Early results of circularity and centration of capsulotomy prepared by three different methods

Abstract

Aim: To compare the difference of capsulotomy produced by precision pulse capsulotomy (PPC), manual (M-CCC), and femtosecond laser assisted capsulotomy (FLAC) in relation to intraocular lens (IOL) centration, circularity and its effect on visual outcomes.

Methods: Prospective, non-randomized comparative study conducted at LV Prasad Eye Institute, Hyderabad, India. Sixty eyes of 52 patients were grouped into 3 (FLAC, PPC and M-CCC) based on capsulotomy techniques used. Twenty consecutive eyes with uneventful phacoemulsification and with no comorbidities affecting the capsulotomy or visual outcome were included in each group. The main outcome measure was IOL centration in relation to capsulotomy and pupil. Secondary outcome measures were post-operative visual acuity, manifest refraction and aberration profile between groups.

Results: At 5wk the visual, refractive outcomes and endothelial cell density were comparable between the 3 groups. The median circularity index of FLAC was statistically significantly different to M-CCC or PPC (1-10) groups (P<0.01) but PPC (11-20) was comparable to FLAC. Decentration of IOL center in relation to capsulotomy was seen only between the PPC (1-10) group and FLAC group (P=0.02). The IOL was well centered in relation to the pupil in all the groups (P=0.46). The quality of vision parameters like the higher order aberrations, spherical aberration, coma, trefoil, modular transfer function, and Strehl ratio were comparable between the groups.

Conclusion: Our study shows that despite differences in the morphology of capsulotomy produced by PPC, M-CCC, FLAC a well-centered IOL can be achieved. The measured capsular morphology parameters do not affect visual outcomes.

Keywords: capsulotomy; femtosecond laser assisted capsulotomy; intraocular lens centration; phacoemulsification; precision pulse capsulotomy.

Figure 1. Marking capsulorrhexis, IOL, and pupil using Image J software

A: Representative retro-illuminated slit-lamp image; B: Initial capsulorrhexis boundary marking using the polygon selection tool in Image J; C: Refined capsulorrhexis boundary based on spline fitting in Image J (Edit>Selection>Fit Spline); D: Masked capsulorrhexis in colour (Edit>Fill+ Edit>Draw); E, F: Selecting IOL boundary using oval selection tool in Image J and drawing it in selected colour (Edit>Draw); G, H: Selecting pupil boundary using oval selection tool in Image J and drawing it in selected colour (Edit>Draw).

Figure 2. Capsulorrhexis and IOL decentration and overlap measurements.

Figure 3. Balloon plot showing a graphical matrix with X-axis showing the procedures, Y-axis showing the quadrants (I-IV)

Freq: Relative magnitude of the cases in each quadrant.