1. Posterior capsular opacification
(Secondary cataract, after cataract)
Definition:
Opacification of the posterior capsule due to partially
absorbed traumatic cataract or following ECCE or
phaco.
PCO is actually misnomer bcz its not the capsule which
opacifies…rather an opaque membrane develops over the PC.

2. Incidence:
PCO is the most common complication of cataract surg.
PCO is a major problem in paediatric cataract surgery
where the incidence approaches 100%.
PCO incidence has been reported to occur in 36%-97%
of patients 2-4 years after ECCE.
The corresponding incidence within 1 year after phaco
was 2%-15 % & within 3 years it was found to range
between 2% and 63%.

3. RISK FACTORS
Nonmodifiable
Age: younger individuals are at a higher risk.
Diabetes: diabetics had significantly severe PCO after
cataract surgery when compared with nondiabetics.
The incidence of PCO is high in eyes with uveitis.
In these
eyes, hydrophobic acrylic IOLs provide a better visual outcome
& lower incidence of PCO than silicone, PMMA or heparin-
coated PMMA IOLs.
Patients with myotonic dystrophy & retinitis pigmentosa
showed a significantly higher incidence & density of PCO.

In traumatic cataracts, the incidence of PCO is significantly
higher and has been quoted to be as high as 92% at the 3-year
follow-up.

4. Modifiable Surgical Techniques
Continuous Curvilinear Capsulorhexis.
Delays the development of central visual obscuration by
facilitating fusion between the edge of the CCC to the PC,
forming a ring which provides a closed environment
restricting LECs migration toward the central PC.
Facilitates in-the-bag fixation of the IOL which enhances
the IOL optic barrier effect, reducing the incidence of
central PCO. There is an increased
Incidence of fibrosis-type PCO in
cases of ciliary sulcus fixation.

5. with a capsulorhexis smaller than the IOL optic, the adhesion
between the anterior capsule & the IOL optic keeps the
anterior lens epithelium away from the
posterior capsule   the
incidence of migration of the anterior
LECs behind the IOL optic.
Modifiable Surgical Techniques
 Anterior Capsule Overlap of IOL Optic.

6. The hydraulic force exerted by hydrodissection causes a
cleavage between the lens capsule & the cortex, which could
cleave mitotically active LECs from the capsule.
Modifiable Surgical Techniques
Cortical Cleaving Hydrodissection.
The edge of the anterior capsule is slightly tented up
by the tip of the cannula, while injecting the fluid.

7. Cortical cleavage hydrodissection.
The cannula is placed immediately
under the anterior capsule. It is
one of the most important
maneuvers to reduce the
incidence of PCO.

8. Modifiable Surgical Techniques
Cortical Clean Up.
Thorough removal of residual cortical fibers  number of
mitotically active cells that have the potential to proliferate
and migrate across the central visual axis.

9. Modifiable Surgical Techniques
Polishing (Scraping) the Anterior Capsule.
Polishing of the anterior capsule has been effective in
reducing fibrotic opacification but ineffective in reducing
regeneratory opacification.

10. Modifiable Surgical Techniques
IOL Factors
 IOL Design
Plate-haptic versus Loop-haptic IOLs. A high rate of ACO
as well PCO (up to 65%) has been reported with the plate
haptic design IOLs, due to incomplete fusion of the anterior &
posterior capsule leaves along the plate haptic axis the lack
of capsule bending at the optic edge. This allows LECs to
migrate centrally onto the posterior capsule  various forms
of LEC fibrosis.

11. Modifiable Surgical Techniques
IOL Factors
 IOL optic Design
Lenses with a plano convex optic (plano posterior) appear to
have a lower rate of PCO than biconvex lenses due to
mechanical or barrier effect of the IOL, which prevents LEC
proliferation & central migration, explains the high incidence
of regeneratory PCO reported with IOL designs that hold the
posterior capsule away from the lens optic.
“No space, No cells”

12. Modifiable Surgical Techniques
IOL Factors
 Optic Edge Design
The discontinuous sharp bend created by the sharp optic
edges of the IOL appeared to induce contact inhibition
(mechanical barrier) of migrating LECs. Therefore, the sharp
optic edge design was found to be
more effective in the prevention
of PCO formation compared with
IOLs with round optic edges.

13. Blocking of LEC migration at posterior sharp
optic edge due to bending of the capsule (left)
compared to round edge IOL (right).

14. Modifiable Surgical Techniques
IOL Factors
 Haptic Designs & Angulation
Haptic angulation reduces the incidence of PCO by maximizing
the barrier effect to migrating LECs at the posterior optic
edge by pushing the IOL backward against the posterior
capsule.

