Using lasers to image the retina

High quality ophthalmic care depends on the accurate assessment of ocular disease. Conventional direct ophthalmoscopy is used widely and provides good two dimensional views of the retina. However, the true nature of retinal disease is apparent only in three dimensions. In diabetic maculopathy, direct ophthalmoscopy can reveal retinal exudates, but the degree of macula oedema, which usually underlies the decision to treat by laser photocoagulation,1 is less clear. In glaucoma, the earliest damage can be seen as thinning of the retinal nerve fibre layer with increased cupping of the optic disc.2 These changes are best viewed stereoscopically. In both cases, disease of the retinal or optic nerve head will change the surface contour of the retina, either elevating or depressing the retinal surface by up to several hundred micrometres. Clearly, the objective quantification of these changes would be of immense benefit in diagnosing disease and monitoring disease progression and response to treatment.