Extending Depth of Focus With Small-Aperture Intraocular Supplementary Device
Purpose
To test the ability of extending depth of focus with the implantation of a small aperture device as a secondary procedure after cataract extraction and monofocal IOL implantation.
Methods
Sixteen consecutive patients with bilateral in-the-bag monofocal IOL implant, best corrected visual acuity of logMAR 0.0 and near emmetropia subjective refraction (Spherical Equivalent Refraction of ± 0.5D) were enrolled. Exclusion criteria included other ocular conditions and corneal astigmatism greater than 2D.They underwent unilateral implantation of a supplementary small aperture device in the non-dominant eye. At three months postoperative, the main outcome variables measured were unilateral uncorrected distance and near visual acuity (UDVA and UNVA). Other variables included bilateral uncorrected distance, intermediate and near acuity, subjective refraction, pupil size and depth perception.
Results
All surgeries underwent without any complications. At 3 months postoperatively, no patients reported any signs of ocular disturbances. Unilateral UDVA on the operated eye was not statistically different before and after surgery (0.025 logMAR ± 0.044 versus 0.025 ± 0.044 logMAR p=1.0). Unilateral UNVA was significantly better after the surgery (0.625 ± 0.382 logMAR versus 0.235 ± 0.145 logMAR p=0.005). There was an increase in bilateral uncorrected acuity both for distance and for near although statistical analysis showed significant difference only for the near vision (distance p=0.061, near p=0.001) . All the other variables analyzed were statistically similar before and after the surgery.
Conclusion
The small aperture device provided an increase in depth of focus in eyes with monofocal IOL implanted in the bag. There was an improvement of uncorrected near vision monocularly and binocularly with no ocular side-effects.