Introduction to prevention of Posterior capsular rent

• 08 May 2020
• Dr. Sourabh Patwardhan
• 2K
• 251

i will be speaking on how to reduce posterior capsular rent in phacoemulsification. aim of the presentation is to address the common mistakes which lead to PCR in a routine case of phaco, understanding surgical anatomy, understanding physics of phaco, use of adjuncts like viscoelstics, pupillary devices, how to prepare microscope, machines and trolley, stepsise common mistakes and how to do surgical audit. a routine case of pphacoemulsification means all cases which do not have expected PCR, so it excludes PPC, Subluxated and traumatic cataracts.
PCR philosophy- in a routine case is 100% avoidable.
Anatomy of anterior chamber-the avarage diameter of lens is around 9mm. the lens thickness varies between 3.5-5.5mm with an average of 5mm in adult nucleus. the central 3.5mm is the harder nuclear part, except in mature cataracts where the entire lens has turned into hard part. In a immature catarct, anterior 1mm is epinucleus and cortex. 0.5mm is posterior epinucleus. So in a immature catarct after removing anterior 1mm, it takes trench to reach upto 1.75 mm depth to divide the nucleus.
how to know that you have reached the proper depth while trenching -for softer and harder cataracts- by taking tip width as yardstick. the usual tip width is 0.9mm, so take double the tip width as yardstick. and also there will be improved red glow. for moderate grade catarcts also, there is decreased resitance as you cross the central harder nucleus. The central 4mm zone is the safe zone for phacoemusification because it is the deepest part of AC, also it is farthest from endothelium. Also, it is safer area in case of surge. Stable anterior chamber is must for safe phaco. for this there has to be balance between inflow and outflow. inflow must match vacuum and aspiration. to increase inflow, you can increase bottle height or iop. sleeve should be of appropriate size. the irrigation should always be inside the chamber. avoid leaky incisions. the safe vaccum and aspiration varies with machine. linear mode is safer. settings shouls be set by surgeon depending on surge and stabilty.
power of phaco- avoid excessive phaco to avoid cut through and set max. power.
in case of small pupil, use methods to enlarge pupil to improve visualisation.
in cetain cases with surge like redundant PC, , it might be required to phaco closer to cornea, in these cases use good quality dispesive viscoelastic to protect the cornea.

Published By Dr. Sourabh Patwardhan

FRCS (UK), MS (AIIMS), DNB, MNAMS, FICO

Director, Nandadeep eye hospital, Sangli,India.
He heads a very popular Phaco training and fellowship program.