Dr. PARTHASARATHI ROY
Abstract: Capsulorhexis is difficult in hypermature intumescent / Morgagnian cataract due to high tension on the capsule.and very often cannot be completed due to peripheral extension or rupture. I have invented an unique approach to capsulorhexis by pharmacomodulation of preoperative pupillary dilatation.
Text:
Postulation of a hypothesis: With minimisation of cycloplegia by
Pharmacomodulation, tension on zonules will be reduced and the capsule will be loose and capsuorhexis will be easier and feasible.
Surgical Technique: Usual phacoemulsion / SICS, without any modification of rhexis technique. Sliding Test and Pitting Test : Visco canula slid to and fro and press on the capsule respectively to demonstrate that due to pharmacomodulation capsule became loose and unyielding.Surgeon had a gut feeling that rhexis can be completed and he found no dfference in ease of doing rhexis from that in immature cataract. Even large rhexis compatible with grade 4 NS removal could be created.
Discussion:
Traditionally in cataract surgery preoperative dilatation of pupil is done by instillation of dilating and cycloplegic drops. However the cycloplegic drop in addition to dilating pupil, increase the tension on the already tense capsule of the intumescent / Morgagnian lens, which makes capsulorhexis very difficult, if not impossible.To reduce the tension on the capsule, I increased the dilution of cycloplegic ( capsule take more accommodated form, Figure 1) 1. Therefore I used 5% Phenylephrine (sympathomimetic, alfa 1 agonist) eye drop at the interval of ten minutes thrice, with 1 in 4 dilution of 1% Tropicamide (parasympatholytic, antimuscarinic) eye drop once only. Diluents used was carboxymethyl cellulose eye drop. Earlier I have experimented in 20 eyes in OPD that this regime of eye drops were sufficient to dilate the pupil and block the pupillary light reaction. To maximise the release of capsular tension, the beta 2 receptor mediated relaxing effect on ciliary muscles was also blocked by instilling Timolol 0.5% eye drop BD for two days and one drop before operation.One drop Flurbiprofen eye drop was also instilled
Extent of deviation from routine pharmacological practice proposed in this study: pupil is conventionally dilated with a combination eye drop containing 5% Phenylephrine and 0.8% Tropicamide.I used 1 in 4 dilution off 1% Tropicamide in place of 0.8% solution and Phenylephrine 5%, both from single drug preparation.
This study on novel approach to capsulorrhexis in hypermatureIntumescent /Morgagnian cataract by pharmacomodulation of preoperative pupillary dilatation is unique, and to the best of our knowledge, no study in this area was undertaken before ..
REFERENCES:
Levin LA, Nilsson Siv FE, Var Hoeve J, Wu SM, Editors , In: Adler’s Physiology of Eye, 11th Edition, 2011, Saunders- Elsevier, London.pp.40-68.
LEGENDS:
Figure 1.Changes of the lens with accommodation.
Video clips will be shown during presentation.
Acknowledgment: The study has been conducted in Regional Institute of Ophthalmology, Medical College Hospital Kolkata, West Bengal with reqiured assistance from Department of Pharmacology School of Tropical Medicine,Kolkata.
Leave a Comment