AFTER CATARACT

Posterior capsular opacification

• Also known as After cataract or Secondary cataract

• Refers to opacity that follows extracapsular cataract extraction

Mechanisms of PCO formation

• Cortical remnants following cataract surgery- may form a thin membrane overlying the capsule- “membranous”

• Cortical fibres trapped between the anterior and posterior capsules along with formation of abortive opaque lens fibres formed from cubical cells underlying anterior capsule- form a dense ring behind the iris- “Soemmering’s ring”

• Proliferation of subcapsular cells to form large balloon like cells which fill the pupillary aperture- “Elschnig’s pearls”

Factors influencing PCO formation

• AGE: > in younger patients (increased fibrous proliferation)

• Surgical procedure: Phacoemulsification with “in the bag” IOL implantation has lesser risk

• Type of IOL used: - PMMA and hydrophilic acrylic IOLs: greater risk- Hydrophobic acrylic and newer generation

silicone IOLs with square edges: lesser chance • Implantation of Capsular Tension Ring: lesser

risk• Duration following surgery: Usually develops a

few months following surgery. Rare to develop >5 yrs after surgery

Treatment

• Thin membranous after cataract /thickened posterior capsule and Elschnig’s pearls: Nd YAG capsulotomy

• Dense membranous as in children: discission using Ziegler’s knife or using vitreous cutter. Thicker non-pliable membranes may require membranectomy using vitreous scissors before they can be aspirated into cutting port

• Soemmering’s ring with clear central PC: no treatment needed