Studies examine AcrySof lenses in children

Three studies follow posterior capsule opacification rates, need for re-treatments.

---In the bag implantation (no posterior capsulorrhexis) in a 4-year-old child (1 year postop).

Evidence points to the decrease of posterior capsule opacification (PCO) in adults receiving the AcrySof (Alcon, Fort Worth, Texas) IOL, but pediatric surgeons are hoping to evaluate the same results in a patient group more prone to cellular migration.

Three studies looked at the incidence of PCO in patients less than 2 years old with congenital or traumatic cataracts. Each surgeon evaluated the need for postoperative treatments and the best technique to manage cell deposits in this difficult age group.

According to Murali K. Aasuri, MD, the AcrySof lens decreases PCO because of the lens material and because of the straight-edge design of the lens, which prevents cellular migration across its posterior side.

“Pediatric cataract surgeons face this problem of posterior capsule opacification,” he said. “The reported rates are obviously higher in pediatric eyes due to the actual mitosis of the epithelial cells.”

According to Stephen S. Lane, MD, “There’s a lot of postoperative inflammation [in pediatric eyes]. They can certainly develop amblyopia, and then there is the problem of early posterior capsule opacification, which has really generated the most interest.”

Small incision lens surgery offers better control, less astigmatism, less anisometropia and faster rehabilitation — all important aspects of operating on young children. These benefits lessen the need for rigid postoperative compliance such as medications and frequent postoperative visits, Dr. Lane said.

Indian study results

---AcrySof IOL with haptics in the bag and optic capture through posterior capsulorrhexis in a 6-year-old child (1 month postop).

Dr. Aasuri spoke about “AcrySof IOL Implantation in Pediatric Eyes” at the American Society of Cataract and Refractive Surgery (ASCRS) meeting in Seattle.

“The development of the AcrySof lens has shown promising results in reducing PCO formation both in adults and also particularly in children,” Dr. Aasuri said. In India, PCO is a common problem in pediatric implants, as are astigmatic changes, IOL surface deposits and postoperative inflammation.

Researchers designed a prospective study of 39 children between March 1997 and March 1999 with congenital or developmental cataracts between the age groups of 5 and 15 years and without operative complications such as capsular tears.

The mean age at surgery was 8.1 years and the follow-up duration was about 16 weeks, ranging between 3 months to about 2 years. Thirty of these were developmental cataracts.

Surgeons used a sclerocorneal internal incision measuring about 3.5 mm and then an anterior capsulorrhexis. Surgeons implanted the AcrySof followed by sutured or sutureless wound closure.

Surgeons excluded four patients with intraoperative complications and analyzed the remaining 35 patients for postoperative astigmatism. They found no significant change in the preoperative to postoperative cylinder values.

In the study, 17 patients achieved 20/40 uncorrected visual acuity or better, five patients achieved between 20/50 and 20/80, and 13 patients had a residual amblyopia.

When surgeons looked at PCO, 30 patients had none and they also had minimal inflammation, no decentration and no pupillary capture, Dr. Aasuri said. Of the remaining five eyes, one had a pupillary capture and four had fine cellular deposits that were insignificant.

Surgeons noted mild PCO in two eyes, a moderate form in one eye and a severe form in the other eye.

“The AcrySof lenses in children tend to reduce the PCO greatly, but does not entirely eliminate it,” Dr. Aasuri said. “There is minimal inflammatory response to the implantation and minimal postoperative astigmatism with a good satisfactory visual outcome.”

Buying time

---In the bag AcrySof IOL implantation in a 5-year-old child. Anterior and posterior capsulorrhexis was performed. Notice Elschnig’s pearls formation (1 year postop).

Dr. Lane has studied long-term data and presented 3-year follow-up data at ASCRS. In his study, he used a 3 mm to 3.5 mm scleral tunnel incision and a highly retentive viscoelastic material to ensure the ease of anterior capsulorrhexis.

He examined 26 eyes with the mean age of 5.8 years and all less than age 10. He used the AcrySof lens in 22 eyes and PMMA in four. Posterior capsulectomy was performed in six of the 26 eyes; two in the AcrySof group and four in the PMMA group.

He followed AcrySof patients a mean of 29 months and PMMA patients for 30 months. He found a comparable postoperative visual acuity in both eyes.

The overall capsulectomy rate was 40%. In the first year, none of the AcrySof patients needed a YAG procedure but all four of the PMMA lenses did. None of the primary posterior capsulectomies that were performed formed fibrous posterior vitreous membranes that needed treatment with a YAG laser.

“It looks from this information that you can buy yourself probably 2 years of time before YAG posterior capsulotomy need be performed,” Dr. Lane said. “There is a significant decrease in the PCO rate with the use of AcrySof lenses. While it does not eliminate the need for YAG laser capsulotomy, it certainly does reduce it with excellent best corrected vision in all groups, having undergone cataract and implant surgery.”

The low incidence and delay in PCO means that capsulotomy is unnecessary in children over the age of 2.

Another Indian surgeon, Rupal H. Trivedi, MD, also examined patients receiving the AcrySof lens. The average age was 5.6 years.

Dr. Trivedi conducted a randomized, prospective study of 74 eyes with cataracts. Group 1 was comprised of 59 patients with congenital cataracts and group 2 had 15 patients with traumatic etiology.

Researchers broke the categories further into four groups — 34 patients without posterior continuous curvilinear capsulotomy (PCCC), 13 patients with a PCCC but no vitrectomy, 20 patients with PCCC and vitrectomy and seven other patients.

Group 1 developed no eyes with central PCO, while in group 2, 12.3% developed central PCO.

Of the 34 eyes without a PCCC, only one eye with a traumatic cataract developed central PCO. In the subgroup that received PCCC alone, no eye developed anterior vitreous phase opacification.

Non-vitrectomized groups did significantly better, Dr. Trivedi said. She suggested reducing the overall length of AcrySof IOLs in children.

For Your Information:

• Murali K. Aasuri, MD, practices at L V Prasad Eye Institute, L V Prasad Marg, Banjara Hills, Hyderabad, Andhra Pradesh 500034, India; (91) 40-360-8262; fax: (91) 40-354-8271. Dr. Aasuri has no direct financial interest in any of the products mentioned in this article, nor is he a paid consultant for any companies mentioned.
• Stephen S. Lane, MD, practices at Associated Eye Physicians, 232 N. Main St., Stillwater, MN 55082; (651) 439-8500; fax: (651) 439-5106. Dr. Lane has no direct financial interest in any of the products mentioned in this article. He is a member of the Medical Advisory Board for Alcon.
• Rupal H. Trivedi, MD, practices at Raghydeep Eye Clinic, Gurukul Road, Gujrat, Ahmedabad Guj 380052, India; (91) 79-7453-303; fax: (91) 79-7411-200. Dr. Trivedi has no direct financial interest in any of the products mentioned in this article, nor is she a paid consultant for any companies mentioned.

• For more information on the AcrySof IOL, contact Alcon Laboratories, 6201 South Freeway, Fort Worth, TX 76134-2099; (800) 862-5266; fax: (800) 241-0677.