corneal edema after cataract surgery

1. A summary of an essay about
Corneal oedema in cataract
surgery
Presented by
Malek Mohammad Al-Kott
M.B. B.Ch.
Faculty of medicine
Al-Azhar University, Cairo
Supervised by
Prof. Dr. Hassan El-Sayed El-Baz
Professor of Ophthalmology
Faculty of medicine
Al-Azhar University, Cairo
Dr.Mahmoud Abdel-Badie Mohamed
Assist. Professor of Ophthalmology
Faculty of medicine
Al-Azhar University, Assiut
Dr. Mohamed abdel-Monem Mahdy
Assist. Professor of Ophthalmology
Faculty of medicine
Al-Azhar University, Cairo
Dr. Ashraf Mohamed Gad Elkareim
Lecturer of Ophthalmology
Faculty of medicine
Al-Azhar University,Assiut
Al-azhar University
Assiut, Egypt
2013
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2. The cornea is the transparent dome shaped layer of the
anterior portion of the outer fibrous coat of the eyeball. The cornea
serves a refractive function accounting for approximately two thirds
of eye’s total optical power while maintaining mechanically tough
and chemically impermeable barrier between the eye and
environment. The cornea must remain clear to have a good vision.(1)
The endothelium plays an important role in regulating stromal
hydration by constantly removing the fluid out of the corneal
stroma. This function is executed by active metabolic pumps in
corneal endothelium so corneal endothelial cell function is the
most important factor for corneal hydration control.(2)
Cataract surgery affect the cornea, and aqueous humor diffuses into
the corneal stroma and produces corneal edema which may be
stromal and/or epithelial, immediate or late onset , reversible or
irreversible (3) .
The incidence of corneal edema following cataract surgery is 5-15%
with intracapsular cataract extraction, 12% with extracapsular
cataract extraction and less than 10% after the use of Viscoelastics
and more than 30%with phacoemulsification(4).
The principal causes of corneal edema in cataract surgery are:-
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1-Surgical trauma by:-
A-Instruments.
B-IOL.
C-Irrigating solutions.

3. D-Ultrasonic vibrations.
E-Temperature.
F-Nuclear fragments.
G- Air bubbles
2-Primary corneal endothelial disease:-
A-Fuchs dystrophy.
B-Low endothelial cell density without guttae.
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3-Chemical injury :-
Many agents used in cataract extraction surgery have been
reported to be toxic to the corneal endothelium which may
lead to corneal oedema , including:
A-Antiseptic solutions used preoperatively.
B- Topical and intracameral anesthetics.
C- Sterilization detergents.
D- Intraocular stains .
E-Preservations in solutions.
F- Free radicals.
G-Residual toxic chemicals on instruments (e.g.,
detergents, dried solutions).
H-Improper concentrations of solutions
(e.g.,antibiotics):-
I-Mistakenly used toxic chemicals, expired
agents, or incorrect solutions (e.g., normal saline
instead of balanced salt solution).
4-IOL syndromes:-
A-Direct endothelial touch.
B-Long-term toxicity(?inflammatory).
5-Contact with other ocular tissues:-
A-Flat chamber.
B-Iris bombe.
C-Suprachoroidal effusion or hemorrhage.

4. D-Vitrous touch or adherence.
6-Detachment of descemet's membrane.
7-Trauma from retained foreign material:-
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A-Nuclear chips.
B-Particulate matter.
8-Postoperative glaucoma.
9-Inflammation.
10-Membranous downgrowth or ingrowth.
11-Brown-McLean syndrome.(5)
Evaluating corneal oedema depends on corneal endothelial cell
density and corneal thickness . Optical slit lamp and ultrasonic
pachymetry are used routinely to measure corneal thickness.
However several new instruments have been recently
developed to determine corneal thickness; these include
Optical coherence tomography, confocal microscopy,
Ultrasonic biomicroscopy, the Scheimpflug camera and
specular microscopes (contact and non contact) which provides
magnified view of a small area of corneal endothelial cells to
measure and record endothelial cell counts.(6)
The aims of treatment is to restore vision and decrease pain ,
this can be achieved with conservative medical measures during
the early phases of corneal edema for up to three months to
elicit a compensated cornea. The treatment often requires
surgical intervention and the most commonly procedure is
penetrating keratoplasty. Also posterior lamellar endothelial
transplantation can be done. (5)

5. References
1-Stephen DK, Roger WB: Structure and function of the cornea. In
Kaufman HE, Barron BA, McDonald MB (eds): The cornea, 2nd ed.
Butter-Heinemann, Washington, 1998; 3-50
2- Ruberti JW and Klyce SD. Nacl osmotic pertubation can modulate
hydration control in rabbit cornea. Exp Eye Res 2003; 76-349
3- Stephen DK: Corneal physiology.In Foster CS, Azar DT, Dolhman CH
(eds): The cornea scientific foundations and clinical practice, 2nd ed.
Lippincott Williams and Wilkins, Philadelphia, 2005,37-58
4-Elisabeth JC, Christopher JR: (1998), ''Corneal changes from ocular
surgery''.In ''The cornea'' ,page 673-696 ; by Kaufman HE, Barron BA,
McDonald MB (eds) , 2nd ed. Butter-Heinemann, Washington.
5- Steinert RF. Corneal edema after cataract surgery. In cataract surgery,
3rd ed. Saunders, Duxbury 2010, 595-602
6- Rockville MD. ''Cataract management guideline panel''. Cataract in
Adults: Management of Functional Impairment, AHCPR publication no
1993, 93-0542.
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