Corneal haze in juvenile and adult keratoconus patients after corneal cross-linking

Purpose Densitometry software for the Oculus Pentacam was used to investigate the treatment outcomes of corneal cross linking (CXL) in adult and juvenile keratoconus patients. Methods A retrospective comparative study was carried out at Manchester Royal Eye Hospital. Corneal densitometry measurements collected before and after CXL treatment for 32 eyes from KC patients, aged between 13 and 39, were divided to 2 groups 13-18 years(juvenile group) and 19-39 years (adult group) was compared to pre and post treatment at 3, 6 and 12 months for each group and between both groups. Results Analysis of densitometry measurements found higher corneal densitometry after CXL which peaks at 3 months post treatment in both groups. There was significant diversity in corneal densitometry measurements at stromal zone 0-2 and 2-6 mm for all layer except the posterior layer for each group p<0.05). Significant differences were found between both groups at six months in the central (p=0.006), posterior (p=0.004) and full depth (p=0.02) layers for zone 0-2 mm.The same layers differed significantly in the 2-6 mm zone in all layers (p=0.01). One year post treatment significant differences were shown in corneal densitometry level between both groups in the 0-2 mm zone of the central layer (p=0.007), posterior layer (p=0.01) and full depth (p=0.03).The central layer in zone 2-6 mm was significantly different between both groups (p=0.04). Conclusions Haze levels post CXL differing in severity in different corneal zones and between both groups.The 0-2 mm and 2-6 mm zones were found to be the most affected area post treatment.Haze reached its maximum level at three months post treatment then appears to differ significantly in improvement level between adult and juvenile group, with the later never returning to pre-treatment clarity in the most anteriorly central zone in juvenile group