Refractive outcomes and quality of vision related to an outbreak of diffuse lamellar keratitis

To report the impact on visual function and corneal aberrations during an epidemic of diffuse lamellar keratitis (DLK).

A retrospective, comparative, and consecutive case-control study was performed, involving 418 eyes operated between March and October 2007 in the refractive surgery unit of one center. Eyes were separated into groups: group 1 (DLK group) included 209 eyes that presented with DLK after LASIK and group 2 (control group) included 209 unaffected, consecutive eyes operated from the beginning of the outbreak. Refractive variables and corneal aberrations were compared between the two groups.

Visual outcomes were significantly different when comparing control eyes and eyes with DLK grades 3 and 4, but not for eyes with DLK grades 1 and 2. Uncorrected distance visual acuity (UDVA) significantly improved from the third month after DLK was diagnosed (Kruskal-Wallis, P=.02). Corrected distance visual acuity (CDVA) did not decrease significantly with DLK grades 1 and 2 (preoperative CDVA vs 1, 3, and 6 months after diagnosis; Mann-Whitney, P>.05, respectively). At the end of follow-up, UDVA and CDVA were not significantly different between the two groups. Eyes suffering from DLK had significantly increased corneal aberrations, except for spherical and astigmatism aberrations, 3 months after being diagnosed (Kruskal-Wallis, P<.05); however, corneal aberrations were not significantly different between the DLK and control groups (Mann-Whitney, P>.05).

The outbreak of DLK did not induce a significant decrease in global visual outcomes, except in severe cases, and postoperative corneal aberrations were not affected.