The local institutional Ethics Committee approved this protocol that sequentially included children (aged 0 to 12 years old) with congenital or developmental unilateral and bilateral cataract.
Eyes with horizontal corneal diameters smaller than 10 mm, persistent fetal vasculature, or other ocular anomalies were excluded.
Children with congenital cataracts diagnosed during the first weeks of life were operated on between the 5th and 6th weeks of life, and in bilateral cataracts, the second eye was operated within 1 to 2 weeks after the first eye, if not on the same day.
After anesthesia, keratometry (K) (Retinomax K-plus 2®, Righton, Tokyo, Japan), tonometry (Tono-Pen XL®, Reichert® Technologies, Buffalo, USA), immersion ultrasound biometry, and pachymetry (OcuScan RxP®, Alcon, Fortworth, USA) were performed. Deuring the surgery, if possible, a single-piece hydrophobic acrylic intraocular lens (IOL) was implanted (Alcon AcrySof® IQ, Alcon, Fortworth) in the bag, and the power as adjusted to minimize myopia in adulthood(6). The posterior capsule is opened, and an anterior vitrectomy is performed via pars plana/plicata after IOL implantation.
In children younger than 1 year, an examination under anesthesia was scheduled every 3 months during the first year of life. In children older than 1 year, the examination was scheduled every 6 months.
In the examination, automated refraction, keratometry (K), tonometry, immersion ultrasound biometry, and pachymetry were performed, using the same instruments mentioned above.
Collaborative children older than 4 years of age were examined in the office. For these children, K and automated-refraction measurements were taken using an automated tabletop refractometer and keratometer (Potec PRK-6000®, Potec, Daejon, Korea), and AL measurements were performed using an optical biometer (IOL Master 500®, Zeiss, Jena, Germany). IOP was measured using a Goldman tonometer coupled with a slit-lamp.
Surgical technique:
Incisions of 1.50 mm wide and 1.5 mm long were performed at 10 and 2 o’clock perilimbals in the clear cornea. Trypan blue was injected into anterior chamber, followed by ophthalmic viscoelastic device (OVD). After that, a capsulorhexis of approximately 5.5 mm was performed using coaxial microforceps. Lens material was aspirated using separate irrigation/aspiration, and the lens epithelial cells from the capsulorhexis rim were removed. OVD was injected in the capsular bag and anterior chamber. The 10 o’clock incision was then enlarged to 2.4 mm. The IOL was injected in the capsular bag. One stitch was performed in a 10 o’clock incision with 10-0 absorbable suture (poliglactin 910, Vicryl®). Then, the conjunctiva was opened at 2.5 mm (children under 2 years old) or 3 mm (children older than 2 years old) from the limbus at 10 o’clock, followed by 1 mm sclerotomy. The anterior chamber OVD was aspirated by separate irrigation/aspiration. Anterior irrigation was maintained through the 2 o’clock anterior incision, and anterior vitrectomy and posterior capsule opening were performed using a 23-gauge vitrector through the sclerotomy. Finally, all incisions were closed using 10-0 absorbable sutures.
The children received intravenous hydrocortisone (Flebocortid® 100mg) 10mg/kg during the surgery and dexamethasone 2mg/ml, 0.2ml subconjunctival immediately after surgery. Gatifloxacin 0.3% (Zymar® Allergan) and prednisolone 1% (pred fort Allergan®) eye drops were applied every 4 h for 15 days, and after that, prednisolone 1% every 6h for a further 15 days. Oral prednisolone (1mg/ml) was also used for 5 days after surgery.