White Cataract: Double-Capsulorhexis Technique in Cataract Surgery скачать в хорошем качестве

White Cataract: Double-Capsulorhexis Technique in Cataract Surgery

The intumescent white cataract poses challenges during many different steps of surgery. This begins in the pre-operative period where biometry is compromised by the completely opaque media and continues into surgery where the absence of a red reflex decreases visualization. But probably the most important step of surgery is creation of the capsulorhexis which is difficult due to the pressure gradient created by a fluid-filled capsular bag. In the case presented here, two small paracentesis incisions are created, each being less than 1 mm in width. This small size is important to pressurize the anterior chamber after the anterior capsule has been stained with trypan blue dye. We avoid making the primary phaco incision at this point because it is much larger, about 2 to 3 mm in width. This large incision will depressurize the anterior chamber and the intra-lenticular pressure will be too high in comparison. Via the small paracentesis, a 25g bent needle cystotome is used to create a small, round capsular opening (Capsulorhexis #1). This round configuration is important since it will not radialize or rip uncontrollably. At this point we can make the main phaco incision with a diamond keratome and insert the phaco probe. Through this small capsular opening, the probe is used to aspirate out the fluid from the capsular bag. Touching the nucleus and rocking it gently will ensure that any fluid behind the nucleus also is aspirated. With the intra-lenticular fluid removed, the pressure in the capsular bag is very low and we can now create our larger, 5-mm diameter opening (Capsulorhexis #2) without fear of inducing the Argentinian Flag Sign which occurs with a radially split capsule which gives the blue-white-blue appearance of that flag. With successful completion of the 5-mm capsulorhexis, the nucleus can be removed using the phaco-chop technique. With the dense nucleus, a mechanical disassembly of the nucleus using the chop technique can reduce the ultrasonic energy and help preserve corneal endothelial cells. The lens implant is inserted into the capsular bag and the case is completed without issues.