Average Ganglion Cell-inner Plexiform Layer Thickness Research Articles

Changes in Peripapillary Microvasculature and Retinal Thickness in the Fellow Eyes of Patients With Unilateral Retinal Vein Occlusion: An OCTA Study.

To evaluate changes in peripapillary microvascular parameters in the fellow eyes of patients with unilateral retinal vein occlusion (RVO) using optical coherence tomography angiography (OCTA) and to determine the relationships between peripapillary microvasculature and retinal nerve fiber layer (RNFL) and ganglion cell-inner plexiform layer (GC-IPL) thickness. Eighty-three patients with unilateral RVO (50 patients with branch RVO and 33 with central RVO) and 83 normal controls were enrolled. OCTA (Cirrus HD-OCT 5000 with AngioPlex) 6 × 6-mm scans centered on the optic disc were acquired. Peripapillary vessel density (VD) and perfusion density (PD) were automatically calculated. The average RNFL and GC-IPL thicknesses in the fellow eyes of RVO patients were significantly thinner than in normal controls (93.5 vs. 96.6 μm, P = 0.013 and 81.3 vs. 84.1 μm, P = 0.003, respectively). In the fellow eyes of patients with unilateral RVO, the peripapillary VD of the inner ring, outer ring, and full area (17.47, 18.50, and 17.89, respectively) were significantly lower than those of controls (17.87, 18.87, and 18.27, respectively). The peripapillary PD of the inner ring, outer ring, and full area (0.456, 0.467, and 0.456, respectively) were also significantly lower than those of controls (0.468, 0.476, and 0.466, respectively). RNFL and GC-IPL thicknesses were correlated with both peripapillary VD and PD. OCTA revealed that peripapillary microvascular parameters in the fellow eyes of patients with unilateral RVO were decreased, and GC-IPL and RNFL thinning were also observed. The RNFL and GC-IPL thicknesses were positively correlated with both peripapillary VD and PD.

Changes in Ganglion Cell–Inner Plexiform Layer Thickness and Retinal Microvasculature in Hypertension: An Optical Coherence Tomography Angiography Study

To investigate retinal blood flow in patients with hypertension using optical coherence tomography angiography (OCTA) and the relationship between blood flow metrics and ganglion cell-inner plexiform layer (GC-IPL) thickness. Retrospective, cross-sectional study. A total of 201 eyes from 117 healthy subjects and 84 hypertensive patients without any ocular abnormalities were included. Hypertensive patients were divided into the 2 groups according to disease periods (<5 years: Hypertension Group 1; ≥5 years: Hypertension Group 2). Macular 3× 3-mm angiography was acquired using the Zeiss Cirrus 5000 OCT instrument. Vessel density (VD), perfusion density (PD), and foveal avascular zone metrics of the superficial capillary plexus were automatically calculated, and the thicknesses of the central fovea, GC-IPL, and peripapillary retinal nerve fiber layer (RNFL) were measured. All measurements were compared among the 3 groups, and retinal blood flow metrics were correlated with the thickness of each retinal layer. Logistic regression analyses were performed to determine the factors associated with prolonged hypertension. The average GC-IPL (P < .001) and peripapillary RNFL (P= .048) thicknesses in Hypertension Group 2 were significantly thinner compared to the control group. The 3mm total area of the VD and PD was also decreased compared to the control group and Hypertension Group 1 (all P < .05), and was significantly correlated with the GC-IPL (VD: r= 0.450, P=.001; PD: r= 0.467, P < .001) and peripapillary RNFL (VD: r= 0.314, P= .027; PD: r= 0.328, P=.023) thicknesses in Hypertension Group 2. Using multivariate logistic analyses, only the average GC-IPL thickness was a significant factor for prolonged hypertension (odds ratio= 0.911, P= .002). In patients with hypertension lasting more than 5 years, inner retinal layer thinning, particularly GC-IPL thinning, was observed, which was significantly correlated with a decrease in retinal blood flow. Therefore, physicians should consider the effects of hypertension on the GC-IPL.

Effects of Measurement Center Shift on Ganglion Cell-inner Plexiform Layer Thickness Measurements.

