Assessing the spatial relationship between fixation and foveal specializations.
Increased cone photoreceptor density, an avascular zone (FAZ), and the displacement of inner retinal neurons to form a pit are distinct features of the human fovea. As the fovea provides the majority of our vision, appreciating how these anatomical specializations are related is important for understanding foveal development, normal visual function, and retinal disease. Here we evaluated the relationship between these specializations and their location relative to the preferred retinal locus of fixation (PRL). We measured foveal pit volume, FAZ area, peak cone density, and location of the PRL in 22 subjects with normal vision using optical coherence tomography and adaptive optics scanning light ophthalmoscopy. Foveal pit volume was positively correlated with FAZ area; however, peak cone density was not correlated with pit volume. In addition, there was no systematic offset of the location of any of these specializations relative to PRL, and there was no correlation between the magnitude of the offset from PRL and the corresponding foveal specialization measurements (pit volume, FAZ area, peak cone density). The standard deviation of our PRL measurements was consistent with previous measurements of fixational stability. These data provide insight into the sequence of events during foveal development and may have implications for visual function and retinal disease.
Department of Cell Biology, Neurobiology, & Anatomy, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226, USA. Electronic address: mwilk@mcw.edu.
Melissa A
MA
Wilk
Department of Cell Biology, Neurobiology, & Anatomy, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226, USA. Electronic address: a.dubis@ucl.ac.uk.
Adam M
AM
Dubis
Department of Biomedical Engineering, Marquette University, 1250 W Wisconsin Avenue, Milwaukee, WI 53233, USA. Electronic address: rfcooper@sas.upenn.edu.
Robert F
RF
Cooper
Department of Ophthalmology, Medical College of Wisconsin, 925 N. 87th Street, Milwaukee, WI 53226, USA. Electronic address: psummer@mcw.edu.
Phyllis
P
Summerfelt
Department of Cell Biology, Neurobiology, & Anatomy, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226, USA; Department of Biomedical Engineering, Marquette University, 1250 W Wisconsin Avenue, Milwaukee, WI 53233, USA; Department of Ophthalmology, Medical College of Wisconsin, 925 N. 87th Street, Milwaukee, WI 53226, USA; Department of Biophysics, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226, USA. Electronic address: adubra@mcw.edu.
Alfredo
A
Dubra
Department of Cell Biology, Neurobiology, & Anatomy, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226, USA; Department of Biomedical Engineering, Marquette University, 1250 W Wisconsin Avenue, Milwaukee, WI 53233, USA; Department of Ophthalmology, Medical College of Wisconsin, 925 N. 87th Street, Milwaukee, WI 53226, USA; Department of Biophysics, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226, USA. Electronic address: jcarroll@mcw.edu.
Joseph
J
Carroll
D000293:Adolescent; D000328:Adult; D000368:Aged; D002452:Cell Count; D005260:Female; D005403:Fixation, Ocular / Q000502:physiology*; D005584:Fovea Centralis / Q000166:cytology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009887:Ophthalmoscopy; D017949:Retinal Cone Photoreceptor Cells / Q000166:cytology* / Q000502:physiology; D041623:Tomography, Optical Coherence; D014792:Visual Acuity; D055815:Young Adult
Cone density; Fixation; Foveal avascular zone; Foveal morphology; Foveal pit