Imaging and Functional Measurements of the Living Human Eye
Frederick W. Fitzke, Ph.D.
Professor of Visual Optics and Psychophysics
BackgroundThe Laboratory of Physiological Optics research covers two broad areas
These non-invasive methods are used to understand properties of human vision and how these are affected by well-defined ocular anomalies. The major clinical conditions under study are retinitis pigmentosa, age-related macular degeneration, and glaucoma.
- the development of novel techniques for imaging the eye and
- investigations of visual function using psychophysical methods.
Area of Research
Several novel methods of imaging have made visible elements of the living human eye which until recently have only been seen in post mortem eyes. We have modified a prototype confocal Laser Scanning Ophthalmoscope to provide high magnification images of the photoreceptor mosaic in the living human eye.
The sponge-like structure of the lamina cribrosa through which all the nerve fibres leave the eye to reach the brain can be seen with sufficient quality to provide quantitative image analysis.
Autofluorescence imaging of the retinal pigment epithelium arising from the age pigment, lipofuscin, reveals its distribution in the normal eye and ocular abnormalities.
Approximately ten times improved depth resolution has been achieved with the new prototype Ocular Coherence Tomography-based imaging device. This high resolution instrument provides images at different depths within the retina which approaches some of the structural details normally seen only with the microscope.
Psychophysical investigations have shown characteristic changes in visual function associated with the structural changes revealed in the imaging studies. The depth plane of best visual acuity was found to correspond to the depth plane of the cone photoreceptor mosaic. Abnormal elongation of the pores of the lamina cribrosa is associated with visual loss in the corresponding part of the visual field. Quantitative autofluorescence imaging reveals a relation between abnormal levels and rod and cone photoreceptor dysfunction.
The combination of imaging and functional studies in the living human eye allows us to further our understanding of the underlying causes of visual loss and the effects of interventions.
New methods of detecting loss of visual field and acuity have been developed. These rely on quantitative analysis techniques combined with presentation of complex data to allow earlier detection of visual field loss.
The manner in which different abnormalities of vision affect specific aspects of visual function are being investigated. For example conventional visual acuity tests may reveal little loss of function despite severe degradation of vision. This leads to the need for new tests of visual function which can more completely describe function.
Specific abnormalities of magnocellular and parvocellular function in glaucoma are being studied to further our understanding of these processes. The use of motion detection perimetry has revealed abnormalities of visual function which precede conventional perimetric losses.
Members of the Laboratory
Postdoctoral Research Fellow
Clinical Measurement Technician
V. LuongOCT Imaging Technician
Honorary Research Fellow
Dr G.M Verdon-Roe
Recent Postdoctoral Fellow
Dr. D Crabb
Recent Past Students
PhD (joint with Prof. J. Marshall) L. Culham 1995
PhD (MRC Studentship) A Wade 1998
PhD (Joint with Prof PT Khaw) 2003 A Kotecha
MD (Joint with Mr RA Hitchings and Prof S Lightman) A McNaught 1997
MD (Joint with Mr RA Hitchings) M Westcott 1999
MD (Joint with Mr RA Hitchings) A Viswanathan
MSc (Joint with Mr M Miller and Prof. M. Morgan) G Verdon-Roe 1995
PhD (Joint with Mr DF Garway Heath) G Verdon-Roe 2006
Recent Past Members of the Laboratory
See publications list for details of collaborators in this work.
This page last modified
11 June, 2007
by David Daniel
- Crabb-DP, Fitzke-FW, McNaught-AI, Edgar-DE,Hitchings-RA. Improving the prediction of visual field progression in glaucoma using spatial processing. Ophthalmology 104:517-524 (1997)
- Bhandari-A, Fontana-L, Fitzke-FW, Hitchings-RA Quantitative Analysis of the lamina cribrosa in vivo using a scanning laser ophthalmoscope. Curr Eye Res 16:1-8 (1997)
- von Rückmann-A, Fitzke-FW, Bird-AC. In vivo fundus autofluorescence in macular dystrophies. Arch Ophthalmol 115:609-615 (1997).
- Guymer-RH, Gross-Jendroska-M, Owens-SL, Bird-AC, Fitzke-FW Laser treatment in subjects with high risk clinical features of age-related macular degeneration. Arch Ophthalmol 115:595-603.
- Poinoosawmy D, Fontana L, Wu JX, Fitzke FW, Hitchings RA (1997) Variation of nerve fibre layer thickness measurements with age and ethnicity by scanning laser polarimetry. Brit J Ophthalmol 81:350-339.
