Application of Purkinje images for pinhole pupilloplasty and relevance to chord length mu.

Purpose: To evaluate the results of pinhole pupilloplasty in cases with high astigmatism and higher-order aberrations (HOAs).

Setting: Dr. Agarwal's Eye Hospital & Research Centre, Chennai.

Design: Case series.

Methods: Pinhole pupilloplasty was performed based on the Purkinje 1 (P1) images formed from the light source of a Lumera surgical microscope; the images served as a reference marker for centration. A single-pass 4-throw technique was used to achieve a pinhole pupil. The preoperative and postoperative pupil diameter, uncorrected (UDVA) and corrected (CDVA) distance visual acuities, simulated keratometry (K), and chord length mu (μ) were assessed, the latter using a Pentacam rotating Scheimpflug camera.

Results: Pinhole pupilloplasty was performed in 8 eyes (8 patients). There was a statistically significant reduction in the mean horizontal and vertical pupil diameters and in the mean pupil diameter from preoperatively to postoperatively (both P < .001). Although the improvement in UDVA was statistically significant (P < .001), the change in CDVA was not. The mean simulated K and mean chord length μ values were significantly lower postoperatively (P = .024 and P < .001, respectively). The reduction in pupil size was more apparent than the reduction in chord length μ. The correlation between the change in chord length μ and the change in pupil size was not significant (r = -0.067, P = .874). The pupil was well centered on the P1 images. No major adverse events or complications occurred postoperatively.

Conclusion: Postoperative results showed a correlation between the improvement in visual acuity and the decrease in pupil size and chord length μ.