MORPHOMETRIC MARKERS AND GENETIC FACTORS OF MYOPIA IN KERATOREFRACTIVE SURGERY

Abstract

Modern keratorefractive surgery requires careful preoperative screening to prevent postoperative complications such as corneal ectasia. Identification of morphometric corneal markers and genetic predisposition plays an essential role in risk stratification and personalized surgical planning.

Purpose – to evaluate optic nerve head (ONH) morphometry in patients with high myopia undergoing keratorefractive surgery and to investigate the potential association between morphometric changes and the MMP-9 rs3918242 polymorphism.

Material and methods
This retrospective study (2024–2026) included 100 of 400 screened LASIK patients at a specialized ophthalmology center. Participants (19–40 years) had high myopia (−6.25 to −8.50 D) and no history of ocular surgery, glaucoma, non-myopic retinal disease, or systemic connective tissue disorders. Patients were classified by ONH morphology into normal discs (n = 40), tilted discs (n = 30), and tilted discs with torsion (n = 30). All subjects underwent comprehensive ophthalmic examination, including visual and refractive assessment, slit-lamp biomicroscopy, tonometry, dilated fundus examination, and fundus photography. ONH parameters (ovality index, tilt, torsion, disc– fovea angle, disc diameter, and peripapillary atrophy (PPA)) were evaluated. MMP-9 rs3918242 polymorphism analysis was performed in 30 patients using PCR-RFLP. Statistical significance was set at p < 0.05.

Results
Genotyping of the MMP-9 rs3918242 polymorphism showed the following distribution: CC (46.7%), CT (40.0%), and TT (13.3%). T allele carriers had significantly higher disc tilt, torsion, and PPA (p < 0.05). Correlation analysis demonstrated positive associations between disc tilt and PPA area (r = 0.61), torsion and PPA area (r = 0.58), and T allele carriage with morphometric changes (r = 0.49). Overall, the results indicate a possible link between extracellular matrix remodeling and optic nerve head deformation in high myopia. The observed association between the rs3918242 polymorphism and morphometric parameters indicates a possible genetic predisposition to structural ocular changes. Thus, combining morphometric and genetic assessment may improve risk stratification in keratorefractive surgery candidates.

Conclusion
Optic nerve head morphometric parameters are significant structural markers of high myopia. Disc tilt and torsion are associated with progressive posterior segment remodeling. The MMP-9 rs3918242 polymorphism is associated with morphometric changes and may serve as a potential genetic marker. Combined morphometric and genetic evaluation can improve patient selection and safety of keratorefractive surgery.