Effect of posterior corneal surface abnormalities after deep anterior lamellar keratoplasty on visual outcomes and high order aberrations.

PURPOSE

To investigate the effect of posterior corneal surface abnormalities following deep anterior lamellar keratoplasty (DALK) on visual outcomes and high order aberrations (HOA).

METHODS

A retrospective cohort study was conducted on DALK cases. Patients were divided into two groups: Group A with posterior corneal surface abnormalities (interface haze, pre-Descemet's scarring, central Descemet's membrane (DM) perforation, and central DM folds) and Group B (control group) with regular posterior surface. Visual acuity, refractive outcomes, contrast sensitivity, and HOA were assessed in both groups.

RESULTS

This study included 84 eyes of 78 patients. Group A included 42 eyes of 38 patients and an equal number of control eyes were randomly included in group B. Group A exhibited significantly lower corrected distance visual acuity (CDVA) compared to Group B (Mean LogMAR 0.45 ± 0.25 in group A vs 0.31 ± 0.21 in group B, P = 0.012). Subgroup analysis revealed the lowest visual acuity in eyes with multiple posterior surface abnormalities, although the difference was not statistically significant. The mean topographic astigmatism was significantly higher in group A than in group B (4.47 ± 2.36 diopters vs 3.11 ± 2.16 diopters, respectively, P = 0.001). No significant differences were found between the 2 groups regarding total eye or corneal HOA. Contrast sensitivity was significantly lower in Group A at lower spatial frequencies (P = 0.013 and P = 0.004 at 3 and 6 cycles per degree, respectively), particularly in eyes with large DM perforations.

CONCLUSION

Posterior corneal surface abnormalities after DALK can negatively impact visual outcomes, especially contrast sensitivity.