Impact of TNF polymorphisms on visual acuity before and after treatment in optic neuritis

Optic neuritis (ON) is a leading cause of acute optic nerve damage in adults [1]. Characterized by inflammation of optic nerve and myelin sheath, ON results in secondary damage to nerve fibers, ultimately leading to apoptosis of retinal ganglion cells. ON can be caused by a wide range of etiological factors, broadly classified as typical and atypical. Usually, typical ON is subacute, unilateral, painless, has better prognosis and associated with multiple sclerosis [2, 3]. Atypical form is thought to be bilateral, has higher recurrence rate and associated with autoimmune disorders, bacterial and viral infections [3, 4]. Tumor necrosis factor (TNF) is a potent pro-inflammatory cytokine [5]. The TNF gene is localized on the short arm of chromosome 6 at position 21.3 (6p21.3). It is though, that single nucleotide polymorphisms (SNP) located in the regulatory region affect the expression of TNF-α. Several polymorphisms have been associated with various infectious and inflammatory diseases at different locations in the TNF-α promoter region [6]. It is observed, that ON patients have ophthalmological changes, such as reduced visual acuity, visual field abnormalities, color vision impairment and afferent defect of the affected pupil [1]. Visual acuity (VA) is a fundamental measure of central vision, assessing the eye’s ability to distinguish fine details [7]. Assessing VA changes before and after the treatment could help to determine the effectiveness of therapeutic interventions and the impact of TNF polymorphisms on visual outcomes for ON patients. This research aims to determine the associations between TNF-863A/C, TNF-308A/G and TNF-238A/G SNPs with ON and visual acuity (VA). DNA was extracted from peripheral blood leukocytes using DNA salting-out method. Genotyping of TNF863A/C, TNF-308A/G and TNF-238A/G SNPs was performed by real-time polymerase chain reaction (RTPCR). Visual acuity (VA) was evaluated for 75 patients before and after ON treatment. Statistical analysis was performed using the “IBM SPSS Statistics 29.0.2.0” package. We analyzed the associations of TNF-863A/C, TNF-308A/G and TNF-238A/G SNPs with VA in ON patients. Comparison of the genotype and allele distributions did not reveal statistically significant differences in VA before and after treatment in the affected eyes.