Paediatric Aphakic Glaucoma

Abstract

Aphakic glaucoma is the most common long-term complication seen following congenital cataract surgery. It has a reported incidence of between 15% and 45%. Many risk factors have been identified including microcornea, early surgery, persistent fetal vasculature, congenital rubella syndrome, Lowe syndrome, chronic inflammation and retained lens material. Diagnosis is often difficult as the classic signs of congenital glaucoma such as epiphora, blepharospasm and buphthalmos are usually absent. Additionally, it is also difficult to perform accurate ocular examinations on young children and examination under anaesthesia is usually required. Surgical intervention is often required with medical treatment providing adjunctive therapy. Surgical techniques performed include trabeculectomy with or without antifibrotic agents, glaucoma drainage devices (valved and non-valved), cyclodestructive procedures, goniotomy and trabeculotomy. Trabeculectomy with mitomycin C and glaucoma drainage devices are the two most commonly performed procedures. In spite of considerable advances having been made in the management of aphakic glaucoma, it still poses a significant management dilemma. Despite best standard of care two thirds of aphakic children end up with a mean visual acuity of ≤ 20/400. Figure 1: Child with right congenital glaucoma and buphthalmos. This is in contrast to paediatric aphakic glaucoma which presents without any obvious clinical signs.The mechanism and pathophysiology of glaucoma occurring in aphakes with open angles following congenital cataract surgery is largely not understood. It has been proposed that the defect responsible for producing the cataract may also affect aqueous outflow causing a form of goniodysgenesis [16]. It has also been suggested that 'barotrauma' to the immature angle may cause damage which would be supported by the high incidence of glaucoma in children who have surgery at a young age [17]. Stuctural changes to the angle drainage complex in the 'soft' paediatric eye have also been postulated, and this may possibly be supported by the possibly lower incidence of glaucoma in pseudophakic eyes [3,[18][19][20][21][22][23][24][25][26][27][28]. The role of the vitreous in aphakic glaucoma is not fully Journal of Clinical & Experimental Ophthalmology J o u rn al of Cl in ic a l & Ex perim en ta l O ph thalmo lo g y

Challenges of Secondary Glaucoma Management Following Congenital Cataract Surgery, Penetrating Keratoplasty and Vitreoretinal Surgery

“…Statistically, the incidence of glaucoma is higher in aphakic eyes than in phakic eyes in the pediatric population. Research has presented possible explanations for the apparent protective effect of intraocular lens implantation; however, selection bias may play a pivotal role, as the ophthalmologist is more likely to choose aphakia in a case with glaucoma risk factors and signs [30]. Glaucoma is an important complication of keratoplasty, and aqueous shunts can be an effective option for managing intraocular pressure (IOP) in these cases [31].…”