key: cord-0707031-l1l99r1s
authors: Schlenker, Amanda; Tadrous, Carol; Ching, Geoffrey; Iovieno, Alfonso; Nathoo, Nawaaz; Liu, Tom; Yeung, Sonia N.
title: Retrospective analysis of ophthalmology referrals to a tertiary academic centre during the COVID-19 pandemic in comparison to the pre-COVID-19 era
date: 2021-03-05
journal: Can J Ophthalmol
DOI: 10.1016/j.jcjo.2021.02.034
sha: a00c3fcbdede30f8ffe0aec95a4f355e4187e7bb
doc_id: 707031
cord_uid: l1l99r1s

OBJECTIVE: This study was conducted to analyze emergency ophthalmology referrals to a Canadian tertiary academic centre during the current coronavirus disease 2019 (COVID-19) pandemic in comparison to pre-pandemic referrals. DESIGN: This was a retrospective chart review looking at emergency referrals seen by the ophthalmology service between March 18 to April 17, 2020 (representing the COVID-19 period) and March 18 to April 17, 2019 (representing the pre-COVID-19 period). METHODS: Data gathered from referral records included patient demographics, timing and site of referral, and ophthalmic diagnosis. Referrals were categorized as urgent or non-urgent, with urgent indicating the need for ophthalmic assessment within 24 hours. RESULTS: The total number of referrals decreased by 54.2% in the COVID-19 period versus the pre-COVID-19 period. There was a similar bimodal age distribution in both periods, with fewer patients over 65 years of age presenting during the pandemic. Tertiary hospital referrals decreased by 62% in the pandemic period, while non-tertiary emergency department referral trends varied and outpatient clinic referrals increased by 16%. Overall, there was a significant shift in the distribution of referral sites (p=0.04). The proportion of urgent referrals increased by 14% during the pandemic; this was not statistically significant. There was no significant change in the timing of referrals nor in the distribution of diagnostic segments. CONCLUSIONS: This study offers insight into the impact of the COVID-19 pandemic on ophthalmology referral patterns in a Canadian context. Moving forward, it helps to guide resource allocation and public education on the importance of seeking necessary eye care.

This study was conducted to analyze emergency ophthalmology referrals to a Canadian tertiary academic centre during the current coronavirus disease 2019 pandemic in comparison to pre-pandemic referrals.

This was a retrospective chart review looking at emergency referrals seen by the ophthalmology service between March 18 to April 17, 2020 (representing the COVID-19 period) and March 18 to April 17, 2019 (representing the pre-COVID-19 period).

Data gathered from referral records included patient demographics, timing and site of referral, and ophthalmic diagnosis. Referrals were categorized as urgent or nonurgent, with urgent indicating the need for ophthalmic assessment within 24 hours.

The total number of referrals decreased by 54.2% in the COVID-19 period versus the pre-COVID-19 period. There was a similar bimodal age distribution in both periods, with fewer patients over 65 years of age presenting during the pandemic. Tertiary hospital referrals decreased by 62% in the pandemic period, while non-tertiary emergency department referral trends varied and outpatient clinic referrals increased by 16%.

Overall, there was a significant shift in the distribution of referral sites (p=0.04). The proportion of urgent referrals increased by 14% during the pandemic; this was not

The Vancouver General Hospital (VGH) Eye Care Centre provides a busy ophthalmic service to a large metropolitan centre. This paper is an epidemiological study which aims to determine the impact of the COVID-19 pandemic on the incidence and distribution of ophthalmic emergencies in Vancouver. We hypothesized that there would be fewer referrals during COVID-19

but an increased proportion of urgent ophthalmic conditions as compared to before the pandemic. Our goal was to appreciate the effects of the pandemic on the public"s willingness to seek eye care, which would then help inform our triaging practices.

This study was a retrospective chart review of emergency referrals seen by the oncall ophthalmology service at the VGH Eye Care Centre. Approval for the study was (representing the pre-pandemic study period). The same calendrical date range from 2019 was selected as the pre-COVID-19 study period to account for potential seasonal variation in emergency referrals.

Patients first presented to referral sites for evaluation. Their cases were discussed by a referring physician with a resident ophthalmologist prior to acceptance for consultation.

Data extracted from referral records included patient age and sex, referring site, timing of presentation by day of the week and time of emergency department (ED) arrival, and ophthalmic diagnosis. Based on the ophthalmic diagnosis, referrals were categorized as either urgent or non-urgent. We defined an urgent referral as one requiring ophthalmic assessment within 24 hours of presentation to the referring site.

Diagnoses were classified as urgent based on practice patterns at our centre in addition to guidelines from other academic centres and ophthalmology societies. [3] [4] [5] [6] To determine if the categorical distribution of patients who presented from March 18 to April 17, 2020 varied from what was expected, a chi-square test was performed on eligible data. Where this analysis was not possible, a Student t-test was used. Both 2019 and 2020 data were used to generate the expected distributions in these analyses to account for differences in sample size between the years, while 2020 data accounted for the observed distributions. Normality of the data was assessed with the Kolmogorov-Smirnov Test. Statistical significance was set at p<0.05. Statistical analysis was conducted using R statistical software.

A total of 379 charts were reviewed over the two study periods. From March 18 to April 17, 2020, we received 119 emergency referrals, which by comparison to March 18 to April 17, 2019 (260 emergency referrals), represents a 54.2% decrease. Referral data such as time of arrival to the ED or referring site was not available for certain patients and in those instances could not be included in the respective data analyses. Sixteen of the referrals in 2019 and 5 of the referrals in 2020 did not present to our clinic for assessment and could not be reached for rescheduling; these were labelled as "no-show" and were not included in the statistical analyses for ophthalmic diagnosis. The no-show rate did not change significantly over the two time periods (6.1% in 2019 and 4.2% in 2020). All data was found to be normally distributed.

Patient age was categorized by decade. The 61-70 age group was the most common to present in both 2019 (21.6%) and 2020 (23.7%). Overall, there was a bimodal distribution of ages in the same pattern in both years without a statistically significant difference between the age groups. Male patients made up a slightly higher proportion of referrals in 2020 (58.0% versus 42.0% female) and there was no significant change in sex distribution between 2019 and 2020.

Referral sites in our study comprised one tertiary care centre (VGH), several non-tertiary (Fig.2) .

In 2019, 38.5% (n=94) of referrals were considered urgent. The proportion of urgent referrals rose to 43.9% (n=50) in 2020. This represented a 14% increase of the proportion of urgent referrals in the pandemic period, but this was not found to be statistically significant (p=0.87).

During the pandemic, most referrals presented during weekdays (80.7%) between 1200-1759 h (41.0%); this was not significantly different from the same period prepandemic (p=0.91). N o (0%) consults were seen directly via telehealth in the 2019 period, 9 (7.6%) patients were seen via telehealth in the 2020 period (p<0.0001). 2 (22%) of these consults were from a rural community, and 1 (11%) was from an inpatient setting at a tertiary hospital; the rest of the consults were from community hospitals or clinics.

Diagnostic categories were adapted from Alangh et al. 7 There was no significant difference between the distribution of diagnostic segments in 2019 and 2020 (p = 0.92).

Anterior segment pathologies represented the most common category in both 2019 and 2020 (Fig. 3) . A breakdown of the most common diagnoses within each diagnostic category is represented in Table 1 for 2019, and in Table 2 for 2020.

There is currently a relative lack of epidemiological data regarding how the COVID-19 pandemic has affected ophthalmic emergency presentations and referral patterns in We hypothesized that there would be a relative increase during times thought to be less crowded during the pandemic (overnight hours or first thing in the morning), but there was no statistically significant shift in this regard. This may be due to overall less crowding of the EDs during COVID-19. Additionally, the baseline distribution of "busy" hours in EDs was likely shifted due to altered working hours for a larger proportion of patients working from home and self-isolating during the pandemic.

We had hypothesized that the number of urgent referrals would be similar between 2019 and 2020 while the number of non-urgent referrals would diminish. What we saw instead, however, was that both urgent and non-urgent referrals decreased in similar fashion; there was a trend towards a greater decrease in non-urgent referrals, but this was not statistically significant. One concern relating to this overall decrease in urgent presentations would be that patients with significant pathologies did not present in a timely fashion, and it remains to be seen what the sequelae of this delay will be for the individual patients and for the population.

