Transpalpebral intraocular pressure measured by Diaton tonometer before, 1 week, and 1 month after transepithelial photorefractive keratectomy in young myopic Saudi patients and its determinants

PURPOSE

To present changes in transpalpebral intraocular pressure (tpIOP) in eyes after transepithelial photorefractive keratectomy (TPRK) in myopic Saudi patients and its determinants.

METHODS

This one-armed cohort included the myopic eyes of Saudi adolescents treated with TPRK in 2020-2021. The difference in tpIOP before surgery, 1 week after surgery, and 1 month after surgery using Diaton was the main outcome. Central corneal thickness (CCT), myopia grade, gender, age, and corneal epithelial thickness before surgery were independent factors. Matched-pair analysis was conducted. The determinants of tpIOP post-TPRK were studied.

RESULTS

Our cohort included 193 eyes of 97 participants (25.6 ± 5.8 years). Mild, moderate, and severe myopia were present in 93, 79, and 21 eyes, respectively. tpIOP was 22 mmHg or more in 5 and 8 eyes at 1-week and 1-month follow-up, respectively. The change in tpIOP ranged from - 7.00 to + 11.0 mmHg at 1 week and - 8.0 to + 26.0 mmHg at 1 month. The median change of CCT at 1 month was 59 μ. Change in tpIOP was not correlated with change in CCT at 1 month (r = -0.107, Pearson P = 0.14). Change of tpIOP was significantly correlated to spherical equivalent (SE) before surgery (matched-pair P < 0.001). SE (Mann-Whitney U P = 0.02) and tpIOP (Mann-Whitney U P = 0.02) before TPRK were significantly correlated to tpIOP >22 mmHg after TPRK.

CONCLUSION

The changes in tpIOP following refractive surgery correlate to the refractive status of the eye and tpIOP before surgery.

Association between corneal refractive surgery and the prevalence of glaucoma: Korea National Health and Nutrition Examination Survey 2010-2012

AIM

To determine the relationship between corneal refractive surgery and the prevalence of glaucoma in the Korean population.

METHODS

Data were obtained from the Korea National Health and Nutrition Examination Survey (KNHANES), a population-based cross-sectional study using a complex, stratified, multistage, probability-cluster survey. This study included 604 eyes that had undergone myopic corneal refractive surgery, and 3389 control eyes without a history of any ocular surgery and having a spherical equivalent (SE) <-3.00 D, obtained from the KNHANES database for the years 2010-2012. Glaucoma diagnosis was based on the International Society of Geographical and Epidemiological Ophthalmology criteria. The association between a history of corneal refractive surgery and the prevalence of glaucoma was analysed using logistic regression analysis, after adjusting for potential confounding factors.

RESULTS

Glaucoma prevalence did not differ between eyes that had and had not undergone corneal refractive surgery (p=0.675). After adjusting for age, sex, SE, and intraocular pressure, multivariate logistic regression analysis found that corneal refractive surgery was significantly associated with an increased risk of glaucoma (OR 9.14, p=0.002; 95% CI 2.22 to 37.69). Subgroup analysis that only included control eyes with a refraction cut-off <-3.70 D found that corneal refractive surgery was not significantly associated with glaucoma.

CONCLUSIONS

History of corneal refractive surgery was associated with a higher prevalence of glaucoma in the Korean population. However, this association was not observed in eyes with a higher degree of myopia.

Comparison between Betamethasone, Fluorometholone and Loteprednol Etabonate on intraocular pressure in patients after keratorefractive surgery

Purpose

The aim of this study was to compare the ocular hypertensive effect of the commercially available Betamethasone, Fluorometholone in Iran and Loteprednol Etabonate in patients undergoing keratorefractive surgery.

Methods

In this prospective randomized clinical trial, 300 eyes of 150 patients were included, and patients were randomly assigned to 3 groups and used one of the 3 steroid drops (Betamethasone 0.1%, Fluorometholone 0.1%, and Loteprednol Etabonate 0.5%) after myopic photorefractive keratectomy (PRK). Intraocular pressure (IOP) was measured 2, 4, and 6 weeks post-surgery. Twenty-two mmHg was set as the threshold IOP for starting anti-glaucoma medication and tapering steroid drops.

Results

Of 300 eyes from 150 patients over the first 6 postoperative weeks, 2 eyes in Fluorometholone group (2%), 12 eyes in Betamethasone group (12%), and 16 eyes in Loteprednol group (16%) had IOP equal or more than 22 mmHg. Analysis of variance (ANOVA) test showed that the rise in IOP was significantly different between groups in the 2nd and 4th (P ≤ 0.001) postoperative weeks but not at 6th week (P = 0.230). An IOP rise equal or more than 10 mmHg was detected in 13 and 15 eyes in Betamethasone and Loteprednol groups, respectively. None of the eyes in Fluorometholone group had such an IOP rise.

Conclusions

Loteprednol and Fluorometholone were associated with the most and least increase in IOP, respectively. The highest pressures were detected 4 weeks after surgery in the Betamethasone and Loteprednol groups and 6 weeks after surgery in the Fluorometholone group. Fluorometholone was the safest among the three examined steroid drops in terms of IOP rise.