Our study looked at the sustained effect of the COVID-19 pandemic and the resulting lockdowns and restrictions on RRD clinical characteristics and outcomes compared to pre-pandemic presentations. Lower numbers of presentations with RRD were initially observed during the first lockdown, consistent with findings from other studies [3,4,5,6,7]. Numbers of RRD presentations increased steadily, approaching Group 1 levels by the lifting of the first national lockdown in July 2020 (with a considerable surplus in September 2020 relative to Group 1 noted). The higher proportion of macula-off RRD during the period of the first lockdown, suggestive of late presentation to ophthalmic services, is also consistent with the findings of other studies [3,4,5,6,7]. However, we found these trends were observed only for the first lockdown period and further restrictions in September and the second national lockdown did not see a difference with pre-COVID-19 levels. A common trend across all our subgroups is that after the introduction of the second national lockdown, little difference is seen between both groups and healthcare systems, and patient attitudes to presentation seem to have reverted to pre-COVID-19 levels.
During the first lockdown period, Poyser et al. observed higher rates of males presenting to their ophthalmic service with VR pathologies , and our previous study also observed the same trend with regards to patients presenting with retinal tears requiring primary retinopexy . This gender disparity was not demonstrated in this study with similar proportions of each gender in both groups.
From the introduction of the second national lockdown period (October 2020, with local restrictions from September 2020), presentations to the ophthalmic service, a surrogate marker for patient attitudes, suggest that the numbers have returned to those of pre-COVID-19 levels. The reasons for this are likely multi-factorial. Relatively little was known about COVID-19 at the time of the first lockdown being enforced, including which groups of people were most at risk. By the timing of the introduction of the second lockdown, patients who may have waited for the resolution of the pandemic prior to presenting may have not anticipated the length of time the restrictions would remain in place. The decline in presentation to emergency services or primary care services was also demonstrated across a range of medical conditions (e.g. myocardial infarctions, cerebrovascular accidents) at the beginning of the lockdown period [14, 15]. However, patient attitudes are unlikely to be the only reason for the reduced presentation. Access to primary care services was also likely to be a contributing factor. Primary care contact for key physical and mental health conditions dropped substantially after lockdown restrictions were introduced in March 2020 and though it showed signs of recovery later on, by July 2020 (lifting of the first national lockdown) it remained below that of pre-lockdown levels . NHS 111, the 24/7 urgent telephone helpline, saw a sharp increase in its utilisation in March 2020 in response to patients being unable to contact primary care contacts; however, over 50% of the calls were not answered. This may have also contributed to the reduction in timely presentations at the start of the first lockdown period as patients may have been unable to obtain their triage advice . With the on-going pandemic, health services had a chance to adapt their policies and emergency services, with more understanding regarding the condition (including how to reduce transmission), to be more accessible to the most at-risk patients. As such, the findings seen at the start of the first lockdown have not been sustained and the numbers presenting to our service have recovered to pre-pandemic levels.
Increase in PVR at presentation, again a marker of delayed presentation, has been repeatedly reported. Patel et al. reported an increase in PVR at presentation in their cohort (13.4% vs. 4.5% in the control group, p = 0.03; ) as did Awad et al. (24.3% vs 9.8% in the control group, p = 0.0471; ). This correlated with their findings of decreased macula-on RRD presentations compared to their pre-pandemic control groups. This was concerning as PVR is the leading cause of retinal detachment surgery failure and studies suggested that over time, we may be faced with the prospect of more complex and challenging retinal detachments to manage with poorer prognoses [4, 7, 18, 19]. Our study, which investigated a larger cohort of patients over a longer period of time, did not observe this finding. Rates of any PVR at presentation were similar in both Groups 1 and 2 (8.2% and 7.8%, respectively) with a slight decrease in PVR‑C noted in Group 2 over the study period (however, this did not reach statistical significance). Our current cohort of patients in this study also includes a significantly greater number of patients than the previously mentioned studies . It is unclear why our cohort of patients did not experience a significantly higher rate of PVR compared to other studies. One reason may be the maintenance of our dedicated ophthalmic theatres for emergency work in our tertiary referral unit during this period. Other units which share theatres with other specialities may have seen a delay in treatment due to the overall disruption of services, particularly around the time of the first lockdown. Throughout the study period, however, our service was able to maintain dedicated VR theatres for emergency work and hence this would have contributed to minimising any delays to treatment. We also found differences in gas tamponade relative to the pre-Covid-19 years. When comparing the year 2020 with each year since 2017 (Supplementary Fig. 1), the year 2020 represents a reduction in oil tamponade from the increasing trend in the years preceding and an increase in longer-acting gas tamponade. Since oil tamponade requires removal of oil at a later date, which takes theatre capacity, there was a shift towards longer-acting gas tamponade use in an attempt to avoid multiple procedures.
We have previously reported that socioeconomic deprivation leads to higher failure rates in a risk-adjusted cohort . However, this study was also the first to look at the impact of socioeconomic deprivation on RRD rates as affected by the pandemic. In our cohort, those from areas of higher socioeconomic deprivation were not as adversely impacted as those from areas of least socioeconomic deprivation. Patients from areas of least socioeconomic deprivation had a higher proportion of macula-off RRD in 2020 relative to the pre-COVID-19 years, an observation not made with the most deprived group (Fig. 3a). Additionally, pre-COVID-19, the least deprived had significantly better visual outcomes compared to during the COVID-19 pandemic.
This observation is in stark contrast to the disparity in the number of cases and mortality rates from COVID-19 seen between those living in areas with the highest levels of socioeconomic deprivation versus those in the lowest. Those living in the areas with the highest levels of socioeconomic deprivation saw significantly higher number of cases of COVID-19 and more than double the mortality rates compared to areas with lower levels of deprivation . This could suggest that those in areas of higher deprivation are less likely to modify their behaviour to comply with lockdown regulations (and hence would be at higher risk of infection) but as a result of not modifying their behaviour, they are more likely to attend health services sooner than those from areas of least deprivation. This is an interesting observation and would benefit from further studies.
Study limitations and strengths
The limitations of our study include its retrospective nature and the lack of case randomisation. Additionally, the lens status at the time of final VA measurements was not available. A prospective study would not have been possible for this comparison because of the serious health effects of COVID-19 on society and the healthcare logistics behind the planning of a prospective study. Besides, we have used RRD surgery as a rate of failed retinal detachment surgery at 3 months, which is a relatively short time to assess the retinal re-detachment rate following primary RRD repair. However, in our study, a significant difference was detected in this period for the least deprived group. Nevertheless, our study is the largest at assessing the sustained effect of COVID-19 with multiple lockdowns on clinical presentation and post-RRD repair outcomes in our group of patients as well as the differences between different levels of IMD.