Primary angle-closure glaucoma (PACG) is a common cause of permanent vision loss worldwide.1 The primary risk factor for PACG is closure of the anterior chamber angle, which leads to impaired aqueous humor outflow and elevated intraocular pressure (IOP). Phacoemulsification alleviates angle closure and provides more robust IOP lowering in cases of PACG than primary open-angle glaucoma (POAG). Therefore, phacoemulsification alone is a viable alternative to combined phacotrabeculectomy for up to two years in eyes with visually significant cataracts.2,3 However, little is known about the differences in longterm outcomes between these two treatments for PACG.
This study by Hansapinya et al. is a follow-up to two randomized control studies comparing the outcomes of medically controlled and uncontrolled cases of PACG treated with phacoemulsification or combined phacotrabeculectomy.2,3 The authors report that phacotrabeculectomy produces greater reduction of IOP and drop dependence but also greater numbers of post-operative complications after five years, similar to previous findings after two years. Interestingly, fewer than 20% of patients in the phacoemulsification group required trabeculectomy after five years, which suggests that phacoemulsification alone provides adequate long-term IOP lowering in most cases of PACG. However, it is also important to recognize that despite treatment, mean deviation (MD) on automated perimetry worsened on average in both groups, although this was not statistically significant due to limited visual field data at the five-year mark.
While this study provides valuable insight into long-term outcomes associated with phacoemulsification and phacotrabeculectomy in patients with PACG, it raises other questions. Patients with controlled PACG responded better to phacotrabeculectomy than phacoemulsification. What is the physiologic basis for this observation? Also, a wide range of IOP lowering was seen in both treatment groups. Are there clinical or biometric parameters that predict better response to one form of treatment over another? These questions present the logical next step in efforts to optimize and personalize clinical care of patients with PACG.