Managing astigmatism to avoid LASIK surprises

Session Details

Session Title: Presented Poster Session: Keratorefractive Surgery Results I

Venue: Poster Village: Pod 2

First Author: : N.Alpins AUSTRALIA

Co Author(s): :                           

Abstract Details

Purpose:

To investigate excess corneal astigmatism post LASIK causing any one or more of symptoms of glare, ghosting, starburst, haloes and reduced contrast sensitivity.

Setting:

Melbourne, Australia

Methods:

A case study of postoperative LASIK symptoms of glare, starbursts, halos and reduced contrast sensitivity (commonly known as GASH) associated with 20/20 unaided visual acuity is investigated. Uncomplicated bilateral treatment of simple myopic astigmatism with the Schwind Amaris 1050 laser had been performed using manifest refraction parameters three years prior. Treatment based solely on refractive parameters can result in excess corneal astigmatism postoperatively. A syndrome termed PALS Syndrome – Predictable, Avoidable, LASIK, Surprise is described where an ocular residual astigmatism (ORA) of >1.00D exists preoperatively, >1.00D corneal astigmatism postoperatively and one or more of the symptoms of GASH is identified.

Results:

The preoperative ORA was right 0.99D Ax 6 and left 1.24D Ax 174, hence targeting the same magnitude of corneal astigmatism. Postoperative resultant corneal astigmatism in right eye was 1.12D @ 90 and left eye was 1.04D @ 85. Unaided visual acuity postop: 20/20 right and left; manifest refraction: right -0.25DS, left plano/-0.25 x 180. Ocular wavefront HOAs right 0.27 um and left 0.40 um. Vector Planning could have reduced the postoperative corneal astigmatism to right 0.59D @ 96 and left 0.74D @ 84 well below the 1.00D threshold for experiencing GASH symptoms without any increase in refractive cylinder remaining.

Conclusions:

Patients can have 20/20 unaided vision post LASIK and still be unhappy due to GASH symptoms. The onset of PALS Syndrome can be avoided by addressing corneal astigmatism in the refractive treatment plan using Vector Planning.

Financial Disclosure:

... gains financially from product or procedure presented