OCT Biomarkers Predicts Treatment Response in Uveitic Macular Edema

A correlation exists between patients’ best corrected visual acuities (BCVA) and an optical coherence tomography (OCT) scan in cases of macular edema secondary to noninfectious uveitis (NIU), according to an investigation published in the American Journal of Ophthalmology. The findings suggest that pretreatment ellipsoid zone integrity, central subfield cystoid spaces, and subretinal fluid (SRF) can help predict a response to treatment with an investigational formation of triamcinolone acetonide (TA).

The investigators conducted the post-hoc correlation and longitudinal treatment analyses of 2 clinical trials, PEACHTREE (ClinicalTrials.gov Identifiers: NCT02595398)  and AZALEA (ClinicalTrials.gov Identifier: NCT03097315), to assess the relationship between BCVA and central subfield OCT features in noninfectious uveitis-related macular edema, a condition with limited anatomic and temporal biomarkers.  

A total of 198 patients with noninfectious uveitis participated in the clinical trials (PEACHTREE, n=160; AZALEA, n=38); 87% had macular edema at baseline. Overall, 134 received TA via suprachoroidal injection and 64 received sham treatment (control). Rescue therapy was administered to 12.9% of the TA group and 72% of the control group.

The researchers found that the mean BCVA was greatest in eyes with a normal baseline ellipsoid zone. It progressively worsened as ellipsoid zone integrity deteriorated to an abnormal status. They also observed that eyes with normal ellipsoid zone status at baseline experienced greater 24-week change in BCVA compared with eyes with an ellipsoid zone considered abnormal by the reading center (11.9 vs 9.4 letters; P =.006). 

The team also found that eyes without central subfield cystoid spaces or central subfield subretinal fluid, or both, at baseline showed less change within 24 weeks than eyes with these findings (without vs with: central subfield cystoid spaces 5.5 vs 13.7 letters; P =.012; central subfield subretinal fluid, 9.5 vs 17.2 letters; P <.001).

Researchers found that, for eyes treated withTA, patients experienced 90% of maximal improvement in central subfield thickness was reached at 3 weeks and in best-corrected visual acuity was reached at 9 weeks. They also demonstrated that eyes with noninfectious uveitis-related macular edema that showed an early response to CLS-TA treatment (central subfield thickness reduction of ≥ 50 μm at 4 weeks) had a greater 24-week change in best-corrected visual acuity than eyes without an early response (14.6 vs 6.5 letters; P =.006).

Limitations of the study included the post-hoc design, lack of specific entry criteria for some anatomical outcomes in the clinical trials, and use of categorical grading rather than continuous measures of central subfield anatomic features.

Disclosure: This research was supported by Clearside Biomedical. Please see the original reference for a full list of disclosures.

Reference

Ciulla TA, Kapik B, Barakat MR, et al. OCT anatomic and temporal biomarkers in uveitic macular edema. Am J Ophthalmol. 2021;0(0). doi:10.1016/J.AJO.2021.10.024