OCT Quantifies Vitreous Cell Density, Grades Posterior Segment Inflammation

Posterior segment inflammation can be graded objectively by using optical coherence tomography (OCT) to determine vitreous cell density, according to research published in the American Journal of Ophthalmology. 

Researchers assessed 61 patients with uveitis (eyes, 74; mean age, 46.8 years; 44% women), analyzing a total of 222 OCT scans. The scans were obtained at 3 separate time points during the disease duration which include active (T0), clinically improving (T1), and resolved (T2) inflammation. Patients underwent visual acuity measurements and vitreous haze haze assessment at each visit. The team calculated vitreous/retinal pigmented epithelium (VIT/RPE)-relative intensity using both manual and automatic measurements and compared measurements obtained via OCT with clinical grading.  

According to the report, vitreous cell density (T0: 4.7 cells/mm²; T1: 1.2 cells/mm²; T2: 0.2 cells/mm²) and VIT/RPE-relative intensity (T0: 0.12; T1: 0.10; T2: 0.08; P <.0001 for both intervals) decreased over the span of clinical visits. Cell density was associated with clinical grades, demonstrating an increase at each grade of the National Eye Institute (NEI) scale. Intraclass correlation coefficient (ICC) between manual and automatic cell density measurements was 0.83 indicating better agreement compared with manual and automatic VIT/RPE measurements (ICC, 0.423). 

Visual acuity improved and vitreous haze reduced as inflammation resolved with participants experiencing a 0.18 logarithm of the minimum angle of resolution (logMAR) improvement and 0.73 haze reduction (0.76 to 0.03) from T0 to T2, respectively (P <.0001 for both). 

“[O]ur study suggests that the vitreous cells density assessed on OCT seems promising and, if additional studies will confirm our results, it could eventually become a good biomarker for objective grading of intraocular inflammation,” according to the study authors.

Study limitations include a retrospective nature, limiting OCT scans to the fovea, and the absence of a control group.

Disclosure: Some study authors declared affiliations with biotech, pharmaceutical, and/or clinical research organizations. Please see the original reference for a full list of authors’ disclosures.