15. Fusion of capsule at haptic-optic junction for different haptic designs.
Acrysof multipiece with nearly
complete fusion.
Acrysof single-piece with
incomplete fusion which may
serve as one entry site (arrows)
for regenerating LECs & no
sharp edge at junction.

16. Modifiable Surgical Techniques
IOL Factors
 Accommodating IOLs
These IOLs have in common a hinge-like junction of haptics to
optic that should allow the shifting of the optic when the
haptics are compressed. This design leads to significant PCO
with most patients needing YAG capsulotomies within the 1st 2
years after surgery
early PCO due to missing barrier along broad haptic-optic junctions
Infolding of haptics due to cap.
constriction

17. Modifiable Surgical Techniques
IOL Factors
 IOL material
Hydrophilic acrylic lenses are more prone to develop PCO than
hydrophobic acrylic lenses or silicone lenses. This may be due
to the high water content being more “inviting” to lens
epithelial cells (LEC) ingrowth or the
fact that the optic edge of IOLs in
this group is never as sharp as with
the hydrophobic materials.
IOL materials:
hydrophobic & hydrophilic.

18. Modifiable Surgical Techniques
IOL Factors
 IOL material
Biocompatibility.
Capsular biocompatibility is defined as the reaction of LECs
and the capsule to the IOL material and design. This
encompasses LEC ongrowth, ACO & PCO.
AcrySof has the lowest rate of fibrosis of the anterior
capsule with no membrane growth (i.e. more biocompatible)

19. Bioadhesive IOL Materials.
Bioactive materials allow a single LEC to bond both to the IOL
& the posterior capsule producing a sandwich pattern including
the IOL, the cell monolayer and the posterior capsule. This
sealed sandwich prevents further epithelial ingrowth 
prevent PCO.
Therefore, a bioactive material such as
hydrophobic acrylic would prevent PCO more than PMMA &
silicone IOLs, which are biocompatible but also bioinert.
Hydrophobic acrylic material binds more firmly to fibronectin,
a plasma protein that is also secreted by LECs, compared with
PMMA, silicone & hydrophilic acrylic materials. Therefore, it
has been established that hydrophobic acrylic materials bind
more firmly with the capsule.

20. Pathogenesis
Viable LECs

21. Lens capsule is a transparent covering that surrounds the lens.
Histologically it is a basement membrane composed of type IV
collagen fibers & sulphated glycosaminoglycans.
The capsule is produced anteriorly by the lens epithelium &
posteriorly by the elongating fiber cells. Though it has no elastic
tissue, it is highly elastic in nature because of lamellar or
fibrillar arrangement of fibers. This property of the lens
gradually decreases with age.
Lens capsule is thickest near equator and thinnest at
posterior pole. Thickness of anterior lens capsule 
with age, whereas thickness of posterior capsule
remains constant or changes slightly.

22. In the normal crystalline lens, the LECs can be divided into 2
different biological zones:
A. The ant. epithelial cells ("A" cells) consists of a monolayer of flat
cuboidal, epithelial cells with minimal mitotic activity. In response
to a variety of stimuli, they proliferate & undergo fibrous metaplasia.
B. The second zone is the equatorial lens bow ("E" cells), in which
cell mitoses, division & multiplication are quite active. New lens
fibres are continuously produced in this zone throughout life. It’s

23. The development of PCO is a very dynamic process.
It involves three basic phenomena: proliferation,
migration, & differentiation of residual LECs.
Clinically, two different components of PCO can be
differentiated, namely a regeneratory and a fibrotic
component. The residual LECs themselves secrete various
cytokines that control the development of PCO

24. •Regeneratory PCO is much more common; it is caused by
posterior migration of the E cells along the posterior
capsule large balloon like bladder cells, known as Wedl
cells which are clinically termed as Elschnig pearls.
Each pearl represents the failed attempt of an epithelial
cell to differentiate into a new lens fiber.

25. ELSCHNIGS PEARLS

26. •Fibrotic PCO is caused by differentiation of A cells into
myofibroblasts which are spindle-shaped, fibroblast-like
cells. They express smooth muscle actin filament & become
highly contractile. These cells proliferate & migrate to the
posterior capsule and form a layer by secreting
extracellular ground substances & a basement membrane
like material causing whitening and wrinkling of the
capsule.

27. Mixture of Elschnig’s pearls and fibrosis on
the posterior capsule

28. Types of PCO
Elschnig pearls
• Proliferation of lens epithelium
• Occurs after 3-5 years
• Usually occurs within 2-6 months
• May involve remnants of anterior
capsule and cause phimosis
Fibrosis

29. Complications of extensive fibrotic reaction of
capsule:
Rhexis contraction IOL decentration
bad visual outcome
spacielly with
multifocal IOLs.
partial buttonholing
With IOL tilt. Arrows
indicate location where
the rhexis has“slipped”
behind the optic.

