Purpose:
To use ultrahigh resolution optical coherence tomography (UHROCT) systems to further evaluate patients complaining of small, discrete central scotomas or focal areas of metamorphopsia with both unremarkable clinical ocular examinations and initial ancillary testing.
Methods:
Twenty-nine patients were selected and imaged based on their visual complaints of a scotoma or focal area of metamorphopsia and initially normal ancillary testing, which could include StratusOCT, fluorescein angiography, visual fields and multifocal ERG. Patients were imaged using prototype or commercially available UHROCT systems capable of axial image resolution between 3.5um to 5um and scan speeds of ~26,000 A scans/second. Each image from the macular cube protocol was qualitatively analyzed for retinal defects especially in the area corresponding to the visual disturbance.
Results:
In seven eyes from seven patients, UHROCT demonstrateddistinct photoreceptor inner/outer segment hyporeflective defects in the fovea.All defects were located between the external limiting membrane and retinalpigment epithelium. The average measured defect width was 76.4um. Follow-up UHROCT in two patients did not show progression of their defects.
Conclusions:
Using higher resolution and faster scanning OCT systems, outersegment retinal defects are found in patients with small, discrete central scotomas or focal areas of metamorphopsia and otherwise unremarkable exam findings. The etiology of these defects is uncertain, though posterior vitreous detachments or retinal microinfarcts could be possible explanations. The diagnosis of these defects allows the clinician to avoid costly, extensive investigations and to reassure patients of the benign, non-progressive nature of their findings.
Keywords: macula/fovea • photoreceptors • imaging/image analysis: clinical