A presentation on corneal edema as a complication of cataract surgery

1. POST-OPERATIVE-CORNEAL
EDEMA
a complication of cataract surgery
PRECEPTOR: Dr (MRS) UZZI I.A OKHUOSAMI F.S Pharm.D

2. OUTLINE
 Cataract (Pathophysiology, surgery, complications of surgery)
 Corneal edema
 Corneal edema as a complication of cataract surgery(
pathophysiology, epidemiology)
 Management of post-operative corneal edema
 Conclusion
 Acknowledgements and References
2

3. FIG 1.0
The Human eye
3

4. WHAT IS CATARACT???
 A cataract is a clouding of the natural intraocular crystalline
lens that focuses the light entering the eye onto the retina.
This cloudiness can cause a decrease in vision and may lead
to eventual blindness if left untreated.1.
 Cataract can also be defined as complete or partial opacity of
the ocular lens.
4

5. PATHOPHYSIOLOGY OF CATARACT
The clear lens of the
eye transmits light
rays entering the eye
and focuses them on
the retina
With aging, lens
proteins progressively
denature causing
increase in density
and yellowish-brown
coloration of the lens2
Other factors such as
blunt-force trauma
can cause thickening
and irreversible
whitening of the lens
The resultant cloudy
lens lacks the ability to
transmit and focus
light rays on the retina
This manifests as
blurry vision or loss of
vision in advanced
cases
5

6. FIG 1.2
Unilateral cataract in the right eye
FIG 1.1
A healthy human eye
Jagat. R(2012) MEAJO. Pediatric Cataract
surgery. Vol. 19:1
6

7. CATARACT SURGERY
Eye
drops(containing an
anesthetic) that
dilate the pupils will
be administered
A tiny cut is made
in the cornea
through which a
probe is inserted
Probe breaks up
cloudy lens into
small pieces which
are sucked out3
The artificial lens is
inserted through the
cut and sits in the
lens capsule. It
unfolds when in
position.
7

8. FIG 1.3
Removal and replacement of an infected lens with an artificial lens during cataract surgery

9. COMPLICATIONS OF SURGERY
 Modern cataract surgery is safe in more than 95% of patients.
In a small number of cases, an intra-operative posterior
capsular rupture can lead to vitreous loss or a dropped
nucleus and can increase the risk of post-operative
complications4.
 CORNEAL EDEMA and CYSTOID MACULAR EDEMA are
common post-surgical complications that occur due to
persistent swelling in the cornea as seen in corneal edema or
in the retina as in cystoid macular edema. In both cases,
patients may notice blurred, foggy vision. The risk of either
occurring is around 1 in 100.
9

10. POST-SURGICAL-
CORNEAL-
EDEMA???
10

11. FIG 1.4
Anatomy of the cornea showing it’s five membranes
11

12. CORNEAL EDEMA
 Corneal edema is the hydration(swelling) of the corneal
stroma due to damage of the corneal endothelium causing
decreased visual acuity.
 It may occur naturally as in the genetic condition; Fuch’s
dystrophy or as a complication of cataract surgery.
 The endothelium continuously pumps fluid from the cornea
keeping it dry and clear as corneal clarity is essential for clear
vision.
12

13. CORNEAL EDEMA AS A
COMPLICATION OF CATARACT
SURGERY
 Corneal edema often resolves within a few days or weeks post-
surgery.
 If the cornea was not healthy prior to surgery, high intraocular
pressure(IOP) can cause the cornea to fail, and severe edema
can result.
 Edema may persist for months after surgery. This may be the
case in Fuch’s dystrophy or extremely dense/difficult to remove
cataracts.
 Some early designs of lenses implanted during surgery caused
injury to the endothelium. However, these implant designs are no
longer manufactured.5
13

14. PATHOPHYSIOLOGY
Corneal tissue
must remain thin
and transparent for
clear vision
The corneal
endothelium is a
hydrophobic barrier
made up of a
single layer of non-
regenerative cells6
Cataract surgery with
or without pre-
existing Fuch’s
dystrophy can injure
the corneal
endothelium
Upon injury,
surviving cells
change shape and
grow larger to fill the
spaces left by the
destroyed cells7
When a lot of cells
are damaged, the
cornea stroma will
be flooded by fluids
causing the
swelling (edema)
14

15. FIG 1.5
The hydrated corneal stroma reduces causes reduced visual performance and
blurred vision as seen in the image above
15

