RTVue Optical Coherence Tomography Research Articles

Keratometric Study of Cornea in Allergic Conjunctivitis Patients

Background: To explore corneal biomechanical changes, identify related factors and determine early indicators of keratoconus (KC) development risk in allergic conjunctivitis (AC) patients. Methods: A total of 50 patients, including 20 eyes without AC and 30 eyes with AC were enrolled in this study. All patients underwent a complete ocular examination, including evaluations of clinical manifestations of AC, corneal tomography and densitometry by Pentacam, corneal biomechanics by Corvis ST, and corneal and epithelial thickness mapping by RTvue optical coherence tomography (OCT). Results: The index of surface variance (ISV), index of vertical asymmetry (IVA), keratoconus index (KI), index of height decentration (IHD) and Belin/Ambrosio enhanced ectasia total deviation index (BAD-D) were significantly higher in the AC group than in the non-allergic conjunctivitis (NAC) group (P < 0.05). The tomography and biomechanical index (TBI) was also significantly higher in the AC group (P =?0.04). The average epithelial thickness in the 2–7?mm annulus was significantly thinner in the AC group than in the NAC group (P < 0.05). The average densitometry of the total cornea and the anterior layer were higher in the AC group than in the NAC group (P < 0.001). The ISV, IVA, KI, IHD and BAD-D were significantly correlated with the TBI and changes in corneal epithelial thickness in AC patients (P < 0.05). The changes in epithelial thickness were closely related to the eye rubbing frequency and allergic sign scores (P < 0.05). CONCLUSIONS: AC patients should be advised to routinely undergo corneal tomographic and biochemical measurements and the TBI could be used an indicator of KC devolopment risk in AC patients.

Effect of phakic collamer intraocular lens with a central hole on structural tests measurements of retinal nerve fiber layer and macula.

To evaluate whether the Visian Implantable Collamer Lens with a central port (V4c ICL®; STAAR Surgical, Switzerland) affects the retinal nerve fibre layer (RNFL), macula and optic nerve head (ONH) measurements obtained by optical coherence tomography (OCT), and Heidelberg Retina Tomography (HRT). This prospective study included myopic patients undergoing V4c ICL® implantation. RNFL thickness, macular thickness, ganglion cell analysis (GCA) and ONH main parameters were evaluated with RTVue OCT (Optovue Inc., USA) and Cirrus-HD OCT (Carl Zeiss Meditec, USA). ONH variables were also analysed with HRT-3 (Heidelberg Engineering, Germany). All measurements were performed before and 1 week and 12 months after the surgery. 31 eyes of 31 patients (mean age 30.1 ± 5.5 years) were included. Comparing with preoperative values, no significant differences in average RNFL thickness were found with RTVue, while a slight increase (4.3 µm) was detected with Cirrus-HD (85.2 ± 10.3 µm, preoperatively) at 1-week postoperatively (89.5 ± 8.3 µm; p < 0.05). Those changes were not observed at the last follow-up visit (86.6 ± 8.6 µm; p = 0.41). Cirrus-HD detected that macular thickness was slightly higher 1 week after surgery, compared with the preoperative examination (3.4% increase; p = 0.04). That difference remained stable at the 12-month postoperative visit (p = 0.01). GCA showed no changes. The ONH analysis with Cirrus-HD determined that rim area (p = 0.03) as well as disc area (p = 0.04) significantly increased. HRT-3 found no significant changes affecting those variables. The implantation of V4c ICL® did not induce a clinically significant impact on the results of the RNFL/ONH analysis with OCT and HRT.

Longitudinal evaluation of RTVue optical coherence tomography in patients with glaucoma and suspected glaucoma and stable visual fields.

