Blue blocking lens implants: A case of severe glare resolved by lens exchange and implantation of a blue blocking intraocular lens – Romesh Angunawela
Recently a businessman in his 40s consulted me with intractable glare following routine uncomplicated cataract surgery at another hospital 18 months previously. Unaided vision was excellent (6/9). Since his surgery he was unable tolerate low wavelength lighting and in particular fluorescent lighting indoors. His symptoms of glare and discomfort were so severe that he needed to wear sunglasses indoors. This was having a huge impact on his life and particular his activities as a businessman as he was unable to cope under indoor lighting and wearing sunglasses at meetings didn’t make for good first impressions. He was quite clear that he could tolerate sunlight very well and was able to play on the beach with his children without sunglasses. The gentleman was extremely well informed and came to me with information about blue blocking lens implants and some case reports of similar cases resolved by lens exchange.
I performed a successful lens exchange and replaced the existing clear lens implant with a yellow SN60WF UV and blue light blocking aspheric Acrysof lens by Alcon. Lens exchange is more complicated than lens insertion as the lens needs to be cut into smaller pieces within the eye to allow it to be removed. Also after many months the natural lens capsule has shrink wrapped around the implant and needs to be carefully separated. There is the risk of tearing the capsule or zonules during the surgery which can mean that an implant can’t be placed within the capsular bag as planned. In this case the patient understood that there were no guarantees with regard to whether the blue blocking lens would actually resolve his symptoms of glare. So severe were his symptoms that he preferred not to see rather than put up with his current symptoms for any longer.
Post operatively symptoms of glare have now resolved and the patient was able to go to his office without sunglasses for the first time in many months. I was very happy to receive a case of wine in gratitude!
Visible light is made of different wavelengths. Blue light occurs at a shorter wavelength of the visible spectrum. Fluorescent lighting emits at lower wavelengths akin to blue light. As the natural human lens ages it becomes yellow and begins to filter lower wavelengths. Lens implant manufacturers developed yellow blue blocking lenses that simulated this natural ageing of the lens some years ago. Potential alleged benefits of such lenses included increased protection of the retina against damaging blue light and potentially reduced risk of age related macular degeneration. Current intraocular lenses all block damaging ultraviolet light. Only yellow lenses block blue light.
The evidence for and against blue blocking lenses remains controversial and divides surgeons. Little firm evidence exists to fully support claims made by the lens industry. As in this case these lenses can be helpful in cases with glare symptoms. However, many many millions of patients have had clear lenses implanted without any problems at all. Perhaps importantly blue blockers don’t seem to cause any significant harm, although changes in sleep patterns and other symptoms have been reported by some.