.

Summary

Significant changes have been made in the design and delivery of ophthalmic care during the COVID-19 pandemic. Some of these, such as telemedicine, may provide value in a postpandemic world.

Purpose

To describe a unique case of LASIK flap fungal keratitis confirmed by next generation sequencing.

Observations

A 56-year-old female presented with refractory keratitis involving her LASIK flap 21 years after surgery. Confocal was positive for filamentous structures. The patient underwent immediate flap amputation followed by topical antifungal treatment. Corneal culture was positive for Acremonium sp. Metagenomic deep sequencing confirmed Acremonium as the primary source of infection and also identified Fusarium as a likely contributor of a mixed fungal infection. Sequencing also identified hay as the likely source of the infection. Treatment resulted in eradication of the infection. The patient's final best corrected visual acuity was 20/30 with rigid contact lens overrefraction.

Conclusions

Metagenomic deep sequencing is a novel diagnostic tool that is increasingly being utilized for diagnosis of refractory keratitis. This case demonstrates the diagnostic potential of deep sequencing for identifying post-LASIK keratitis and reinforces the utility of LASIK flap amputation in the setting of tectonic flap instability due to keratolysis.

Importance

This case highlights several important clinical points for treating LASIK flap keratitis and highlights the emerging role metagenomic sequencing has in the diagnosis of infectious keratitis. This is first known case using next generation sequencing to diagnose a post-LASIK infectious keratitis.

Purpose

To describe a case of central corneal ulceration in a newborn secondary to congenital entropion.

Observations

Corneal ulcers during infancy are rare and may occur secondary to congenital structural anomalies, including congenital entropion. Correct anatomic eyelid position in newborns is challenging to determine with closed eyelids, and eyelid squeezing during crying and discomfort adds to this challenge.

Conclusions and importance

This report reinforces the importance of careful examination of the adnexa in infants with corneal ulcers while they are most comfortable, usually after topical anesthesia and prior to placement of eyelid speculum. Ophthalmologists caring for infants must be able to detect this condition because prompt entropion repair is necessary for corneal ulcer resolution and prevention of permanent vision loss.

Background

To determine if there is a difference in the quantity of microbial flora of the conjunctiva in individuals practicing head submersion ("dunk") versus no head submersion ("no-dunk") during hot tub use.

Methods

In this double-blind randomized clinical trial, healthy volunteers aged ≥ 18 years were recruited. Participants were randomized to head submersion versus no head submersion during a 15-minute hot tub soak. Study personnel, masked to the dunk or no-dunk group assignment, obtained conjunctival cultures before and immediately after hot tub use. De-identified specimens were submitted to the clinical microbiology laboratory for culture and analysis. The main outcome measure was the difference in the quantity of organisms cultured from the conjunctiva before and after hot tub exposure, as determined using a defined ordinal scale. A two-tailed Student's t-test was performed to compare the total microbial colony counts between the two arms. Simpson's diversity was used to measure the changes in organism diversity between the arms.

Results

Of 36 enrolled subjects, 19 were randomly assigned to the dunk and 17 were assigned to the no-dunk groups. Water samples obtained from all hot tubs were culture negative. Eleven of 19 eyes (58%) from the dunk group and eight of 17 eyes (47%) from the no-dunk group had negative conjunctival bacterial cultures before and after hot tub exposure. However, six of 19 eyes (32%) and four of 17 eyes (24%) of the dunk and no-dunk groups, respectively, were culture-positive after, but not before hot tub exposure. The quantity of organisms before and after hot tub exposure was not significantly different between the two arms (P = 0.12). However, the dunk group only showed a small increase in the quantity of organisms after as compared to before hot tub use (P = 0.03). None of the samples from subjects or hot tubs were culture-positive for Acanthamoeba.

Conclusions

Head submersion in a public hot tubs during a 15-minute soak does not appear to change conjunctival flora, as determined by culture plate yield, this does not eliminate the association between hot tub use and devastating and painful corneal blindness. Therefore, our recommendation is to remove contact lenses prior to hot tub use, avoid head submersion in a hot tub, and urgently seek ophthalmological help if any eye pain and/or decrease in vision is experienced after hot tub use.

Purpose

To report our experience with 2 cases of Capnocytophaga keratitis.

Methods

This is a retrospective study of case reports. We present the clinical presentation, diagnosis, and treatment strategies of 2 patients who presented with Capnocytophaga keratitis.

Results

Both patients had risk factors including systemic immune compromise and ocular trauma. Both patients had robust inflammatory keratitis with necrosis. Case 1 demonstrates identification of Capnocytophaga with traditional microbiologic techniques. Case 2 demonstrates the use of unbiased metagenomic deep sequencing for identification of this unusual corneal pathogen.

Conclusions

Capnocytophaga is a rare and aggressive infection. Even when traditional culture identifies the pathogen rapidly, keratitis can progress to perforation. In cases of severe keratitis in which traditional culture methods are unrevealing, metagenomic deep sequencing has potential to provide actionable diagnoses.

Background

In a prior study at the start of the pandemic, we reported reduced numbers of Google searches for the term "conjunctivitis" in the United States in March and April 2020 compared with prior years. As one explanation, we conjectured that reduced information-seeking may have resulted from social distancing reducing contagious conjunctivitis cases. Here, after 1 year of continued implementation of social distancing, we asked if there have been persistent reductions in searches for "conjunctivitis," and similarly for other communicable disease terms, compared to control terms.

