New Delhi: Dinesh Gupta, 56, of Ahmedabad has lost his vision partially and says it happened after he contracted Covid-19 in June. “On 10 June, I was admitted to hospital because I tested positive. A few days after I was discharged on 18 June, I noticed black spots in my vision and immediately rushed to hospital. After my initial scans, the doctor told me that I would have to be rushed for surgery.”
Gupta said he has been told he will have to permanently undergo treatment in his left eye for cataract-like symptoms, a problem he didn’t have before.
Meanwhile, Deepak Patel, a 27-year-old daily-wage labourer in Ahmedabad who has recovered from Covid-19, has lost 80 per cent of his vision, having suffered severe retinal damage due to a vascular blockage.
“A week after I recovered from Covid, I felt my vision blurring. Initially, my physician told me that it was possibly due to post-Covid fatigue. As days passed, my vision got worse and I was referred to a retina specialist. I was given injections to make the clot go away,” he said, adding that he is unlikely to recover his vision.
Dr Harjit Singh Bhatti of the All India Institute of Medical Sciences (AIIMS) Delhi said he has not “come across a lot of Covid patients complaining of eye damage”. “But in the past few days, I have had one patient complain of loss of vision. Since she was old and a recovered Covid-19 patient we could not find the cause of the blindness,” he said.
Doctors say there are no large-scale studies so far to conclusively prove a connection between Covid-19 and vision problems, but many recovered patients have been reporting eye issues. A possible explanation offered for this phenomenon is that Covid infection has been linked to thrombosis, or the emergence of clots in the body’s circulatory system.
Speaking to ThePrint, doctors say there is not enough evidence for recovered patients of Covid-19 to begin worrying just yet, but urge caution. They advise early intervention for any vision problem experienced in the aftermath of a Covid infection.
Problems patients are facing
Dr Parth Rana, an Ahmedabad-based ophthalmologist who runs a private hospital, said he had been visited by at least 12 recovered Covid patients for consultations on eye problems.
According to ophthalmologists, recovered Covid-19 patients have been primarily reporting two types of eyesight-related problems.
The first — and more common — is temporary loss of vision due to a suspected weakening of muscles. “Post Covid-19, most patients complain of fatigue. This means that the muscles of their body do not have enough energy to function, because of which their eye muscles get weak and they witness a blurring of vision,” said Dr Rana.
“This is the milder of the two problems and patients usually recover and are able to regain their eyesight once their body is able to effectively heal and provide enough fuel for the muscles to function,” he added.
The second issue is the more problematic one. Opthamologists refer to it as central retinal artery occlusion or “vascular blockage”.
In June, it was reported that autopsies conducted on Covid patients revealed that the disease is not just respiratory, but also ravages the circulatory system. Other pieces of research as well as doctor experiences have pointed to a link between Covid-19 and thrombosis, or clotting in blood vessels, which can obstruct the flow of blood through the circulatory system.
While some vessels (arteries and veins) are big enough to let the clots travel, others — like those in the eyes or hands — are too narrow. A clot passing through the vessels in the eyes can thus get stuck and stop the blood supply to the retina.
Bengaluru-based ophthalmologist Dr Rajashekar Y.L. said, “We have been seeing a lot of Covid-19 recovered patients coming to eye hospitals after weeks to months of recovery with various eye conditions.”
According to Rajashekar, who serves as president of the Karnataka Ophthalmic Society, “some of the more common eye problems we are seeing are redness of eyes and conjunctivitis-like conditions, a corneal condition called keratitis (inflammation of the cornea), conjunctival chemosis, which appears like swollen eyes, double vision due to nerve paralysis in the eye, and cases of vascular blockages as well”.
Dr Subhendu Boral, a retina specialist based out of Kolkata, said he had also witnessed “increased cases of central retinal artery occlusion (CRAO) or ‘vascular blockage’ along with conjunctivitis-like conditions”.
“I have seen a particular increase in referrals of patients with CRAO, a rare disease, which previously had an incidence rate of 1-2 patients a year. This year, in the last six months, I have treated about 7 such (recovered Covid) patients. These numbers may seem small but considering the rarity of the disease this is about a 300 per cent rise in the number of cases.”
Dr Boral said he would earlier not “feel the need for surgically operating such patients because they were too few in number”, preferring a long-term approach with drugs.
“With the increasing incidence of such blockages, we are now exploring the possibility of operating and removing the thromboembolism,” he added.
Dr Rana said he uses low-molecular-weight heparin (LMWH) or blood thinners to dissolve the clots in such patients.
“If this clot is not treated in the first four to six hours, then it can cause damage to the retina. But if this is left untreated for 24 hours or more, it can lead to permanent blindness,” he added.
“This is why whenever a Covid patient complains of blindness or loss of eyesight, the doctor should immediately check their retina because it can lead to permanent damage in their eyes,” said Rana.
While the use of blood thinners like aspirin is debatable and comes with its own side-effects, doctors say they are using them as precautionary treatment for Covid patients with comorbidities like diabetes and blood pressure, conditions which can lead to thickening of blood.
Dr Rajashekar said it is “important that Covid-recovered patients keep a check to ensure good health of their eyes but they should, at the same time, not worry about losing eyesight as a side-effect of Covid”.
“Timely treatment and the right care is of the essence and can go a long way in ensuring good health for their eyes,” he added.
‘Take it with a pinch of salt’
While the trend of eye issues has been noticed across the country, Dr Rajashekar said it should be taken with a pinch of salt since there are no large-scale studies establishing a link between Covid and eye problems.
“We have come across several such cases by now and are seeing an increase in the number of cases with vascular blockage but their cause is still unknown,” he added.
“It could possibly be because of Covid or because of old age. Studies on cardiovascular effects of Covid-19 have been conducted so far but no large-scale study has been conducted to address loss of eyesight as a long-term effect of Covid-19,” he said. “It is a relatively new problem that has emerged among patients.”
Dr Aparna Mukherjee, a scientist with the Indian Council of Medical Research (ICMR), India’s apex medical research agency that has been at the forefront of the country’s response to the pandemic, said they are keeping watch to assess if there is indeed a trend.
“We are observing the post-Covid clinics that are being set up but we need doctors to report such cases to us if they observe a recurring pattern. Once such cases are reported and a larger trend is observed, only then we can determine the causality of the problem. For now, there could be various reasons leading to such retinal problems,” she added.
A doctor at the post-Covid-19 clinic at Safdarjung Hospital said they hadn’t witnessed any cases of eye issues so far. “We have had a functional clinic for the last two months and we haven’t had a lot of patients walking in. We have only had a few patients complain of fibrosis in lungs.”