To longitudinally compare isolated structural parameters obtained using RTVue optical coherence tomography in patients with glaucoma and suspected glaucoma with stable visual fields. All patients were required to have a reliable SITA Standard 24-2 Humphrey Visual Field test. Visual field stability was defined as having <5 points with p<5% and/or having no points with p<1% and/or p<0.05% in the glaucoma progression analysis comparison graph. Furthermore, the glaucoma assessment strategy was used in optical coherence tomography. The study included 75 eyes from 75 patients, 43 of which had glaucoma and 32 had suspected glaucoma. The mean visual field intervals were 29.57 ± 9.65 months between the first and third tests. No visual field parameter variations (mean deviation, pattern standard deviation, and visual field index) and no retinal nerve fiber layer or optic disk parameter variations between the first and third tests were observed (p>0.05 for all), and no retinal nerve fiber layer parameter variations throughout the study were observed, except for optic disk parameters presenting with cup volume changes (p=0.004). However, ganglion complex cells presented a progressively decreased average ganglion cell complex parameter, with a variability of -0.98% ± 3.71% (p=0.04) between the first and third tests. By contrast, the global loss volume progressively increased throughout the study, with a variability of 14.71% ± 44.52% (p=0.04) between the first and third tests. The inferior ganglion cell complex parameter was significantly decreased between the first and third tests (p=0.02). The present findings suggest that patients with glaucoma or suspected glaucoma with stable visual fields may present structural ganglion complex cell progression as assessed using RTVue optical coherence tomography.

Relationship Between Macular Microvasculature and Visual Acuity in Advanced and Severe Glaucoma

To evaluate the correlation between structural parameters and visual acuity (VA) in advanced glaucoma. Prospective, cross-sectional study. A total of 238 eyes from 238 patients (82 were men and mean ± SD age was 59.9 ± 13.8 years) from a tertiary center were divided into an advanced (mean deviation of 24-2 visual field tests from -12.01 to -20.0 dB) and severe (< -20 dB) glaucoma group. Structural parameters were obtained by RTVue (Optovue Inc) optical coherence tomography and angiography. Pearson correlation, partial correlation adjusted for age and axial length, and receiver operating characteristic curves to detect decreased VA (<20/25) were performed. In the advanced glaucoma group (133 eyes), superficial (Pearson correlation coefficient, r = -0.46, P < .001; partial correlation coefficient, r'=-0.30, P < .001) and deep macular vessel densities (VDs) (r=-0.47, P < .001; r'=-0.30, P < .001) showed highest correlation with VA. The area under the receiver operating characteristic curves of the superficial parafoveal/macular VDs were 0.816 (95% CI, 0.735-0.897) and 0.808 (95% CI, 0.725-0.891), respectively. In the severe glaucoma group (105 eyes), deep nasal grid VD (r=-0.31, P=0.002; r'=-0.35, P < .001) showed highest correlation with VA. Deep macular VD showed better correlation with VA than other structural parameters. The area under the receiver operating characteristic curves of deep macular VD and deep nasal grid VD were 0.740 (95% CI, 0.632-0.849) and 0.748 (95% CI, 0.640-0.857), respectively. Macular VD showed better correlation with VA in advanced glaucoma. Deep macular VD, especially nasal grid, may be a promising structural parameter in severe glaucoma.

Study of State of Interface “Intraocular Lens — Posterior Capsule” Depending on Size of Capsulorhexis in Senile Cataract Phacoemulsification

Purpose. To study the state of interface “intraocular lens (IOL) — posterior capsule (PC)” depending on diameter of capsulorhexis in phacoemulsification of senile cataract.Patients and methods. 227 patients (227 eyes) were examined after phacoemulsification of senile cataract at LenSx femtosecond laser (Alcon, USA). The study did not include patients with corneal opacities, signs of axial displacement of lens, with irido- and phacodonesis, glaucoma, axial length less than 22 mm and more than 26 mm. Depending on diameter of performed capsulorhexis, we formed 3 groups: 1st group — 76 eyes with diameter capsulorexis 5.5 mm; 2nd group — 73 eyes with 5.0 mm; 3rd group — 78 eyes with 4.5 mm. We studied type of interface “IOL — PC”, the maximum value of PC diastasis and the maximum depth of its folds using an RTVue-100 Optical Coherence Tomography (Optovue, USA) on the first day after the operation.Results. The maximum number of eyes with absence of contact between IOL and PC was noted in the 3rd group (62.8 %), the largest number of eyes with full contact between IOL and PC (63.2 %) was in the 1st group. The minimum average depth of the PC folds (111.1 ± 32.7 μm) was noted in the 1st group, and the maximum (165 ± 75.4 μm) — in the 2nd group.Conclusion. The analysis showed that type of interface “IOL — PC” in the first day after phacoemulsification of senile cataract depends on diameter of capsulorhexis. The largest number of eyes (64.6 %) with full contact between IOL and PC was observed in the group of patients with capsulorhexis 5.5 mm, and the smallest (6.4 %) — in eyes with diameter capsulorexis 4.5 mm. Presumably, the main reason for the absence or incomplete contact between IOL and PC is the presence of viscous dispersive between them. The deformation of PC in the form of folds does not directly depend on diameter of capsulorhexis and, obviously, is due to the uneven tension of the capsular bag by the IOL haptics.

