The Incidence of Glistenings in the 2017 Intraocular Lenses Made by Alcon and Abbott Medical Optics

The Incidence of Glistenings in the 2017 Generation of Hydrophobic Acrylic Lenses Manufactured by Alcon and Abbott Medical Optics

The purpose of this study is to seek academic/non-industry research funding support to independently investigate the incidence and density of lens glistenings in cataract patients who are implanted with the latest generations of intraocular lenses (IOL) manufactured by Alcon and AMO Medical Optics.

Glistenings are tiny, clear sparkling, fluid-filled microvacuoles that form within a lens after it has been placed in the eye. Glistenings are seen in all lenses but certain lenses develop a higher number of glistenings than others. The effect of glistenings on patients' visual functioning is largely unknown.

The occurrence of glistenings is in part related to the manufacturing technique. In 2013, manufacturers have claimed that recent improvements in manufacturing process have reduced the occurrence of glistenings. There is a lack of independent evaluation of this claim. We would like to assess independently: 1) How frequently do glistenings occur in patients implanted with the 2015 generation lenses? 2) Is there a difference in glistening occurrence between lenses manufactured by Alcon and Abbott Medical Optics (AMO) - the two largest companies in eye care products?

Two-hundred and seventy-six patients will be randomly assigned to receive Alcon or AMO lenses for their cataract surgery at the Kensington Eye Institute (KEI). After surgery, patients will be instructed to return for follow-up visits at 1 month, 6 months, 12 months and 18 months to assess for the occurrence of glistenings. If glistenings are observed at an earlier follow-up visit (e.g., the 6 month visit), patients will still be instructed to come for future visits so that changes in the glistenings over time can be observed.

Project Time-line:

Months 1-8: Participants recruiting, surgical operations, follow-up visits. Months 9-24: follow-up visits, data entry, cleaning and analysis, early results presentation, manuscript preparation and final report.

Inclusion Criteria:

• Patients consulting 5 surgeons for cataract surgery in the surgeon's primary offices
• Patients aged 18 years or older
• Patients who signed the consent form

Exclusion Criteria:

• Individuals who cannot understand English in either written or verbal form and do not have language assistance available (e.g. from family members, friends)
• Patients with co-existing condition of corneal disease
• Patients with co-existing condition of uveitis
• Patients with co-existing condition of optic nerve disease
• Patients with co-existing condition of macular disease
• Patients with co-existing condition of diabetes
• Patients with co-existing condition of severe glaucoma (i.e. C/D ratio >=0.9 AND the patient is on glaucoma treatment)
• Patients with prior refractive surgery
• Patients with complications of cataract surgery occurred during or after surgery