COVID-19 and the Eye: Impact of COVID-19 Pandemic on Clinical, Surgical and Research Activities in Ophthalmology

Since the outbreak of the novel SARS-CoV-2 virus in early 2020, globally, more than 500 million cumulative cases of COVID-19 have been confirmed as of May 2022, resulting in about 6 million deaths [1]. Physical distancing measures, face masks and home confinement have been adopted worldwide to limit the transmission of the disease, while vaccination programs proved effective in reducing admissions to intensive care. However, as the state of emergency continued, there has been a growing interest in the long-term medical and social effects of the pandemic.

Among others, ophthalmological practice has been affected by the pandemic to a varying extent. On one hand, ocular diseases may arise as a direct effect of SARS infection. Viral conjunctivitis is the most common ophthalmic manifestation, and it is especially frequent in symptomatic COVID-19 patients. Furthermore, a wide variety of vascular, inflammatory and neurological diseases of the posterior segment have also been recorded, including central retinal vein occlusion, central retinal artery occlusion, posterior uveitis, vitritis, paracentral acute middle maculopathy and acute macular neuropathy [2]. Mass vaccination holds a key role in the management of the pandemic, but it has recently been reported by several authors that acute corneal transplant rejection may occur weeks after COVID-19 mRNA vaccine administration [3].

On the other hand, restrictive measures for the containment of the pandemic may be indirectly responsible for ocular diseases. The home confinement of school-aged children is a subtle threat. Insufficient time spent outdoors and near work activities are recognized as important risk factors for myopia development and progression (“quarantine myopia”). Delaying ophthalmic examination due to COVID-19 concerns may further exacerbate this condition, possibly leading to amblyopia and visual disability [4]. Furthermore, it has been reported that sustained near point demands due to the excessive use of computers, tablets and smartphones can also trigger acute acquired concomitant esotropia [5]. Conversely, the sudden shift in lifestyle (home confinement) led to a significant reduction in the number of eye injuries, as demonstrated by the decreased access to emergency care [6]. The increased burden of myopia is a serious concern for our healthcare systems, and a post-pandemic ophthalmological surveillance program may be a successful way to reduce visual impairment and sight-threatening complications [4].

During the pandemic, an increased incidence of dry eye syndrome has been reported, likely caused by both higher exposure to visual display terminals and the widespread use of face masks (“mask-associated dry eye”). The displacement or incorrect fitting of the mask, resulting in air leaking around the eyes and rapid evaporation of tears, is considered the main causative mechanism [7].

Finally, restrictive measures also had a detrimental impact on the organization of clinical and surgical activities. Dell’Omo and colleagues compared the number of eye surgical procedures performed in Italy during the 2-month-long lockdown due to COVID-19 (March–April 2020) with those performed in the corresponding period of the year 2019. Elective surgeries were impacted the most, showing a 96.4% reduction, while urgent surgeries and intravitreal injections (IVIs), respectively, reduced by 50.2% and 48.6% [8]. Pellegrini and colleagues also reported a 73.0% decrease in the number of visits at the ophthalmological emergency department during the national lockdown in Italy compared to the same period of the previous year [9]. Even after lockdown, many patients avoided attending medical visits due to fear of being infected with COVID-19.

Limited access to ophthalmological care may lead to late diagnoses, unsatisfying management, or even irreversible visual impairment, especially among patients who require close follow-up and chronic treatments. In particular, delaying or reducing the required number of IVIs in patients determines an increased risk of vision loss. Due to the high number of patients requiring IVI therapy, a multi-step algorithm to prioritize the most severe cases was developed [10,11]. When possible, sustained-release intravitreal implants may be preferred [12].

In conclusion, the troublesome, yet necessary, impact of public health safety measures against COVID-19 pandemic should be promptly addressed in the ophthalmological setting. Patients should be encouraged to follow an appropriate scheduling of visits. Saving costs, resources and time has played a key role during the pandemic, often making the difference between therapeutic success and failure. When possible, telemedicine offers novel benefits to patients in terms of saving time and costs while avoiding physical contact [13].