Scleral thicknesses of the posterior and equatorial portions can provide predictive data for central serous chorioretinopathy (CSCR), according to a study published in Retina. The researchers report that in eyes with CSC, the posterior sclera is much thicker than in healthy eyes. High resolution ultrasonography technologies were used to develop the necessary scleral data from both the posterior and equatorial regions.

A current theory on the sclera’s relationship to CSCR appears to be borne out by this research. Investigators reviewed charts of 40 CSCR or peripapillary pachychoroid syndrome patients (79 eyes) at a community-based retina clinic in New York, along with 23 healthy individuals (46 eyes), during a 3-month period. Thirty-one men and 9 women in the case group averaged 58±12 years of age, and 14 men and 9 women in the control set had a mean age of 60.7±8.4 years. 

To establish depth by region, retinal-choroidal thickness with OCT was subtracted from total wall thickness and measured by ultrasonography. Results show mean subfoveal scleral thickness was significantly greater, 1.3 mm, in the case cohort than the control set (0.86 mm, P <.001). Equatorial scleral thickness was similarly deeper for CSCR patients (0.61 mm) than in control individuals, (0.42 mm P <.001). 


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Also, subfoveal choroidal thickness was significantly different between groups (P =.025 OD, P =.029 OS). A new finding of this study involved correlation between equatorial scleral thickness and prediction of subfoveal choroidal thickness (P =.010). 

In multivariate analysis, subfoveal choroidal thickness was a predictor for CSCR (P =.032). Notably, scleral thicknesses strongly and independently predicted the disorder, in posterior (P <.001) and equatorial (P =.001) regions. Adding these variables to the equation revealed age and sex were not significant predictors. Involvement of the 2 scleral regions in pathology of CSCR confirms the “venous overload choroidopathy” theory, which suggests that congestion within the choroid is a mechanism of disease. Investigators speculate that both posterior and equatorial scleral thicknesses contribute, each with their own unique mechanisms.

Axial lengths (ALs) of the 2 groups were comparable (P =.64). AL and scleral thicknesses at each region showed strong similarity between right and left eyes, suggesting a genetic factor for CSCR. These findings may indicate a genetic predisposition that is impacted by phenotype aspects such as stress and sleep interruptions; resulting in a thicker sclera. Men also have thicker sclera than women, which may lead to greater risk.

Corticosteroids create an additional impact. These drugs can increase resistance to aqueous outflow and change trabecular meshwork (TM) morphology. Prior research has also found scleral fibroblasts responded to corticosteroids, not exactly, but similarly to TM cells.

Limiting the analysis was inclusion of patients of somewhat older age, or those with previous photodynamic treatment. Alternately, scleral regions were imaged directly, using high-resolution tools. 

“It may be possible to conceive treatments for CSC that target the sclera,” the publication says.

Disclosures: One study author has declared affiliations with the biotech, pharmaceutical, and medical device industries. Please see the original reference for a full list of disclosures.

Reference

Spaide RF, Fisher YL, Ngo WK, Barbazetto I. Regional scleral thickness as a risk factor for central serous chorioretinopathyRetina.2022;42(7):1231–1237. doi:10.1097/IAE.0000000000003485