Eye Health – Prevention to Early Detection
Mr Sanjay Shah, Consultant Ophthalmic Surgeon responsible for the Eye Clinic at Leatherhead Hospital
There are currently 2 million people in the UK with sight loss, and this is expected to increase to 4 million by 2050. The risk of sight loss increases with age (1 in 5 risk over age 70, 1 in 2 risk age 90). Over 50% of sight loss is avoidable.
After explaining the parts of the eye essential for clear vision, Mr Shah defined the common eye diseases as : Cataracts, Glaucoma, Age Related Macular Disease (AMD), and Diabetic Retinopathy. Of these the major cause of severe sight loss is AMD, with Cataracts being a common condition (30% of population over 65 years). Cataract surgery is the commonest planned surgical procedure in the UK with 350,000 operations annually.
Cataracts are a clouding of the lens, causing reduced vision which is not improved by glasses, reduced brightness/colour appreciation, glare (night driving), induced short-sightedness, multiple images/ghosting. Previously surgery was only considered when vision was reduced to a certain level, now surgery is performed if vision is limiting the quality of life or the ability to work or carry out normal daily activities (driving).
Glaucoma is elevated eye pressure which damages the optic nerve and causes a gradual irreversible loss of initially peripheral vision. In the early stages it has no symptoms, and affects 2% of the population over 40. The risk increases with age, and is affected by family history, Afro-Caribbean heritage, short-sightedness, diabetes.
AMD is the commonest cause of permanent visual impairment in the elderly affecting 2% of the population over 50, 20% in those over 85. There are two forms of AMD, Dry AMD which is the commonest form (90%) causing a gradual loss of central vision, and Wet AMD (10%), where there is a gradual growth of new fragile blood vessels beneath the retinal surface leading to a more rapid irreversible deterioration of vision. Wet AMD is now treatable, but early detection is important.
Diabetic Retinopathy (DR) is the commonest cause of blindness in the working age group in the UK (4% of the population suffer from diabetes). DR is damage to the small retinal blood vessels, good control of diabetes and blood pressure reduces the risk and progression of DR. Early detection and treatment halves the risk of visual loss – all diabetic should have annual retinal photography.
Glaucoma, AMD, and Diabetic Retinopathy can all cause irreversible sight loss with few symptoms in the early stages, but all are treatable. Thus prevention is very important, with early detection/diagnosis, and regular review/monitoring. The equipment recently donated by the League of friends is key to this early detection and diagnosis.
The Thomson Digital Vision Testing System is used for testing all eye condition, and is essential the modern replacement for the traditional fixed chart which had a series of letters of decreasing size.
The (Zeiss) Humphrey Visual Field Analyser is used to test for glaucoma by checking the field of view.
The Pachymeter Corneal Thickness Equipment is a hand held ultrasonic device used as part of the testing for glaucoma (which has no symptoms is the early stages), and gives an objective assessment of corneal thickness, essential for diagnosis and monitoring.
The (Zeiss) OCT Scanner is a very expensive piece of equipment which enables objective imaging of the optic nerve and macula, and is used to diagnose AMD and Glaucoma. This is a non-invasive and non-contact system which gives high resolution images of retinal layers and optic nerves fibres, enabling numerical analysis of macular thickness and optic nerve thickness. In addition to allowing early diagnosis, it enables serial scanning to monitor the disease and the effectiveness of its treatment.
Mr Shah concluded his talk by thanking the League of friends for their generous donation of equipment which will enable the Leatherhead Eye Service to be a ‘one stop shop’ for the diagnosis and monitoring for glaucoma (as per NICE guideline), using the Pachymeter, Humphrey Visual Field Analyser, and the OCT optic nerve scanner. Also the early diagnosis of wet AMD using OCT macular imaging.
Finally Mr Shah answered questions related to specific patient’s conditions, and also gave general advice about preventing eye problems, the key feature being:
• Using sunglasses (CE approved to block UV)
• Not smoking
• Diet (supplements are available)
• Regular visits to an optician