Corneal biomechanical changes in allergic conjunctivitis

BackgroundTo explore corneal biomechanical changes, identify related factors and determine early indicators of keratoconus (KC) development risk in allergic conjunctivitis (AC) patients.MethodsA total of 50 patients, including 20 eyes without AC and 30 eyes with AC were enrolled in this study. All patients underwent a complete ocular examination, including evaluations of clinical manifestations of AC, corneal tomography and densitometry by Pentacam, corneal biomechanics by Corvis ST, and corneal and epithelial thickness mapping by RTvue optical coherence tomography (OCT).ResultsThe index of surface variance (ISV), index of vertical asymmetry (IVA), keratoconus index (KI), index of height decentration (IHD) and Belin/Ambrosio enhanced ectasia total deviation index (BAD-D) were significantly higher in the AC group than in the non-allergic conjunctivitis (NAC) group (P < 0.05). The tomography and biomechanical index (TBI) was also significantly higher in the AC group (P = 0.04). The average epithelial thickness in the 2–7 mm annulus was significantly thinner in the AC group than in the NAC group (P < 0.05). The average densitometry of the total cornea and the anterior layer were higher in the AC group than in the NAC group (P < 0.001). The ISV, IVA, KI, IHD and BAD-D were significantly correlated with the TBI and changes in corneal epithelial thickness in AC patients (P < 0.05). The changes in epithelial thickness were closely related to the eye rubbing frequency and allergic sign scores (P < 0.05).ConclusionsAC patients should be advised to routinely undergo corneal tomographic and biomechanical measurements, and the TBI could be used as an indicator of KC development risk in AC patients.Trial registrationCorneal Biomechanical Changes of Allergic Conjunctivitis, NCT04299399. Registered March 3, 2020 - Retrospectively registered.

PRESENCE OF PERIPHERAL LESIONS AND CORRELATION TO MACULAR PERFUSION, OXYGENATION AND NEURODEGENERATION IN EARLY TYPE II DIABETIC RETINAL DISEASE.

The impact of peripheral retinal lesions (PL) visualized with ultra-wide-field imaging on diabetic retinopathy (DR) remains unclear. The purpose of this study was to assess the presence of PL and their association with macular microvasculopathy, metabolic dysfunction, and neurodegeneration in patients with Type II diabetes and early retinal disease. Forty-five degree color fundus (Topcon) and 200° ultra-wide-field images (Optos) were assessed for the presence and severity of DR. Lesions anterior to the 45° were considered peripheral. The foveal avascular zone area, perimeter and acircularity index, and foveal full-retina and parafoveal superficial/deep complex vessel density were evaluated with RTVue optical coherence tomography angiography. Vessel oxygen saturation was measured with oximetry. Peripapillary retinal nerve fiber and individual macular retinal layer thicknesses were measured with Spectralis optical coherence tomography. Among the 161 eyes (80 left eyes) of 81 patients (34 female), 64 (39.8%) showed higher levels of DR on ultra-wide-field than on 45° fundus images (P < 0.0001). PL were identified in 97 eyes (60.3%) and in 59 among 115 eyes without central signs of DR. No significant correlation to biomarkers of central microvascular disease (foveal avascular zone/vessel density variables), oxygen saturation, and retinal layer thickness was found. Ultra-wide-field imaging helps to detect more eyes with early DR due to the detection of PL, which appear independently of biomarkers of macular microvascular impairment, metabolic function, and neuropathy in eyes without central signs of DR. These results suggest that the evaluation of the retinal periphery may become crucial in DR screening if PL are proven to influence disease outcomes.

