ABSTRACT
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.
ABSTRACT
PURPOSE: To determine whether corneal sensitivity is different between the two genders. METHODS: Corneal sensitivity of 130 normal volunteers, including 77 women and 53 men aged 20-35 years, with no history of previous ocular surgery was measured using the Cochet-Bonnet esthesiometer. Measurements were done on five corneal regions: central, nasal, inferior, temporal and superior. The findings were compared between men and women using the non-parametric Mann-Whitney U test. RESULTS: Mean age of male subjects was 28.0 years and that of female participants was 26.8 years (P = 0.063). There was a significant difference in corneal sensitivity between men and women in the superior (P = 0.013), temporal (P = 0.020) and inferior (P = 0.046) regions. There was no significant difference in corneal sensitivity in the central (P = 0.862) and nasal (P = 0.273) regions. CONCLUSION: Except for the central and nasal regions, corneal sensitivity is significantly higher in men as compared to women. The reason for this difference is not yet evident.
ABSTRACT
BACKGROUND: The present study sets out to determine normal corneal sensitivity in five corneal regions and its changes with age in an Iranian population. METHODS: The corneal sensitivity of the centre of the cornea and at four corneal regions, namely, nasal, inferior, temporal and superior at 2.0 mm from the limbus of the right eye of 596 subjects aged 15 to 81 were measured using a Cochet-Bonnet aesthesiometer. All measurements were performed by the same examiner at 18 degrees centigrade and 35 per cent humidity between 2:00 and 5:00 pm. The subjects were divided into six age groups of 15 to 25 years, 26 to 35, 36 to 45, 46 to 55, 56 to 65 and over 65 years, respectively. Since the measurement outcomes were not continuous, the data was analysed using non-parametric statistics. RESULTS: The frequency of corneal sensitivity of 60 mm in all corneal regions was decreased with advancing age after 35 years (χ(2) p < 0.001). The strongest correlation between age and corneal sensitivity was for the centre of the cornea (-0.52), followed by nasal (-0.49), temporal (-0.48), inferior (-0.47) and superior (-0.46) regions of the cornea, which had significant negative correlations (p < 0.001). The five different corneal regions showed significant differences of corneal sensitivity (p < 0.001). In different age groups, the difference was seen in the three lower age groups of 1, 2 and 3, while in the three older age groups of 4, 5 and 6, there were no differences in corneal sensitivity among five corneal regions (p > 0.05). CONCLUSION: Based on the findings of the current study, all regions of the cornea showed a faster reduction in sensitivity with age in this sunny environment compared to the results of previous studies.
