UK hospitals assess eye damage after solar eclipseBMJ 1999; 319 doi: http://dx.doi.org/10.1136/bmj.319.7208.469 (Published 21 August 1999) Cite this as: BMJ 1999;319:469
Public health warnings about the dangers of looking at the sun with unprotected eyes during the solar eclipse earlier this month seem to have been heeded by most British viewers. Several thousand people rang helplines or attended special eclipse clinics after experiencing the event, but the number of cases of solar retinopathy reported by eye hospitals and units was lower than was widely feared. Almost a week after the eclipse, on 11 August, the BMJ has learned of at least 14 confirmed cases during inquiries to leading eye centres.
On Monday 16 August, Moorfields Eye Hospital in London reported six confirmed cases. Other totals were as follows: Birmingham Eye Hospital (five), Derbyshire Royal Infirmary's eye unit (three), and Bristol Eye Hospital (one suspected case). No confirmed cases were reported in any of the specialist units serving Scotland, Wales, or Northern Ireland. Most of the known cases resulted from looking at the sun without protecting the eyes. In one of the more serious cases the patient had reportedly looked at the sun for around 20 minutes without protection.
For several weeks before the eclipse, several agencies had run campaigns warning of the dangers of looking directly at the sun during the event. There were fears that because the eclipse was occurring at the height of summer, when the sun nears its zenith, over densely populated areas, the incidence of retinal injury would be greater than after similar events in the past. “We are quite pleased that the number of people suffering solar retinopathy is relatively low, and it shows that the campaign and health education messages worked and did reach the vast majority of the population,” said Jonathan Dowler, consultant ophthalmic surgeon at Moorfields hospital.
Widespread cloud cover over large areas of the United Kingdom is also likely to have played a part in keeping down the number of cases of serious eye damage. Although the number of confirmed cases is small, early indications are that after the eclipse many more people used eclipse helplines, run by some of the eye hospitals. Moorfields received 1600 calls, and Birmingham and Bristol received 300 each At Moorfields hospital 220 people presented at the accident and emergency department, and at Birmingham Eye Hospital 64 patients were seen at special eclipse clinics.
Callers to the helplines included people worried about the lasting effects of glare, about headaches, and blurred vision. Most were false alarms One overseas tourist who sought help in Glasgow said that she was worried because she had not been exposed to the Scottish sun before Another Glasgow patient was concerned that her face had been turned yellow by the eclipse but was told that her longstanding liver problem was the culprit.
There are two main mechanisms of retinal injury from solar radiation. Thermal burn is caused by looking at the sun through a telescope or through other optical aids, which can cause a temperature rise of10-25°C in the retina. But the most common form of solar retinopathy is caused by looking at the sun without eye protection. A retinal temperature rise of as little as 4°C can trigger photochemical injury to the retinal receptor cells. The condition can occur without pain and without being immediately apparent. No treatment has been shown to be effective for solar retinopathy. In some cases the retinal changes seem to be reversible, but in others there is permanent loss of the photoreceptors. In a study after an eclipse in Turkey in 1976, around 10% of those with damage had permanent visual loss to the extent that they were not able to read a car number plate at 25 yards (23 metres) with the affected eye or eyes.
Simon Keithley, a consultant ophthalmologist based in Basingstoke, is asking all members of the Royal College of Ophthalmology to provide data on the incidence of solar retinopathy before and after the eclipse. He expects to have the data, collected via the college's postal surveillance system, by October.