Types of Intra Ocular Lens (IOLs)

Types of Intra Ocular Lens (IOLs)

Monofocal IOL: This is the most common. Unlike your natural lens, which can stretch or bend to help your eye focus, this implant stays focused at one fixed distance. If yours focuses at a distance, you might be able to see things far away but need glasses to read or see close up.

Multifocal implant: Like glasses with bifocal or progressive lenses, this lens has areas that help you see things at different distances. It could take several months for your brain to adapt so your vision seems natural.

Accommodating IOL: This flexible option acts more like your natural lens and focuses at more than one distance. It makes you less likely to need reading glasses.

Toric IOL: You’ll get this is if you have astigmatism, or a cornea that’s more rugby ball-shaped than round. This can make vision blurry all over, not just close up or far away. This lens lessens astigmatism so you won’t need glasses to correct it after your surgery.

Large diameter IOLs are preferred to facilitate visualisation and treatment of the peripheral retina in Diabetic Retinopathy.

Corneal hypoesthesia (numbness) is common in diabetic patients. Special care should be taken to protect the corneal epithelium during surgery. Corneal abrasions during or after surgery may be slow to heal and lead to recurrent corneal injury. Small-incision surgery can minimise further decrease in corneal sensation. Due to corneal hypoesthesia and the increased risk of infection, patients with diabetes are poor candidates for long-term aphakic (without natural lens) contact lens wear. Thus a posterior chamber intraocular lens (IOL) should be inserted when possible.

With modern minimally invasive cataract operations most studies agree that the risk of enhanced post op Diabetic Retinopathy progression after cataract surgery is small in patients without severe Non Proliferative Diabetic Retinopathy (NPDR)or preexisting Diabetic Macular Edema (DME) 11. Poor visual outcomes are related to poor metabolic control rather than cataract surgery in these cases.

In eyes where there is pre-existing DR there is an increased risk of DME, or progression of existing DME in the post-operative period and Best Corrected Visual Acuity (BCVA) gains are limited without further intervention. Anti VEGF therapy at the time of surgery is advocated.

Surgery may cause a rapid acceleration of retinopathy, induce rubeosis (growth of blood vessels on the iris) or lead to macular changes, such as macular edema or cystoid macular edema. The worst outcomes may occur in operated eyes with active proliferative retinopathy and/or pre-existing macular edema 1.

Timing of cataract surgery has shifted in recent years to that of choosing to have cataract surgery earlier rather than later and this has contributed to improved visual outcomes.