Dr. Rajendra Prasad, P14714, Dr. Anurag Badhani
Purpose: Is to evaluate the efficacy of a new surgical approach Hydissect, in minimizing the risks of
Posterior capsular rupture in complex posterior polar cataract.
Methods: We advocated a new surgical technique Hydissect, low vacuum controlled bimanual cataractous plaque extraction with simultaneous posterior capsular rhexis in 6 cases of complex posterior polar cataract, having complete adhesion of cataractous plaque and posterior capsule. All patients were selected randomly from the RP Eye Institute, Vasant Kunj New Delhi during a year 2013-2014 seen in the eye OPD.
Discussion: Posterior polar cataract is one of the difficult and complex surgical challenges posed to the most of the cataract surgeons because of its high likelihood of intra operative posterior capsule rupture.
High incidence of posterior capsular rupture is primarily due to the complex developmental malformation of lenticular fibers and capsule at the central posterior pole of crystalline lens. The incidence has been put as high as 26 -36 % even by the leading cataract surgeons.
Most of the surgical strategies and phacodynamics aim at preventing posterior capsular rupture, which is only possible if there is no adherence of cataractous plaque with the capsule. But in those cases where there is a complete fusion of cataractous plaque and posterior capsule there is no way to prevent capsular tear.
So our surgical approach should aim to prevent the capsular tear until the conclusion of the extraction procedure and minimize the risks of loss of lens material into the vitreous cavity and maximize the benefits by implanting the IOL in to the capsular bag.
HYDISSECT is low vacuum, bimanual irrigation and aspiration controlled cataractous plaque extraction and simultaneously creating posterior capsular rhexis. Since capsule is firmly fused with the cataracts plaque we have to resort to a controlled removal of plaque along with the posterior capsule, creating a successful controlled posterior capsulorrhexis
Surgery should begin with a clear corneal incision, which could be biplaner or triplaner incision on the steep axis of cornea. Extreme care is taken not to over pressurize the anterior chamber or capsular bag to prevent posterior capsule rupture. Over inflation of anterior chamber or capsular bag may blow out the posterior capsule.
Capsulorrhexis could be initiated with hypodermic needle or rhexis forceps. Rhexis should be of 4-5 mm not larger than 5mm, a larger opening may not leave adequate support for a sulcus-fixated IOL if the posterior capsule is compromised.
Special care should be taken while hydro dissection and hydro delineation are performed. Cortical cleaving hydro dissection should be avoided as the fluid wave created may extend to the weak area of the posterior capsule and lead to hydraulic rupture of the posterior capsule. Perform multiple quadrants hydro dissection and gently inject tiny amounts of fluid such that the fluid wave could not extend across the posterior capsule. Perform hydro delineation to precisely demarcate the central core of nucleus and to create a mechanical cushion of epinucleus over the fragile posterior capsule. Rotation of the cataract should be avoided as torqueing forces being transmitted to the posterior capsule may dislodge the capsular cataract complex into the vitreous.
Before inserting the phaco probe in to the anterior chamber reduce the bottle height to 60 – 70 cm and phaco parameters to reduce the hydraulic pressure on the capsule. The anterior cortex and the epinucleus are then removed using low aspiration and as little phacoemulsification as possible. For nuclear emulsification it is always better to create a central trench and divide, this gives us a better control of nuclear manipulation over the cataractous plaque. Inner nucleus is then extracted and emulsified with slow motion phacoemulsification using minimal ultrasound energy without applying posterior stress. Remaining nucleus is then aspirated layer by layer towards the plaque.
Once the nucleus is removed, part of epinucleus is phaco aspirated. Then we use irrigation and aspiration mode with bimanual system to aspirate epinucleus and cortical material with partial segmentation technique. Each layer of epinucleus and cortex is sequentially aspirated layer by layer till we reach the central portion of PPC. Epinucleus and cortical matter are broken off at least 4 mm away from central zone of cataractous plaque. This would prevent pulling stress on the capsule and minimize the risk of capsular tear and leaving a protective layer over the posterior polar region until the conclusion of the extraction procedure.
Many a times central plaque is completely fused to the posterior capsule along with the plate of over hanging epinuclear membrane, we have to resort to a controlled removal of plaque along with the posterior capsule, creating a successful controlled posterior capsulorrhexis. To detach the central plaque and membrane we used Hydissect that is low vaccum controlled bimanual irrigation and aspiration cannula to create a controlled posterior capsulorrhexis. Bimanual system provides better control over needle or forceps since while creating the rhexis we continuously maintain anterior chamber pressure.
Once the rhexis and vitrectomy is complete, routine in the bag IOL implantation is done. IOL should be slowly and gently inserted into the bag and rotate the lens to the proper angle before permitting its haptics to open. If the posterior continuous curvilinear capsulorrhexis fails, then we will forward capture the optic through the anterior capsulorrhexis with the haptics in the bag. In case we loose posterior capsular support completely, then the anterior capsulorrhexis becomes a critical backup and IOL is implanted into the sulcus.
Results:This technique has enabled us to reduce the incidence of posterior segment complications in those cases where central plaque is completely fused to the posterior capsule. Surgery was conducted successfully in all the 6 eyes. The incidence of successful posterior capsular rhexis was 100 %, vitrectomy was required in 2 out of 6 cases (33.3 %), in the bag IOL was placed in all our cases 6 of 6 cases (100 %).
Conclusion: Complex posterior polar cataract a difficult surgical situation could be simplified with a new surgical technique Hydissect.
Dr. Rajendra Prasad
MD (OPH) AIIMS
Director RPEI
1201, SECT, B, POCKET, 1
VASANT KUNJ
NEW DELHI
INDIA
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