Corneal and lens densitometry after corneal collagen cross-linking for keratoconus

PurposeThe study aimed at investigating retrospectively the values of corneal and lens densitometry using the Pentacam Scheimpflug system after corneal cross-linking (CXL).Materials and methodsThis study included 50 eyes of 50 patients who had undergone CXL for keratoconus. The Pentacam Scheimpflug system was used before the procedure to measure objectively the corneal and lens densitometry values. The same measurements were recorded during the follow-up visits at 1, 3, 6, and 12 months using the Scheimpflug image taken at the same axis as at the baseline visit. During the same preoperative and follow-up visits, slit-lamp examination was performed by the same examiner to grade the corneal haze on a scale from 1 to 4.ResultsThe mean Scheimpflug corneal densitometry at baseline was 16.30 ± 1.90 (measured on a scale of 100). At 1 month postoperatively, the corneal densitometry increased to 28.81 ± 4.33. Between 6 and 12 months postoperatively, there was a decrease in the corneal densitometry values by 4.78, which was statistically significant (P < 0.001). At 12 months postoperatively, the corneal densitometry did not return to baseline levels. At baseline, the mean preoperative clinical haze at slit-lamp was 0.31 ± 0.70 (grading from 0 to 4). At 1 month, there was a statistically significant increase in the clinical haze by 1.40 (P < 0.001). Regarding Scheimpflug lens densitometry values, it was 7.91 ± 2.51 at baseline and 7.93 ± 2.61 at 12 months postoperatively.ConclusionScheimpflug corneal densitometry and the clinical corneal haze peaked at 1 month, followed by a gradual decline. They reached near baseline levels at 12 months, but at significantly higher values. Lens densitometry was not affected by CXL.