Pigment Epithelial Detachment Volume Predicts Conbercept Visual Gains for Some

Measuring pigment epithelial detachment volume with OCT can help determine if conbercept will be effective in patients with nonpolypoidal choroidal vasculopathy.

Pigment epithelial detachment volume (PEDV) at baseline is negatively correlated with short and long-term best-corrected visual acuity (BCVA) gains in patients with nonpolypoidal choroidal vasculopathy, according to a study published in BMC Ophthalmology. In the future, pigment epithelial detachment parameters may be recognized automatically by an artificial intelligence system and may provide as an output the predicted visual acuity, the authors speculate. 

This retrospective study included 159 eyes of 159 patients with neovascular age-related macular degeneration (nAMD). All patients were managed with injections of conbercept and a 12 months of follow up, between March 2017 and July 2019. 

Patients were classified into 2 groups: those with polypoidal choroidal vasculopathy (n=77) and those with nonpolypoidal choroidal vasculopathy (n=82). The researchers used optical coherence tomography (OCT) to assess the eyes for pigment epithelial detachment volume, height, width, and type (serous, fibrovascular, drusenoid, or hemorrhagic) and any possible correlation with visual gain at 3 and 12 months.

With the popularity and development of artificial intelligence (AI), radiomics and other methods, we can work on a predictive model where the parameters of PED are automatically identified by inputting OCT images, and thus output the predicted visual acuity in the future research.

The OCT evaluations also determined intraretinal cystoid fluid (IRC), subretinal fluid (SRF), and vitreomacular adhesion (VMA). 

Among the eyes in the nonpolypoidal group, 59 eyes had SRF, 28 eyes had IRC, 45 eyes had pigment epithelial detachment, and 20 eyes had VMA. They underwent a mean total injections of 4.43±2.29. 

Among the patients in the polypoidal group, SRF was found in 65 eyes, IRC in 18, pigment epithelial detachment in 59, and VMA in 17. They underwent 5.71±1.90 mean total injections.

For eyes of both groups, the presence of SRF or VMA was not found to correlate with baseline BCVA, or BCVA gain at 3 or 12 months. The presence of IRC was negatively correlated with baseline BCVA but not with BCVA gain at 3 or 12 months. The presence of pigment epithelial detachment was negatively correlated only with BCVA gain at 12 months. However, pigment epithelial detachment type was not found to correlate with BCVA gain. Pigment epithelial detachment type “may predict morphologic prognosis but not functional prognosis,” according to the researchers. 

The authors did not find a correlation between pigment epithelial detachment height and visual gains in either group. Among the nonpolypoidal group, pigment epithelial detachment width was negatively correlated with BCVA gain at 12 months (r=-0.305, P =.044), and pigment epithelial detachment volume was negatively correlated with both visual gain at 3 months (r=-0.329, P =.027) and 12 month (r=-0.312, P =.037). 

The researchers explain that these findings indicate pigment epithelial detachment volume at baseline can help predict BCVA gains at 3 and 12 months in patients with nonpolypodial choroidal vasculopathy. The study authors speculate that this could be due to the association of PED with choroidal neovascularization (CNV), where larger CNV is associated with poorer prognosis for vision. Pigment epithelial detachment volume also better reflects the scope and extent of the lesion, according to the researchers. 

“With the popularity and development of artificial intelligence (AI), radiomics and other methods, we can work on a predictive model where the parameters of PED are automatically identified by inputting OCT images, and thus output the predicted visual acuity in the future research,” the study authors report. “This will provide us with a basis for treatment and provide patients with highly reliable prediction results.”

The limitations of this study include its retrospective nature, incomplete coverage of the entire retinal tissue by the relatively spaced OCT raster scan, and the necessity of manual corrections during the volume calculation process.

References:

Shu Y, Ye F, Liu H, Wei J, Sun X. Predictive value of pigment epithelial detachment markers for visual acuity outcomes in neovascular age-related macular degeneration. BMC Ophthalmol. 2023;23(1):83. Published online: March 3, 2023. doi:10.1186/s12886-023-02797-5