Abstract
Purpose: :
To describe retinal morphological and functional changes associated with isolated foveal hypoplasia (IFH) in two brothers.
Methods: :
Morphological documentation: color and red free (RF) retinography, fundus autofluorescence (FAF), spectral-domain optical coherence tomography (sOCT), (RF, FAF and sOCT: HRA Heidelberg Engineering). Functional tests: Full field and multifocal electroretinography (ERG, and mfERG) recorded according to ISCEV standards (Espion E2; Diagnosys LLC), Ishihara color test, visual filed testes (24-2 full threshold: Humpfrey, Zeiss) and microperimetry (MAIA; CenterVue) were performed.
Results: :
Fundus examination reveals typical absence of foveal reflex and depression. FAF shows the absence of normal hypoautofluorescence in the foveal area. Multifocal-ERG showed reduced, but present amplitude density increase in the foveal area. Mean P1 amplitude density was: ring 1: 13.8; ring 2: 10.7; ring 3: 9.7; ring 4: 6.9; and ring 5: 5.2 nV/deg2, and microperimetry revealed a relative stable paracentral fixation with minor reduction of sensitivity thresholds in all 4 eyes.
Conclusions: :
IFH causes foveal pigmentary abnormalities that can be highlighted by AF, but sOCT should be considered crucial evaluation for differentiation of this rare condition and other macular dystrophies, as described before (Querques et al., 2008). Functional changes appear to be related to the reduction of foveal photoreceptor density increase in the fovea, but interestingly, mfERG data indicates that there might be certain photoreceptor density increase at retinal centre, which could be related to the preference for a central fixation position.
Keywords: retina • electrophysiology: clinical