Two target locations for corneal inlay implantation combined with laser in situ keratomileusis

KAMRA Inlay Implantation for Presbyopia Compensation: A Retrospective Evaluation of Patient Satisfaction and Subjective Vision 12-Month Postoperative

PURPOSE:

The aim of the study is to evaluate patients' satisfaction and subjective vision 12 months after monocular KAMRA corneal inlay implantation for the surgical compensation of presbyopia.

SUBJECTS AND METHODS:

Medical records of patients who underwent corneal inlay implantation in the nondominant eye between 2013 and 2014 were retrospectively reviewed. Data were collected from several centers in Lebanon. Patients with hyperopia or myopia with presbyopia between 45 and 70 years not suffering from any other ocular pathology were eligible for inclusion. Twelve-month postoperative satisfaction score was evaluated in all patients as well as the subjective vision score for near, intermediate, and distant tasks.

RESULTS:

This study included 73 patients. Almost 95% (69/73) of patients were satisfied or very satisfied with their vision and 93% (68/73) never or almost never used reading glasses while performing daily tasks. Subjective vision scores were found to be higher for distant and intermediate tasks performed during the day than for those performed during the night (P < 0.001). The average subjective vision score for reading a book or a newspaper in dim light was the lowest among all average subjective vision scores. No difference in satisfaction was found between patients with myopia or hyperopia or between males and females.

CONCLUSION:

The implant of a small-aperture corneal inlay resulted in a substantial improvement in patients' distant, intermediate, and near subjective vision, better in normal light than in dim light, and most patients became spectacles independent.

The Sensitivity of Clinical Outcomes to Centration on the Light-Constricted Pupil for a Shape-Changing Corneal Inlay

PURPOSE

To assess the clinically acceptable range of inlay decentration with respect to the light-constricted pupil center and the coaxially sighted corneal light reflex (CSCLR) for an inlay (Raindrop Near Vision Inlay; ReVision Optics, Inc., Lake Forest, CA) that reshapes the anterior corneal surface.

METHODS

In this retrospective, observational cohort study of 115 patients with emmetropic or low hyperopic presbyopia who were implanted with a shape-changing corneal inlay, visual acuity, task performance (in good and dim light), reports of halos and glare, and satisfaction data were collected from the preoperative and 3-month postoperative examinations. Inlay centration with respect to the pupil center and CSCLR was determined from the center of the inlay effect derived from iTrace (Tracey Technologies, Houston, TX) wavefront measurements. Multivariate regression models assessed the influence of inlay position on visual outcomes.

RESULTS

On average, monocular uncorrected near visual acuity (UNVA) improved 4.9 ± 1.7 lines in the treated eye, with no loss in binocular distance vision. Eighty-three percent of implants were centered radially within 0.5 mm of the pupil center. Multivariate analysis of decentration with respect to both the pupil center and CSCLR revealed no significant interaction with the above clinical outcomes, with the exception of UNVA in the treated eye (all P > .05, α = 0.05). For decentration of less than 0.75 mm, the change in UNVA was less than 1 line.

CONCLUSIONS

Distance and near visual acuity, task performance, severity of halos and glare, and satisfaction were independent of radial decentration of the Raindrop Near Vision Inlay of less than 0.75 mm from the light-constricted pupil. [J Refract Surg. 2018;34(3):164-170.].

Method of locating the visual axis objectively

PURPOSE

To locate the visual axis of the eye objectively.

METHOD

Based on three-beam scanning laser radar microprofilometry, a technique is proposed to objectively locate the visual axis of the eye. The laser beam consists of three components, two of them being shifted relatively to the central one by differing frequencies, filtered in spatially orthogonal directions. The centre of the foveola is defined as the crossing of steepest inclinations determined in the specific beam positions on the trajectory of scanning. The position of the cornea crossing by the visual axis is designated by the optical axis of the measuring instrument.

RESULTS

Nanometer sensitivity was confirmed in a preliminary test.

CONCLUSIONS

The proposed technique can be incorporated into any clinical wavefront sensing instrument and can be used for centration-sensitive vision correction, as well as for other instances when knowing the exact position of the fovea is important.