Estimation of angle kappa and pupil barycentre configuration in myopic tilted disc syndrome

To evaluate the angle kappa and pupil barycentre configuration in patients with myopic tilted disc syndrome (TDS).

Thirty-five eyes of 35 patients with TDS were included in the study. Thirty-five eyes of 35 age- and sex-matched healthy subjects were enrolled in the control group. All measurements were performed with the Lenstar LS 900. Angle kappa was calculated according to Pythagorean theorem using the x and y co-ordinates of the pupil centre. Pupil dx and pupil dy values (pupil dx: x co-ordinate of pupil centre relative to corneal apex, pupil dy: y co-ordinate of pupil centre relative to corneal apex) were used to evaluate the pupil barycentre configuration. Central corneal thickness, white to white (cornea diameter), pupil diameter, anterior chamber depth, lens thickness, and axial length were also measured.

The calculated mean angle kappa distance was 0.27 ± 0.15 mm in the TDS group and 0.29 ± 0.23 mm in the control group (p = 0.42). The mean pupil dx was -0.01 ± 0.24 mm in the TDS group and -0.17 ± 0.14 mm in the control group (p = 0.006). The mean pupil dy was -0.02 ± 0.13 mm in the TDS group and -0.05 ± 0.22 mm in the control group (p = 0.65).

The pupil barycentre in TDS cases was statistically significantly closer to the corneal vertex on the horizontal plane compared to the control group. However, there was no statistically significant differences in terms of angle kappa and pupil dy values between the groups. According to our results, refractive surgery can be performed safely with respect to complications related to decentration of ablation zone and decentration of multifocal intraocular lenses in these groups of patients.