Polarimetry of the retinal nerve fiber layer

Tuulonen, Anja; Pj, Airaksinen

doi:10.1097/00055735-199604000-00006

Cited by 12 publications

(7 citation statements)

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“…The need to quantify structural damage to the optic nerve has led to the development of imaging devices for measuring the number and distribution of retinal ganglion cell (RGC) axons. The imaging techniques presently available for measuring the number of retinal cells are optical coherence tomography (OCT), retinal thickness analysis (RTA), and scanning laser polarimetry (Gdx); the latter measures retinal birefringence (retinal depolarization of light) 52–55 . OCT provides the most direct measurement of the thickness of the inner superficial retinal layer where the RGC axons are located, and has been used extensively in the diagnosis of early glaucoma 52,54,56 .…”

Section: Discussionmentioning

confidence: 99%

Recovery of canine retina and optic nerve function after acute elevation of intraocular pressure: implications for canine glaucoma treatment

Grozdanić¹,

Matic²,

Betts³

et al. 2007

Veterinary Ophthalmology

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Purpose To characterize the timing and extent of functional recovery in healthy canine eyes exposed to acute elevation of intraocular pressure (IOP). Methods Acute elevation of IOP was induced in 14 healthy Beagles by elevating IOP above the levels of systolic blood pressure for 60 min (average elevation was between 100 and 160 mmHg). Menace, dazzle and pupillary light reflexes (PLR) were tested at 1, 7, 14 and 28 days post elevation. Optical coherence tomography was used to evaluate retinal thickness preoperatively and at 15 and 30 days post elevation. Results One day post elevation all animals were blind in the operated eye (no positive menace), 5/14 had positive PLR and 10/14 had positive dazzle response. Seven days post elevation 4/14 animals had positive menace response and all animals (14/14) had positive dazzle and PLR responses. Fourteen and 28 days post elevation all animals had positive menace, PLR and dazzle responses. Optical coherence tomography analysis revealed significant thinning of the inferior retina (pre elevation: 156.3 ± 4.8 µ m; 15 days post elevation: 125 ± 10.4 µ m; 30 days post elevation 123 ± 11.9 µ m; P < 0.01,  ). The superior retina, however, did not show any detectable decrease in thickness compared to control eyes (pre elevation: 193.8 ± 2.6 µ m; 15 days post elevation: 176.9 ± 8.5 µ m; 30 days post elevation 176.9 ± 7 µ m; P = 0.057,  ). Conclusions Detailed functional and morphologic analysis revealed precise information about retinal damage after acute elevation of IOP. Canine retina has the capacity to recover at least some visual function even at 14 days after acute elevation of the IOP. More aggressive medical and surgical treatment of canine glaucomatous patients may be indicated despite complete loss of visual function, PLR and dazzle responses in early days after development of an acute glaucomatous attack.

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Section: Discussionmentioning

confidence: 99%

Recovery of canine retina and optic nerve function after acute elevation of intraocular pressure: implications for canine glaucoma treatment

Grozdanić¹,

Matic²,

Betts³

et al. 2007

Veterinary Ophthalmology

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“…Numerous papers have been published establishing the relationship between the phase shift and true RNFL thickness in both healthy patients and patients with glaucomatous loss,3 4 and the measurements were found to be reproducible within a time period when structural change has not occurred 5 6. Since these basics of the technology were established, many studies have tested the ability of both the early clinical device, the Nerve Fibre Analyzer (Laser Diagnostic Technologies, San Diego, California), and the current device used most predominantly clinically, the GDx (Carl Zeiss Meditec, Vista, California) 7 – 11.…”

