Comparison between the effects of natural and surgical menopause on eye

Tear function, macular, choroidal and retinal nerve fiber layer thickness, hormon levels and the relationship between these and duration of menopause was evaluated among women with surgical menopause and natural menopause in order to investigate the clinical effects created by the absence of ovaries on the eye tissues and physiology. This study was performed in Abant İzzet Baysal University Department of Ophthalmology with the participation of 40 women with surgical menopause and 45 woman with natural menopause followed by department of Obstetric and Gynocology between December 2013 and December 2015 with the permission of faculty ethic comission. All participants with a history of systemic or ocular disease was excluded. Further women that taking hormone replacement treatment was not included. A complete ophthalmologic exam was performed and retina, choroid, retinal nerve fiber thickneses was obtained. For statistical analysis; independent-samples T test, Pearson and Spearman corralation analysis was applied. P<0.05 was set as statistical significance. Mean values of intraocular pressure, retinal nerve fiber layer thickness, central corneal thickness between two groups were significantly different. In surgical menopause group central cornea was thicker (p=0,027) but contrary Central retinal thickness and intraocular pressure were lower ( p=0,025, p=0.044 respectively). Estradiol and retinal nerve fiber layer were negatively correlated ( r=-0,285 p=0,031). TSH and duration of menopause, intraocular pressure and duration of menopause were also negatively correlated. (r= -0,233 p=0,040 and r=-0,285 p=0,031 respectively). Schirmer score and break-up time expressed positive correlation ( r=0,437 p>0.001). The lower intraocular pressure in the surgical menopause group may be a result of abrupt and significant decrease of serum androgen hormone levels. Global retinal nerve fiber layer was thinner in natural menopause group which was matching with the intraocular pressure difference which may leads practitioners pay more attention on this group for the risk of glaucoma development. It was raported that estradiol and hormon replacement treatment are protective on retinal nerve fiber and increase retinal blood flow. In our study a negative correlation was found between estradiol and retinal nerve fiber layer thickness. In natural menopause group central corneal thickness was also thinner which may be attributed to higher mean age. No statistical difference was found among groups at schirmer scores and break-up times but break-up time was negatively correlated with the menopause duration (r=-0,233 p=0.04). It might be thought that menopause duration was more important than the hormonal status for the tear film durability. Consequently, there are physiological and functional differences between surgical and natural menopause groups owing to hormonal inequality. To produce clinically utilizable results, more prospective studies are needed. Key words: Natural menopause, Surgical Menopause, Optic Coherence Tomography, Tear function, Intraocular pressure