Long-Term Persistence of the LAPPEL Sign After Treatment in Pediatric Familial Exudative Vitreoretinopathy: A Three-Year Follow-Up

To describe the long-term clinical course of persistent Late-phase Angiographic Peripheral or Posterior Pole Leakage (LAPPEL) sign in a child with familial exudative vitreoretinopathy (FEVR) and highlight its potential significance as a marker of ongoing retinal vascular activity. Observational case report. A 4.5-year-old boy presented with bilateral optic disc edema, retinal vascular tortuosity, papillomacular intraretinal fluid, and temporal peripheral avascular retina. Wide-field fluorescein angiography demonstrated bilateral fern-like late-phase leakage involving the peripheral retina and posterior pole, consistent with the LAPPEL sign, together with optic disc leakage. The patient was diagnosed with stage 2B FEVR and underwent peripheral laser photocoagulation, cryotherapy, and intravitreal bevacizumab. Macular edema and optic disc swelling improved substantially, with final visual acuity of 20/20 in the right eye and stable 20/63 in the left eye. However, serial ultra-widefield fluorescein angiography over a three-year follow-up demonstrated persistent bilateral LAPPEL positivity despite marked anatomical improvement. Genetic testing did not identify pathogenic variants in currently recognized FEVR-associated genes. Persistent LAPPEL positivity despite resolution of exudative manifestations may reflect chronic retinal vascular dysfunction rather than transient exudative activity alone. This observation highlights the potential value of ultra-widefield fluorescein angiography in long-term FEVR monitoring. However, whether persistent LAPPEL positivity predicts disease progression or warrants additional treatment remains uncertain.