The longitudinal follow-up of a newly proposed OCTA imaging finding (SSPiM) and the importance of it as a new biomarker for treatment response in diabetic macular edema

Graefes Arch Clin Exp Ophthalmol. 2024 Aug;262(8):2491-2502. doi: 10.1007/s00417-024-06457-2. Epub 2024 Mar 26.

Abstract

Purpose: This study aimed to evaluate the frequency of SSPiM (suspended scattering particles in motion), systemic risk factors, ocular findings, progression characteristics, and treatment response in diabetic retinopathy (DR) patients.

Methods: In this prospective study, a total of 109 eyes of 109 patients with diabetic macular edema (DME) were included. Demographic characteristics and systemic data of the patients were recorded. In addition to a detailed ophthalmological examination, optical coherence tomography (OCT) and OCT angiography (OCTA) imaging were performed. According to the OCTA images, the patients were divided into two categories: SSPiM detected (SSPiM +) and undetected (SSPiM -). The patients were followed up at 0, 3, and 6 months. Treatment responses at 6 months in treatment-administered patients with and without SSPiM were examined.

Results: The frequency of SSPiM in DME cases was found to be 34.9%. No significant correlation was found between SSPiM and demographic characteristics, systemic, and biochemical parameters (p > 0.05). It was observed that SSPIM was most frequently localized in the outer nuclear layer adjacent to the outer plexiform (81.6%). SSPiM appearance disappeared in 7 (19.4%) of 36 patients with SSPiM who had regular follow-up for 6 months. In 4 (11.1%) of these seven patients, hard exudate plaques developed in the areas where SSPiM disappeared. Regarding treatment response at 6 months, the decrease in CMT was statistically significantly lower in the SSPiM group compared to cases without SSPiM.

Conclusion: SSPiM is a finding seen in approximately one-third of DME patients and may adversely affect the response to the treatment.

Keywords: Diabetic macular edema; Hyperreflective fluid; OCT biomarker; OCTA biomarker; Optical coherence tomography angiography; Suspended scattering particles in motion; Treatment resistance.

MeSH terms

  • Aged
  • Angiogenesis Inhibitors* / administration & dosage
  • Angiogenesis Inhibitors* / therapeutic use
  • Biomarkers
  • Diabetic Retinopathy* / diagnosis
  • Disease Progression
  • Female
  • Fluorescein Angiography* / methods
  • Follow-Up Studies
  • Fundus Oculi*
  • Humans
  • Intravitreal Injections*
  • Macula Lutea / diagnostic imaging
  • Macula Lutea / pathology
  • Macular Edema* / diagnosis
  • Macular Edema* / drug therapy
  • Macular Edema* / etiology
  • Male
  • Middle Aged
  • Prospective Studies
  • Time Factors
  • Tomography, Optical Coherence* / methods
  • Visual Acuity*

Substances

  • Angiogenesis Inhibitors
  • Biomarkers