16. PATHOPHYSIOLOGY cont’d
 If the number of destroyed cells exceeds the threshold
necessary to maintain normal functioning of the cornea, fluids
seep through and hydrate the corneal stroma.
 This excessive hydration interferes with normal spacing of the
proteins (Type I collagen fibrils) of the cornea.
 As corneal edema progresses and worsens, first stromal and
then intercellular epithelial edema develops.
 Epithelial edema is associated with the development of bullae;
hence, the term bullous keratopathy
Bullae + IOL= PBK
Bullae without IOL= ABK
IOL= Intra-ocular-lens
ABK=Aphakic bullous keratopathy
PBK=Pseudophakic bullous keratopathy
16

17. FIG1.6
Pseudophakic bullous keratopathy (PBK). Large multiple bullae, such as depicted
here, are associated with moderate to severe pain and discomfort.
17

18. EPIDEMIOLOGY
 The exact incidence rate for corneal edema is unknown. It is
however, estimated that 0.1% of patients undergoing cataract
surgery will develop this problem.
CORNEAL OEDEMA
AGE SEX RACE FIG1.7
Older
patients
(>50ye
ars) are
more
prone
No
known
associ
ation
No
known
associ
ation
18

19. EPIDEMIOLOGY cont’d
 Despite an increase in the overall number of cataract
surgeries performed, cases of ABK and PBK have decreased.
 The overall drop in the incidence of post-operative corneal
edema reflects the rapid development and improvement of
both intraocular lens design and cataract surgical technique7.
19

20. TREATMENT/MANAGEMENT
 Treatment of corneal edema is based on the exact cause. There
is no treatment to promote the healing of the destroyed
endothelial cells though, the extent of the edema can be
controlled.
A. HYPERTONIC DROPS AND OINTMENTS: Patients with
early/mild corneal edema may benefit from the use of
hypertonic/concentrated saline agents to reduce corneal
thickness.
 Examples: 2% and 5% Hypertonic saline solution and ointment.
 Mode of action: These agents work by creating an osmotic
gradient via a tear film outside the cornea that pulls fluid from
the cornea.
20

21. Cont’d
As evaporation from the tear film is minimal at night with the
eyes closed (therefore, the tears are less hypertonic), corneal
edema tends to be worse in the morning. Use of hypertonic
Nacl 5% ointment at night and/or a hypertonic solution early in
the morning limits this build-up of edema.
A typical regimen is Hypertonic Nacl (Muro128®) 2% drops
used hourly in the affected eye until noon (4-5 times). As the
day progresses, evaporation from the tear film begins to
create relative hyper-tonicity of the tears, drawing fluid from
the cornea. This accounts for the typical history of improved
vision towards the end of the day.
21

22. Cont’d
 Side effects: Nil or minor (e.g mild burning or irritation). Rare
severe side effects include; severe allergic reactions, eye
pain and changes in vision8.
B. ANTI-INFLAMMATORY AND IOP-LOWERING AGENTS:
Treatment of edema in eyes with borderline endothelial
function should be focused on ocular inflammation and
elevated intraocular pressure if present.
The IOP inside the eye may become elevated due to
inflammation in the eye following surgery causing the
drainage angle inside the eye to be blocked. If the pressure
is 25mmHg - 35mmHg, the patient should begin IOP-
lowering drops.
22

23. Cont’d
 Examples of anti-inflammatory agents: Ketorolac 0.4% qid,
Diclofenac 0.1% (Voltaren®) t.i.d and Corticosteroids such as
Prednisolone acetate 1% solution 2-4 times daily used for not
more than 10 days.
 Mode of action: NSAIDs act by blocking the cyclo-oxygenase
enzymes, COX-1 and COX-2(mediates production of
prostaglandins that contribute to the inflammatory response and
ocular disease). Inhibition of COX-2 determines the clinical
efficacy of an ophthalmic NSAID.
 Side effects: Mild effects include; Burning and stinging, itchy
eyes, dizziness, headache. Serious effects include; Eye pain,
eye discharge and blurred vision9.
23

24. Cont’d
 Examples of IOP-lowering drugs: Selective alpha 2-adrenergic
agonists such as Brimonidine 0.2% (Alphagan®) t.d.s or beta-
adrenergic blockers such as Timolol 0.25% and 0.5% b.d
ophthalmic preparations.
 Mode of action: These drugs lower IOP by reducing the
production of aqueous humor and facilitating it’s outflow.
 Side effects: Timolol may cause eye irritation, double vision,
drowsiness and in severe cases, fainting, breathing difficulties
and sudden weight gain10. Brimonidine may cause blurred
vision, red/swollen eyelids, sore throat and in sever cases, blind
spots, dizziness and rash11.
24