Further insight into the epidemiological trends in emergent ophthalmic care associated with the initial wave of the COVID-19 pandemic can be derived from European publications on this topic. These studies found a 65% to 73% decrease in the number of ophthalmic emergencies in 2020 in comparison to a comparable period. [8] [9] [10] Comparatively emergent diagnoses were agreed to have increased by 7.4 to 11

percentage points while those that were comparatively less emergent decreased by 8.6

to 14.1 percentage points. 8, 9 These findings were in line with those found by the current study, as would be expected from studies carried out in similar public healthcare institutions in the midst of the pandemic.

The most notable limitation of this study is that it is retrospective in nature, hence it lacks the design and data on confounding factors to most accurately characterize ophthalmic referrals. Another limitation is that this is a relatively small sample size, looking at one month for each period compared, and hence with a larger data pool, more power can be applied to our statistical analyses. Furthermore, we only looked at the very beginning of lock downs during the first wave. Population behaviour and public healthy guidance all experienced dramatic shifts in the subsequent months.

This study provides data comparing the most commonly referred ophthalmic pathologies to the on-call ophthalmology service at the VGH Eye Care Centre before and during the COVID-19 pandemic. Information gleaned from this study offers insight into how this pandemic has affected referral patterns to ophthalmology. Knowledge regarding the most common presentation to our ophthalmic department during the current pandemic will aid our department in better preparedness moving forward. The steep drop in eye-related visits was likely a result of pandemic lockdown and careavoidance behaviour, so one potential area of improvement may be further increased utilization of telehealth in ophthalmic triage to counteract this effect. This shift to teleophthalmology has been seen and explored further in depth in other eye care institutions such as Moorfields Eye Hospital. 11

Another area of improvement could be increasing access for community clinicians to arrange expedited ophthalmic referrals. For example, a rapid access clinic at the teaching hospital will help patients bypass the ED and reduce risk of exposure. It would be of utmost importance to continue to find ways to educate the public as well as primary healthcare providers as to which eye conditions are considered urgent and thus needing immediate attention, even in the midst of a pandemic.

During a pandemic lockdown, it appears that all patients, both with urgent and nonurgent eye complaints, stayed away from EDs. It is key to note that there was a trend towards a rise in the percentage composition of urgent consults. In addition, the notable decrease in urgent consults from tertiary EDs and corresponding increase in number of presentations from non-ED sites may suggest that there was a shift in burden and distribution of ophthalmic disease during the early stages of the pandemic. As such, it is paramount for ophthalmologists across Canada to increase awareness and to improve accessibility to eye care for patients during similar scenarios in the future. 

Optic neuritis (1.8) Cranial nerve palsy (1.8)

Facial burns (1.8) Orbital wall fractures (0.9) Orbital foreign body (0.9) Lid laceration (0.9)

Posterior vitreous detachment (11.4) Diabetic retinopathy (3.5) Vitreous syneresis (2.6) Hemorrhagic posterior vitreous detachment (2.6) Retinal vein occlusion (2.6)

High myopia (0.9) Refractive monocular diplopia (0.9)

Anterior uveitis (5.3) Herpetic related (3.5) 

Sustainable practice of ophthalmology during COVID-19: challenges and solutions

The impact of COVID-19 pandemic on ophthalmological emergency department visits

List of urgent and emergent ophthalmic procedures

Canadian Retina Society (CRS) Position Statement on Intravitreal Injections and the Management of Retinal Diseases during the COVID-19 Crisis

Moorfields Ophthalmic Risk Stratification Implementation Guideline Version 2

Retrospective analysis of ophthalmology referrals to a tertiary academic teaching centre

Ophthalmic referrals from emergency wards a study of cases referred for urgent eye care (The R.E.S.C.U.E Study)

Impact of the COVID-19 pandemic on ophthalmic emergency services in a tertiary hospital in Spain

Ophthalmological emergencies and the SARS-CoV-2 outbreak

The impact of COVID-19 pandemic on ophthalmological emergency department visits

Creating the Moorfields' virtual eye casualty: video consultations to provide emergency teleophthalmology care during and beyond the COVID-19 pandemic

All authors have no conflict of interest to declare relevant to the subject of this study.

Financial support: None Additional contributions: None