Except for the treatment of PED, scleral lens fitting is delayed until the inflammatory condition of the ocular disease has subsided sufficiently in the normal course of the disease or by medical treatment. The timing for fitting these lenses is determined by the patient’s response to a wearing trial. In case of discomfort and significantly increased bulbar conjunctival redness, the fitting process is postponed.
Cicatricial conjunctival changes and the presence of a symblepharon often require the lens design to be adapted to anatomic changes induced by compromised fornices. Fitting the largest possible scleral lens does not prevent the recurrence of incised symblepharon, however, this rarely presents an obstacle to the successful use of these lenses. The additional challenges posed by the need to fit smaller scleral lenses usually can be overcome by customizing the lens design.
Tear-fluid interchange is key to the wearing tolerance of fluid-ventilated, gas permeable scleral lenses, and the presence of a visible tear meniscus is mandatory. When natural tear production is reduced due to certain ocular conditions, goblet cell secretions often remains normal that causes mucous debris accumulating in the tear pool, requires frequent removal of the lens for cleaning and filling with fresh artificial tears (or normal saline) to maintain clear vision.
Risk of bacterial keratitis is more when lens is worn on extended wear basis in case of PED or along with topical steroids. This must be weighed against the potential benefits for each patient.
Irregular shapes of eyes can be fitted with specially derisgne scleral lenses after taking an eye impression, for precies fitting.