Visual acuity and central retinal thickness: fulfilment of retreatment criteria for recurrent neovascular AMD in routine clinical care

BACKGROUND: To evaluate the fulfillment of retreatment criteria in recurrent neovascular age-related macular degeneration (nAMD) for a pro-re-nata treatment regime with ranibizumab in routine clinical care. METHODS: Data from patients with treatment-naive nAMD were analysed retrospectively. As an 'upload', all patients had received three-monthly intravitreal ranibizumab injections in a university eye hospital and were then seen by ophthalmologists in private practice who referred them back in case of recurrence. Recurrence was defined as a decrease of visual acuity (VA) of one line or more (functional retreatment criteria), a central retinal thickness (CRT) increase of at least 100 µm upon Optical Coherence Tomography (OCT) examination (morphological retreatment criteria) or a new macular haemorrhage (clinical retreatment criteria). RESULTS: We included 92 patients (36 men and 56 women). The mean VA before retreatment of a recurrence was -0.63 ± 0.33 logMAR and improved significantly (p<0.001) by 0.10 ± 0.16 logMAR to -0.53 ± 0.28 logMAR thereafter. Mean CRT before retreatment was 278.07 ± 87.56 µm and decreased significantly (p<0.001) by 71.22 ± 106.93 to 206.85 ± 60.30 µm. Evaluation of the fulfillment of retreatment criteria revealed functional retreatment criteria in 82.6% of patients. However, upon re-evaluation of VA using Early Treatment Diabetic Retinopathy Study (ETDRS) charts in the treatment centre, mean decrease of VA was 10 letters as compared with the end of upload therapy. All patients presented an increased CRT when treated for recurrence of nAMD (mean increase 69.47 µm), but the morphological retreatment criteria (CRT increase of 100 µm or more) were fulfilled in only 44.4% of patients upon Spectral Domain OCT (SD-OCT) evaluation in the treatment centre. CONCLUSIONS: In a routine clinical care, evaluation of VA using ETDRS charts seems to be more sensitive than Snellen VA testing. Quantitative OCT-based retreatment criteria (eg, increase of CRT of 100 µm or more) appear to be not sensitive enough in a clinical setting with referring ophthalmologists.