A Brief History of Cataract Surgery. Normal Eye Anatomy. The lens is the focusing mechanism of our eye – as we age it gradually clouds, making our vision fuzzy.
The development of cataract surgery proceeded in spurts – we can trace the insights of a few brilliant, creative people that have given us the modern cataract surgery technique we enjoy today
Indian physician Sushruta wrote SushrutaSamhita (6 century BC)– ancient Sanskrit manual for surgery – book 6 describes cataract surgery. Information travelled west to Greece and east to China
Celsus – Latin Encyclopedist at time of Christ – wrote De Medicinae - describes cataract surgery
Filters high-energy UV AND Blue Light – this slight yellow color of the lens is thought to be protective for macular degeneration.
One piece design, Acrylic material
Concentric ring design but more sophisticated that the ReZoom lens
Center targets reading (allows reading in bright light - large pupil diminishes this and focuses primarily at distance in dim light)
Drawbacks – halos at night
- poor contrast sensitivity
- negative dysphotopsias
Hinged lens, allowing lens to move forward with accomodative effort
Controvertial if it indeed works or how long it works
No glare or halos
Final position in eye varies due to hinged design, therefore, final refaction can vary – on average 1/3 of patients with this lens require a second surgery to focus them at distance
Correcting Astigmatism their appearance in the 1980’s. Material and insertion techniques have changed as materials improve and ideas innovate.
Astigmatism occurs when the cornea is not perfectly spherical. It is typically corrected with glasses or contact lenses.
With cataract surgery, astigmatism can be corrected by two ways – lateral relaxing incisions (LRI’s) and the toric IOL.
LRI’s are paired cuts on the cornea that help round the cornea, making it more spherical. Each person heals differently and, althoughtLRI’s work, they are inexact. They also contribute to dry eye problems from the additional corneal surgery.
Toric IOLS are very precise in the astigmatism range they are available. Their main drawback is price.
The Toric Intraocular lens