Objective

The aim of this study was to determine if reduction in searches in the United States for terms related to conjunctivitis and other common communicable diseases occurred in the spring-winter season of the COVID-19 pandemic, and to compare this outcome to searches for terms representing noncommunicable conditions, COVID-19, and to seasonality.

Methods

Weekly relative search frequency volume data from Google Trends for 68 search terms in English for the United States were obtained for the weeks of March 2011 through February 2021. Terms were classified a priori as 16 terms related to COVID-19, 29 terms representing communicable conditions, and 23 terms representing control noncommunicable conditions. To reduce bias, all analyses were performed while masked to term names, classifications, and locations. To test for the significance of changes during the pandemic, we detrended and compared postpandemic values to those expected based on prepandemic trends, per season, computing one- and two-sided P values. We then compared these P values between term groups using Wilcoxon rank-sum and Fisher exact tests to assess if non-COVID-19 terms representing communicable diseases were more likely to show significant reductions in searches in 2020-2021 than terms not representing such diseases. We also assessed any relationship between a term's seasonality and a reduced search trend for the term in 2020-2021 seasons. P values were subjected to false discovery rate correction prior to reporting. Data were then unmasked.

Results

Terms representing conjunctivitis and other communicable conditions showed a sustained reduced search trend in the first 4 seasons of the 2020-2021 COVID-19 pandemic compared to prior years. In comparison, the search for noncommunicable condition terms was significantly less reduced (Wilcoxon and Fisher exact tests, P<.001; summer, autumn, winter). A significant correlation was also found between reduced search for a term in 2020-2021 and seasonality of that term (Theil-Sen, P<.001; summer, autumn, winter). Searches for COVID-19-related conditions were significantly elevated compared to those in prior years, and searches for influenza-related terms were significantly lower than those for prior years in winter 2020-2021 (P<.001).

Conclusions

We demonstrate the low-cost and unbiased use of online search data to study how a wide range of conditions may be affected by large-scale interventions or events such as social distancing during the COVID-19 pandemic. Our findings support emerging clinical evidence implicating social distancing and the COVID-19 pandemic in the reduction of communicable disease and on ocular conditions.

Background

Recurrent conjunctivitis epidemics are prevalent worldwide. Aetiologies are often undetermined.

Methods

We surveyed conjunctivitis researchers about perceived trends in prevalence, incidence and aetiologies of conjunctivitis epidemics.

Results

Of the 155 participants, 7% endorsed globally variable and dynamic microbial aetiologies of conjunctivitis epidemics. Increased incidence of conjunctivitis epidemics over the last decade were reported by 21% of respondents. Peak seasons differed between the northern and southern hemispheres.

Conclusions

There is regional equipoise regarding the increasing incidence and emerging underlying aetiologies of epidemic conjunctivitis. Further investigation of global surveillance and microbial characterization of conjunctivitis outbreaks could improve prevention and outcomes.

Purpose

Acanthamoeba keratitis often is refractory to medical and surgical therapy, primarily because of the remarkable resilience of Acanthamoeba cysts. In this study, we directly compared the cysticidal activity and potency of several candidate medical therapies in vitro.

Design

Experimental study.

Participants

In vitro Acanthamoeba specimens obtained from 9 patients with keratitis seen at the Francis I. Proctor Foundation from 2008 through 2012.

Methods

The minimum cysticidal concentration (MCC) of povidone iodine, natamycin, and chlorhexidine was investigated using an established assay technique. The relative potency of each agent was estimated starting with concentrations commonly used in clinical practice and determining the number of two-fold dilutions required to reach the MCC. Statistical comparisons of relative potency were performed using bootstrap simulations and permutation tests.

Main outcome measures

Minimum cysticidal concentration and the number of two-fold dilutions required to reach the MCC.

Results

The MCC for chlorhexidine ranged from 3.1 to 25 μg/ml (median, 12.5 μg/ml; interquartile range [IQR], 6.25-12.5 μg/ml), the MCC for natamycin ranged from 390.6 to 3125 μg/ml (median, 390.6 μg/ml; IQR, 390.6-781.2 μg/ml), and the MCC for povidone iodine ranged from 0.3 to 78.1 μg/ml (median, 2.4 μg/ml; IQR, 0.6-9.8 μg/ml). Doses commonly used in clinical practice (povidone iodine 1%, natamycin 5%, and chlorhexidine 0.04%) were approximately 12, 7, and 5 two-fold dilutions higher than the drug's corresponding median MCC, respectively (P < 0.001, comparing 3 drugs). Povidone iodine 1% had the highest potency of the 3 medications tested, requiring more dilutions than natamycin 5% (P < 0.001) and chlorhexidine 0.04% (P < 0.001) to reach the MCC.

Conclusions

All 3 medications demonstrated in vitro cysticidal activity in each of the 9 isolates. The potency of 1% povidone iodine was greater than standard formulations of natamycin or chlorhexidine. Although its clinical efficacy is yet to be determined, povidone iodine may be considered as a potential adjuvant treatment in cases of recalcitrant Acanthamoeba keratitis.