Viscoelastic-injecting cystotome

Cataract Following Pars Plana Vitrectomy: A Review

Introduction: The indications for pars plana vitrectomy (PPV) have increased over the years. The vitreous is no longer considered an inert ocular structure and it is well known that its removal has anatomical and physiological consequences. The vitreous is no longer considered an inert ocular structure. The vitreous plays a key role as an intraocular physiologic oxygen regulator. In order to maintain its transparency, the crystalline lens needs protection from an excessive oxygen exposure. PPV leads to progression of nuclear sclerosis in most eyes.Methods: A systematic review of the literature was conducted using Embase and Medline databases. Articles studying the physiology, pathogenesis and surgical treatment of cataract after PPV were included in this review.Results: The pathogenesis of cataract formation after PPV remains unclear. Predisposing factors include advanced patient age, preexisting nuclear sclerosis, light toxicity, intraoperative oxidation of lens proteins, use of silicone oil or intravitreal gas, mechanical trauma and the duration of exposure to an irrigating solution.Conclusion: Cataract surgery in vitrectomized eyes presents with more technical difficulties, is more challenging and often has a higher risk of intraoperative and postoperative complications than in non vitrectomized eyes. There is no standardized technique or management in these cases; therefore, it requires more precautions during surgery.

Pars plana vitreous tap for phacoemulsification in the crowded eye

This technique facilitates phacoemulsification and foldable intraocular lens (IOL) implantation in eyes with extremely crowded anterior segments. An automated pars plana vitreous tap is used to expand the anterior segment when extremely shallow anterior chambers do not deepen sufficiently with viscoelastic injection alone. This technique permits successful completion of pupilloplasty, capsulorhexis, phacoemulsification, and foldable IOL implantation in these high-risk eyes.