Repeatability and Agreement of Macular Thickness Measurements Obtained with Two Different Scan Modes of the Optovue RTVue Optical Coherence Tomography Device

Objectives:To evaluate the repeatability and agreement of macular thickness measurements obtained with E-MM5 and MM6, two different scan modes, on the Optovue RTVue optic coherence tomography (OCT) device.Materials and Methods:Three consecutive macular thickness measurements in 30 healthy volunteers were taken using the OCT device E-MM5 and MM6 scan modes. The repeatability and agreement of these measurements obtained from the two scan modes and divided into nine anatomical regions based on early treatment diabetic retinopathy study were subjected to statistical analysis.Results:The mean age of the participants was 29.7±6.39 years. Intraclass correlation (all ICC values ≥0.86) and coefficient of variation (all coefficient of variation values ≤2%) analyses of consecutive OCT measurements in the nine regions of the macula obtained in both E-MM5 and MM6 scan modes gave high repeatability rates. Mean macular thickness values in the foveal region were 243.76±21.79 μm in E-MM5 mode and 247.04±19.83 μm in MM6 mode (p=0.543). Values for measurements obtained in E-MM5 and MM6 scan modes in parafoveal macular regions were also statistically similar (p>0.05 for all). However, a statistically significant difference was observed between the two modes in perifoveal macular measurements, except in the superior region.Conclusion:The Optovue RTVue OCT device gives highly repeatable measurement results for macular thicknesses in both E-MM5 and MM6 scan modes. However, it should be considered that measurements performed in E-MM5 and MM6 modes give different results in perifoveal regions.

Comparison of Optic Disc Parameters in Hyperopic and Emmetropic Eyes of Healthy Children with HRT and OCT.

To investigate, through Heidelberg retina tomography II (HRT II) and RTVue-100 optical coherence tomography (OCT), normal parameters of the optic nerve head (ONH) in highly hyperopic children, and compare these with a group of children with low hyperopia and emmetropia, as fundus examination of highly hyperopic children often shows crowding of the optic disc, which may be difficult to distinguish from mild optic disc swelling. ONH of the higher hyperopic eye was examined with HRT II and the peripapillary nerve fiber layer (RNFL) with RTVue-100, in 6 to 15-year-old full-term children with normal visual acuity and spherical equivalent ≥ + 3.0 D (hyperopic group) and < + 3.0 to - 1.0 D (emmetropic group). Thirty highly hyperopic children and 33 emmetropic controls had a mean spherical equivalent of + 5.1 ± 1.5 D and a mean age of 8.4 ± 2.8 years, and + 1.0 ± 1.2 D and 9.6 ± 2.6 years, respectively. There was no significant difference in OCT-assessed RNFL thickness between the two groups. Compared to the emmetropic group, following HRT parameters were significantly smaller in the hyperopic group: Disc area (1.41 vs. 1.68 mm2, p = 0.023), cup area (0.19 vs. 0.37 mm2, p = 0.0001), cup volume (0.03 vs. 0.08 mm3, p = 0.02), cup/disc area (0.13 vs. 0.20, p = 0.006), linear cup/disc (0.33 vs. 0.42, p = 0.004), and mean cup depth (0.13 vs. 0.17 mm, p = 0.019). In children, ONH of highly hyperopic eyes are smaller than those of emmetropic eyes. RNFL thickness and neural rim volume are similar to emmetropic eyes. They can therefore appear more crowded.

Impact of the anti-aquaporin-4 autoantibody on inner retinal structure, function and structure-function associations in Japanese patients with optic neuritis.

