The Effectiveness Of Intrastromal Non-Cut Through Femtosecond Laser Assisted Astigmatic Keratotomy For The Correction Of Low Order Aberration Corneal Astigmatism In Cataract Surgery
Published 2024 - 42nd Congress of the ESCRS
Reference: PP12.10 | Type: Poster | DOI: 10.82333/6cp4-8757
Authors: Elsa L.C. Mai* 1 , Chaokai Chang 2
1Ophthalmology,Far Eastern Memorial Hospital,Taipei,Taiwan, Province of China;Electric Engineering,Yuan Ze University,Taoyuan,Taiwan, Province of China;Optometry,Yuanpei University,Hsinchu,Taiwan, Province of China, 2Ophthalmology,Nobel Eye Institute,Taipei,Taiwan, Province of China;Optometry,Da Yeh University ,Changhua,Taiwan, Province of China
Purpose
Diamond knife surgical Arcuate Keratotomy (AK) and Limbal relaxing incision (LRI) has been around for decades. With Femto assisted cataract surgery gaining popularity, Femto AK is being used during cataract surgery as well. However, cut through AK produce cornea wound, add to post op irritation after surgery and increase risk of infection, epithelia scaring and NV invagination from peripheral in ocular surface disease cases. We have innovated a non-cut-through totally intrastromal arcute keratotomy by using the benefit of intrastromal cutting property of the femto laser (Z8) as in CLEAR refractive surgery.The purpose of our study is to devise a method to overcome side effects and investigate the effectiveness and nomogram for this method.
Setting
A Retrospective non-randomized single center study in a Refractive Laser center & Tertiary teaching hospital.
Methods
A retrospective chart review of 32 patients undergoing Femto assisted cataract surgery plus femto assisted AK were collected. Astigmatic data from patient's pre-surgical Pantacam, Lenstar, Verion & Topcon keratometer and post-surgical Pentacam and Topcon were extracted. Vector analysis of the astigmatism and Low order aberration from Pentacam topography were analysed, along with patient’s pre-surgical and post-surgical VA, subjective cornea sensation were charted by using OSDI questionnaire. For patients with larger then -1.50D of regular astigmatism, toric IOL are supplemented, the remaining astigmatism were eliminated by touch up surgery with Femto AK surgery. Statistic calculation by vector analysis are chart into nomogram.
Results
The picture of the non-cut-through totally intrastromal arcute keratotomy immediate post Femto laser with air bubble intrastromally and cornea photo one day post surgery after bubble subsided are shown. In one case of regular asymmetric astigmatism of -1.63 and -2.07 D at the superior and inferior corneas (with the rule). The vector analysis showed a -1.08 D astigmatism at 83 degrees. With calculation, Femto AK with Arc Length of 25 degree and 35 degree 9mm from the cornea central was done. Pre-surgical and post-surgical Vector analysis show a decrease of astigmatic vector for up to -0.9D are seen in our cases.
Conclusions
Femto-AK with non-cut-through method for performing arcuate keratotomy or Astigmatic keratotomy is an easily attainable method to combine with cataract surgery, it did not add any extra time or effort to the original Femto-AK surgery. But the Femto AK procedure itself is surprisingly more time consuming then other Femto procedures such as lens fragmentation due to the architacture of the cutting procedure. Although the case number are limited, we managed to device an approximated nomogram for this more patient friendly method.