Cataract surgery outcomes in eyes with previous radial keratotomy

Session Details

Session Title: Cataract Surgery: Special Cases

Session Date/Time: Tuesday 17/09/2019 | 08:30-10:30

Paper Time: 09:42

Venue: Free Paper Forum: Podium 2

First Author: : C.Soare UK

Co Author(s): :    D. Patel   A. Ionides                          

Abstract Details

Purpose:

Cataract surgery in eyes that have previously undergone radial keratotomy (RKs) presents challenges ranging from lens power calculation, intra- and post-operative complications as well as post-operative refractive visual surprises.  Although cataract surgery is the most common surgery performed in the UK and outcomes of cataract surgery are closely audited at national level, there are no real world data to allow prediction of surgical outcomes in patients with previous radial keratotomies. We aim to report the largest study to date to analyse the visual and refractive outcomes of cataract surgery in patients with previous RKs.

Setting:

Moorfields Eye Hospital NHS Foundation Trust, London, United Kingdom

Methods:

We retrospectively reviewed the medical records of 100 eyes (65 patients) with previous RKs who had undergone routine cataract surgery with monofocal intraocular lens (IOL) implantation between January 2004 and December 2018. Outcomes included LogMAR unaided and/or best corrected visual acuity (BCVA), biometry, complications and also the pre- and post-operative refraction as well as the effects of different formulas used for IOL calculations on predictive error (PE).  Where data was available, for 72 eyes, we retrospectively calculated the predicted refraction of the same IOL power if Haigis had been used and compared it to the achieved refractive outcome.

Results:

BCVA improved from 0.40 to 0.10 in eyes without co-pathology, and from 0.72 to 0.24 in eyes with co-pathology. Haigis formula (19 eyes) resulted in a mean PE of -0.36D, versus -0.38D for Double-K SRK/T (55 eyes) and +1.14D for SRK/T (18 eyes). 52.6% eyes were within 0.5D and 68.4% within 1D of the predicted refraction for Haigis, versus 32.7% and 52.7% with Double-K SRK/T, and 27.8% and 38.9% for SRK/T. For the 72 eyes, Haigis formula would have resulted in 45.8% eyes within 0.5D and 69.4% eyes within 1D from predicted.

Conclusions:

This is the largest study to report visual and refractive outcomes of cataract surgery post RK and demonstrates that although BCVA compares with the UK national benchmarks, significantly fewer eyes with previous RK were within 0.5D of target. Although the Haigis formula was only used for 19 eyes, it had a better predictability of the spherical equivalent compared with Double-K SRK/T, without the need to estimate the corneal power in order to predict the effective lens position, making it more reliable in eyes with flattened corneas post RK. The most frequent complication was RK dehiscence (8%) requiring suturing.

Financial Disclosure:

None