Photorefractive keratectomy for patients with preoperative low Schirmer test value.
OBJECTIVE
To compare dry eye signs and symptoms between patients with preoperative low and normal Schirmer test after Photorefractive keratectomy (PRK).


METHODS
In this prospective, nonrandomized, comparative case series, 76 eyes of 76 patients were preoperatively categorized into two groups according to selected criteria for characterization of tear film status: the low Schirmer test value (STV) group and the normal STV group. For the tear function assessment, we performed a Schirmer test with and without anesthesia, tear break-up time (TBUT) test, and measurement dry eye symptoms using the Farsi translation of Ocular Surface Disease Index (OSDI) questionnaire pre- and 3 months post-operation.


RESULTS
Postoperatively, the Schirmer and TBUT values were significantly lower in both groups than preoperatively (all p < 0.05). Deterioration in tear secretion was significantly greater in the low STV group (p = 0.012), but tear stability was more compromised in the normal STV group (p = 0.021). The changes in OSDI score were not significant between the two groups.


CONCLUSIONS
These results demonstrated that tear function deteriorates after PRK. Therefore, patients with low preoperative Schirmer test values should be thoroughly assessed for dry eye before proceeding with refractive surgery to eliminate postoperative complication.
Department of Optometry, School of Rehabilitation, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
Elham
E
Tanbakouee
Ophthalmology Department, Isfahan University of Medical Sciences, Isfahan, Iran.
Mohammad
M
Ghoreishi
Department of Optometry, School of Rehabilitation, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
Mohammad
M
Aghazadeh-Amiri
Department of Basic Sciences, School of Rehabilitation, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
Mehdi
M
Tabatabaee
Research and Development Department, Persian Eye Clinic, Isfahan, Iran.
Mohadeseh
M
Mohammadinia
Photorefractive keratectomy; Schirmer test; Tear function