How long does the recovery of corneal sensitivity in different corneal regions take after LASEK?

AIM:To determine the corneal sensitivity recovery period after laser-assisted sub-epithelial keratectomy(LASEK)refractive surgery and investigate the effects of ablation depth on it.METHODS:In this study examinations were performed on 90 right eyes of 90 people(34 males and 56 females)with an age range of 20-35 and an average of 22.26±3.8 years old.A sensation of 5 corneal regions,including the center and 4 mid-peripheral regions,i.e.,nasal,inferior,temporal,and superior,each at a distance of 2 mm from the center of the cornea were measured with a Cochet-Bonnet esthesiometer device in 3-time points including before LASEK,1 and 3mo after the surgery,respectively.LASEK was performed on individuals with stabilized myopia of -1.00 to -7.00 diopters and astigmatism of less than 2.00 diopters.Furthermore,the individuals were divided into three groups regarding ablation depth.RESULTS:The highest level of corneal sensitivity before surgery was related to the center of the cornea(59.1±7.76),and the highest level of corneal sensitivity loss was also related to this region.The sensation of all measured corneal regions significantly reduced 1mo postoperatively and returned to their preoperative levels 3mo after surgery(mean of 5 corneal regions in levels of preoperation:58.2±6.48,1mo postoperation:57.3±5.84,3mo postoperation:58.2±5.49;P<0.05).A significant relationship was found between ablation depth and corneal sensitivity changes in the center and temporal regions(P<0.05).CONCLUSION:Corneal sensitivity in myopia and low astigmatism decreases after LASEK and reaches the preoperative level within 3mo.The depth of ablation during surgery affected the recovery of corneal sensitivity.

Implantable collamer lens for residual refractive error after corneal refractive surgery

AIM：To assess the safety,efficacy,predictability and stability of implantable collamer lens（ICL） for residual refractive error after corneal refractive surgery.METHODS： This study evaluated 19 eyes of 12 patients who underwent ICL implantation after corneal refractive surgeries.They were followed up for 1y to 5y of uncorrected distance visual acuity（UDVA）,corrected distance visual acuity（CDVA）,manifest refractive error,flat and steep K value,axial length,intraocular pressure,corneal endothelial cell density,adverse events after ICL surgery.RESULTS： The mean follow-up period was 39.05 ±19.22 mo（range,1-5y）.Spherical equivalent refractive error changed from-7.45±3.02 D preoperatively to-0.85±1.10 D 1wk to 1mo after ICL implantation,with the safety and efficacy indices being 1.12 and 1.15,respectively.A total of 52.63% of eyes were within ±0.5 D of the predicted spherical equivalents,73.68% were within ±1.0 D.A trend of mild regression towards myopia with axial elongation after 5y was observed.One eye with mild anterior capsule opacity and retinal detachment 1y after surgery were observed.CONCLUSION： ICL implantation is safe and effective for the correction of residual refractive error after corneal refractive surgeries,especially in moderate to high residual myopia.