25. Cont’d
C. SURGICAL PROCEDURES: These include; Anterior
Stromal Puncture, Bandage contact lenses and Corneal
Transplant.
1) Anterior Stromal Puncture: Patients who have poor visual
potential and severe pain can benefit from this safe, simple
cost-effective procedure12.
 Small superficial punctures are placed in the affected area
of the cornea with depths just at the Bowman’s layer.
 A bandage contact lens is the applied as an adjunct and left
for 7-14 days to hold the healing epithelium in place as it
grows back over the cornea13.
25

26. Cont’d
2) Bandage contact lenses: These are soft lenses useful for the
temporary relief of pain and discomfort due to bullous
keratopathy.
 They must not be too tight as this may worsen the edema
especially when used at night.
 They can increase the risk of infections. Therefore, antibiotics
are prescribed for corneal edema patients using Bandage
lenses.
 A broad-spectrum antibiotic such as Polymyxin-B ophthalmic
drop/ointment used 2-4 times a day for 7-10 days is
recommended.
Bandage contact lens
26

27. Cont’d
3) Corneal Transplant: Ultimately, if vision is substantially impaired,
the surgeon can transplant the entire cornea.
 Corneal transplant, when paired with glasses or contact lenses,
often restores vision to a significant degree.
 Only the endothelial layer of cells may be replaced in cases of
advanced edema resulting in fewer side effects than a full
transplant.
 The procedures used are called Deep Lamellar Endothelial
Keratoplasty or Descemet’s Stripping Endothelial
Keratoplasty14.
27

28. ACKNOWLEDGEMENTS
 Dr(Mrs.) Uzzi I.A
 Pharm Faransa C.
 Pharm Ogie R.U.
28

29. REFERENCES
 Alpa S. Patel MD(2014). Cataract. American Academy Of Ophthalmology.
Available from eyewiki.aao.org/Cataract
 Ocampo J, etal(2014). Senile Cataract. eMedicine [MedScape]. Available from
emedicine.medscape.com/article/1210914-overview
 Christian Nordqvist(2014). What are Cataracts? What causes Cataracts?
Medical News Today. Available from
medicalnewstoday.com/articles/157510.php
 Elsie C, Omar A(2010). Complications of Cataract Surgery. Clinical and
Experimental Optometry. DOI: 10.1111/j.1444-0938.2010.00516.x
 University of Washington Medical Center(2015). Corneal Edema. Available from
uwmedicine.org/health-library/Pages/corneal-edema.aspx
 Brunton L, Chabner B, Knollman B(2010). Corneal endothelium. Goodman &
Gilman’s The Pharmacological Basis of THERAPEUTICS (12th ed). Mc Graw Hill
Medical, California: pp1774-1775
 Taravella M, etal(2014). Post-Operative-Corneal-Edema. eMedicine
[Medscape]. Available from emedicine.medscape.com/article/1193218-overview
29

30.  Drugs.com [ Micromedex® , Cerner Multum™ , etal(2015) ]. Sodium chloride
drops: Indications, Side Effects, Warnings. Available from drugs.com/cdi/sodium-
chloride-drops.html
 The American Society of Health-System Pharmacists(2011). Diclofenac
Ophthalmic. US. National Library of Medicine[MedlinePlus]. Available from
nlm.nih.gov/medlineplus/druginfo/meds/a606003.html
 The American Society of Health-System Pharmacists(2010). Timolol Ophthalmic.
US. National Library of Medicine[MedlinePlus]. Available from
nlm.nih.gov/medlineplus/druginfo/meds/a682043.html
 The American Society of Health-System Pharmacists(2011). Brimonidine
Ophthalmic. US. National Library of Medicine[MedlinePlus]. Available from
nlm.nih.gov/medlineplus/druginfo/meds/a601232.html
 Zauberman N, etal(2014). Anterior Stromal Puncture for the Treatment of
Recurrent Corneal Erosion Syndrome: Patient Clinical Features and Outcomes.
American Journal of Ophthalmology Vol. 157, Issue 2: pp273-279
 Fan M, etal(2014). Anterior Stromal Puncture. American Academy of
Ophthalmologists. Available from eyewiki.aao.org/Anterior_Stromal_Puncture
 Taravella M, etal(2014). Post-Operative-Corneal-Edema. eMedicine [Medscape].
Available from emedicine.medscape.com/article/1193218-treatment
30

31. THIS HAS
BEEN FUN!!
31
Starships were meant
to fly…hands up and
touch the sky