Corneal sensitivity recovery following automated lamellar keratoplasty and laser in istu keratomileusis

Purpose. In order to understand the wound healing process by recovery of neural regeneration after automated lamellar keratoplasty (ALK-Chiron Vision) and laser in situ keratomileusis (LASIK-Nidek EC-5000), corneal sensitivity by aesthesiometer (Cochet-Bonnet instrument) was determined postoperativey. Method. Each group contained 32 eyes (ALK and LASIK) and with the similar mean age of patient (ALK: 29.4, LASIK: 28.3). The location of corneal sensation testing including center of cut corneal disc, nasal peripheral of cut corneal disc, corneal flap base and uncut outer portion of cornea (as a control group) at post-operative 1 week, 2 weeks, 1 month, 2 months and 3 months. Result. The percentage of sensation recovery of central corneal disc by ALK and LASIK at 1 month, 2 months and 3 months were: 84.4%, 90.6% 93.8% and 68.7%, 78.1%, 93.7% respectively. We further divided the LASIK group into 2 subgroups: < -8.0 Diopter and >-8.0. Diopter.The mean corneal touch threshold of ALK /LASIK at 1w, 2w, 1m and 2ms were 12.6/3.3, 24/26.7, 41/42.6, 493/49.2. Conclusions. The result revealed the prolong corneal sensitivity recovery in LASIK group compared with ALK group. There was more decrease in corneal sensitivity in myopia > -8.0 D subgroup than in myopia < -8.0 D subgroup at post-LASIK 1 week (t-test < 0.05), and this may be induced by more laser ablation . This longer neurotrophic condition in LASIK than ALK may coresponded to the less wound healing effect by LASIK. However, this may also prolong the ocular surface abnormality postoperatively.