Investigation Of Refraction, Corneal Astigmatism And Ocular Residual Astigmatism Values In Healthy Individuals According To Age Groups

To investigate the differences of refraction degree, keratometric astigmatism (KA) and ocular residual astigmatism (ORA) values in healthy individuals who applied to ophthalmology outpatient clinic for routine eye examination in terms of age groups.

Trabzon Kanuni Training and Research Hospital

Patients admitted to the Ophthalmology Clinic of Trabzon Kanuni Training and Research Hospital between March 2019 and February 2020 were included in the study. Refraction values were recorded as spherical, spherical equivalent (SE), cylindrical and cylindrical axis. Ocular residual astigmatism (ORA) values were calculated by vectorial power analysis. Exclusion criteria were any previous ocular surgery, trauma, any ocular/systemic disease, history of amblyopia and failure to achieve adequate agreement in autorefractometer measurements. Refraction, keratometric astigmatism (KA) and ORA distributions and incidences were calculated separately for age groups.

A total of 1003 patients were included in the study. The mean age was 33.5±19.2 years (4 - 80). Mean SE values (-0.21±1.7 D), spherical values (0.08±1.7 D), total astigmatism (TA) values (-0.61±0.8 D), KA values (-0.61±0.85 D) and ORA values (-0.76±0.4 D) were observed in all patients. For all cases, TA and KA values higher than (0.75 D) were 23.7% and 44.9%, respectively. Age distribution is shown in Figure 1 and the distribution of mean SE values and mean TA, KA, ORA values according to age groups is shown in Figure 2. The highest mean KA and ORA values were concentrated in the age groups of 10 - 19 and 70 - 80, respectively. There was a significant positive correlation between KA and ORA (r= 0.16; p< 0.001).

Respect of TA, it may be important that KA and ORA compensate each other. The reason why ORA values are higher in advanced age may be age-related changes in the crystalline lens.