4 Intraocular Lenses

Question 1

Which part of the GRIN crystalline lens of the human eye has the highest refractive index?

Answer 1

Nucleus

Question 2

Refraction in human eye is due to? (Pick one)

Anterior surface of lens
Posterior surface of lens
Refractive indices of the grin lens
Anterior +posterior+ GRIN lens

Answer 2

Anterior + posterior + GRIN lens

Question 3

At accommodative state, the refraction of the crystalline lens is?

Answer 3

31.85D

Question 4

The intraocular lens does three main things:

________ solution for vision loss due to ‘cataract’ formation

Continuous vision solution for ‘__________’

____________ vision or similar to nature crystalline lens

Answer 4

Surgical
Presbyopia
Accommodating

Question 5

__________ lens provides higher image quality with minimal spherical aberration.

The ______ the aperture, the higher spherical aberration, and vice versa.

Symmetrical IOLs with a refractive index of _.46 (acrylic) and a 3.0m aperture, you would show perfect modulation up to about +__.0D.

For powers up to +__D the modulations remain stable, any higher than +__D, image quality drops significantly

Answer 5

Aspherical

Larger

1.46. +15.0D

+25D. +25D

Question 6

Regarding monofocal intraocular lens, what three things can you give the patient?

Human lenses in the eye are __mm, but the IOLs are only 6mm.

Fiol =A - 2.5 axial length - 0.9 x keratometer reading

Where A is the constant by the manufacturers.

what is A= 118.2, axial length =23mm and K= 43.5D. What’s the answer?

For every 1mm you’re off, that’s _.__ diopters off!

Answer 6

Distance vision correction.
Non accommodative lens
Very high image quality

12mm

118. 2- 2.5 x 23 - 0.9x 43.5 = +21.6D
119. 55D!!

Question 7

For a tri-focal IOL, what’s the best acuity you can get at distance, intermediate, and near Add?

What are these in diopters?

Multifocal IOLs claim to provide decent continuos vision at the cost of image ________ and unwanted glare and _____. Surgeons don’t approve

Answer 7

20/20, 20/40, 20/32
20D, 21.75D, 23.5D

Quality. Halos

Question 8

Extended range of vision IOL is also called the _____ of _____ IOL. Claims to provide _________ vision and at the same time, minimize unwanted phenomena.

Their vision is 20/20 from distance until about __cm from the eye. The mean acuity of 20/40 or better through _._D of defocus

Answer 8

Depth of focus. Continuous

60cm. 2.5D

Question 9

What is considered the “holy grail of IOL”? It mimics the natural lens behavior and provides additional 1D of vision compared to _________ lens. It is NOT an ____________ lens.

Challenges in IOL industry:

Smaller incision, under _mm.

PCO- posterior capsule __________ which is a lens epithelial cell growth but there’s no solution for it yet. Pts have decreased VA, but can easily be treated by the ___ laser capsulotomy

Answer 9

Accommodative intraocular lens!

Monocular lens. Accommodative lens.. even though the FDA says so. lol

2mm

Opacification

YAG laser