Abstract
Purpose:
To investigate the relationship between tear menisci and corneal subbasal nerve density in patients after Laser In Situ Keratomileusis (LASIK).
Methods:
Thirty-two low to moderate myopic eyes of 16 patients were enrolled. The height (H) and area (A) of upper (U) and lower (L) tear menisci (TM), UTMH, UTMA, LTMH, and LTMA, were measured by real-time anterior segment OCT before and at 1 week, 1 month, 3 months after surgery. Central, temporal and nasal corneal subbasal nerve densities were measured by corneal confocal microscopy before and at 1 month, 3 months after surgery.
Results:
Tear menisci parameters and corneal nerve densities all decreased significantly postoperatively (post hoc, P<0.05). After the surgery, lower tear menisci height (LTMH) increased from 207.85±43.94μm at 1 week to 238.55±34.07μm at 1 month (post hoc, P<0.01), and 273.33±44.91μm at 3 months (post hoc, P<0.01). The lower tear menisci area (LTMA) increased from 22640.07±3730.23μm2 at 1 week to 25523.10±3991.37μm2 at 1 month (post hoc, P=0.011), and 27859.86±3234.15μm2 at 3 months (post hoc, P=0.039). Interestingly, temporal and nasal nerve densities increased from 1325.35±286.44 and 7450.51±700.73μm/mm2 at 1 month to 1861.44±143.54 and 8053.21±1043.85μm/mm2 at 3 months (post hoc, P<0.01), respectively, while the central nerve density decreased from 1866.83±292.63μm/mm2 at 1month to 1694.02±192.83μm/mm2 at 3 months after surgery (post hoc, P=0.022). Furthermore, LTMA at 1 month was found to be significantly correlated with the nasal nerve density (r=0.380, P=0.032) at 1 month; and LTMA at 3 months was significantly correlated with central nerve density (r=0.360, P=0.043) at 1 month after LASIK.
Conclusions:
Our findings suggest that lower tear menisci were recovering continually in 1 week to 3 months after LASIK, which were accompanied by the increased temporal and nasal corneal nerve densities. The amount of tear secretion after LASIK might depend on residual corneal nerves at 1 month rather than corneal nerve recovery.
Keywords: 486 cornea: tears/tear film/dry eye •
683 refractive surgery: LASIK