In a recent study published in Vision, researchers investigated the prevalence and risk factors linked to visible optic disc lamina cribrosa pores (LCPs) in a large cohort of individuals with African ancestry.
Give me some background first.
Primary open-angle glaucoma (POAG) is the most common form of glaucoma and disproportionately affects individuals of African ancestry.
These individuals are:
- Four to five times more likely to have POAG
- 15 times more likely to experience vision loss from glaucoma compared to European Americans
Now, talk about the study.
This study included 1,551 patients (2,943 eyes) aged 35+. Investigators analyzed participants identified during clinical visits to:
- Scheie Eye Institute
- Perelman Center for Advanced Medicine
- Philadelphia Veteran Affairs (VA) Medical Center
- Mercy Fitzgerald Hospital
- Two neighboring ophthalmology clinics in Philadelphia
Who was included in the study?
Participants self-identified as:
- Black African ancestry
- Afro-Caribbean
- African American
Participants were categorized as:
- Glaucoma case
- Glaucoma suspect
- Control
How was the study conducted?
At enrollment, participants were interviewed and underwent an ophthalmic examination.
The interviews gathered information about participants that included:
- Demographic information
- Lifestyle information
- Family-related and past medical history
Note: Family-related and past medical history were also collected from patient medical records.
Findings?
The researchers found that LCPs were associated with:
- Greater degrees of optic disc cupping
- Higher proportions of African ancestry
And the data?
During their multivariable analysis of 1,187 glaucomatous eyes, the researchers discovered that LCPs were more likely to be present in eyes with:
- Cup-to-disc ratios (CDR) of ≥0.9
- Adjusted risk ratio (aRR) 1.11, 95%, Confidence interval (CI): 1.04–1.19(p = 0.005)
- Cylindrical-shaped cups
- aRR 1.22, 95%, CI: 1.11–1.33
- Bean pot-shaped cups
- aRR 1.24, 95%, CI: 1.13–1.36
When compared to:
- Conical cups
- The nasalization of the central retinal vessels (aRR: 1.33)
- Moderate cup depth (aRR: 1.24) and deep cups (aRR: 1.27) vs shallow cups
Limitations?
The study authors noted there was variability in the treatment status and types among the patient cases, which could have affected associations between LCPs and variables such as intraocular pressure (IOP).
They also mentioned that the grading of cup features is subjective, making it less reliable than objective processes.
What else?
Additionally, the authors did not assess features such as eye length or other refractive measures, which they stated may have affected LCPs visibility and grader evaluation.
Further, they noted many of the early images collected from the 90-day range of participants’ first screening date did not include corresponding phenotypic data, and much of the data was tagged as missing.
Go on …
The authors added lamina cribrosa (LC) morphology continued to change, especially in eyes with glaucoma, as deformation and remodeling of the neural and connective tissues of the optic nerve head occurred.
Due to this, the cross-sectional nature of the study limited their analysis. They cited that this cross-sectional nature also prevented the ability to determine causality in terms of their significant associations.
Lastly, it was noted that the study may be limited in generalizability, as it lacked a variety of ethnic groups to create comparisons.
Expert opinion?
The authors concluded that their results, “should inform those who manage patients with glaucoma, encouraging them to carefully follow patients who manifest LCPs in order to allow for timely treatment to prevent progression of the disease.”
Take home.
These findings suggest visible LCPs may be a potential risk factor when identifying severe disease and could signal to practitioners that a patient requires further monitoring.