Subthreshold micropulse laser for retinal pigment epithelium detachment: subtype-stratified outcomes and predictors...

Pigment epithelium detachment (PED) arising from various macular diseases can significantly impair visual function. Although subthreshold micropulse laser treatment (SMLT) shows promise for PED, comparative data across subtypes and factors influencing outcomes remain limited.

We included patients with visually significant macular PED who underwent SMLT between January 2017 and April 2023. Visual acuity and PED dimensions were recorded at baseline and follow-up. PEDs were classified as serous (sPED), drusenoid (dPED), or polypoidal (pPED) using fluorescein fundus angiography/indocyanine green angiography and optical coherence tomography. Within-group changes were assessed using paired t-tests (or Wilcoxon signed-rank tests where appropriate), and a linear regression analysis was used to identify prognostic factors.

Forty-two patients (42 eyes; mean age 60.90 years; 59.5% male patients) were included: 27 with sPED, 10 with dPED, and 5 with pPED. Patients with sPED were significantly younger (mean 53.00 years) than those with dPED (77.20) and those with pPED (71.00; P < 0.001). Overall, BCVA improved modestly after SMLT (mean -0.07 LogMAR; P = 0.046), although no individual subgroup reached significance. Significant PED area reduction was observed only in sPED (P = 0.043). Baseline BCVA was the strongest independent predictor of both BCVA improvement (β = -0.288, P = 0.001) and PED area reduction (β = -627,865, P = 0.004). Multiple SMLT sessions were often required for sPED, whereas 60.0% of pPED eyes needed adjunctive anti-VEGF therapy.

SMLT was associated with modest visual and anatomic improvements, with statistically significant PED area reduction observed only in sPED eyes; the absence of a control arm limits causal inference. Baseline BCVA was the strongest predictor of outcomes. Larger controlled studies are needed to establish the efficacy of SMLT across PED subtypes.