Lenses, Intraocular clinical trials

Visual Field Changes in TECNIS ZCB00 Monofocal vs. TECNIS Symfony Extended Depth of Focus Intraocular Lens Implantation

Glaucoma is a leading cause of blindness worldwide. Damage to the optic nerve results in vision loss gradually. This vision loss can be detected by using visual field testing, and is a way of monitoring glaucoma progression. As this population ages, cataracts develop, and patients need to undergo cataract surgery to replace the cloudy crystalline lens with an artificial intraocular lens (IOL). The standard of treatment is implantation of a monofocal IOL, but this limits depth of focus and does not allow clear vision at both distance and near without glasses post-operatively. Multifocal and trifocal lenses split light into multiple distinct foci at near, intermediate and far distances without glasses correction. However, these lenses have been shown to reduce contrast sensitivity and impair visual field testing results, and are not recommended in patients with glaucoma. The TECNIS Symfony IOL has recently been approved by Health Canada and offers an extended range of vision with a single elongated focal point to allow patients to see at both distance and near. The lens is advertised to enhance contrast sensitivity, but it is currently unknown whether the TECNIS Symfony IOL impacts visual field testing. We will study the visual field changes in patients undergoing both TECNIS ZCB00 monofocal and TECNIS Symfony extended depth of focus IOL implantation during cataract surgery. The results of this study will impact the advice cataract surgeons give to patients with glaucoma, regarding whether this population of patients would benefit from a standard monofocal IOL implantation or an extended depth of focus TECNIS Symfony IOL implantation.