Needle Stromal Hydration of Cataract Surgical Incisions

1. Needle Stromal Hydration of Cataract Surgical Incisions Y Athanasiadis, G Nithyanandarajah, P Scollo, B Sharma, A Dorgam & A Sharma Moorfields at Bedford Eye Department, Bedford, United Kingdom A simple and effective alternative to previously described hydration methods All authors declare no financial interest

2. Introduction • Post cataract surgery, a clear corneal incision (CCI) can be made more water tight via anterior stromal wound hydration, potentially reducing the risk of infection. • The conventional stromal hydration approach is to hydrate the lateral walls of the CCI itself. Some also infiltrate the roof / anterior portion of the wound with a cannula with the potential risk of Descemet membrane detachment and collapse of the anterior chamber. • A more effective alternative (the ‘Wong Way’) involves the creation of a supra-incisional pocket by keratome before making the CCI. This supra-incisional pocket, anterior to the CCI, is later hydrated creating a downward pressure on the CCI from the outside, whilst the IOP seals the CCI from the inside. Thus the CCI itself is not hydrated (as per the conventional approach) but pressure-sealed preventing wound leakage.

3. Rationale for a new approach … In practice however, the depth of the supra-incisional pocket is not certain, thus carrying the potential risk of disturbing wound architecture. We therefore cannot be sure that an incision anterior to our CCI does not cause long-term refractive changes. In attempt to circumvent any such potential pitfalls and in any case simply this method whilst retaining its benefits (primarily the prevention of postoperative endophthalmitis), we propose an alternative technique that is simpler, quicker, easier to perform and one that involves less damage to the corneal stroma.

4. Our Technique… Involving no supra-incisional pocket • On completion of cataract surgery a 30gauge yellow needle is attached to a 1ml syringe filled with balanced salt solution (BSS). • The needle is embedded into the cornea bevel down just above the main CCI, being advanced halfway into the stroma , bevel pointing posteriorly. • The BSS is then injected into the corneal stroma until diffuse whitening is observed. Video: Demonstrating Technique. If resistance is felt from occlusion of the needle opening by stromal matter, simply withdrawing the needle fractionally will allow egress of fluid from the syringe into the cornea

5. In Practice… • The point of insertion and track of the needle into the cornea is minute and one should not anticipate any complications related to this. • The actual architecture of the wound is not disturbed and damage to the surrounding structures such as Descemet’s membrane with resultant detachment cannot occur. • Learning curve of the technique is not expected to be significantly steep. We are now routinely using this method in all of our surgeries and we have not encountered a single case of hypotony or endophthalmitis.

6. Outcome Water-tight wounds in 50 consecutive cases, even on external posterior wound pressure and in some cases application with fluorescein testing showed no leak. Figure: OCT Scan showing swelling of anterior stroma first post operative day Our technique is a simple and effective alternative to previously described hydration methods. Further studies are needed to compare its effectiveness to other techniques.