Section: Scanning Laser Polarimetrymentioning

confidence: 99%

Imaging of the retinal nerve fibre layer for glaucoma

2008

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Background Glaucoma is a group of diseases characterised by retinal ganglion cell dysfunction and death. Detection of glaucoma and its progression are based on identification of abnormalities or changes in the optic nerve head (ONH) or the retinal nerve fibre layer (RNFL), either functional or structural. This review will focus on the identification of structural abnormalities in the RNFL associated with glaucoma. Discussion A variety of new techniques have been created and developed to move beyond photography, which generally requires subjective interpretation, to quantitative retinal imaging to measure RNFL loss. Scanning laser polarimetry uses polarised light to measure the RNFL birefringence to estimate tissue thickness. Optical coherence tomography (OCT) uses low-coherence light to create high-resolution tomographic images of the retina from backscattered light in order to measure the tissue thickness of the retinal layers and intraretinal structures. Segmentation algorithms are used to measure the thickness of the retinal nerve fibre layer directly from the OCT images. In addition to these clinically available technologies, new techniques are in the research stages. Polarisation-sensitive OCT has been developed that combines the strengths of scanning laser polarimetry with those of OCT. Ultra-fast techniques for OCT have been created for research devices. The continued utilisation of imaging devices into the clinic is refining glaucoma assessment. In the past 20 years glaucoma has gone from a disease diagnosed and followed using highly subjective techniques to one measured quantitatively and increasingly objectively.

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“…It is well known in clinical practice that RNFL defects are very early signs of glaucoma, since they represent the first step in the glaucomatous morphological loss in the retina 1. Analysis of RNFL properties using black and white photographs requires a well trained examiner and does not provide real quantitative information about the thickness.…”

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confidence: 99%

Scanning laser polarimetry of the retinal nerve fibre layer in primary open angle and capsular glaucoma

Holló

Süveges

Nagymihály

et al. 1997

British Journal of Ophthalmology

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Aims-To evaluate the clinical value of scanning laser polarimetry with the nerve fibre analyser type II in primary open angle glaucoma (POAG) and capsular glaucoma. Methods-Scanning laser polarimetry was performed on one eye of 30 patients suVering from POAG, 25 patients suVering from capsular glaucoma, and on 35 healthy control subjects. The retinal nerve fibre layer (RNFL) thickness values were compared among the groups. Reproducibility of the measurements was calculated and the influence of pilocarpine induced miosis on the results was investigated. Results-RNFL thickness in the superior and inferior sectors, as well as along the total circumference was significantly lower in both glaucoma groups than in the control eyes (p<0.05). None of the thickness values diVered between the two glaucoma groups. Reproducibility was comparable in all groups; the coeYcient of variation varied between 3.0% and 8.9% for the diVerent sectors investigated. Miosis had no significant impact either on the thickness values or on the reproducibility (p>0.05). Conclusion-The results suggest that scanning laser polarimetry is a useful method for nerve fibre layer analysis in glaucoma, and that it is not influenced by the pupil size. (Br J Ophthalmol 1997;81:857-861) Glaucoma is a progressive optic neuropathy which means that gradual loss of the nerve fibres causes diVuse and localised thinning of the retinal nerve fibre layer (RNFL). It is well known in clinical practice that RNFL defects are very early signs of glaucoma, since they represent the first step in the glaucomatous morphological loss in the retina.1 Analysis of RNFL properties using black and white photographs requires a well trained examiner and does not provide real quantitative information about the thickness. However, a recently developed computerised technique, scanning laser polarimetry, provides both qualitative and quantitative information on the morphology and thickness of the RNFL, and results are available within a few seconds. In order to test the clinical value of the method we calculated its reproducibility and compared RNFL thickness results for healthy eyes and for eyes suVering from primary open angle glaucoma and from capsular glaucoma. The impact of pilocarpine induced miosis on the thickness values and reproducibility was also investigated.

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Polarimetry of the retinal nerve fiber layer

Cited by 12 publications

References 0 publications

Recovery of canine retina and optic nerve function after acute elevation of intraocular pressure: implications for canine glaucoma treatment

Recovery of canine retina and optic nerve function after acute elevation of intraocular pressure: implications for canine glaucoma treatment

Imaging of the retinal nerve fibre layer for glaucoma

Scanning laser polarimetry of the retinal nerve fibre layer in primary open angle and capsular glaucoma

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