I have a 41-year-old female patient whom I have examined every two years for the last 20 years. She has always been +0.75 DS in each eye and always managed 6/5 with each eye in turn. Today she was +2.50 DS in the right eye with 6/6 and +0.75 DS in the left with 6/5. With direct ophthalmoscopy, the macula in each eye looked healthy? What is going on?
This sounds very suspicious. Some people do have an increase in hyperopia as they approach middle years due to a loss of flexibility in the crystalline lens. However, in my experience, this type of increase in hyperopia affects both eyes equally or nearly equally. A +1.75 DS increase in the right eye and no increase in the left is odd. This means it is very unlikely to be due to age-related changes in the crystalline lens.
It strongly suggests that something is under or in the retina and that something is increasing in size and pushing up the retina. This has the effect of making the refractive length of the eye shorter; in effect, the eye becomes more hyperopic and needs more plus to achieve optimal visual acuity.
Now the question is, what could be under the retina causing this increase in hyperopia. A raised macula will be difficult to see with direct ophthalmoscopy because the technique does not produce a stereoscopic image. Amsler grid or central visual field testing may help confirm the existence of a sub- or intraretinal mass.
Two things come to mind and neither of them is good. The first is choroidal neovascularisation and the second choroidal melanoma. Choroidal neovascularisation is unlikely because the patient is too young for age-related macular degeneration and is not a high myope; high myopes often develop choroidal neovascularisation as part of a myopic maculopathy process. It may be a choroidal melanoma that is currently subretinal.
The patient needs to be examined by a specialist in ocular oncology as this condition may be life and sight-threatening.