- Westcott MC, Mcnaught AI, Crabb DP, Fitzke FW, Hitchings RA (1997) High resolution automated perimetry in glaucoma. Brit J Opthalmol 81:452-459.
- Fitzke FW, Masters BR, Buckley RJ, Speedwell L. (1997) Fourier Transform Analysis of Human Corneal Endothelial Specular Photomicrographs. Exp Eye Res 65:205-214.
- Bhandari A, Crabb DP, Poinoosawmy D, Fitzke FW, Hitchings RA, Noureddin BN. (1997) Effect of surgery on visual field progression in normal-tension glaucoma. Ophthalmology 104:1131-1137.
- Viswanathan_AC, Fitzke_FW, Hitchings_RA (1997) Early detection of visual field progression in glaucoma: a comparison of PROGRESSOR and STATPAC-2 Brit J Ophthalmol, 81:1037-1042.
- Viswanathan_AC, Hitchings_RA, Fitzke_FW (1997)How often do patients need visual field tests? Graefes-Arch-Clin-Exp-Ophthalmol. 235:563-568
- A. Gh.Podoleanu, M. Seeger, G. M. Dobre, D. J. Webb, D. A. Jackson, F. W. Fitzke. (1998)"Transversal and Longitudinal Images from the Retina of the Living Eye Using Low Coherence Reflectometry", Journal of Biomedical Optics 3:12-20.
- Fontana L, Bhandari A, Fitzke FW, Hitchings RA (1998) "In vivo morphometry of the lamina cribrosa and its relation to visual field loss in glaucoma" Current Eye Research 17:363-369 (1998).
- von Rückmann-A, Fitzke-FW, Gregor-ZJ (1998) "Fundus autofluorescence in patients with macular holes imaged with a laser scanning ophthalmoscope" Brit J Ophthalmol 82: 346-351.
- Votruba M, Fitzke FW, Holder GE, Carter A, Bhattacharya SS, Moore AT (1998) "Clinical features in affected individuals from 21 pedigrees with dominant optic atrophy" Arch Ophthalmol 116:351-358.
- Wade AR, Fitzke FW (1998) In vivo imaging of the human cone-photoreceptor mosaic using a confocal laser scanning ophthalmoscope. Lasers and Light 8(3):129-136.
- Westcott MC, Fitzke FW, Hitchings RA. Abnormal motion displacement thresholds are associated with fine scale luminance sensitivity loss in glaucoma. Vision Res 1998;38(20):3171-80.
- Podoleanu AG, Dobre GM, Seeger M, Webb DJ, Jackson DA, Fitzke FW, Halfyard AS "Low coherence interferometry for en-face imaging of the retina" Lasers and Light 8(3):187-192 (1998)
- Westcott MC, Fitzke FW, Viswanathan AC, Hitchings RA. "Reaction-Times For Motion Detection Are Significantly Prolonged In Glaucoma" Vision Research (submitted)
- Lois N, Halfyard AS, Bunce C, Bird AC, Fitzke FW "Reproducibility of fundus autofluorescence measurements obtained using a confocal scanning laser ophthalmoscope" Br J Ophthalmol 83:276-279 (1999)
- Westcott MC, Fitzke FW, Crabb DP, Hitchings RA. Characteristics of frequency-of-seeing curves for a motion stimulus in glaucoma eyes, glaucoma suspect eyes, and normal eyes. Vision Res 1999;39(3):631-9.
- Viswanathan AC, McNaught AI, Poinoosawmy D, Fontana L, Crabb DP, Fitzke FW, et al. Severity and stability of glaucoma: patient perception compared with objective measurement. Arch Ophthalmol 1999;117(4):450-4.
- Downes SM, Fitzke FW, Holder GE, Payne AM, Bessant DA, Bhattacharya SS, et al. Clinical features of codon 172 RDS macular dystrophy: similar phenotype in 12 families. Arch Ophthalmol 1999;117(10):1373-83.
- von Ruckmann A, Fitzke FW, Bird AC. Distribution of pigment epithelium autofluorescence in retinal disease state recorded in vivo and its change over time. Graefes Arch Clin Exp Ophthalmol 1999;237(1):1-9.
- Zhang X, De Alwis M, Hart SL, Fitzke FW, Inglis SC, Boursnell ME, et al. High-titer recombinant adeno-associated virus production from replicating amplicons and herpes vectors deleted for glycoprotein H. Hum Gene Ther 1999;10(15):2527-37