Refractive and Corneal Astigmatism After Implantation of a Supraciliary Drainage Device in Microinvasive Glaucoma Surgery.

PURPOSE: To assess the short-term impact of stand-alone MINIject (iSTAR Medical SA) implantation on astigmatism in a single-center retrospective study.

METHODS

Refractive and corneal astigmatism was investigated based on preoperative and postoperative subjective refraction and Scheimpflug tomography measurements at 3 months (D90) using power vectors: the spherical equivalent M and the Jackson cross cylinder projections to the 0° and 90° (J0) and to the 45° and 135° meridian (J45).

RESULTS

A total of 60 eyes with glaucoma or ocular hypertony from 54 patients were included. Refractive cylinder did not change after stand-alone implantation (CD0 = -1.48 ± 1.52 diopters [D] vs CD90 = -1.36 ± 1.20 D, P = .30) and, analogously, no time course was observed in three-dimensional vector analysis (P > .99). Anterior corneal surface astigmatism showed a near-significant change (P = .07) in the two-dimensional vector analysis (J0; J45), primarily driven by the J0 component (P = .03), whereas the posterior surface remained unaffected (P = .4). The mean absolute surgically induced astigmatism was 0.78 ± 0.53 D for the anterior surface and 0.22 ± 0.21 D for the posterior surface.

CONCLUSIONS

Supraciliary MINIject implantation may induce minor short-term changes in anterior corneal astigmatism. However, when implanted as a stand-alone procedure, it does not affect refractive astigmatism. Therefore, astigmatic changes do not require specific emphasis during patient counseling.