M Francoz

Ocular Surface Epithelial Thickness Evaluation with Spectral-Domain Optical Coherence Tomography

PURPOSE To use in vivo spectral-domain optical coherence tomography (SD-OCT) to measure corneal, limbal, and bulbar conjunctival epithelial thickness. METHODS A total of 156 eyes of 79 subjects were enrolled in four groups: young control (YC group), < 40 years; middle-aged control (MAC group), > 40 years; patients with dry eye syndrome (KCS group); and patients with glaucoma or ocular hypertension treated with intraocular pressure (IOP)-lowering medication (G group). The central corneal epithelium (CE) thickness, and the limbal (LE) and bulbar conjunctival epithelium (BCE) thickness in four quadrants were measured using SD-OCT. RESULTS The mean thicknesses of the CE, LE, and BCE of the YC group were 48.3 ± 2.9 μm, 83.0 ± 14.3 μm, and 42.0 ± 7.5 μm, and for the MAC group were 48.8 ± 3.0 μm, 84.3 ± 10.1 μm, and 42.2 ± 7.9 μm, respectively. The ocular surface epithelial thickness was not significantly different between the YC and MAC groups. CE thicknesses were not significantly different between the KCS, G, and control groups. The mean LE thicknesses were significantly lower in the KCS and G groups compared with the MAC group. The mean BCE was significantly thicker in the KCS and G groups compared with the MAC group. CONCLUSIONS Anterior segment SD-OCT can provide a noninvasive evaluation of ocular surface epithelial thickness. LE and BCE thickness was modified in dry eye patients and patients using IOP-lowering eye drops, whereas aging seemed to have no effect.

Reproducibility of macular ganglion cell-inner plexiform layer thickness measurement with cirrus HD-OCT in normal, hypertensive and glaucomatous eyes.

Aim To evaluate the intraobserver and interobserver reproducibility of macular retinal ganglion cell–inner plexiform layer (GC–IPL) thickness measurement by automated detection on Optical Coherence Tomography (OCT) images in normal, hypertensive (ocular hypertensive (OHT)) and glaucomatous eyes. Methods A total of 138 eyes were enrolled in three groups: 69 normal, 35 OHT and 34 primary open-angle glaucoma eyes. All patients underwent a complete ocular examination, 24-2 automated perimetry, biometry and pachymetry. Macular imaging was performed in each eye using the Cirrus HD-OCT 4000 with software V.6.0. (Carl Zeiss Meditec, Dublin, California, USA) three times on the same day by each of two observers, and the GC analysis (GCA) algorithm provided parameters expressed as average, minimum and six sectoral GC-IPL thicknesses. Reproducibility was assessed by intraclass correlation coefficient (ICC), coefficient of variation (CV) and test-retest variability (TRTV) calculated as 1.96 times the SD. Results Mean GC–IPL thickness was 82.27±7.37 μm, 76.84±7.01 μm and 66.16±11.16 μm in normal, OHT and glaucoma groups, respectively. GC–IPL thickness was significantly lower in glaucomatous eyes than in normal and OHT eyes (p<0.0001 for all parameters). In all groups, ICC ranged from 96.4 to 99.9% and 92.5 to 99.8%, CV ranged from 0.41 to 2.24% and 0.55 to 1.67%, and TRTV ranged from 0.61 to 2.64 μm and 0.83 to 2.22 μm for intraobserver and interobserver reproducibility, respectively. Conclusions To the best of our knowledge, this is the first study of GCA algorithm reproducibility in normal, OHT and glaucomatous eyes. The reproducibility of GC–IPL thickness measurements using the Cirrus HD-OCT GCA algorithm was found to be highly satisfactory. GC–IPL thickness may be a promising new OCT parameter for analysis of ganglion cell damage in glaucoma.

Analyse du complexe cellulaire ganglionnaire maculaire (GCC) en tomographie par cohérence optique (SD-OCT) dans le glaucome

Early detection of ganglion cell loss is possible with new algorithms for the assessment of the Macular Ganglion Cell Complex (GCC) by SD-OCT. The various data acquisition protocols used by the various versions of software, as well as their accuracy and reproducibility, must be taken into account. Current results show similar ability to detect glaucoma as compared to Retinal Nerve Fiber Layer thickness (RNFL), with some limitations, possible artifacts, and interpretation pitfalls which must be taken into account. The role of the significance map and of various indices (Focal Loss Volume, Global Loss Volume, GCIPL minimum...); data obtained in the setting of various clinical entities (tilted disc, peripapillary atrophy, large and small optic discs, high myopia...); and detection of progression, especially in advanced glaucoma, underline the role of macular GCC analysis as a complementary method to peripapillary RNFL thickness. The diagnostic precision and better reproducibility of these new software protocols offer new perspectives in the detection and management of progression in various stages of the management of glaucomatous optic neuropathy.