30. CLINICAL EVALUATION
Decreased VA, Visually significant PCO is defined as
 BCVA by 2 snellan’s lines.
Impaired contrast sensitivity.
Glare disability.
Hinders examination of the peripheral fundus.

31. Source: American Journal of Ophthalmology 2014; 157:171-179.e1 (DOI:10.1016/j.ajo.2013.08.016 )
Copyright © 2014 Elsevier Inc. Terms and Conditions
no grade, PCO
No grade, PCO absent or only affecting the
peripheral capsule.
PCOGrading

32. Grade 1
Grade 1: any PCO affecting an area 4 mm in
diameter around the visual axis, but not
obscuring the retina .
Copyright © 2014 Elsevier Inc. Terms and Conditions
Source: American Journal of Ophthalmology 2014; 157:171-179.e1 (DOI:10.1016/j.ajo.2013.08.016 )
PCOGrading

33. Grade 2
Grade 2, central PCO slightly obscuring the
view of the macula, but permitting an
assessment of the C/D ratio .
Source: American Journal of Ophthalmology 2014; 157:171-179.e1 (DOI:10.1016/j.ajo.2013.08.016 )
Copyright © 2014 Elsevier Inc. Terms and Conditions
PCOGrading

34. Source: American Journal of Ophthalmology 2014; 157:171-179.e1 (DOI:10.1016/j.ajo.2013.08.016 )
Copyright © 2014 Elsevier Inc. Terms and Conditions
Grade 3
Grade 3: central PCO slightly obscuring the
view of the macula, but permitting an
assessment of the C/D ratio.
PCOGrading

35. Source: American Journal of Ophthalmology 2014; 157:171-179.e1 (DOI:10.1016/j.ajo.2013.08.016 )
Copyright © 2014 Elsevier Inc. Terms and Conditions
Grade 4
Grade 4, central PCO sufficiently obscuring
the view of the entire fundus
PCOGrading

36. Surgery-related factors to reduce PCO:
A well-centered Capsulorrhexis edge overlapping the
IOL optic edge around the entire circumference.
Multiquadrant cortical cleaving hydrodissection
enhances cortical clean up.
Aspiration of LECs from the anterior capsule during
cataract surgery
How to Achieve a Low PCO Rate?

37. IOL-Related Factors to Reduce PCO
How to Achieve a Low PCO Rate?
•In the bag fixation enhances IOL optic barrier.
•Bio compatible IOL. Acry sof IOL is the most
biocompatible.
•Sharp posterior optic edge (the most effective method
to  PCO).
•Maximum IOL OPTIC -PC contact.

38. Experimental devices:
Sealed capsule irrigation for PCO prevention
Sealed capsule irrigation (SCI).
This small, flexible, soft silicone device seals the capsulorhexis
temporarily allowing the isolated safe delivery of irrigating
solutions containing pharmacological or non-pharmacological
agents into the capsular bag following cataract surgery without
exposing surrounding IO structures to potentially toxic
substances.

39. PCO is a major problem in paediatric cataract surgery where
the incidence approaches 100%. This is thought to be due to
the higher proliferative capacity of lens epithelial cells in
the young compared with the old.
Dense PCO & secondary membrane formation is particularly
common following paediatric IOL implantation. A delay in
diagnosis can cause irreversible amblyopia.
PCO in Children

40. A heparin coated PMMA IOL reduces inflammation & the
incidence of PCO .
Low molecular weight heparin added to the irrigating fluid
during cataract surgery has resulted in less fibrin and
pigment deposits on the lens.
The capsular tension ring (CTR) may be useful. When the
CTR is in place inside the capsular bag it exerts a 360°
tangential tension on the posterior capsule
Primary posterior CCC & primary anterior vitrectomy may be
necessary to prevent or eliminate the onset of central PCO.
Surgical Prevention

41. In younger children, visual axis obscuration due to PCO can
be treated with pars plana vitrectomy and membranectomy.
In older children , Nd: Yag posterior capsulotomy.
Treatment

42. Treatment of capsular opacification
Nd:YAG laser capsulotomy
• Accurate focusing is vital
• Apply series of punctures
in cruciate pattern
• 3 mm opening is adequate
• Indications
 BCVA bcz of hazy PC
– Hazy PC causing
inadequate fundus view
– Monocular Diplopia or
glare

43. Posterior capsule following a Nd:YAG laser
posterior capsulotomy

44. Potential complications
• Damage to implant
• Cystoid macular oedema
- uncommon
• Retinal detachment
- rare except in high myopes
•Short-term increase in IOP
•No improvement in the visualization
of the peripheral retina
•Increases the overall costs for
cataract treatment
•Not available in large parts of the
developing world.
•Difficult to perform in young
children.
•ocular inflammation
Disadvantage