Eyeworld

58 | EYEWORLD | APRIL 2020 ATARACT C needle. The haptic is pulled back into the eye using 25-gauge forceps and placed on the iris. This haptic can then be and redocked in the new 30-gauge needle at a proper 180-degree location for better centration." To prevent tilt, Dr. Fram maintains the side with the proper haptic tunnel and entry. Additionally, the shorter pass should be red- ocked with a more symmetric tunnel length or distance from the surgical limbus. "For pupillary capture, a peripheral iridec- tomy should be attempted first," Dr. Fram said. "An ultrasound biomicroscopy should also be performed to evaluate tilt. If it's amendable, a [peripheral iridectomy] may be sufficient. If not, then the persistent optic capture of the pupil can be resolved by refixating the haptic closest to the side of the pupil that is captured. The new pass should be more posterior." Tips to ease Yamane One tip Dr. Yamane recommends to help surgeons with the technique is to first practice inserting the haptic in the needle. "After that, pay attention to the positional relationship between the wounds," Dr. Yamane said. Dr. Fram urged meticulous marking, mov- ing the main incision temporally, and keeping the proximal haptic outside of the eye prior to docking. "Understanding the tunnel length (1.5 mm) and orientation (20 degrees to the limbus) was also critical to shortening my learning curve," Dr. Fram said. "I recommend practic- ing with a simulation model, such as SimulEYE [InsEYEt]." Dr. Ayres agreed practice of the technique is critical and mentioned courses offered by ASCRS and the American Academy of Oph- thalmology. "Don't forget to keep the eye formed, us- ing an AC maintainer is critical in these cases," Dr. Ayres said. "Talking the case through with a surgeon experienced in the technique is also helpful." Dr. Fram has found that those consider- ations depend on the selected IOL. She looks at the recommended A-constant of the manu- facturer and uses information from doctor-hill. com, as well as the biometry results. Dr. Fram aims for in-the-bag calculations (plano to –0.50 D) and has found the Holladay calculation most reliable. Although Dr. Ayres uses a similar approach, he has experienced more variability with scleral- fixated IOLs. "I tend to place my IOLs more posterior than other surgeons," Dr Ayres said. "I like to place my IOLs approximately 3 mm posterior to the limbus. We have found that 50% of our patients with this technique are within 0.5 D of intended target, [and] those that fall outside 0.5 D tend to be on the myopic side." Eye marking and incision placement The best way to mark the eye is through use of diathermy, Dr. Yamane said, but dyes are also acceptable. He then creates the main wound at 1:00 and the scleral tunnel at 3:30 and 9:30. Dr. Ayres uses a centration guide, like an LRI or toric marker, to ensure 180-degree place- ment of the scleral tunnels. He creates scleroto- mies at 12 o'clock and 6 o'clock. "My preference is to make them 3 mm posterior to the limbus, and I make my sclera tunnel 2 mm in length," Dr. Ayres said. Preventing decentration Decentration occurs when the marks and subse- quent scleral tunnels are not 180 degrees apart and centered, Dr. Fram said. Tilt occurs when tunnel lengths are not symmetric or the distance from the limbus is not equal on each side. Insertion angle of the needles is important to control tilt. The needle stabilizer helps to make the insertion angle constant. "Decentration can be dealt with sometimes by trimming one haptic shorter," she said. "However, if it is severe, then you can pick the side that looks better centered and redock the other side at the true 180 degrees. The haptic flange can be cut on a bevel and checked that it will feed into a new 30-gauge, thin-walled continued from page 57 Contact Ayres: brandonayres@me.com Fram: nicfram@yahoo.com Yamane: shinyama@yokohama-cu.ac.jp Relevant disclosures Ayres: Alcon, Carl Zeiss Meditec, MicroSurgical Technology Fram: None Yamane: None

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