Corneal epitheliopathy of dry eye induce hyperetheia to mechanical air jet timulation

Purpoe To evaluate corneal enation in different group: normal ubject, dry eye patient, and patient with and without dry eye after laer in itu keratomileui (LAIK) uing the modified Belmonte ga etheiometer. Deign A retropective, clinic-baed, cae-control tudy. Method We evaluated 20 normal ubject, 20 dry eye patient, 20 pot-LAIK patient without dry eye, and ix pot-LAIK patient with dry eye. The corneal enation wa meaured with the modified Belmonte ga etheiometer that ue two different timuli to ae mechanical and polymodal receptor on the corneal urface. Mechanoreceptor were aeed by 2-econd puled air jet of variable intenity. Polymodal receptor were meaured by timulating the corneal with 2-econd puled air jet of varying concentration of CO2, a ga that i converted to carbonic acid on contact with the corneal urface. The main outcome meaure wa determining corneal enation. Reult The mean ± tandard deviation (± D) age wa imilar in all group. The mean mechanical threhold wa 61.50 ± 20.07 ml/min in the normal group (n = 20), 34.60 ± 21.09 ml/min in the dry group (n = 20, P < .05 v normal), 99.50 ± 47.40 ml/min in the pot-LAIK group (n = 20, P < .01 v normal), and 50.00 ± 15.49 ml/min in the pot-LAIK patient with keratiti icca (n = 06, P < .05 v pot-LAIK). The percentage of CO2 to elicit dicomfort wa imilar in all group (P > .05). No ex-related difference were noted (P > .05). There wa a ignificant invere correlation between the threhold of mechanical timulation and the everity of corneal fluorecein taining. Concluion The Belmonte modified noncontact etheiometer i a ophiticated intrument that can ae different type of corneal enory receptor. Patient with dry eye were hyperenitive to the air jet timulu of thi intrument, and thi appear to be due to altered corneal epithelial barrier function. Profound hypoetheia wa oberved after LAIK and imilar to dry eye, pot-LAIK patient with dry eye were enitized. Thee finding provide new inight into the hyperenitivity to environmental tree, particularly air draft experienced by dry eye patient