The authors report the association between corneal refractive surgery and the prevalence of glaucoma in a Korean cross-sectional population-based study (KNHANES: Korea National Health And Nutrition Examination Survey). The case group (n = 604) was composed of participants with a previous history of myopic corneal refractive surgery and the control group (n = 3389) was composed of participants with a refractive error between -3 diopters and -12 diopters. Only the right eye of each participant was analyzed and eyes with a previous history of any other ocular surgery were excluded. Noteworthy, preoperative refractive status of the case group was not collected in the database.
After adjustment with age, sex, spherical equivalent and intraocular pressure (IOP), the authors observed a 9.14 higher risk to develop glaucoma after a myopic corneal refractive surgery compared to a group of myopic participants without surgery. Increasing age, male, increasing IOP and decreasing spherical equivalent were also associated to a higher prevalence of glaucoma.
The authors pointed out that corneal refractive surgery could induce transient IOP spikes during the suction ring step of the LASIK procedure as well as an ocular hypertension induced by a postoperative prescription of topical corticosteroids.
However, despite authors' findings in a large population sample, the association between a previous history of myopic corneal refractive surgery and a higher prevalence of glaucoma still remains uncertain.
Indeed, there are some concerns about the matching and the comparability of the case and the control group with a much higher number of female participants (69.3% vs 48.6% respectively) and the absence of preoperative refractive status in the case group. Then, while PRK procedure does not require a suction ring and is less likely to induce transient IOP spikes, the surgical procedure was not provided. Additionally, despite a study based on a large population sample, the analysis may lack of statistical power. Indeed, glaucoma prevalence was 3% in the case group (18 eyes) and confidence interval of the association between the prevalence of glaucoma and corneal refractive surgery was quite large (OR: 9.14 (95%CI:2.22;37.69)).
In conclusion, myopic corneal refractive surgery may lead to a higher prevalence of glaucoma. However, this association would need to be confirmed in other prospective cohort studies before providing robust recommendations for a refractive surgery procedure in myopic patients.