Letter to the Editor re: Dry Eye and Meibomian Glands in Vitiligo

Dear Editor,

Recently, we read an interesting study by Taheri et al.[1] entitled “Dry Eye and Meibomian Glands in Vitiligo”, focusing on meibomian gland (MG) function and the lipid tear film in vitiligo patients. They included 86 patients and controls, evaluated them with comprehensive ophthalmic physical examination to clarify the status of dry eye as well as MG structure and function. In this letter, we would like to address methodological comments regarding their paper.

In this study, the authors mentioned that patients with any systemic or ophthalmic diseases, patients using contact lenses, and patients taking drugs which may affect the lacrimal gland were excluded. Also, participants were not allowed to use artificial tears 2 hours before ophthalmic examinations. We commend their efforts in choosing appropriate subjects to remove any confounding factors; however, they did not consider cigarette smoking status. As we know, smoking is a possible cause of dry eye disease (DED) due to its influence on the quantity and quality of the tear film, as well as its reduction of corneal and conjunctiva sensitivity, which leads to chronic inflammation.[2]

In addition, vitiligo patients using topical medications, especially immunosuppressant agents such as cyclosporine A for the periocular  area should be excluded, as cyclosporine A has beneficial effects on the status of DED.[3] It has been reported that cyclosporine A is helpful in halting the autoimmune-associated cascade and improving melanocyte pigments in vitiligo disease.[4] Therefore, including vitiligo patients with peri-ocular involvement taking topical cyclosporine A could affect the dry eye parameters, as cyclosporine A may improve the DED.

Furthermore, it has been shown that MG dysfunction and lid wiper epitheliopathy with lid-parallel conjunctival folds are involved in pathophysiology of contact lens-associated dry eye.[5] Therefore, excluding not only current contact lens users but also recent contact lens users is necessary as it takes time (i.e., a couple of months) to recover to normal.

Finally, in their article, the authors recruited participants from Birjand city and they used the English version of the Ocular Surface Disease Index (OSDI) questionnaire, whereas the subjects were native Persian speakers. As we know, every questionnaire should be used in scientific studies after cultural and language adjustment for the target population because literally translated texts may have some conceptual flaws. As a Persian version of the OSDI has been validated by Pakdel et al.[6], it may be feasible to use the validated questionnaire instead of an English version or a mere translation.

Overall, we think that the results of the paper would be more valid if the authors had considered the above-mentioned points.