Abstract
Purpose :
Glaucoma associated with Axenfeld Rieger Syndrome (ARS) is often refractory, presents in advanced stage and requires surgical intervention. An in-vivo study of the angle using high definition ASOCT showed some prominent alternate routes of aqueous drainage in these children. Hence this study was conducted to look at routes of aqueous drainage in children with ARS.
Methods :
A cross-sectional single center observational study comparing ARS children with Primary congenital glaucoma (PCG) was conducted. Study population for clinical arm consisted of 32 treated patients of ARS and 28 children with PCG old enough (≥8 years) to cooperate for ASOCT (Spectralis, Heidelberg Inc.). Children (20) formed the control arm. High resolution in vivo ASOCT of ARS subjects was used to assess the angle and the cornea and compared with the PCG arm and the control arm. For histopathology, ARS corneal tissues (5) harvested for keratoplasty were compared with those of PCG (5) and bullous keratopathy corneae (5).
Results :
On ASOCT, ARS eyes displayed severe angle dysgenesis in form of iris adhesions over the TM visible as PAS, membrane over TM (46%) and absent Schlemm's canal (83%) as causes of angle dysgenesis (90%); this was comparable to PCG eyes. Besides this, they showed well-defined intra-corneal dilated cisterns forming discrete communications either with supraciliary aqueous drainage pathway (5/32, 15.6%; figure 1a) or conventional pathway of aqueous drainage (4/32, 12.5%;figure 1b) or both (figure 1c). No such finding was perceived in eyes with PCG or healthy controls. (p<0.001; chi square test) Histo-pathologically, presence of large intracorneal cisterns lined by basement membrane were confirmed in ARS eyes (Figure 2a), which was significantly greater in dimensions compared to those seen in PCG (Figure 2b), PBK (Figure 2c) or controls (p<0.01; Wilcoxon rank sum test).
Conclusions :
Despite the presence of severely distorted angle drainage in ARS, these intracorneal communications with both conventional and unconventional pathways of aqueous drainage could be considered the alternative aqueous drainage pathways in the affected eyes. This could explain why many ARS patients present with glaucoma later in life.
This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually.