Delayed corneal haze after combined photorefractive keratectomy and corneal cross-linking in non-keratoconus patients.

PURPOSE: To assess the incidence rate of corneal haze after combined simultaneous photorefractive keratectomy (PRK) and accelerated (10-min, 9 mW/cm2) corneal cross-linking (CXL) for non-keratoconus.

METHODS

This is a retrospective cohort study on patients without keratoconus underwent simultaneous CXL-PRK. Uncorrected visual acuity (UCVA), best corrected visual acuity (BCVA), manifest refraction, corneal keratometry, and corneal haze were evaluated.

RESULTS

Included were 92 eyes of 55 subjects with mean age of 31.42 ± 4.62 years and mean follow-up time of 13.83 ± 11.24 months (range: 6 to 46 months). Mean UCVA improved significantly from 1.06 ± 0.36 to 0.14 ± 0.17 logMAR after procedure (P = 0.01), but the mean BCVA worsened significantly from 0.02 ± 0.05 to 0.08 ± 0.11 logMAR (P = 0.01). Significant corneal haze occurred in 18 eyes (19.6%). Among them 11 eyes (61.1%) developed corneal haze in first postoperative year. The BCVA deteriorated in 83.3% (15/18) of hazy eyes while 63.5% (47.74) of eyes without haze formation did not have any change of BCVA (P < 0.001). The UCVA improved in majority of eyes with (88.9%, 16/18) or without (97.3%, 72/74) haze formation (P = 0.18). Densitometry analysis showed that the densest layer of cornea in eyes with haze was anterior layer at 10-12 periphery zone followed by anterior layer at 2 mm central zone.

CONCLUSION

Nearly one-fifth of eyes develops significant corneal haze after CXL-PRK procedure. Despite of UCVA improvement, the loss of BCVA in eyes with corneal haze, suggests that CXL-PRK procedure should be approached with caution.