What IOLs is suitable for you?
Few real case scenarios from my clinic patients’ file:
* Visual acuity is assessed with Snellen Visual Acuity Chart
Case 1:
A 70 year-old housewife with bilateral cataract with 6/18 visual acuity for her right eye and 6/12 for her left eye. Besides daily chores as housewife she also likes to do some sewing and reading.
She underwent cataract surgery with monofocal IOL implant (her choise; cheaper compares to premium IOL). She could see 6/9 clearly post-operatively. She only need near/reading glasses (ready-made) when she does reading or sewing at home.
Case 2:
A 56 year-old hawker who is very short-sighted (high myopia -7 dioptres both eyes) wanted spectacle-free after cataract surgery. He had moderate cataract in both eyes. Right eye was seeing 6/36 and left eye was seeing 6/24 before surgery.
Multifocal IOL was implanted during cataract surgery and he could see 6/6 post operatively. He is very happy with his vision after cataract surgery; as he no longer have mist-covering his glasses while preparing hot noodles for his customers. He also drives with no problem.
Case 3:
A 47 year-old van driver complained of blurring of vision of his both eyes. He was wearing a pair of glasses with minus power. His right eye’s glasses was -6.00/-0.75 x 20 and left eye’s was -4.75/-0.50 x 173. His visual acuity was 6/24 in his right eye (about 50% reduction of normal vision) and 6/12 in his left eye (about 20% reduction of normal vision).
IOL power measurement and eye assessment was done before cataract surgery. He was found to have very high cornea astigmatism of 1.4 Dioptre in his right eye and 1.85 Dioptre in his left eye. I found out that his glasses was under-prescribed by his optometrist because he could not tolerate glasses with full-correction of his astigmatism.
This was a tricky case. As a cataract surgeon, I definitely want the best visual outcome for him. I explained every details regarding his refractive status and reasons why he should need a Toric IOL. A Toric IOL with full correction of his myopia and astigmatism was finally agreed-upon and selected. Multi-focal IOL was not recommended to him in view of possibility of him seeing ‘rings of light’ while driving at night; bearing in mind he is a working van driver.
He was scheduled for cataract surgery on RE followed by LE in 2 days interval. At one week post-operatively’ he was seeing 6/6 in both eyes. His refraction done at 6 weeks post op was RE: pl/-0.25 x 40 seeing 6/6; LE pl/-0.50 x 30 seeing 6/6. He is a very happy patient – spectacle free with very good vision; for he had never seen better than this before!
* A person with high refractive error seldom sees 6/6 with glasses even before his cataract developes. This is because the prism effect from thick glasses distorts the image of the object he sees. This problem could be eliminated with the accurately measured intra-ocular lens (IOLs) power. The current advances in IOL technology, optical quality, material and design have provided our patients with very good quality of vision after cataract surgery.