Posters

Optical quality metrics after transepithelial hyperopic photorefractive keratotomy in 10 year postoperative laser anterior ciliary excision

Poster Details

First Author: K.Rocha USA

Co Author(s):    A. Hipsley   D. Lin                 

Abstract Details

Purpose:

To objectively evaluate long term stability and effective range of near and intermediate vision in patients with Laser Anterior Ciliary Excision (LaserACE) after hyperopic transepithelial photorefractive keratotomy (PRK).

Setting:

Storm Eye Institute, Medical University of South Carolina & Pacific Laser Eye, Vancouver Canada.

Methods:

Six eyes of 3 patients underwent transepithelial PRK surgery using topography guided no-touch excimer laser technology (Schwind) to correct progressive hyperopia occurring from previous laser vision correction (LVC) surgery. Patients had received laser anterior ciliary excision (LaserACE) surgery an average of 10 years prior with a 2.94um Er:YAG laser to create micro-excisions in the sclera in three critical anatomical zones. A ray-tracing aberrometer was used to objectively measure higher-order aberrations (HOA), depth of focus (DoF), the visual Strehl ratio based upon the optical transfer function (VSOTF), true accommodation, and the effective range of focus 10 years after LaserACE treatment.

Results:

The average patient DoF increased from 0.65 D prior to LaserACE, to 1.49 D 10-years after LaserACE treatment. True accommodation averaged 0.25 D for all patient eyes 10-years after LaserACE treatment. Effective range of focus averaged 1.56 �Â�± 0.36 D for all eyes. Changes in SA, Coma, Trefoil, defocus, and accommodation were noted. VSOTF averaged 0.48 �Â�± 0.13, while the average difference in HOA was 0.6 (m). Near and intermediate visual acuity was significantly improved after hyperopia was corrected by 1-3 lines.

Conclusions:

The LaserACE procedure is not on the visual axis, therefore these patients could still receive correction to their hyperopic regression. Ray-tracing technology can objectively measure visual outcomes including an objective measure of true accommodative ability versus pseudoaccomodation. These patients show an improvement of their effective visual range of focus with both true- and pseudo-accommodative ability improvements 10-years after the LaserACE procedure. Successful hyperopic correction using transepithelial PRK allowed the patients to utilize the originally restored accommodation and depth of focus. LaserACE provided improvement in near vision functionality in these LVC patients with long-term stability.

Financial Disclosure:

gains financially from product or procedure presented, receives consulting fees, retainer, or contract payments from a company producing, developing or supplying the product or procedure presented