Capacités diagnostiques de l’analyse des différentes couches maculaires par SD-OCT dans le glaucome primitif à angle ouvert☆☆☆

PURPOSE The purpose of this study is to evaluate the diagnostic ability of segmentation of the various internal macular layers by spectral domain optical coherence tomography (Cirrus HD-OCT, Carl Zeiss Meditec (CZM), Dublin, CA, USA) and to compare it to that of the peripapillary retinal nerve fiber layer (cpRNFL) in primary open angle glaucoma (POAG). MATERIALS AND METHODS This study included 252 eyes diagnosed with primary open angle glaucoma (POAG) (164 early POAG, 44 moderate POAG and 44 advanced POAG) and 223 eyes of control subjects. All patients underwent visual field testing (Humphrey Field Analyser, SITA-Standard 24-2, CZM), and SD-OCT imaging (Cirrus HD-OCT) of the macular and optic nerve head regions (ganglion cell analysis (GCA), macular cube 200×200; optic disc cube 200×200). OCT macular scans were segmented into macular nerve fiber layer (mNFL), ganglion cell layer with inner plexiform layer (GCIPL), outer retinal layers, and ganglion cell complex (GCC) (mNFL+GCIPL). Glaucoma discriminating ability was assessed using the area under the receiver operator characteristic curve (AUC) for all macular parameters and mean circumpapillary retinal nerve fibre layer (cpRNFL). RESULTS For the entire POAG population of this study, the minimum GCIPL index provided greater diagnostic ability than the other parameters studied, with a statistically significant difference in their AUC (minimum GCIPL [0.887], mean GCIPL [0.865], GCC [0.863], cpRNFL [0.823], mean mNFL [0.786] and minimum mNFL [0.742]). The results were similar in the early POAG group but without any statistically significant difference with the cpRNFL parameter. In the moderate POAG group, the diagnostic ability was similar for all indices, whereas in the advanced POAG group, minimum GCIPL and GCC gave the largest AUC indices. DISCUSSION AND CONCLUSION The minimum macular GCIPL is a new index obtained with the GCA algorithm of the Cirrus HD-OCT. It appears to have an excellent ability to detect glaucoma at every stage and demonstrates performance comparable to that of the cpRNFL parameter, in combination with which it may provide important complementary information for clinical practice.

Rétinopathie ischémique chronique bilatérale : à propos d’un cas ☆

La sténose de l’artère carotidienne est définie par une réduction de la lumière par une plaque d’athérosclérose, artérite, ou une dysplasie fibromusculaire. Son incidence est élevée et représente 10 % de la population âgée de plus de 60 ans. Le syndrome d’ischémie oculaire (SIO) chronique, appelée rétinopathie hypotensive, est une forme rare et sévère d’ischémie des segments antérieurs et postérieurs de l’œil secondaire à une sténose sévère ou d’occlusion de l’artère carotidienne.

Optical Coherence Tomography in the Inner Retinal Layers

Optical coherence tomography (OCT) in the inner retinal layers is a new and very interesting tool for glaucoma diagnosis and follow-up. New spectral domain-OCT with layer segmentation analysis is able to measure thickness from the 3 layers containing parts of the retinal ganglion cells. Dendrites from the retinal ganglion cells form the inner plexiform layer, cellular bodies form the ganglion cell layer and axons form the nerve fiber layer. Glaucomatous apoptosis of ganglion cells causes thinning of the inner layers. Numerous OCT devices produce macular maps of thickness for theses layers, with a reference to a normative database. Nevertheless, the thickness difference between normal and glaucomatous patients is small and OCT must be realized and analyzed very carefully to avoid false results due to artifacts or poor quality scanning. Macular inner layers mapping is a very promising tool for glaucoma, complementary with peripapillary retinal nerve fiber layer and optic nerve head analysis.

Macular ganglion cell-Inner plexiform layer thickness measurement and reproducibility with SD-OCT

Purpose To evaluate the macular retinal ganglion cell‐inner plexiform layer (GC‐IPL) thickness with automated detection and analyze the intra and interobservator reproducibility in normal, ocular hypertensive (OHT) and glaucomatous eyes.

Evaluation of the flicker defined form test versus matrix, in normal and glaucoma eyes

Purpose To evaluate a new perimetric test, the Flicker Defined Form (FDF), and to analyze its capacity to detect visual field defect, comparatively to Matrix, in normal subjects and patients treated for primary angle glaucoma (POAG).

Glaucoma diagnostic accuracy : comparison of RTVue-100 and Cirrus HD

Purpose To compare diagnostic performance of peripapillary retinal nerve fiber layer and macular complex acquisitions in both Cirrus HD and RTVue OCTs.

Structure–function relationship: assessment of macular ganglion cell complex with FD‐OCT and standard automated perimetry

Purpose This study aims to evaluate relationship might exist between new indices of structural damage provided by FD‐OCT which analyses macular ganglion cell complex (mGCC) and functional indices collected in standard automated perimetry (SAP).