COMPARING VISUAL OUTCOMES IN MATCHED PATIENTS RECEIVING A LOW CYLINDER POWER TORIC IOL OR A NON-TORIC IOL

To evaluate the visual and refractive outcomes of the Alcon Clareon^® T2 (low cylinder power) IOL relative to the Clareon^® non-toric IOL. The T2 toric IOL has a 1.00 D cylinder at the IOL plane, corresponding to a nominal 0.65 D at the corneal plane.

Single ophthalmology clinic.

Patients presenting for routine cataract surgery in one or both eyes, where at least one eye qualified for implantation of the T2 lens, were enrolled. The qualifying eye was randomized to a T2 lens or a non-toric lens. If both eyes of the same subject qualified for inclusion, then they received the same lens type in each eye. Enrollment was planned for 30 T2 eyes and 20 non-toric eyes.

Subjects were evaluated at a single visit three months postoperative. All testing was monocular. Testing included uncorrected and corrected distance visual acuity, and the manifest refraction. Low contrast (10%) visual acuity was tested under photopic and mesopic conditions, with and without glare. The sine wave contrast sensitivity was also tested under photopic and mesopic conditions (without glare). These latter two tests were conducted with the distance correction in place.

Fifty eyes of 43 subjects were included. Subjects were matched for age (p = 0.59), sex (p = 0.30), mean keratometry (p = 0.44), anterior corneal astigmatism (p = 0.97), axial length (p = 0.12) and anterior chamber depth (p = 0.40).
Postoperatively there was no statistically significant difference in the spherical equivalent refraction (p = 0.08). Residual refractive cylinder was statistically significantly lower in the T2 group (0.22 ± 0.22 vs. 0.59 ± 0.28, p < 0.01). The T2 group also had uncorrected logMAR distance visual acuity nearly one line better than the non-toric group, (0.00 ± 0.08 vs. 0.09 ± 0.13). This difference was also statistically significant (p < 0.01).

Low contrast acuity was not statistically significantly different between the two lens types in either mesopic or photopic conditions, with or without glare (p = 0.49). Photopic and mesopic contrast sensitivity were also not statistically significantly different between the two lens types (p = 0.71 and p = 0.63, respectively).

The data show that use of the low cylinder power lens provided significantly better uncorrected visual acuity, with no significant differences in contrast sensitivity or low contrast acuity. The achieved cylinder correction was consistent with expectations.