PurposeAn autoantibody against aquaporin-4 (AQP4 Ab) is highly specific for neuromyelitis optica spectrum disorder and plays a pathogenic role in this disease. The purpose of this study was to investigate the impact of AQP4 Ab on inner retinal structure, function, and the structure−function relationships in eyes with optic neuritis.MethodsThirty five eyes from 25 cases who had received visual function tests and RTVue optical coherence tomography (OCT) measurement at least six months after the latest episode of optic neuritis were enrolled. Patients with multiple sclerosis were excluded. AQP4 Ab was measured using a cell-based assay. Visual acuity, mean deviation (MD) of the Humphrey visual field SITA standard 30–2 tests, retinal nerve fiber layer (RNFL), ganglion cell complex (GCC) thicknesses, and other clinical variables were compared between the AQP4 Ab-positive and -negative groups. Parameters associated with visual functions were evaluated by generalized estimating equation (GEE) models.ResultsThe AQP4 Ab-positive group (20 eyes from 12 cases) had a higher proportion of bilateral involvement and longer duration of follow-up than the AQP4 Ab-negative group (15 eyes from 13 cases). Linear mixed effect models revealed worse MD and visual acuity in AQP4 Ab-positive eyes than those in AQP4 Ab-negative eyes after adjusting for within-patient inter-eye dependence, whereas there were no differences in RNFL and GCC thickness between the two groups. In seropositive eyes, GEE regression analyses revealed that depending on age and the number of recurrences of ON episodes, OCT parameters correlated strongly with MD and more weakly with visual acuity.ConclusionsReductions in RNFL and GCC thickness were proportional to the visual field defect in eyes with AQP4 Ab but not in eyes without AQP4 Ab. The presence of AQP4 Ab probably plays a critical role in retinal ganglion cell loss in optic neuritis.

Distinguishing between contact lens warpage and ectasia: Usefulness of optical coherence tomography epithelial thickness mapping

To distinguish between corneal ectasia and contact lens-related warpage by characteristic patterns on corneal topography and optical coherence tomography (OCT) epithelial thickness maps. Casey Eye Institute, Portland, Oregon, USA. Prospective and retrospective case series. Axial and mean power maps were obtained on corneal topography systems. Epithelial thickness maps were generated using RTVue OCT. A sector divider was applied to all maps. The locations of the minimum epithelial thickness, maximum epithelial thickness, maximum axial power, and maximum mean power were determined based on sector averages. Agreement was defined as the extremums occurring in the same or adjacent sectors. Twenty-one eyes with keratoconus, 6 eyes with forme fruste keratoconus (better eye of asymmetric keratoconus), and 15 eyes with contact lens-related warpage were identified. The keratoconus and forme fruste keratoconus eyes had coincident topographic steepening with epithelial thinning. The locations of minimum epithelial thickness and maximum axial power agreed in 90% of the keratoconic eyes, while the minimum epithelial thickness and maximum mean power agreed in 95% of them. Conversely, the warpage eyes had coincident topographic steepening with epithelial thickening and normal pachymetry maps. The locations of maximum epithelial thickness and maximum axial power agreed in 93% of the warpage eyes, while the maximum epithelial thickness and maximum mean power agreed in all warpage eyes. Results show that epithelial thickness maps and corneal topographic maps are powerful synergistic tools in evaluating eyes with abnormal topography and can help differentiate between keratoconus and nonectatic conditions.

Comparison of Several Parameters in Two Optical Coherence Tomography Systems for Detecting Glaucomatous Defects in High Myopia.

To compare the diagnostic powers of parameters of the RTVue and Cirrus-HD optical coherence tomography (OCT) systems in detecting glaucoma in highly myopic eyes. For this study, 28 glaucoma patients with high myopia (HM-G) and 28 high-myopia controls (HM-C) were enrolled. The circumpapillary retinal nerve fiber layer (cp-RNFL) and ganglion cell complex (GCC) parameters in the RTVue-OCT, and the ganglion cell-inner plexiform layer (GCIPL) and cp-RNFL parameters in the Cirrus HD-OCT, were obtained for each subject. The receiver operating characteristics curve (ROC) was used to assess the diagnostic ability of each parameter, and the areas under the curves (AUROCs) of those parameters were compared. In both OCTs, the macular parameters showed significantly higher diagnostic power than the cp-RNFL thickness. The minimum GCIPL (0.977), inferotemporal GCIPL (0.947), and vertical cup/disc (C/D) ratio (0.968) showed the best performances among all of the Cirrus HD-OCT parameters. The focal loss volume (FLV) (0.964), global loss volume (GLV) (0.899), and vertical C/D ratio (0.899) showed the best performances among all of the RTVue-OCT parameters. Among the parameters with high diagnostic ability in each protocol of the two OCTs, the superior sector of the cp-RNFL had significantly lower abilities than the FLV and the minimum of the GCIPL (P < 0.05) in detecting glaucoma in high myopia. The macular measurements had significantly better glaucoma detection abilities than the cpRNFL thickness in the high-myopia subjects in both RTVue-OCT and Cirrus HD-OCT, with no significant differences in the diagnostic ability between the two macular parameters.

