Comparison of safety and efficacy of CA-CXL and HPMC-CXL in keratoconus with thin cornea

Session Details

Session Title: Corneal Cross-Linking

Session Date/Time: Monday 16/09/2019 | 16:00-18:00

Paper Time: 17:24

Venue: South 5

First Author: : J.Goyal INDIA

Co Author(s): :    S. Chaudhary   R. Arora   R. Anjum   V. Veerwal                    

Abstract Details

Purpose:

To evaluate and compare the efficacy and safety of Contact lens-assisted CXL(CACXL) using iso-osmolar riboflavin 0.1% in 20% dextran and iso-osmolar riboflavin 0.1% in Hydroxy-propyl Methyl Cellulose(HPMC)-assisted CXL in keratoconus in thin cornea.

Setting:

A prospective interventional study, conducted at Guru Nanak Eye Centre, Maulana Azad Medical College, New Delhi, India.

Methods:

Forty eyes with progressive keratoconus with thin cornea(pachymetry <440um) were randomly divided into two groups. Using Dresden protocol, priming was done with iso-osmolar riboflavin in 20% dextran in CACXL; and iso-osmolar riboflavin in HPMC in HPMC-CXL group. 90µm thick contact lens was put post priming in CACXL throughout the UV irradiation. Intra-operative pachymetric changes were measured using ultrasonic pachymetry. Post-operative outcomes were measured at 6months between the groups.

Results:

Mean pre-operative corneal thickness was 424.75±9.94µ in CACXL and 425.7±8.23µ in HPMC-CXL group which reduced to 374.85±10.1µ and 373.75±11.56 post epithelial removal. Intra-operative functional corneal thickness increased significantly by 98.2±9.9 and 88.6±20.07 in CACXL and HPMC-CXL groups, respectively. A significant decrease in steep keratometry was seen post-operatively in both groups(p0.0001 in CACXL; p0.004 in HPMC-CXL). Demarcation line was comparable between the two groups(245.75±25.91µ in CACXL, 247.3±31.15µ in HPMC-CXL). No significant decrease in endothelial cell density was noted at 6 months in either group. Significant improvement in BCVA was seen in HPMC-CXL group at 6 months(p0.04).

Conclusions:

Intra-operative functional corneal thickness increased significantly in both the CXL procedures. Demarcation line was seen at an adequate depth with no significant decrease in endothelial count in either group, suggesting that both procedures are safe and effective for thin corneas of upto 370µ(with epithelium). However, in terms of visual outcome and flattening of cone, HPMC-assissted CXL may be preferable procedure over CACXL in keratoconus with thin corneas.

Financial Disclosure:

None