EXTENDED REPORT

Enhanced corneal compensation for scanning laser polarimetry on eyes with atypical polarisation pattern

M Tóth and G Holló

Department of Ophthalmology, Semmelweis University, Budapest, Hungary

Correspondence to:
Correspondence to:
Dr G Holló
Tömö u 25–29, 1083 Budapest, Hungary; hg{at}szem1.sote.hu

Aim: To investigate the potential advantage of an enhanced corneal compensation algorithm (ECC) compared with variable corneal compensation (VCC) in the analysis of scanning laser polarimetric (SLP) images with atypical retardation pattern (ARP).

Methods: SLP-VCC images with ARP (typical scan score (TSS) <80) of one eye of each of 27 glaucoma patients and 19 healthy subjects were compared with the corresponding SLP-ECC images obtained at the same session.

Results: ARP was present in 10.4% of the normals and 15.5% of the glaucoma patients imaged with SLP-VCC over 9 months. In both groups TSS was higher for ECC than for VCC (p<0.001). In glaucoma TSNIT, superior and inferior average thickness values were significantly lower, and TSNIT (measuring ellipse around the optic nerve head in the four (temporal, superior, nasal, inferior) quadrants) standard deviation was significantly higher with ECC than with VCC (p<0.001). In the normal group nerve fibre indicator (NFI) was lower with ECC than with VCC (p = 0.007). TSNIT average was smaller and TSNIT standard deviation was higher with ECC (p<0.001). Superior and inferior average thickness did not differ between VCC and ECC in the normal group.

Conclusions: The new ECC software substantially improves polarimetric image analysis on eyes showing atypical polarisation pattern.

Abbreviations: ARP, atypical retardation pattern; ECC, enhanced corneal compensation; RNFLT, retinal nerve fibre layer thickness; SLP, scanning laser polarimetry; TSNIT, measuring ellipse around the optic nerve head in the four (temporal, superior, nasal, inferior) quadrants; TSS, typical scan score; VCC, variable corneal compensation

Keywords: enhanced corneal compensation; GDx; glaucoma; retinal nerve fibre layer; scanning laser polarimetry

CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this?

This article has been cited by other articles:

• Horn, F. K., Mardin, C. Y., Laemmer, R., Baleanu, D., Juenemann, A. M., Kruse, F. E., Tornow, R. P. (2009). Correlation between Local Glaucomatous Visual Field Defects and Loss of Nerve Fiber Layer Thickness Measured with Polarimetry and Spectral Domain OCT. IOVS 50: 1971-1977 [Abstract] [Full Text]  
• Gotzinger, E., Pircher, M., Baumann, B., Hirn, C., Vass, C., Hitzenberger, C. K. (2008). Analysis of the Origin of Atypical Scanning Laser Polarimetry Patterns by Polarization-Sensitive Optical Coherence Tomography. IOVS 49: 5366-5372 [Abstract] [Full Text]  
• Morishita, S, Tanabe, T, Yu, S, Hangai, M, Ojima, T, Aikawa, H, Yoshimura, N (2008). Retinal nerve fibre layer assessment in myopic glaucomatous eyes: comparison of GDx variable corneal compensation with GDx enhanced corneal compensation. Br. J. Ophthalmol. 92: 1377-1381 [Abstract] [Full Text]  
• Choi, J, Kim, K H, Lee, C H, Cho, H, Sung, K R, Choi, J Y, Cho, B-J, Kook, M S (2008). Relationship between retinal nerve fibre layer measurements and retinal sensitivity by scanning laser polarimetry with variable and enhanced corneal compensation. Br. J. Ophthalmol. 92: 906-911 [Abstract] [Full Text]  
• Medeiros, F. A., Bowd, C., Zangwill, L. M., Patel, C., Weinreb, R. N. (2007). Detection of Glaucoma Using Scanning Laser Polarimetry with Enhanced Corneal Compensation. IOVS 48: 3146-3153 [Abstract] [Full Text]  
• Sehi, M., Ume, S., Greenfield, D. S., Advanced Imaging in Glaucoma Study Group, (2007). Scanning Laser Polarimetry with Enhanced Corneal Compensation and Optical Coherence Tomography in Normal and Glaucomatous Eyes. IOVS 48: 2099-2104 [Abstract] [Full Text]  
• Mai, T. A., Reus, N. J., Lemij, H. G. (2007). Structure-Function Relationship Is Stronger with Enhanced Corneal Compensation than with Variable Corneal Compensation in Scanning Laser Polarimetry. IOVS 48: 1651-1658 [Abstract] [Full Text]  
• Bowd, C., Medeiros, F. A., Weinreb, R. N., Zangwill, L. M. (2007). The Effect of Atypical Birefringence Patterns on Glaucoma Detection Using Scanning Laser Polarimetry with Variable Corneal Compensation. IOVS 48: 223-227 [Abstract] [Full Text]  
• Reus, N. J., Zhou, Q., Lemij, H. G. (2006). Enhanced imaging algorithm for scanning laser polarimetry with variable corneal compensation.. IOVS 47: 3870-3877 [Abstract] [Full Text]  
• Sehi, M, Guaqueta, D C, Greenfield, D S (2006). An enhancement module to improve the atypical birefringence pattern using scanning laser polarimetry with variable corneal compensation. Br. J. Ophthalmol. 90: 749-753 [Abstract] [Full Text]