Flanged fixation secures IOL haptics within the sclera

February 24, 2017

Article

Flanged IOL fixation is a simple, minimally invasive, and effective technique for transconjunctival intrascleral fixation of a three-piece IOL, said Shin Yamane, MD, PhD, at the inaugural Retina World Congress.

Reporting clinical outcomes from a prospective, noncomparative, interventional case series that included 100 eyes of 97 patients, Dr. Yamane concluded that the novel fixation method provided good IOL fixation along with firm haptic fixation.

“At follow-up to 6 months, the mean refractive difference from the predicted value calculated with the SRK/T formula was only -0.21 D, and mean IOL tilt measured by swept-source optical coherence tomography was only 3.44º,” said Dr. Yamane, assistant professor, Department of Ophthalmology and Micro-technology, Yokohama City University Medical Center, Yokohama, Japan.

“There have been no cases of IOL dislocation after surgery,” Dr. Yamane added.

Kouros A. Rezaei, MD, who was a co-chair of the session, commented, “This is a very elegant technique."

"One of the biggest challenges for scleral-fixated IOLs is that the haptic breaks during manipulation, and this technique will prevent that from happening,” said Dr. Rezaei, associate professor of ophthalmology, Rush University Medical Center, Chicago.

Novel fixation procedure

All 100 eyes included in the series had at least 6 months of follow-up, 86 eyes were seen at 12 months, 46 at a 24-month visit, and 14 eyes had been followed to 36 months.

The novel IOL fixation procedure was used in eyes with aphakia, a dislocated posterior chamber IOL, or a subluxated crystalline lens. Eyes were excluded if they had a preoperative IOP ≥25 mmHg while on topical therapy, scleritis, or if the patient was <20 years old.

The procedure involves initial marking of the eye followed by a 27-gauge or 25-gauge vitrectomy. Then then IOL is injected into the anterior chamber and a sclerotomy made with a 30-gauge thin wall (30-G TW) needle. The IOL’s leading haptic is inserted into the lumen of the 30-G TW needle, and the trailing haptic inserted into the lumen of a second 30-G TW needle. The needles are used to externalize the haptics, and the tips of the haptics are cauterized to create a flange. Then, using the needles, the flanges are pushed back and fixed into the scleral tunnel.

Presenting an OCT image taken at the 6-month follow-up, Dr. Yamane provided confirmation that the flange of the IOL haptic was fixed inside the sclera.

Analyses of preoperative and postoperative visual acuity showed significant improvements in mean uncorrected and best corrected visual acuity for the series at all available follow-up intervals ranging from 6 to 36 months. Corneal endothelial cell density was also measured, and the data raised no safety concerns.

Explaining the use of the 30-G TW needle for performing the procedure, Dr. Yamane noted its inner and outer diameters are ideal when compared with the haptic diameter of the IOLs and the flange.

Four different IOLs were used in the 100 eyes. They included the X-70 (Santen), ZA9003 (Abbott), PN6A (Kowa), and MA60MA (Alcon Laboratories). The haptic diameter for the four IOLs ranges from 0.14 mm to 0.17 mm. The 30-G TW needle has an inner diameter of 0.20 mm and an outer diameter of 0.30 mm.

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“A 27-G needle has an inner diameter of 0.22 mm, and so it would be possible to insert the haptics of these IOLs into the needle’s lumen," Dr Yamane said. "However, the outer diameter of the 27-G needle is 0.40 mm, and so it is too large compared to the flange.”

He noted that the four IOLs used in the series have an overall length of 13 mm. Even though a 14 to 15 mm length would be considered better for scleral fixation, Dr. Yamane said that he has used the flanged IOL technique with the 13-mm length IOLs in over 150 eyes without any problems.

Dr. Yamane has no relevant financial interests to disclose.