The Lens Flashcards
Phacoemulsification
This is the modern technique for cataract surgery in which the lens is broken up using
ultrasound energy and aspiration
Iridodonesis
Movement of the iris that occurs secondary to lens instability
Phacodonesis
Movement of the lens that occurs secondary to lens instability
Nuclear sclerosis
The hardening of the lens that occurs naturally in animals. The hardening scatters light
(increased relucency) such that the lens appears ‘cloudy’. This does not cause vision loss and is typically
evident by age 7 in cats and dogs
Cataract
Any opacity of the lens or lens capsule
Parallax
Utilizing the appearance of one object relative to another to determine depth.
Lens Zonules
small collagen fibrils arising from the ciliary body that attach to the equator of the lens,
securing the lens’ position within the eye
Intumescent Cataract
Intumescent means ‘swollen’. This type of cataract is common in diabetics in which
cataract progression is driven by an osmotic effect as a result of entrapped sorbitol and fructose within the
lens capsule
Aldose reductase
enzyme that converts glucose to sorbitol and fructose which become trapped within the
lens capsule, causing an osmotic pulling effect. The lens swells creating an intumescent cataract.
Lens luxation
complete detachment of the lens from the lens zonules. The lens typically shifts anteriorly
or posteriorly following luxation
Lens subluxation
partial detachment of the lens from the lens zonules. The lens typically shifts side to side
with subluxation, revealing an aphakic crescent
Aphakic crescent
Phakic refers to lens. Aphakic, is therefore without a lens. A lens subluxation displays a
crescent shaped area in which the lens in visibly displaced, known as an aphakic crescent
