Cataracts, Functional Visual Loss, Loss of Visual Contrast Sensitivity, Visual Acuity Reduced Transiently
Conditions
Keywords
Cataract surgery, Intraocular lens, Glistenings
Brief summary
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.
Detailed description
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.
Interventions
DEVICEAlcon 1 piece SA60AT lens
Optic Diameter: 6.0 mm, Overall length: 13.0 mm, Material: Ultraviolet-absorbing Acrylate/Methacrylate Copolymer
DEVICEAMO 1-piece AABOO lens
Optic Diameter: 6.0 mm, Overall length: 13.0 mm, Material: Ultraviolet-blocking hydrophobic acrylic
Sponsors
Kensington Eye Institute
University of Toronto
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
SINGLE (Subject)
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No
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
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Incidence and density (severity) of glistenings at 18-month follow-up visit | 18-month follow-up | To determine if glistenings develop, eyes are dilated and examined. Photographs of the IOLs will be taken with a slit lamp camera for documentation. These photographs will then be assessed for glistenings in two ways: first by trained ophthalmology staff, and second using the ImageJ software Glistenings will be counted and graded on a scale of 0 to 5+ as following: 0\. No glistening 1. Less than 10 glistenings 2. 10 to 25 glistenings 3. 25 to 50 glistenings 4. 50 to 100 glistenings 5. Greater than 100 glistenings |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Contrast sensitivity in eyes with glistenings at 18-month follow-up visit | 18 month follow-up | Contrast sensitivity: the ability of the visual system to distinguish between an object and its background. This will be tested with the Vector Vision CSV-1000HGT. |
| Glare disability in eyes with glistenings at 18-month follow-up visit | 18 month follow-up | Glare disability: the difficulty seeing in the presence of very bright light such as night-time lighting or sunshine. This will be tested using the Brightness Acuity Tester (BAT). |
| Visual acuity in eyes with glistenings at 12-month follow-up visit | 12-month follow-up | Best corrected visual acuity: acuteness/clearness of vision. This will be tested with the ETDRS (early treatment diabetic retinopathy study) chart |
| Contrast sensitivity and glare disability in eyes with glistenings at 12-month follow-up visit | 12-month follow-up | Contrast sensitivity: the ability of the visual system to distinguish between an object and its background. This will be tested with the Vector Vision CSV-1000HGT. |
| Glare disability in eyes with glistenings at 12-month follow-up visit | 12-month follow-up | Glare disability: the difficulty seeing in the presence of very bright light such as night-time lighting or sunshine. This will be tested using the Brightness Acuity Tester (BAT). |
| Visual acuity in eyes with glistenings at 18-month follow-up visit | 18 month follow-up | Best corrected visual acuity: acuteness/clearness of vision. This will be tested with the ETDRS (early treatment diabetic retinopathy study) chart. |
| Contrast sensitivity in eyes with glistenings at 6-month follow-up visit | 6-month follow-up | Contrast sensitivity: the ability of the visual system to distinguish between an object and its background. This will be tested with the Vector Vision CSV-1000HGT. |
| Glare disability in eyes with glistenings at 6-month follow-up visit | 6-month follow-up | Glare disability: the difficulty seeing in the presence of very bright light such as night-time lighting or sunshine. This will be tested using the Brightness Acuity Tester (BAT). |
| Incidence of glistenings at 12-month follow-up visit | 12-month follow-up | To determine if glistenings develop, eyes are dilated and examined. Photographs of the IOLs will be taken with a slit lamp camera for documentation. These photographs will then be assessed for glistenings in two ways: first by trained ophthalmology staff, and second using the ImageJ software Glistenings will be counted and graded on a scale of 0 to 5+ as following: 0\. No glistening 1. Less than 10 glistenings 2. 10 to 25 glistenings 3. 25 to 50 glistenings 4. 50 to 100 glistenings 5. Greater than 100 glistenings |
| Incidence of glistenings at 6-month follow-up visit | 6-month follow-up | To determine if glistenings develop, eyes are dilated and examined. Photographs of the IOLs will be taken with a slit lamp camera for documentation. These photographs will then be assessed for glistenings in two ways: first by trained ophthalmology staff, and second using the ImageJ software Glistenings will be counted and graded on a scale of 0 to 5+ as following: 0\. No glistening 1. Less than 10 glistenings 2. 10 to 25 glistenings 3. 25 to 50 glistenings 4. 50 to 100 glistenings 5. Greater than 100 glistenings |
| Visual acuity in eyes with glistenings at 6-month follow-up visit | 6-month follow-up | Best corrected visual acuity: acuteness/clearness of vision. This will be tested with the ETDRS (early treatment diabetic retinopathy study) chart. |
Countries
Canada
Outcome results
None listed