Dry eye assessment, whether in association with a pre-LASIK assessment or not, involves both history taking (which can be simplified with various questionnaires) as well as an anterior segment eye examination using a slit lamp microscope, in conjunction with eyedrops such as fluorescein. Less commonly used tests include Schirmer testing, where a piece of filter paper is placed on the eyelid for 5 minutes and the amount of paper wetting measured.
Unfortunately, it has been found that the results from this are variable and often do not correlate with the other symptoms and signs found in a particular patient. Therefore this is rarely used nowadays.
Briefly, dry eye patients that I advise against laser refractive surgery include those with a recent history of Accutane use or systemic disease associated with dry eyes such as Sjogren syndrome. Also, those with significant corneal ‘dry spots’ (punctate corneal epithelial erosions) which extend to the centre of the cornea would be pre-treated for their dry eye first. After a varying period of time, if the condition improves significantly, laser refractive surgery can then be considered. There are some patients where the dry eye state persists despite intensive treatment, in which case they would be advised against surgery even without a history of systemic disease.
I believe that no ethical doctor would ‘push’ a patient towards having LASIK done, if he/she honestly believes that the patient is at high risk of suffering from the effects of very dry eye afterwards. In any case, if you have any doubts about the procedure at all, remember that glasses and contact lenses are perfectly good alternatives for providing good, clear vision.
