Susanne Gardner, Pharm.D.
Dr. Ralph Chu recently shared his clinical experience with the new Crystalens HD™ (Bausch & Lomb), approved by the FDA. The lens features a proprietary modification of the optic design that retains the single image on the retina yet increases focal range. The Crystalens HD is part of Dr. Chu's comprehensive cataract and refractive surgery practice, where a wide variety of refractive surgery procedures, including lens implants, are available to patients. Dr. Chu was a participant in the FDA clinical trial that resulted in the approval and availability of the lens in June of this year. His clinical experience to date closely parallels the findings of the FDA study. A higher percentage of his patients implanted with the new Crystalens HD lens have improved reading ability and better visual acuity, with no loss of contrast sensitivity, as compared with previous generations of lenses.
The Crystalens HD features a unique change in the central asphericity of the optic that produces an optic optimized for reading. As the lens is not a multifocal lens, patients do not notice a loss of contrast, and do not experience increased glare and haloes compared with earlier lenses. Dr. Chu cites an approximate 1.5 line improvement in reading vision in his patients compared with previous generations of accommodating lenses. The Crystalens HD, therefore, represents an evolutionary improvement from the 4.5 and the 5.0 optic for improved reading, with minimal optical aberrations.
A unique feature of this lens is the expansion and improvement of the depth of visual field via one focal point and image on the retina, as opposed to multiple images on the retina, which can distort the quality of vision. The FDA findings mirror early anecdotal results experienced with the Crystalens HD. FDA study results showed that both contrast sensitivity and depth of focus were improved. Near visual acuity (DCNVA) at 4 to 6 months postoperatively was 20/40 or better in 81.4% of eyes. Uncorrected near visual acuity (UNVA) at 4 to 6 months was 20/40 or better in 90.7% of eyes. Best corrected near visual acuity (BCNA) was correctable to 20/32 or better in 100% of eyes, and 20/20 or better in 89% of eyes. Uncorrected distance visual acuity (UDVA) was 20/40 or better in 77.1% of eyes. Results of the clinical trial underscored an enhanced depth of focus producing improved near vision without compromise of intermediate or distance vision. Notable in the FDA study were the improved results in reading by Day 1, with a substantial number of patients already reading in the J2 and J1 range, an unexpected early improvement in reading vision.
Dr. Chu emphasizes that his patients are interested in the quality of vision after lens implant, as much as the expanded range of focus. Most of his patients receive bilateral implants with the same presbyopic corrective lens placed in both eyes, although customized approaches are offered to patients requiring a different lens in each eye for the desired range of vision. Patients today have the exciting opportunity to become educated about lens implant choices, and to make appropriate decisions. Although a variety of factors come into play, choosing the best lens for the patient results in the best visual outcome. In his current experience, Dr. Chu finds the new Crystalens HD accommodating lens offers an "optimized optic surface that helps improve reading vision, with no increases in glare and halo over previous generations of the Crystalens".
Y. Ralph Chu, MD, is Medical Director of the Chu Vision Institute in Edina, Minnesota, and is Adjunct Assistant Professor of Ophthalmology at the University of Minnesota, Minneapolis.