Dry eye and corneal sensitivity after high myopic LASIK.

PURPOSE: To assess subjective symptoms and objective clinical signs of dry eye and investigate corneal sensitivity after high myopic LASIK.
METHODS: Twenty eyes of 20 patients with a mean age of 34 +/- 7.5 years who had undergone high myopic LASIK 2 to 5 years previously and 10 eyes of 10 controls with a mean age of 39.8 +/- 10.4 years were enrolled in the study. Clinical signs of dry eye and subjective dry eye symptoms were determined. The corneal sensitivity was assessed using non-contact esthesiometer.
RESULTS: The preoperative spherical equivalent refraction was -11.40 +/- 1.40 diopters (D) (range: -9.10 to -14.00 D) and the intended spherical equivalent refraction correction was -10.40 +/- 1.10 D (range: -8.30 to -12.50 D). Schirmer's test score was 14.4 +/- 8.9 mm in patients and 9.0 +/- 4.2 mm in controls (P = .066). The break-up time was 15.9 +/- 11.2 seconds in patients and 14.0 +/- 10.0 seconds in controls (P = .505). The mean corneal sensitivity was 73.5 +/- 29.6 mL/min in patients and 78.0 +/- 18.7 mL/min in controls (P = .666). The majority (55%) of patients still reported dry eye symptoms. Ocular surface disease index indicating degree of dry eye symptoms was significantly higher in LASIK patients (18.6 +/- 13.4%) compared to controls (7.5 +/- 5.7%; P = .022).
CONCLUSIONS: The majority of patients who received LASIK for high myopia reported ongoing dry eye symptoms, although objective clinical signs of tear insufficiency and hypoesthesia were not demonstrable. We assume that symptoms represent a form of corneal neuropathy rather than dry eye syndrome.