Supracapsular glued IOL in progressive subluxated cataract maintains intact vitreous face

Issue: November 2018

ByAmar Agarwal, MS, FRCS, FRCOphth

BySoosan Jacob, MS, FRCS, DNB

Progressive causes of zonular dehiscence may be associated with late subluxations and dislocations of the IOL. The general strategies to avoid this include either two- or three-point fixation of the capsular bag during primary surgery even in lesser degrees of subluxations or a lensectomy with anterior vitrectomy and scleral/iris fixation of the IOL. The latter leads to anterior hyaloid face and vitreous disturbance with consequent disadvantages.

One of the authors (Jacob) described a technique in 2013 (https://www.youtube.com/watch?v=jpkMsVaDvnA) for supracapsular fixation of a glued IOL in order to retain an intact anterior hyaloid face and avoid disturbance of the vitreous while at the same time providing stable long-term fixation of the IOL. This is for patients with a progressive zonular pathology in which the bag is not hugely decentered. This includes progressive causes of subluxation such as pseudoexfoliation, megalophthalmos, high myopia, aniridia, Marfan syndrome and homocystinuria — cases in which, despite in-the-bag IOL with scleral fixation using a capsular tension ring or segment at the time of the first surgery, progressive zonular dialysis can cause a subluxation from a different quadrant.

The supracapsular glued IOL technique maintains an intact hyaloid face and avoids disturbance of the vitreous while at the same time providing the stable long-term fixation that is given by the glued IOL technique.

Figure 1. Supracapsular glued IOL avoids vitreous disturbance and provides long-term stable IOL fixation in progressive zonular pathologies. Child with aniridia, severe photophobia and glare (a). Intact but weak zonules (b). Continuous curvilinear capsulorrhexis done (c). Phacoemulsification and cortex aspiration proceeded with (d). Posterior CCC performed (e). Haptics of the aniridia glued IOL sequentially exteriorized in a supracapsular plane without entering the vitreous cavity or disturbing the anterior hyaloid face. Anterior chamber maintainer provides continuous infusion. Cohesive ophthalmic viscosurgical device may also be used to create space (f and g). Supracapsular aniridia glued IOL (h).

Technique

This is performed by first completing phacoemulsification using all the precautions taken for cataract surgery in a subluxated cataract. An anterior chamber maintainer or a trocar anterior chamber maintainer may be used to allow infusion into the anterior chamber when required. Capsular hooks may be used to provide intraoperative support to the bag. Once the cortex is removed, proceed with supracapsular implantation of the glued IOL. Instead of the usual ab externo sclerotomies that enter the vitreous cavity in the glued IOL technique, in this case sclerotomies are created with a bent 23-gauge needle passed ab interno parallel to the iris, in the plane between the anterior capsule and the iris to exit on the scleral surface under the scleral flap. This avoids any entry into the vitreous cavity. This step is facilitated by loosening the capsular hooks to allow the bag to move posteriorly. Injecting a cohesive viscoelastic under the iris also helps by pushing the iris upward and the capsular bag downward in the quadrant of the scleral flap.

PAGE BREAK

The haptics of a three-piece foldable IOL are then sequentially exteriorized with 23- or 25-gauge microforceps introduced through the sclerotomy anterior to the anterior capsule. A cohesive ophthalmic viscosurgical device injected to expand the supracapsular plane and to push the posterior capsule backward helps in easily performing this. Similar to the glued IOL, haptics are tucked into limbus-parallel 26-gauge intrascleral Scharioth tunnels, and scleral flaps and conjunctiva are closed with fibrin glue.

Advantages

Supracapsular fixation of a glued IOL offers the advantages of retaining the capsulo-zonular barrier, having an intact hyaloid face and avoiding disturbance of the vitreous. Better separation of the posterior chamber from the vitreous cavity leads to less endophthalmodonesis and pseudophakodonesis. These advantages decrease the incidence of postoperative posterior segment complications such as retinal detachment and cystoid macular edema. At the same time, this technique also provides stable long-term fixation of the IOL. These advantages are important in progressive pathologies, especially if already associated with a higher incidence of retinal complications such as subluxation with high myopia and Marfan syndrome.

A capsular tension ring is not implanted for fear of late dislocation of the bag-ring complex due to the progressive etiology of subluxation. Relaxing cuts may be made on the anterior capsule and posterior capsule either at the time of surgery or with a YAG laser in the postoperative period to avoid capsular phimosis.

For more information:
Amar Agarwal, MS, FRCS, FRCOphth, is director of Dr. Agarwal’s Eye Hospital and Eye Research Centre. Agarwal is the author of several books published by SLACK Incorporated, publisher of Ocular Surgery News, including Phaco Nightmares: Conquering Cataract Catastrophes, Bimanual Phaco: Mastering the Phakonit/MICS Technique, Dry Eye: A Practical Guide to Ocular Surface Disorders and Stem Cell Surgery and Presbyopia: A Surgical Textbook. He can be reached at 19 Cathedral Road, Chennai 600 086, India; email: dragarwal@vsnl.com; website: www.dragarwal.com.

Disclosure: No products or companies that would require financial disclosure are mentioned in this article.