1. Cataract Lens rEPLACEMENT
By: Paul Rizzo and Harry Ramsamooj

2. Vision
Light passes through the cornea, the transparent front covering of the eye.
It continues through the pupil, the size of which is regulated by the iris.
The lens refracts (bends) light to focus it onto the retina.
The retina contains rod cells and cone cells, which transmit the stimulus to the optic nerve.
The optic nerve sends the signal to the brain

3. The Anatomy of the Eye

4. Function of the Lens

5. Structure of the Lens The lens consists of three structures:
Lens Capsule: This is a smooth, transparent membrane of collagen and GAGs. It is transparent and elastic to allow the lens to bend.
Lens Epithelium: Cells of this simple cuboidal epithelium have Na+/K+ ATPase pumps, which export water and import vital nutrients. The epithelial cells also serve as progenitors of the lens fibers.
Lens Fibers: These elongated cells have gap junctions that keep them packed tightly and in parallel layers (laminae) along the lens. They have no nuclei or organelles.
The lens is transparent because:
The lens fibers are densely packed and lack organelles.
It is avascular.
It contains little water.

6. Cataracts
A clouding of the lens inside the eye which leads to a decrease vision.
Cataract surgery is the commonest single surgical procedure carried out in the developed world.
Clouding is caused by new lens fibers continuing to form while old fibers are not replace, but instead remain there.
One of the few structures of the body that continue to grow during life.

8. Causes of Cataracts Age Trauma Radiation Genetics Skin diseases
Drug use

9. ICCE Intracapsular Cataract Extraction
The lens and surrounding capsule are removed in one piece
Requires the largest incision
High complication rate and slow recovery due to the incision size
Sutures required to close the wound
Patient wears an eye patch during recovery
Rarely used

10. ECCE Extracapsular cataract extraction
Used for advanced cataracts where the lens is too dense to phacoemulsify
Larger incision to remove the lens in one piece
Incision closed with sutures at the end of surgery
Slow recovery
Performed less frequently than phacoemulsification

11. MSICS Manual Small Incision Cataract Surgery
Lens is removed through a small, self-sealing scleral tunnel (no sutures)
Although the incision is small (5.5 mm), it is still larger than the incision in phacoemulsification
Popular in the developing world

12. Phacoemulsification Most modern type of cataract surgery Most common
Takes minutes, requires minimal sedation
Small incision ( mm)
No sutures needed to close the wound
Fastest recovery time

13. Phacoemulsification Surgical: Anesthesia Corneal incision
Capsulorhexis
Phacoemulsification
Irrigation and Aspiration
Lens insertion
Salt water Injection

14. Cost of Treatment Varies based on the type of lens implanted
$2699-$4337
Covered by most insurance
Types of Intraocular Lens
Monofocal
Multifocal
Presbyopia-correcting
Astigmatism-correcting (toric)

15. Biomaterials Involved
PMMA
Silicone
Acrylic

16. Recovery Short post-op recovery time
Advised to avoid straining or heavy lifting for a month
Eye shield used at night

17. Benefits/Complications of Procedure
Improved vision i.e. less cloudy, sharper images
Can correct nearsightedness/farsightedness
Consequences
Retinal detachment
Endophthalmitis
Corneal/cystoid macular edema
Posterior capsular opacification

19. Crystalens Bausch & Lomb
First and only FDA-approved IOL that uses the natural focusing ability of the eye
In clinical trials, patients implanted with a Crystalens (88.4%) could see better at all distances than patients implanted with a standard IOL (35.9%)

20. Thank you!

21. Bibliography
Allen, David. "Cataract and Surgery for Cataract." BMJ.com. BMJ Publishing Group Ltd, 13 July Web. 17 Apr
Haddrill, Marilyn. "Cataract Surgery Cost." All About Vision. Access Media Group LLC., 21 Mar Web. 25 Apr
"Cystoid Macular Edema (CME)." : University of Michigan Kellogg Eye Center. Regents of the University of Michigan, n.d. Web. 25 Apr. 2013
"Is Crystalens Right for You?." Crystalens. Bausch & Lomb, Web. 17 Apr
"Learning More About: Cataracts." Eyeglass Guide. Transitions Optical, Inc., Web. 17 Apr
"Image Library." Bausch and Lomb Web. 17 Apr
"Featured Video: Cataracts." Amylex Pharmaceuticals Web. 17 Apr
Randleman, Bradley J. "Cataract Surgery." MedicineNet Web. 17 Apr