A recent study published in Ophthalmology evaluated the surgical outcomes and risk factors for failure in surgeries for childhood glaucoma.
Give me some background.
Childhood glaucoma is a group of diverse diseases characterized by elevated intraocular pressure (IOP) and pathological ocular changes that—if not treated properly—can lead to irreversible vision loss.
- Of note: Childhood glaucoma is an avoidable cause of vision loss in pediatric patients, responsible for 3% of childhood blindness in the United States.
Surgery is often the first-line treatment, since medications are often ineffective and poorly tolerated in pediatric patients.
- However: Data on surgical outcomes is limited due to the small sample sizes and low prevalence of this disease.
Now talk about the study.
In this retrospective cohort study, investigators used the American Academy of Ophthalmology’s (AAO) Intelligent Research in Sight (IRIS) Registry to analyze demographic and clinical data of patients under 18 years old who underwent glaucoma-related procedures between Jan. 1, 2013 and Dec. 31, 2019.
- Quick refresher: The IRIS Registry is a large, comprehensive eye disease clinical registry that includes nearly 24% of the U.S. population, making it an optimal dataset to investigate the treatment outcomes of rare diseases.
Failure was defined as having any of the following:
- Intraocular pressure (IOP) > 21 mmHg
- IOP reduction < 20% of baseline
- IOP < 5 mmHg
- Any additional IOP-lowering procedure
- Loss of light perception
- Removal of eye or chemodenervation
- Diagnosis of phthisis bulbi
Primary and secondary outcome measures: The proportion of eyes that failed for glaucoma-related surgical procedures and factors associated with failure, respectively.
Findings?
In total, 2,380 eyes were included in the analysis and failure was recorded in 1,081 eyes (45.4%) at a mean of 9.1 months.
Factors associated with a higher likelihood of failure were:
- Younger age (hazard ratio [HR]: 1.12, 95% confidence interval [CI]: 1.06-1.18, per 5 years)
- Higher IOP on the index date (HR: 1.10, 95% CI: 1.08-1.12, per 3 mmHg)
- Worse visual acuity (VA) on the index date (HR: 1.33, 95% CI: 1.23-1.44, per 1 unit higher logMAR)
- Concurrent uveitis (HR: 1.41, 95% CI: 1.16-1.71)
- More glaucoma medications on the index date (HR: 1.18, 95% CI: 1.14-1.22, per 1 medication)
- Systemic IOP-lowering medication (HR: 1.71, 95% CI: 1.44-2.03)
- Complication of hyphema (HR: 13.5, 95% CI 5.03-36.46)
Anything else?
Compared to ab interno angle-incision surgery, the following procedures were associated with higher failure rates:
- Iris-based surgery (HR: 2.26, 95% CI: 1.64-3.12)
- Iris-based laser (HR: 1.94, 95% CI:1.50-2.50)
- Trabecular/angle-based implants (HR: 3.83, 95% CI: 2.00-7.33)
One or more reoperations were required in almost 18% of eyes, and the 3-year failure rates of angle surgery were 34.5% and 39.2% for primary congenital glaucoma (PCG) and juvenile open-angle glaucoma (JOAG), respectively.
Moreover: A higher proportion of eyes with poor vision were:
- Aphakic
- Used more intense medication
- Had ocular comorbidities
Take home.
These findings demonstrate that surgical failure was common in 45% of all cases among first-recorded procedures performed for childhood glaucoma.
The following factors were predictors for failure:
- Younger age
- Higher IOP at index
- Worse VA at index
- Concurrent uveitis
- More intense preceding medication
Next steps?
In the future, “studies focused on a larger cohort of infantile glaucoma patients (via dedicated clinical registries) may address the knowledge gaps on the outcomes and cost-effectiveness of glaucoma surgery performed on these patients,” the study authors explained.