Anterior segment optical coherence tomography (AS-OCT) performed preoperatively with a proprietary system (Visante, Carl Zeiss Meditec) in patients with very shallow anterior chambers who are undergoing cataract surgery improves the safety of the procedure. AS-OCT allows surgeons to modify the surgical strategy. Double filling with cohesive and dispersive ophthalmic viscoelastic devices can preserve the surgical space.
"The quality indicators in modern cataract surgery are changing. In our opinion, the routine cataract procedure will change and be highly personalized to the individual patient within the next 5 years. Because of this, new classes of cataract cases are recognized more frequently, such as those with shallow anterior chambers," Dr. Kusa said. She is a consultant, Centro Microchirurgia Ambulatoriale, Monza, Italy.
Dr. Kusa described the usefulness of the AS-OCT system for imaging the anterior chamber depth, lens vaulting, and the condition of the angle for planning the surgery preoperatively. She showed an image from a patient with hyperopia who had an angle open only 2° and at high risk of developing glaucoma.
A total of 42 eyes were included in this study. In these eyes, the anterior chamber depth was less than 2.4 mm. All eyes were double-filled with a 2.3% sodium hyaluronate viscoelastic (Healon 5, Advanced Medical Optics) to widen the anterior chamber and for safer management of the capsulorrhexis. Despite this careful technique, Dr. Kusa reported, a four times greater loss of endothelial cells was seen following cataract surgery in these eyes.
Dr. Kusa said she was pleased with the results of the study. The anterior chamber depth increased by 63% at 6 months after surgery. She showed the results in a patient in which the preoperative angle was 8°; after surgery it was 73°.
"[The AS-OCT system] provides us with a precise measurement of the anterior chamber depth, the angle width, and the corneal thickness. In patients with an anterior chamber depth less than 2.4 mm, we modified our surgical strategy and maintained the space with repeated injections of [2.3% sodium hyaluronate viscoelastic] and [1% sodium hyaluronate viscoelastic (Healon. Advanced Medical Optics)]," she said.
Within 3 months after surgery, the mean anterior chamber depth increased by 63%. In all eyes, the angle opened by a mean of 141.6%. The IOP also decreased by a mean of 21%.
"An extremely important factor for us is that we are treating patients 20 to 25 years before most individuals undergo cataract surgery. The most important goal is to avoid any complication that can prevent us from obtaining good refractive results," Dr. Kusa said. "In our opinion, using anterior chamber OCT technology preoperatively and the use of double the amount of viscoelastic during surgery are very good approaches for improving the outcomes and decreasing complications in these difficult eyes."