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.