Interocular Symmetry of Macular Ganglion Cell Complex Thickness in Young Chinese Subjects

PurposeTo report interocular differences in macular ganglion cell complex (mGCC) thickness in young Chinese subjects using RTVue-100 optical coherence tomography (OCT).MethodsThis was an observational, cross-sectional study. The mGCC thickness was measured in 158young Chinese subjects using RTVue-100 OCT. The normal ranges of the interocular differences were determined as falling between the 2.5th and 97.5th percentiles. Right and left eyes were compared using a paired t test. Pearson correlation analysis was performed to assess the relationships between mGCC thickness and other potential factors. The relationships between the interocular difference in the average mGCC thickness and the potential factors were evaluated by univariate and multivariate linear regression analysis.ResultsThe mean interocular difference in the average, superior, and inferior mGCC thickness were 0.19 ± 2.69 μm, 0.22 ±3.14 μm, and 0.25±3.34 μm, respectively, which were not statistically significant. The 2.5th and 97.5th percentiles of interocular difference for mean average mGCC thickness were -4.82μm and 4.38μm, for superior mGCC thickness, -6.67 μm and 7.04 μm, and for inferior mGCC thickness, -6.75 μm and 6.27 μm. There was a strong correlation between the right and left eyes for all the studied parameters, including spherical equivalent (SE) and axial length (AL). Interocular difference in SE (p = 0.007) were independently correlated with the interocular difference in average mGCC thickness.ConclusionsThere was no significant relative interocular difference in mGCC thickness in young Chinese subjects. Interocular difference exceeding the normal limits should be considered significantly asymmetrical, and suggestive of pathology.

Evaluation of a New Software Version of the RTVue Optical Coherence Tomograph for Image Segmentation and Detection of Glaucoma in High Myopia

To compare the current (6.3) and a novel software version (6.12) of the RTVue-100 optical coherence tomograph (RTVue-OCT) for ganglion cell complex (GCC) and retinal nerve fiber layer thickness (RNFLT) image segmentation and detection of glaucoma in high myopia. RNFLT and GCC scans were acquired with software version 6.3 of the RTVue-OCT on 51 highly myopic eyes (spherical refractive error ≤-6.0 D) of 51 patients, and were analyzed with both the software versions. Twenty-two eyes were nonglaucomatous, 13 were ocular hypertensive and 16 eyes had glaucoma. No difference was seen for any RNFLT, and average GCC parameter between the software versions (paired t test, P≥0.084). Global loss volume was significantly lower (more normal) with version 6.12 than with version 6.3 (Wilcoxon signed-rank test, P<0.001). The percentage agreement (κ) between the clinical (normal and ocular hypertensive vs. glaucoma) and the software-provided classifications (normal and borderline vs. outside normal limits) were 0.3219 and 0.4442 for average RNFLT, and 0.2926 and 0.4977 for average GCC with versions 1 and 2, respectively (McNemar symmetry test, P≥0.289). No difference in average RNFLT and GCC classification (McNemar symmetry test, P≥0.727) and the number of eyes with at least 1 segmentation error (P≥0.109) was found between the software versions, respectively. Although GCC segmentation was improved with software version 6.12 compared with the current version in highly myopic eyes, this did not result in a significant change of the average RNFLT and GCC values, and did not significantly improve the software-provided classification for glaucoma.

Influence of a new software version of the RTVue-100 optical coherence tomograph on the detection of glaucomatous structural progression.

