In The Global Impact of COVID-19 on Eyecare and Eye Health – Part 1, we explored how the COVID-19 pandemic and associated safety measures have restricted access to eyecare and prompted rapid changes in the provision and delivery of eye health services worldwide. The evolution of clinical services may benefit patients in the long term, but as the pandemic continues into its second year, it is worth exploring areas in which COVID-19 may have led to an adverse direct or indirect impact on ocular health.
Direct effects of COVID-19 on the eye
According to a recent meta-analysis of published studies, approximately 11% of COVID-19 patients have exhibited direct ocular effects (1). Typically, the complications appear to be relatively mild and short-term. The most common ocular manifestation of COVID-19 infection is unilateral or bilateral conjunctivitis (typically viral), while ocular pain, dry eye, floaters, eyelid dermatitis and keratoconjunctivitis have also been reported. A study from Anglia Ruskin University has found that sore eyes appear among the most commonly reported symptoms of COVID-19 and that ocular symptoms manifest simultaneously to other COVID-19 symptoms.
The treatment of patients with severe complications of COVID-19, which required prolonged prone-position ventilation, has led to some more serious ocular complications. Case studies have been published relating to ICU patients who developed significant periorbital edema, two of whom also developed orbital compartment syndrome (increased IOP of 2- to 3-fold in prone positioning) and papillophlebitis (optic disc elevation with associated hemorrhages) following four to nine 18-hour ventilation sessions in the prone position.
Indirect effects of COVID-19 on the eye
The indirect effects of COVID-19 are much broader and relate to various causative factors, including service delays, lifestyle and behavioural changes and psychosocial impacts. While the long-term ocular health and quality of life impact of COVID-19 will be challenging to quantify, significant concerns exist. Some evidence has started to emerge, which clinicians may need to address in the post-COVID pandemic period.
Service delays and cancellations
Since COVID-19 emerged, lockdowns and concerns about virus exposure have caused cancellations and delays to routine appointments. These measures present a particular challenge in treating age-related conditions, given that the mortality from COVID-19 is highest in the age group of patients most likely to suffer eye disease. Treatment of neovascular age-related macular degeneration with vascular endothelial growth factor (VEGF) inhibitors therapy is an obvious example, as regular and frequent treatments are necessary for optimal outcomes in most patients. Delays in the care of new-onset and persistently active cases are a reality because the potentially life-threatening risk of COVID infection may outweigh the risk of recurrence and visual loss. How big this risk of visual loss is, and over what period it may manifest, remain unclear. Even after the lockdowns and risks of COVID have hopefully receded, waiting lists for care for this and other conditions such as cataracts and glaucoma will take time to address. They will inevitably lead to vision loss which may have a significant and lasting quality of life impact.
Lifestyle and behavior change
A new article of clothing has emerged in the past year, the face mask, which has also given rise to a new phenomenon known as Mask Associated Dry Eye (MADE). Widespread use of face masks, while essential for the prevention of novel coronavirus transmission, may cause ocular dryness and irritation due to increased airflow upwards from under the mask. This accelerates evaporation of the tear film and may result in ocular surface irritation or inflammation.