[Importance of the Watzke-Allen test in diagnostics and staging of macular holes]

The Watzke-Allen test (WAT) is a simple diagnostic tool designed for the diagnosis of full thickness macular holes (FTMH) but due to the rapid progress of imaging diagnostics it was replaced by spectral domain optical coherence tomography (SD-OCT) of macular pathologies. The aim of this study was to examine if the WAT is able to distinguish between the different FTMH stages.

In 57 eyes of 57 patients with clinical evidance of FTMH, the WAT was first performed followed by SD-OCT examination and a distinction was made between a negative (slit beam normal) and a positive sign (slit beam modified as groove and hourglass configuration or completely broken).

In 49 out of 57 patients the WAT was positive (hourglass 46 patients and broken 3 patients). Based on the SD-OCT results the following diagnoses were made: lamellar macular holes (LMH, 3 patients), vitreomacular traction (VMT, 4 patients), small macular hole (≤ 250 µm,  5 patients), medium sized macular hole (250-400 µm, 11 patients) and large macular hole (≥ 400 µm,  34 patients). In 91 % of the patients with medium and large FTMH, the WAT was positive, whereas the WAT was positive in only 67 % of patients with small FTMH, VMT and LMH. The sensitivity for large and medium FTMH was 93 % but the specificity was only 33 %.

The WAT was positive in a high percentage of patients with large and medium sized macular holes as well as patients with small macular holes and LMH. The sensitivity of certain indications for treatment was 93 % but the specificity was only 33 %; therefore, the WAT alone is not suitable for a certain preoperative differentiation of macular alterations.