Abstract
Purpose :
To evaluate higher order aberrations in patients with keratoconus, comparing to different crosslinking techniques in a follow up of 3 months.
Methods :
Prospective, comparative, non-randomized, interventional study of 21 eyes of 15 subjects. CXL procedure using either stromal (12 eyes) or transepithelial (9 eyes) techniques was performed. The uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), keratometric values, RMS and vertical coma were determine at baseline and 3 months postoperatively. STATA 12 software and t-test were used for statistical analysis.
Results :
A total 21 eyes with documented progressive keratoconus were included. The preoperative mean UDVA for CXL epi-off group was 0.67±0.36 logMAR, whereas for CXL epi-on group was 1.06±0.13.(p>0.05) Postoperative values for both groups were 0.60±0.40 logMAR and 1.08±0.29 logMAR respectively.
Preoperative CDVA was in the epi-off group was 0.26±0.16 logMAR, with a mean value of 0.19±0.14 logMAR at 3 months postoperatively. On the other hand the epi-off group went from 0.52±0.41 logMAR to 0.37±0.27 logMAR after the procedure.
The mean keratometric values in the epi-off group changed from 49.71±4.33 D (43.84-61.03) preoperatively, to 50.01±4.28 (44.69-62.26) after CXL (p>0.05). On the other hand, in the epi-on group, baseline K values changed from 52.49±4.07 D (47.43-59.73) to 52.67±4.09 D (47.3-60.67) without a significant change at 3 months post-op. (p>0.05)
Regarding aberrometric variables such as Root mean square (RMS) and vertical coma preoperative values for the stromal group were 2.62±1.03 and 1.98±1.09 respectively and 2.88±0.79 and 2.46±0.66 for the transepithelial group. Postoperative values were 2.41±0.98 and 1.79±1.04 for the stromal group and 3.00±0.75 and 2.59±0.54 for the transepithelial group.
Conclusions :
Results of CXL at 3 months show that both procedures are safe. Epi-off CXL may be effective in halting the progression of keratoconus and aberrometric changes due to ectatic disorders. Apparently, the aberrometric changes continue to increase in the epi-on technique although a larger sample and longer follow-up are needed.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.