Photorefractive keratectomy after cataract surgery in uncommon cases: long-term results

AIM： To evaluate the efficacy and safety of the excimer laser correction of the residual refractive errors after cataract extraction with intraocular lens（IOL） implantation in uncommon cases.METHODS： Totally 24 patients with high residual refractive error after cataract surgery with IOL implantation were examined. Twenty-two patients had a history of phacoemulsification and IOL implantation, and two had extra-capsular cataract extraction with IOL implantation. Detailed examination of preoperative medical records was done to explain the origin of the post-cataract refractive errors. All patients underwent photorefractire keratectomy（PRK） enhancement. The mean outcome measures were refraction, uncorretted visual acuity（UCVA）, best corrected visual acuity（BCVA） and corneal transparency and follow up ranged from 1 to 8 y.RESULTS： The principal causes of residual ametropia was inexact IOL calculation in abnormal eyes with high myopia and congenital lens abnormalities, followed by corneal astigmatism both suture induced and preexisting. After cataract surgery and before the laser enhancement the mean spherical equivalent（SE） was-0.56±3 D ranging from-4.62 to ＋2.25 D in high myopic patients, instead it was-1±1.73 D ranging from-3.25 to ＋3.75 D in the astigmatic eyes, with a mean cylinder of-3.75±0 ranging from-3 to ＋5.50 D. After laser refractive surgery the mean SE was 0.1±0.73, ranging from-0.50 to ＋1.50 in the myopic group, and it was-0.50±0.57 ranging from-1.25 to ＋0.50 in astigmatic patients, with a mean cylinder of-0.25±0.75. In myopic patients the mean UCVA and BCVA were 0.038±0.072 logMAR and 0.018±0.04 respectively, both ranging from 0.10 to 0.0. In astigmatic patients, the mean UCVA and BCVA were 0.213±0.132 and 0.00±0.0 respectively, UCVA ranging from 0.50 to 0.22 and BCVA was 0.00. All patients presented normal corneal transparency. No ocular hypertension was detected and no corneal haze was observed. All registered values remained stable also at the end line evaluation.CONCLUSION： The excimer laser treatment of residual refractive errors after cataract surgery with IOL implantation in abnormal eyes resulted in satisfactory and stable visual outcome with good safety and efficacy.

Post photorefractive keratectomy corneal ectasia

Dear Editor,We write to describe two cases of corneal ectasia occurred after photorefractive keratectomy.Due to the wide diffusion of refractive surgery,many ophthalmologists attempted to identify the risk factors and prevention methods to avoid such severe complication of this technique.

Cataract surgery on post radial keratotomy patients

This study aims to evaluate and to compare three different approaches of cataract surgery to patients with previous radial keratotomy（RK）, and to analyze the mechanical properties of the cornea after cataract surgery. Three groups of patients, each one including 8 eyes of patients with 16 RK incisions. The first group includes eyes with the first cataract incision superiorly, the second group in the temporal area, the third group in temporal area and a precautionary stabilizing suture across the RK incision adjacent to the main tunnel. In the first group intraoperative dehiscence occurred in three eyes（37.5%）： it required immediate application of a suture. In the second group dehiscence occurred intraoperatively in two radial scars（20%）： it required immediate application of a suture. In the third group, no intraoperative dehiscences were observed. The stabilizing suture of the RK incision works safer, with a lower risk of dehiscences and less postoperative astigmatism.