Cross-Polarization Photography of the Nerve Fiber Layer

Kues, Henry A.; D’Anna, Salvatore A.; Arkell, Sheila; Robin, Alan L.; Quigley, Harry A.

doi:10.1001/archopht.1984.01040030684019

Cited by 36 publications

(16 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…' Image quality can be improved by various combinations of filmy6 filter^^.^ proce~sing,~ by varying the and by the use of polarising filters. 13 The aim of any change in photographic technique is to gain contrast without loss of information in the fine detail of the nerve fibre bundles. Astronomical photography has for many years used the photographic technique of unsharp masking to examine star systems in galaxies.…”

supporting

confidence: 39%

Simplification of unsharp masking in retinal nerve fibre layer photography

Barry

Cooper²,

Eikelboom³

1990

Australian and New Zealand Journal of Ophthalmology

View full text Add to dashboard Cite

Fundus photography is now an established tool for showing early changes in the retinal nerve fibre layer (RNFL). RNFL defects may precede glaucomatous visual field defects by up to five years and any improvement in photography should aid RNFL defect analysis. We have found that the use of an unsharp mask has helped to visualise the RNFL and by using readily available darkroom materials the process of unsharp mask preparation has been simplified. Key words:Fundus photography, high magnification, large format film, retinal nerve fibre layer, unsharp mask.Damage to the retinal nerve fibre layer (RNFL) may be the first visible sign of pathology in chronic glaucoma.',2 Critical examination of the RNFL3 relies on the use of high quality red-free photog r a p h~.~ Photography of the RNFL uses spectral reflection of red-free light from the superficial retina. ' Image quality can be improved by various combinations of filmy6 filter^^.^ proce~sing,~ by varying the and by the use of polarising filters.13 The aim of any change in photographic technique is to gain contrast without loss of information in the fine detail of the nerve fibre bundles. Astronomical photography has for many years used the photographic technique of unsharp masking to examine star systems in galaxies. l4 Similarly, photographic subtraction has been in use in radiology since 193S5 and has been suggested for use in fluorescein angi~graphy'~.'~ and monochromatic fundus and RNFL photography.18An RNFL negative contains a large range of densities which are often difficult to transfer to photographic paper or film unless darkroom techniques such as 'dodging' or 'burning-in' are used. These techniques are difficult to control, are time consuming and are not precisely repeatable without computerised enlarger control.Unsharp masking has the advantage of being simple and reproducible without the disadvantage of changing the original negative. This paper describes a simplified technique of unsharp masking for RNFL prints and transparencies. Unsharp masking is a photographic method of compressing the tonal range of a negative and improving fine detail. MethodsIn order to reduce the variables in the preparation of an unsharp mask the contrast of films, unsharp masks and optimum unsharp mask density were determined by computerised image analy~is.'~ We have attempted to simplify the processing of the unsharp mask by using chemicals and materials available in most darkrooms so that enhanced RNFL images can be conveniently prepared.Our current method for RNFL photography consists of a Zeiss FF4 fundus camera, Kodak Technical pan 2415 film and a Zeiss RI red-free

show abstract

supporting

confidence: 39%

Simplification of unsharp masking in retinal nerve fibre layer photography

Barry

Cooper²,

Eikelboom³

1990

Australian and New Zealand Journal of Ophthalmology

View full text Add to dashboard Cite

show abstract

“…In addition, the cross-polarisation technique used by the device has been shown to increase the visibility of the choroid, optic disc, and blood vessels and also accentuate nerve fibre layer defects by reducing nerve fibre layer reflectivity 6 7. However, cross-polarisation also decreases specular reflected light from the internal limiting membrane that can be helpful for photography of certain retinal pathology 6…”

Section: Resultsmentioning

confidence: 99%

A mobile phone-based retinal camera for portable wide field imaging

et al. 2013

View full text Add to dashboard Cite

Digital fundus imaging is used extensively in the diagnosis, monitoring and management of many retinal diseases. Access to fundus photography is often limited by patient morbidity, high equipment cost and shortage of trained personnel. Advancements in telemedicine methods and the development of portable fundus cameras have increased the accessibility of retinal imaging, but most of these approaches rely on separate computers for viewing and transmission of fundus images. We describe a novel portable handheld smartphone-based retinal camera capable of capturing high-quality, wide field fundus images. The use of the mobile phone platform creates a fully embedded system capable of acquisition, storage and analysis of fundus images that can be directly transmitted from the phone via the wireless telecommunication system for remote evaluation.

show abstract

“…Therefore, we employed a successive exclusion protocol, comparing first the cameras, then using the camera that was found to be the better choice to compare the films, and using the selected camera and film to compare the filters. We chose to compare the Zeiss FF-11 1 and the Canon CF-6OZ cameras because they were available to us and because they have been consistently used in most photographic studies to date Airaksinen et al 1982Airaksinen et al , 1984Sommer et al 1983Sommer et al , 1984. The combination of Plus-X film and Spectrotech 540 filter was used in the camera comparison because this was the method of choice for most initial reports on nerve fiber layer photography through the 1970s (Hoyt et al 1972;Miller & George 1978); this was also the technique previously used in our photography service (Peli et al 1986).…”

mentioning

confidence: 99%

Nerve fiber layer photography

Peli

Hedges

McInnes

et al. 1987

Acta Ophthalmologica

View full text Add to dashboard Cite

Observation of the retinal nerve fiber layer with red-free light is an important means of evaluating optic nerve integrity. Many investigators have attempted to increase the usefulness of the technique by improving photographic procedures. Most reports comparing various parameters neither indicate the method of comparison nor give quantitative measure of the improvement gained with different films, filters, cameras, or processing procedures. We have compared in a masked fashion the parameters most recently recommended in the literature. Twelve trained observers compared 12 masked pairs of nerve fiber layer photos taken from the same eye in the same manner on two cameras and preferred those taken with a Canon CF-60Z camera 69% of the time and those taken with a Zeiss FF-111 17% of the time (this difference was statistically significant, P less than 0.01). Fourteen observers compared 14 pairs of photographs and judged Panatomic-X film to be superior to Plus-X film 51% of the time and both films to be of the same quality 25% of the time (this difference was also significant P less than 0.05). Fifteen observers compared 12 pairs and preferred the Standard SE-40 blue filter 2:1 over the green Spectrotech 540 filter. This difference was not statistically significant, and the preference was found to be dependent on fundus pigmentation and clarity of the media. The blue filter gave better contrast for the nerve fiber layer in patients with lightly pigmented fundi, and use of the green filter resulted in less light scatter in patients with ocular media opacities.

show abstract

Cross-Polarization Photography of the Nerve Fiber Layer

Cited by 36 publications

References 12 publications

Simplification of unsharp masking in retinal nerve fibre layer photography

Simplification of unsharp masking in retinal nerve fibre layer photography

A mobile phone-based retinal camera for portable wide field imaging

Nerve fiber layer photography

Contact Info

Product

Resources

About