Correlation of Vitreomacular Traction with Foveal Thickness, Subfoveal Choroidal Thickness, and Vitreomacular/Foveal Angle

PURPOSE

To investigate the structure of vitreomacular traction (VMT), specifically, if a correlation exists between 1) the VMT type/grade and the central foveal thickness (CFT) and subfoveal and adjacent choroidal thickness, 2) the vitreomacular/foveal angle (VMFA) and the CFT and subfoveal and adjacent choroidal thickness, and 3) the diameter of vitreomacular adhesion (VMA) and CFT and subfoveal and adjacent choroidal thickness.

MATERIALS AND METHODS

Retrospective, multicenter image analysis study. We analyzed raster scans of the macula taken with spectral-domain optical coherence tomography (SD-OCT) of 61 eyes of 55 patients with VMT. Conventional scans of the vitreoretinal interface were analyzed to measure CFT and the degree of VMFA. Enhanced depth imaging (EDI) scans were analyzed to measure the choroidal thickness in the macula. The multivariate test of means and the t-test were used for statistical comparisons.

RESULTS

There was no statistically significant difference in CFT between focal vs broad and concurrent vs isolated type VMT. Central (p = 0.009), nasal (p = 0.004), and temporal (p = 0.007) subfoveal choroidal thickness was significantly higher in broad VMT compared to focal VMT. There was difference in both CFT (p = 0.035) and central (p = 0.005), nasal (p = 0.01), and temporal (p = 0.001) choroidal thickness between moderate and severe VMT. There was a correlation between VMFA and CFT, where a wider angle was associated with increased CFT (p = 0.026). The broader VMA was associated with increased central subfoveal (p = 0.032), nasal (p = 0.05), and temporal (p = 0.01) choroidal thickness.

CONCLUSIONS

Eyes with broad VMT have thicker choroid than eyes with focal VMT, which have a more open vitreomacular angle. The angle of VMT is related to distinct CFTs.

The ISNT rule in glaucoma: revisiting with spectral domain optical coherence tomography

PURPOSE

To evaluate the ability of the neuroretinal rim (NRR) rules determined using spectral domain optical coherence tomography (SDOCT) in diagnosing glaucoma and to study the effect of optic disc size and disease severity on the diagnostic ability of these rules.

METHODS

In a cross-sectional study, 125 eyes of 96 glaucoma patients and 96 eyes of 72 control subjects underwent optic nerve head (ONH) imaging with SDOCT. Inferior (I), superior (S), nasal (N) and temporal (T) NRR areas were automatically determined by the sdoct software. Diagnostic abilities of ISNT (I > S > N > T), IT (I > T) and ST (S > T) rules in glaucoma were evaluated using sensitivity, specificity and likelihood ratios (LR). Effect of optic disc size and disease severity [based on mean deviation (MD) on visual fields] on the diagnostic ability of the NRR rules was evaluated using regression models.

RESULTS

Sensitivities of ISNT, IT and ST rules were 80.8%, 60.0% and 29.6%, respectively, and the specificities were 32.3%, 84.4% and 93.8%, respectively. Positive LRs of ISNT, IT and ST rules were 1.19, 3.84 and 4.74, respectively, and negative LRs were 0.60, 0.47 and 0.75, respectively. Sensitivities of ISNT (coefficient: -1.06, p = 0.02) and IT (-0.71, 0.05) rules decreased with increasing disc size. Positive LR of IT rule increased significantly (-0.01, 0.04) with decreasing MD, and negative LR of IT rule decreased (got better) significantly (0.26, 0.05) with decreasing disc size.

CONCLUSIONS

Neuroretinal rim rules, as determined by SDOCT, do not allow robust differentiation of glaucomatous from non-glaucomatous discs.

Ability of different scanning protocols of spectral domain optical coherence tomography to diagnose preperimetric glaucoma

PURPOSE

To evaluate the ability of the optic nerve head (ONH), retinal nerve fiber layer (RNFL), and ganglion cell complex (GCC) parameters of spectral domain optical coherence tomograph (SDOCT) in detecting preperimetric glaucoma.

METHODS

In a cross-sectional study, 34 preperimetric glaucoma eyes (34 patients) and 72 control eyes (72 subjects) with large physiologic optic disc cupping underwent ONH, RNFL, and GCC imaging with SDOCT. Preperimetric glaucoma was diagnosed in the presence of glaucomatous optic neuropathy on masked evaluation of optic disc photographs by two glaucoma experts and normal visual fields. The ability of SDOCT parameters to discriminate preperimetric glaucoma eyes from eyes with large physiologic cups was evaluated by areas under the receiver operating characteristic curves (AUC), sensitivities at fixed specificities, and likelihood ratios (LR).

RESULTS

All SDOCT parameters were significantly different (P < 0.05) between the two groups. The ONH, RNFL, and GCC parameters with best AUCs to differentiate preperimetric glaucoma from eyes with large physiologic cups were vertical cup to disc ratio (0.76), inferior quadrant RNFL thickness (0.76), and inferior quadrant GCC thickness (0.75), respectively. Sensitivities at 95% specificity of SDOCT parameters ranged between 15% and 29%. Likelihood ratios of outside normal limits category of parameters ranged between 3 and 11, and within normal limits category between 0.5 and 0.8.

CONCLUSIONS

Diagnostic abilities of ONH, RNFL, and GCC parameters of SDOCT to differentiate preperimetric glaucoma eyes from control eyes with large physiologic cupping were only moderate.

Evaluation of multimodal imaging in carriers of X-linked retinitis pigmentosa

The aim of this study was to investigate visualization of the tapetal-like reflex using current imaging modalities and evaluate SD-OCT changes in known carriers of X-linked retinitis pigmentosa (XLRP); the objective being the development of an optimal protocol for clinicians to identify carriers. Ten XLRP carriers (19 eyes) were examined using color fundus photography, 488 nm reflectance (488-R), near-infrared reflectance (NIR-R), autofluorescence (AF) and spectral domain optical coherence tomography (SD-OCT) imaging (Spectralis SLO-OCT, Heidelberg). Horizontal line scans through the fovea were acquired in all subjects and in a group of 10 age-similar controls. Peripheral SD-OCT scans (extending to 27.5° eccentricity) were also acquired in both eyes of 7 carriers. MP-1 microperimetery (10-2 pattern; Nidek) was performed in one eye of each carrier. For the XLRP carriers, a tapetal reflex was observed with all imaging modalities in 8 of 19 eyes. It had the same retinal location on color fundus, 488-R and NIR-R imaging but a different location on AF. The tapetal reflex was most easily detected in 488-R images. The horizontal foveal SD-OCT scans were qualitatively normal, but measurements showed significant outer retinal layer thinning in all eyes. Additionally, the 14 eyes with peripheral SD-OCTs demonstrated patchy loss of the inner segment ellipsoid band. Microperimetry exhibited patchy visual sensitivity loss in 9 eyes. Full field ERGs were variable, ranging from normal to severely abnormal rod and cone responses. Our findings suggest that an optimal protocol for identifying carriers of XLRP should include 488-R imaging in a multimodal approach. Peripheral SD-OCT imaging and central retinal layer quantification revealed significant structural abnormalities.