To compare the current (6.3) and a novel software version (6.12) of the RTVue-100 optical coherence tomograph (RTVue-OCT) for detection of glaucomatous inner macular retinal thickness (ganglion cell complex [GCC]) and retinal nerve fiber layer thickness (RNFLT) progression. In this prospective, observational study, 109 participants (17 healthy controls, 20 patients with ocular hypertension, and 72 patients with glaucoma) were investigated with RTVue-OCT at 6-month intervals (mean follow-up 5 years). One eye per participant was evaluated. Long-term measurement variability (residual standard deviation) was significantly lower with software version 6.12 than version 6.3 for all parameters in the total population, the normal controls, and the glaucoma group, respectively (p≤0.0065). The between-software-version difference of residual standard deviation did not correlate with the measured thickness for any parameter. In the glaucoma group, the negative GCC slopes (µm/visit) were significantly (p&lt;0.001) steeper, while the negative RNFLT slopes were either similar or less steep with software version 6.12. Significantly more significant negative GCC parameter slopes were found in the glaucoma group and the total population with version 6.12, while no between-software-version difference was seen for the other groups, and for the RNFLT parameters in all groups. The new software version reduces long-term RNFLT and GCC measurement variability, provides steeper GCC progression slopes, and provides more cases of significant GCC progression slopes in glaucoma than the current software version. Since version 6.12 is employed in the recently introduced Widefield RTVue-XR instrument, it may improve detection of glaucomatous progression in clinical practice.

Influence of a new software version of the RTVue-100 optical coherence tomograph on ganglion cell complex segmentation in various forms of age-related macular degeneration.

Previously, we have shown that age-related macular degeneration (AMD) influences glaucoma classification with the ganglion cell complex (GCC) parameters of the RTVue-100 optical coherence tomograph (RTVue-OCT) in nonglaucomatous eyes. Now, we reevaluated the influence of AMD on GCC image segmentation and classification for glaucoma on the same eyes, using a new version of the software. GCC images of nonglaucomatous eyes [30 healthy, 19 with early/intermediate AMD, 16 with subfoveal choroidal neovascularization (CNV), and 19 after intravitreal antiangiogenic treatment of CNV, CNV-anti-VEGF] were reanalyzed with software versions 6.3 (the currently available version) and 6.12 (a version not yet commercially released). Global loss volume (GLV) was significantly reduced with version 6.12 in all groups (P≤0.0416). Segmentation errors were seen in 2 versus 0 of the normal eyes (P=0.500), 8 versus 0 of the early/intermediate AMD eyes (P=0.0312), 16 versus 6 of the CNV eyes (P=0.0080), and 18 versus 3 of the CNV-anti-VEGF eyes (P=0.0004) with software versions 6.3 and 6.12, respectively. For focal loss volume the distribution of the classification results differed significantly between the software versions in the CNV and CNV-anti-VEGF groups (P=0.0312 and 0.0160, respectively). For both groups more eyes were classified as "within normal limits," and less as "outside normal limits" with software version 6.12 than with version 6.3. For nonglaucomatous AMD eyes the frequency of GCC segmentation errors was significantly reduced, GLV was significantly lower (more normal), and the classification for glaucoma was more correct with software version 6.12 than with version 6.3.

RTVue Optical Coherence Tomography as an Imaging Modality for Scleral Thickness

Purpose: To examine RTVue (Optovue, Inc) optical coherence tomography (OCT) as a method for measuring scleral thickness. Methods: A prospective, single-center study of eyes with a variety of ocular diseases (no scleral diseases) was performed to image scleral thickness utilizing the RTVue OCT. Repeated measurements of scleral thickness were performed using a line scan 3 mm from the limbus in the inferior nasal and inferior temporal quadrants of each eye. Obtained values were analyzed statistically. Results: A total of 25 eyes in 14 subjects were measured. An average of 3 measurements per location per eye were taken. The mean scleral thickness 3 mm from the limbus was 654.22 μm. The average standard deviation of the measurements from each location was 30.88 μm. The Original Research Article Cramer et al.; OR, 3(4): 95-99, 2015; Article no.OR.2015.016 96 boundary of the conjunctiva and sclera was easily distinguishable. Conclusion: The results of this study suggest that RTVue high-resolution OCT is a user-friendly modality for measuring scleral thickness.

