Retinal nerve fibre layer thickness measurements in childhood glaucoma: the role of scanning laser polarimetry and optical coherence tomography

Purpose A central diagnostic tool in adult glaucoma is the peripapillary retinal nerve fibre layer (pRNFL) thickness. It can be assessed by scanning laser polarimetry (SLP) or optical coherence tomography (OCT). However, studies investigating the relevance of pRNFL measurements in children are rare. This study aims to compare the glaucoma diagnosing ability of SLP and OCT pRNFL thickness measurements in a paediatric population. Methods This retrospective study included 105 children (glaucoma: 22 (21.0%); healthy glaucoma suspects: 83 (79.0%)) aged 4–18 years, examined with SLP (GDxPro/ECC, Carl Zeiss Meditec) and spectral-domain OCT (SPECTRALIS®, Heidelberg Engineering). The thickness of pRNFL sectors was compared between diseased and healthy participants. Areas under the receiver-operating characteristic curves (AUC) and logistic regression results were used to compare the glaucoma discriminative capacity between SLP and OCT measurements. Results Using OCT, pRNFL thickness was decreased in the superior, nasal, and inferior quadrants of glaucoma patients compared to healthy controls (P < 0.001, each). With SLP, such a difference was only observed in the inferior quadrant (P = 0.011). A correlation between glaucoma diagnosis and OCT-measured pRNFL thickness was found in all quadrants (P < 0.001) other than the temporal. With SLP, a correlation was found for the total average thickness (P = 0.037) and inferior quadrant (P = 0.0019). Finally, the AUCs of OCT measurements were markedly higher than those of SLP (e.g., inferior quadrant: OCT 0.83, SLP 0.68). Conclusion pRNFL thickness measurements using both OCT and SLP, correlate notably with the presence of glaucoma. In general, the diagnostic performance of pRNFL thickness measurements seems higher for OCT than for SLP. Thus, pRNFL thickness measurements could provide important information, complementing conventional clinical and functional parameters in the diagnostic process of paediatric glaucoma.

Diagnostic Accuracy of Glaucoma Tests in Everyday Practice

Purpose To evaluate the performance of various tests with automated and subjective evaluation for primary diagnostics of glaucoma in a normal clinical setting. Methods Subjects referred because of suspicion of glaucoma were recruited. All subjects had full ophthalmologic evaluation with stereophotography of the optic nerve head (ONH), red-free retinal nerve fiber layer (RNFL) photography, scanning laser polarimetry (SLP), optical coherence tomography (OCT), and standard automated perimetry (SAP). Analysis of all results was made jointly by 5 glaucoma specialists, with a consensus for each eye as healthy, glaucomatous, or glaucoma suspect. Results from each method were evaluated against this consensus, followed by a subjective evaluation of each method by a glaucoma specialist, comparing this with automated classification by the devices. Results Of the 101 subjects and 202 eyes examined, 23 eyes were by consensus glaucomatous, and 23 were glaucoma suspect. Sensitivity was best with ONH photos and worst with SAP, while SLP had a better sensitivity but poorer specificity than did RNFL photographs and OCT. Subjective evaluation of SLP, OCT, and SAP data gave better sensitivity and specificity than did classification by numeric values from the devices only, with OCT performing better in automatic classification than did SLP or SAP. Conclusions None of the current methods is superior to others in diagnosing glaucoma, and the accuracy of automated tests was better when subjectively evaluated by an experienced ophthalmologist. Diagnosis of glaucoma should be based on a combination of test results interpreted by a clinician.

THE ANALYSIS OF THE FREQUENCY AND LOCATION OF PERIPAPILLARY RETINAL DEFECTS REVEALED BY SCANNING LASER POLARIMETRY

The medical screening included 375 patients (680 eyes): Group 1 - patients with POAG with myopia; Group 2 - Patients with POAG associated with emmetropia and hyperopia; Group 3 - patients with myopia; Group 4 - patients with hyperopia. All the patients underwent laser polarimetry. The frequency and location of RNFL defects was analyzed. The patients with POAG observed RNFL defects significantly more often than patients without the disease. The patients of Group 1 had had lesions in the upper RNFL part before and to a greater extent, the patients of Group 2 - the lower part of RNFL.