First Author: Y.El Sayed EGYPT
Co Author(s): A. Abdelrahman
Purpose:
This is a prospective study that looks at the safety and efficacy of patching the tube of glaucoma valves, in the paediatric age group, with the rim of penetrating keratoplasty (PKP) grafts.
Setting:
: This study was performed in an institutional setting at Cairo University teaching hospital.
Methods:
Children aged ? 14 years and requiring valve implantation to control their glaucoma had an Ahmed valve inserted in the superotemporal quadrant. The plate was sutured 8-10 mm from the limbus. The tube was then inserted into the anterior chamber and loosely secured to the sclera by a 9/0 nylon suture. A corneoscleral rim obtained from the remnants of a PKP graft was cut to desired size and used to cover the tube starting from the limbus and extending at least 6 mm posteriorly. The patch was sutured in place and the conjunctiva was closed tightly.
The primary outcome measures were development of patch-related complications (conjunctival exposure, tube erosion or adjacent corneal complications such as dellen formation). Secondary outcome measures were intraocular pressure (IOP) reduction and the rate of success defined as achieving an IOP? 21 mmHg without glaucoma medications and without the development of any visually- threatening complications.
Results:
Seventeen eyes of 12 patients aged 7 months to 14 years (mean 3.16±4.18years) were included in the study. Six eyes had Ahmed FP7 valve, 5 had FP8, 3 had S2 and 3 had S3 valves implanted. Patients were followed for at least 2 years postoperatively. The mean IOP dropped from 29.6 mmHg preoperatively to 12.8 mmHg at the last follow-up. Conjunctival retraction was noted in 3 eyes, only one of which required surgical revision. There were no cases of tube erosion or corneal surface complications. The patch survived well and was still seen under the conjunctiva in all cases at the last follow-up visit. Complete success was achieved in 9 eyes (53%). One eye developed late postoperative endophthalmitis, but apart from that there were no other visually-threatening complications and no eyes that required valve explantation.
Conclusions:
Corneoscleral rim patching is a safe alternative to donor sclera and other patches. In addition to being readily available and economical, the relatively thicker tissues at the limbal area may provide longer lasting cover for the tube, reducing the risk of late erosion. This is especially important in children with glaucoma. A longer follow-up is however needed to determine patch survival over time.
Financial Disclosure:
None