Agreement in Quantitative Anterior Chamber Angle Metrics between RTVue and Cirrus Spectral Domain Optical Coherence Tomography

Purpose: To investigate the agreement between two spectral domain optical coherence tomography (SD-OCT) instruments in Schwalbe’s line (SL) based anterior chamber angle parameters and to evaluate their repeatability and reproducibility. Methods: The inferior irido-corneal angle of 114 eyes from 59 participants (29 glaucoma and 30 normal) were scanned twice with the Optovue SD-OCT and Cirrus SD-OCT under controlled low luminance conditions. SL angle opening distance (SL-AOD) and SL trabecular-iris-space area (SL-TISA) were graded by masked certified graders at the Doheny Image Reading Center. Results: The mean SL-AOD/SL-TISA was 623±271μm/ 0.221 ± 0.106 mm2 for the Cirrus and 611 ± 267 μm/ 0.215 ± 0.112 mm2 for the RTVue. Excellent repeatability (intraclass correlation coefficient ICC>0.934), excellent intragrader reproducibility (ICC>0.957) and very good intergrader reproducibility (ICC>0.877) were observed with both instruments in SL-AOD and SL-TISA. The agreement between Cirrus and RTVue was excellent (ICC 0.943 for SL-AOD and 0.900 for SL-TISA). Conclusion: Both instruments provide consistent and reproducible measurement of SL-AOD and SL-TISA. The excellent agreement between them allows for direct comparisons of angle measurements acquired with different SDOCTs and can lead in the introduction of criteria that could be valid across different platforms

Reproducibility of Optovue RTVue Optical Coherence Tomography Retinal Thickness Measurements and Conversion to Equivalent Zeiss Stratus Metrics in Diabetic Macular Edema.

To evaluate the reproducibility of central subfield thickness (CST) and volume measurements from optical coherence tomography (OCT) images obtained with Zeiss Stratus and Optovue RTVue, and formulate equations to convert these measurements from RTVue to 'equivalent' Stratus values. Cross-sectional observational study from 309 eyes of 167 participants with diabetes and at least one eye with central-involved diabetic macular edema (DME; Stratus CST ≥ 250 μm) that underwent two replicate Stratus scans followed by two replicate RTVue scans centered on the fovea. The Bland-Altman coefficient of repeatability for relative change in CST (the degree of change that could be expected from measurement variability) was not significantly different on Stratus and RTVue scans (10% and 16%, respectively). The replicate Stratus CST was within 10% of the initial Stratus measurement 93% of the time; the CST conversion equation predicted a Stratus value calculated from the observed RTVue value within 10% of the observed Stratus thickness 91% of the time. Bland-Altman limit of agreement for relative change in CST between measurements observed on different machines was 23%, comparing predicted versus actual Stratus measurement. RTVue thickness reproducibility appears similar to Stratus. Conversion equations to transform RTVue measurements to Stratus-equivalent values within 10% of the observed Stratus RT are feasible. CST changes greater than 10% when using the same machine or 20% when switching from Stratus to RTVue, after conversion to Stratus equivalents, are likely due to a true change beyond measurement error. Conversion equations to translate central retinal thickness measurements between OCT instruments is critical to clinical trials.

Changes in Area of Conjunctiva and Tear Meniscus Measured Using Anterior Segment Optical Coherence Tomography after Conjunctivochalasis Surgery

Purpose: To evaluate cross-sectional areas of conjunctiva and tear meniscus of conjunctivochalasis using Fourier-Domain RTVue-100 optical coherence tomography (OCT) before and after conjunctivochalasis surgery. Methods: Thirty-one patients (33 eyes) with symptomatic conjunctivochalasis were recruited for this study between June 2013 and April 2014. All patients underwent crescent-shaped conjunctiva resection and amniotic membrane transplantation. Anterior segment OCT (AS-OCT) imaging was performed and tear break-up time was evaluated prior to and 3 months after the conjunctivochalasis surgery. Cross-sectional areas of conjunctiva and tear meniscus of conjunctivochalasis at 7 locations (1 center, 3 nasal and 3 temporal areas) were measured in all patients. Results: The mean age of patients was 66.3 ± 10.8 years. Cross-sectional areas of conjunctivochalasis at all locations significantly decreased from 0.487 ± 0.42 mm to 0.007 ± 0.011 mm (p < 0.001), whereas no significant changes in cross-sectional areas of tear meniscus at all 7 locations were observed after the surgery. Mean tear break-up time significantly increased from 2.26 ± 0.69 sec to 3.81 ± 1.22 sec following the surgery. Conclusions: Using AS-OCT, in this study we showed that areas of conjunctiva decreased and areas of tear meniscus were unchanged after conjunctivochalasis surgery. J Korean Ophthalmol Soc 2015;56(4):509-514