LAUSR

© BMJ Publishing Group Limited 2023. No commercial reuse. See rights and permissions. Published by BMJ. DESCRIPTION A young female patient in her early 30s presented with a circumscribed hypopigmented macular lesion and hyperpigmented foveal scar in the right eye (OD) (figure 1A) better appreciated on fundus autofluorescence (figure 1B). She had been referred with a diagnosis of cystoid macular oedema OD and had received posterior subtenon injection of triamcinolone from another eye centre but with no visual improvement. The welldefined circumscribed morphology of the macular lesion raised a strong clinical suspicion of it being a sequela of optic disc pit maculopathy. However, repeated and careful examination of the fundus images, including a 30° image of the optic disc (obtained using the Zeiss 450 plus fundus camera) did not reveal an optic disc pit (figure 1C). Initial spectraldomain optical coherence tomography (OCT) through the optic nerve head (ONH) using 48 radii scan (Spectralis by Heidelberg) also failed to reveal the optic pit and depicted only a few cavitations along temporal slope of ONH (figure 2A,B). Owing to the strong suspicion, a repeat OCT scan, this time in the raster mode with 0.5 mm separation between the scanning lines, was undertaken. It was only after this that a breach in the membrane over ONH was revealed, confirming the presence of occult disc pit (figure 2C,D). The minimal separation that can be obtained using the radial scan with the Spectralis OCT is 7.5° (with 48 radial lines) and as seen in our patient, it is possible to overlook small lesions with this degree of separation. Hence, we herein highlight that a dense raster scan through the optic disc has a higher potential of identifying the lesion and must be employed in all cases with high suspicion of occult disc pit. Circular OCT scan centred on the optic disc is also a sensitive method of detecting occult disc pit. It can detect marked reduction in the retinal nerve fibre layer thickness consistent with the location of the optic pit.