In search of better technique for management of childhood cataract a comparative study comprising lensectomy, ECCE and scleral tunnel surgery was undertaken. The objectives are to evaluate the techniques of, visual outcome and complications of cataract extraction with or without posterior chamber intra ocular lens implantation in children.
The treatment of childhood cataract,congenital or developmental cataract is a perpetual problem that challenges the ophthalmologists throughout the world. Early management of these cases not only restores vision but also prevents further complications like nystagmus, strabismus or amblyopia. Clearance of lenticular opacity and correction of gross refractive error in these patients is an emergency, because lack of timely intervention leads to severe amblyopia. The majority of ophthalmologists in USA, both cataract surgeons and paediatric ophthalmologists favour implantation of intraocular lenses in children down to age two. Many are now advocating the indications below 2. How ever, there is a definite growing acceptance of the role of intraocular lenses in children because of recent development of continuous circular capsulorhexis, placement of intraocular lenses in the bag and posterior capsulorhexis with or without anterior vitrectomy. Anterior vitrectomy seems to eliminate the risk of developing a secondary cataract which is a post operative complication of great concern.
The purpose of this study was to evaluate the better technique, compare the different techniques for, result of, cataract extraction and primary posterior chamber lens implantation in children.
The study was conducted in the department of Ophthalmology, Rajah Muthiah Medical College Hospital, Annamalai University between 1994-2000. We studied a consecutive series of 30 eyes in 24 children attending to ophthalmology OPC of RMMCH, out of which 10 eyes underwent Transparsplana lensectomy(TPPL), 10 ECCE and IOL implantation and in rest 10, Scleral Tunnel Cataract Surgery and IOL Implantations were performed. Twenty five ( 83.33%) eyes had developmental or congenital cataract and 5 ( 16.66%) had traumatic cataracts. A cataract that is present at birth is considered congenital cataract and one that appears at later date is considered developmental. The children ranged in age from 2 yrs to 14 yrs at the time of surgery. The follow up period ranged from 6 months to 7 yrs. Informed consent was obtained from the parents of each child. They were given information on the risks, benefits and alternatives to the procedure. The contraindication to intraocular lens implantation included age younger than 1 year, chronic uveitis, glaucoma,microphthalmos with corneal diameter less than 9 mm,dislocated lenses and cases assigned for TPPL. In bilateral cases the most severely affected eye was operated on first and the fellow eye after 2-3 months.
In most of the cases, keratometry readings, A scan biometry and comprehensive ophthalmic examinations were performed before surgery. In young and uncooperative children where even visual acuity could not be assessed, fixation pattern or loss of central red reflex was considered an indication of surgery and a standard +20.5 D IOL was implanted.
Mydriatics of the operated on eye was achieved with 1% Tropicamide and 10% phenylephrine. All the surgeries were performed under general anaesthesia by a single surgeon who is well experienced with both TPPL and Tunnel Cataract Surgery. The eye was prepared for surgery in standard fashion.
Two small conjunctival flaps created. Sclerostomy was done with MVR blade,2.5mm from the limbus,one for infusion canula and other for lensectomy cutter. With the same MVR blade the posterior capsule was cut and lens matter was mobilized. The lensectomy cutter (Storz) was introduced, the entire lens was removed along with a portion of anterior vitreous. The infusion was maintained with Ringer’s solution. The wound was closed with 10/0 nylon suture. Injection cefazoline 100mg and dexamethasone 2mg was injected s/c into the upper fornix. Over the years this was a superior surgical procedure to other conventional surgeries as there was no chance of leaving behind residual lens matter. One can achieve nearly complete removal of lens much easily with the help of automated vitrector so after cataract is almost nil, there is no damage to cornea, early ambulation is possible and overall post operative visual outcome is better.
Following a small conjunctival flap, a 3mm limbal incision was given, entry to A/C was made. A/C was reformed with viscoelastic. A 26G needle cystitome was introduced, a rhexis or can opener capsulotomy was performed. Ringer’s lactate solution was used as intraocular irrigating solution, lens matter was removed with simcoe I/A canula. IOL was implanted either in the bag or in the sulcus after extending the incision. The wound was closed with 10/0 nylon suture. Injection cefazoline 100mg and dexamethasone 2 mg was injected s/c into the upper fornix.