Impact of the COVID-19 Pandemic on the Incidence and Characteristics of Culture-Positive Microbial Keratitis at a Tertiary Eye Hospital in the UK.

Purpose: The COVID-19 pandemic has led to drastic changes to the daily lives of those living in the United Kingdom. We hypothesized that the effect of the imposed lockdown on both behaviour and social interaction has the potential to influence the characteristics of microbial keratitis presenting locally to Manchester Royal Eye Hospital - a major tertiary eye centre in the UK. Methods: We conducted a retrospective case-note review of all positive corneal scrape cultures identified by our local microbiology laboratory during the year since the announcement of lockdown measures in the UK (23 March 2020 to 23 March 2021). Culture results were compared with previously collated, published "baseline" data from prior to the onset of the COVID-19 pandemic (2004-2019). Statistical analysis was undertaken, predominantly looking at the incidence of microbial keratitis and the variety of cultured pathogens. Results: A total of 6243 corneal scrape results were reviewed. Comparison of data between the COVID-19 pandemic and subsequent lockdown did not show a significant change in the incidence of culture-positive microbial keratitis: mean annual positive samples during 2004-2019 were 128 (35%) vs 91 (29%) during lockdown (P=0.096). No statistically significant shifts in the incidence of organism subtypes - fungi, acanthamoeba, Gram-positive bacteria, or Gram negative bacteria - were identified (P=0.196, 1, 0.366, and 0.087, respectively). Conclusion: Contrary to our hypothesis, our results suggest that the COVID-19 pandemic did not alter the incidence or characteristics of microbial keratitis presenting to Manchester Royal Eye Hospital in the year following the implementation of lockdown measures in the UK.

Trans-conjunctival Erosion of a Novel SIBS Microshunt After Revision Surgery Using Mitomycin C.

This article describes the first reported case of trans-conjunctival Preserflo microshunt erosion after revision surgery augmented with mitomycin C. Recommendations to avoid this complication include removal of original microshunt and limiting secondary application of mitomycin C.

A small gene sequencing panel realises a high diagnostic rate in patients with congenital nystagmus following basic phenotyping.

Nystagmus is a disorder of uncontrolled eye movement and can occur as an isolated trait (idiopathic INS, IINS) or as part of multisystem disorders such as albinism, significant visual disorders or neurological disease. Eighty-one unrelated patients with nystagmus underwent routine ocular phenotyping using commonly available phenotyping methods and were grouped into four sub-cohorts according to the level of phenotyping information gained and their findings. DNA was extracted and sequenced using a broad utility next generation sequencing (NGS) gene panel. A clinical subpanel of genes for nystagmus/albinism was utilised and likely causal variants were prioritised according to methods currently employed by clinical diagnostic laboratories. We determine the likely underlying genetic cause for 43.2% of participants with similar yields regardless of prior phenotyping. This study demonstrates that a diagnostic workflow combining basic ocular phenotyping and a clinically available targeted NGS panel, can provide a high diagnostic yield for patients with infantile nystagmus, enabling access to disease specific management at a young age and reducing the need for multiple costly, often invasive tests. By describing diagnostic yield for groups of patients with incomplete phenotyping data, it also permits the subsequent design of 'real-world' diagnostic workflows and illustrates the changing role of genetic testing in modern diagnostic workflows for heterogeneous ophthalmic disorders.

Macular pseudohaemorrhage secondary to Allen Dot artefact.

A 34-year-old highly myopic (-11.00 D) woman presented to eye clinic with a 3 day history of right eye paracentral blurring. Visual acuities were 6/6 bilaterally. Clinical examination was normal. Fundus photography showed the classic appearance of a macular haemorrhage. This is a recognised complication of high myopia and would have accounted for the patient's symptoms. However, further photography showed that the haemorrhage seemed to 'jump' around the fundus and was even present in the fellow eye. The apparent haemorrhage was revealed to be an imaging artefact. The 'Allen Dot' is a 6 mm black mask incorporated into retinal cameras to reduce reflection. Rarely, in highly myopic eyes, optical artefact can result. To the best of our knowledge, we are the first in the literature to report artefacts from the Allen Dot masquerading as ophthalmic disease. This case re-iterates the importance of clinical examination, especially in high myopes, given the current trend towards virtual clinics.

Postcoital visual loss due to valsalva retinopathy.

A 29-year-old male patient presented to eye emergency clinic after noticing a left paracentral scotoma on waking. On direct questioning the patient revealed an episode of vigorous sexual intercourse the preceding evening. During orgasm the valsalva manoeuvre can produce a sudden increase in retinal venous pressure resulting in vessel rupture and haemorrhagic retinopathy. Valsalva retinopathy is managed conservatively and the patient's symptoms resolved spontaneously without intervention. This case report highlights the importance of focused history taking of patients which can thereby obviate the need for further investigations. This case also emphasises the importance of considering sexual activity as a cause of stress-induced pathology.