Outcomes of Ahmed glaucoma valve in paediatric glaucoma following congenital cataract surgery in persistent foetal vasculature

Purpose To evaluate the outcomes of primary Ahmed glaucoma valve in refractory secondary glaucoma following congenital cataract surgery, particularly in persistent foetal vasculature. Method Retrospective review of paediatric patients after Ahmed glaucoma valve implantation for refractory post-lensectomy glaucoma in a tertiary referral centre in Spain. Surgical complications, additional and/or replacements of Ahmed glaucoma valve, intraocular pressure, cup-to-disc ratio, glaucoma medications and final visual acuity were studied. Results A total of 29 eyes, 41% with persistent foetal vasculature and 59% with non-persistent foetal vasculature were included with mean follow-up of 105 +/- 67 and 74 +/- 45 months, respectively, after first Ahmed glaucoma valve implant. Median survival time for the first Ahmed glaucoma valve was significantly lower in persistent foetal vasculature (7.0 +/- 3.2 months) compared to non-persistent foetal vasculature (over 129 months), p = 0.001. The cumulative probability of success in persistent foetal vasculature and non-persistent foetal vasculature eyes with Ahmed glaucoma valve were, respectively, 37.5% and 88.2% at year 1 and 28.1% and 71.9% at year 5. Cox regression model suggested persistent foetal vasculature as predictive risk factor of time to Ahmed glaucoma valve failure (hazard ratio: 5.77, p = 0.004). Four eyes developed phthisis bulbi. Mean intraocular pressure prior glaucoma surgery was 32.66 +/- 6.73 mmHg and decreased to 16.54 +/- 2.75 mmHg (p < 0.001) at final visit. The most frequent early postoperative complication was severe hypotony (32.6%) which tended to be self-limiting. Vitreous haemorrhage was associated with persistent foetal vasculature (p = 0.024). Ahmed glaucoma valve replacements after complications and additional Ahmed glaucoma valve implantations due to unsatisfactory intraocular pressure were more common in the persistent foetal vasculature group. Conclusion Eyes with persistent foetal vasculature and secondary glaucoma after congenital cataract surgery followed by AGV implantation had a higher number of complications and a decreased probability of success compared to the non-persistent foetal vasculature group. Both groups achieved a significant decrease in intraocular pressure; thus, Ahmed glaucoma valve may be considered as first-line treatment in refractory glaucoma following congenital cataract surgery.