To the Editor:
I read with interest the article entitled “Management of Primary Angle-Closure Glaucoma” (PACG).1 The article was a thorough yet concise protocol for the management of PACG, organized in a manner that is relevant to clinicians managing such cases. I am in agreement with the following key messages conveyed by the authors: (1) offer a peripheral laser iridotomy for all PACG patients and argon laser peripheral iridoplasty if plateau iris configuration is present; (2) if early peripheral anterior synechiaes are present, goniosynechialysis (GSL) combined with cataract extraction may mechanically reopen the drainage angle but for long-standing cases with trabecular meshwork damage, the effect of GSL may be limited; and (3) in such cases, a trabeculectomy may be required for pressure reduction.
Over the years, researchers from Hong Kong and Singapore have contributed significantly to the literature on PACG, providing us with more evidence-based management. We have learned that cataract extraction lowers intraocular pressure (IOP), but having a higher IOP and using more antiglaucoma medications preoperatively may hinder the IOP-lowering response of cataract extraction in PACG eyes.2
Diagnostic tools have also been enhanced from traditional gonioscopy and dark-room prone position test to 3-dimensional anterior segment optical coherence tomography. Despite these technologies, the diagnosis of PACG may not be as clear in some clinical scenarios, such as those with angle-closure configuration and glaucomatous optic neuropathy but normal IOP as measured during clinic hours. Perhaps future research involving 24-hour IOP monitoring may help differentiate among the following possible distinctions: (1) normal-tension glaucoma with subsequent age-related angle narrowing, (2) intermittent angle closure with glaucomatous optic neuropathy, or (3) PACG in evolution with high IOP occurring outside of clinic hours.
In addition, as early cataract extraction becomes a more widely accepted treatment of PACG, research into the role of minimally invasive ab interno surgeries may offer new modalities to bypass the diseased trabecular meshwork after mechanically reopening the angles with cataract extraction and/or GSL.3
Jacky W. Y. Lee, FRCSEd
Dennis Lam & Partners Eye Center
E-mail: [email protected]
1. Lai J, Choy BN, Shum JW. Management of primary angle-closure glaucoma. Asia Pac J Ophthalmol (Phila)
. 2016; 5: 59–62.
2. Tham CC, Leung DY, Kwong YY, et al. Factors correlating with failure to control intraocular pressure in primary angle-closure glaucoma eyes with coexisting cataract treated by phacoemulsification or combined phacotrabeculectomy. Asia Pac J Ophthalmol (Phila)
. 2015; 4: 56–59.
3. Lai JS. The role of goniosynechialysis in the management of chronic angle-closure glaucoma. Asia Pac J Ophthalmol (Phila)
. 2013; 2: 277–278.