Pain Indicates Neurological Function, Better Outcomes Following Cyclophotocoagulation

ophthalmologist checking patient's eye while Covid19 spread-stock photo
Thai Myopia child checking his eye test besides the optician at the hospital, Bangkok Thailand
Researchers encourage early intervention in treating children with microbial keratitis and advise clinicians to exercise caution in using cyclophotocoagulation for pediatric patients.

The absence of pain at microbial keratitis (MK) presentation is negatively associated with resolution following cyclophotocoagulation (CPC), according to research published in the Journal of the American Association for Pediatric Ophthalmology and Strabismus.

Researchers retroscopically reviewed the medical histories of 312 patients with childhood glaucoma (CG) who underwent CPC at a single center between 2014 and 2020. They found that MK developed in 37 eyes of 33 children following CPC (mean age 11±5 years, 51% girls). MK incidence was 1.8% (95% CI, 0.3-3.2) and the median time between the procedure and MK development was 4 years.

Following MK treatment, visual acuity was worse than 20/400 to light perception in 27 eyes and 20/200 or better in 6 eyes. The remaining eyes had no light perception (n=2) or visual acuity between 20/200 and 20/400 (n=2). Approximately half of all eyes required 2 CPC procedures and 4 eyes needed 3 CPC treatments.

The researchers found that 20 eyes did not report pain at MK onset. MK resolved in 17 eyes following treatment while 8 eyes either underwent evisceration or experienced phthisis. Keratoplasty failed in 6 eyes. Eyes without pain at presentation of MK had significantly lower odds (OR, 5.0; 95% CI, 1.1-23.8; P =.04) of gaining resolution.

The team determined that pain at presentation was associated with resolution of MK after management.

“Nerve abnormalities may be caused by corneal disease, and conversely, nerve pathology can contribute to corneal pathology,” according to the investigators. “The relationship between pain and the host’s immune system is critical for the eye’s health. The absence of pain in much of our cohort could suggest corneal nerve damage.”

Limitations of the study included a one-armed cohort, small sample size, and lack of objective methods to evaluate corneal anesthesia following CPC.


Sesma G, Ahmad K, AlBakri A, et al. Incidence and outcomes of microbial keratitis after cyclophotocoagulation to treat childhood refractory glaucoma. J AAPOS. Published online May 4, 2022. doi:10.1016/j.jaapos.2022.01.009