MAR 04, 2011
The authors conducted this retrospective review to determine the incidence of visual axis opacification (VAO) requiring a second surgery after cataract surgery during the first year of life. The authors reviewed the medical records of all patients younger than one year who had primary single in-the-bag hydrophobic acrylic IOL implantation at one of two medical centers. They found that within 12 months of the initial surgery, 23.6 percent of eyes required a second surgery for VAO, with the rate 3.5 times higher in female than male infants but similar between IOL models. Additionally, eyes implanted with a symmetric biconvex IOL maintained a clear visual axis for longer than eyes with an anterior asymmetric biconvex IOL.
The study included 72 patients (72 eyes). One eye was chosen randomly in bilateral cases. The mean age at cataract surgery was 6.0 months. The authors noted instances of the need for surgery for visually significant VAO that occurred up to 12 months after the initial surgery.
VAO surgery occurred a mean of 6.2 ± 2.9 months after initial surgery. The procedure was required in 25 percent of eyes that received the AcrySof MA60AC IOL and in 23 percent of eyes that received AcrySof SA60AT, SN60AT or SN60WF IOLs. The earliest time between cataract and secondary VAO surgery was relatively later (9.0 months) with the SN60WF IOL, the only symmetric biconvex IOL included in the study, than with the MA60AC (4.4 months), SA60AT (2.2 months) or SN60AT IOL (2.0 months), which are all anterior asymmetric biconvex IOLs. The authors also found that eyes that underwent initial cataract surgery within the first six months of life were more likely to require a second surgery for VAO (35.1 vs. 11.4 percent; P = 0.018).
This paper, which is written by some of the best surgeons in the world, provides more evidence that our current standard technique is wrong. Although I have many years of experience with pediatric cataract, I have none with this very early age group. I have followed Howard Gimbel's lead and now perform posterior rhexis and capture a three-piece lens optic through the rhexis after viscodefining Berger's space with haptics in the bag. The term, "buttonhole" technique, coined by Rupert Menapace, is technically difficult, but results in a zero VAO rate. By not breaching the anterior hyaloid, the eyes are quieter, and I believe they will be less prone to cystoid macular edema, retinal detachment and glaucoma.