Our authors studied the effects of measurement center shift on ganglion cell-inner plexiform layer (GCIPL) thickness measurements in Cirrus spectral-domain optical coherence tomography (SD-OCT). The measurement center shift affects the GCIPL thickness measurement depending on the distance of shift. The purpose of this study was to explore changes in macular GCIPL thicknesses measurements after manual shifting of the measurement center using SD-OCT. A prospective study was conducted. A total of 30 normal eyes of 30 subjects were included in the study. An experienced examiner obtained two consecutive measurements of GCIPL thickness using SD-OCT. Coefficients of repeatability were calculated for the average, minimum, and sectoral (superotemporal, superior, superonasal, inferonasal, inferior, and inferotemporal) thicknesses. Next, the measurement center was manually shifted from the foveal center. Three measurement centers were horizontally placed at 59-μm intervals from the foveal center, and two further centers were placed 176 μm apart. Also, three measurement centers were vertically placed at 47-μm intervals from the foveal center, and two further centers were placed 142 μm apart. The thickness of GCIPL was measured again at each shift point, and the changes of thickness before and after movement were analyzed. When the measurement centers were shifted to positions 59 μm horizontally or 47 μm vertically from the fovea, no significant changes in GCIPL thicknesses were evident. However, upon more pronounced shifting, the average GCIPL thickness of the direction of the shift region was significantly lower than baseline, whereas the GCIPL of the diametrically opposite sector was thicker than baseline. The impact of changes associated with shifting of the measurement center should be taken into consideration when measuring GCIPL thickness in patients with retinal diseases, glaucoma, or neuro-ophthalmological conditions.

Ganglion cell-inner plexiform layer thickness by swept-source optical coherence tomography in healthy Korean children: Normative data and biometric correlations

The purpose of this study was to identify the normative values of ganglion cell-inner plexiform layer (GCIPL) thickness in healthy Korean children using swept-source optical coherence tomography (SS-OCT) and to investigate the correlations of age, refractive error, axial length (AL), retinal nerve fiber layer (RNFL) thickness and cup-to-disc (C/D) ratio with GCIPL thickness. Children aged between 3 and 17 who had visited our pediatric ophthalmology clinic were enrolled. Each subject underwent full ophthalmic examinations including RNFL thickness, C/D ratio and GCIPL thickness measurement by SS-OCT as well as AL measurement by partial-coherence interferometry. A total of 254 eyes of 127 children were included. The mean average GCIPL thickness was 71.5 ± 5.35 μm; the thickest sector was the superonasal and the thinnest the inferior. According to multivariate regression analysis, average GCIPL thickness was significantly associated with spherical equivalent and RNFL thickness (P < 0.0001 for both): the higher the myopia or the thinner the RNFL thickness, the thinner the GCIPL thickness. In conclusion, this study provides an SS-OCT-based pediatric normative database of GCIPL thickness that can serve as a reference for early detection and follow-up of glaucoma and optic nerve diseases in children.

Optic nerve changes in chronic sinusitis patients: Correlation with disease severity and relevant sinus location.

PurposeThis study was to evaluate whether optic nerve damage occurs in eyes with adjacent chronic sinusitis.MethodsData were collected from eighty-eight eyes of 46 chronic sinusitis patients and 93 eyes of 57 normal controls. Visual sensitivity using standard automated perimetry (SAP) and inner retinal thickness using optical coherence tomography (OCT) were measured. The Lund-Mackay system was used to quantify radiographic findings on the ostiomeatal unit CT scan with a numerical score representing the severity of sinusitis.ResultsThere was a significant positive correlation between the pattern standard deviation (dB) and Lund-Mackay score (P = 0.031). Nasal retinal nerve fiber layer (RNFL) thickness, average, minimum, superotemporal, superior, superonasal, and inferonasal ganglion cell-inner plexiform layer (GCIPL) thickness were negatively correlated significantly with Lund-Mackay score (all, P < 0.05). Eyes with grade 2 opacification of the posterior ethmoid sinus showed a significantly lower mean deviation (dB) and higher pattern standard deviation (dB) than those with clear respective sinuses (P = 0.007 and <0.001, respectively). Eyes with grades 1,2 and 3 opacification of the sphenoid sinus had a significantly less average RNFL thickness (P = 0.004, <0.001, and <0.001, respectively) and a significantly less average GCIPL thickness (P = 0.004, 0.003, and 0.003, respectively) than those with a clear sphenoid sinus.ConclusionsStructural and functional optic nerve changes were correlated with the severity of chronic sinusitis. Inflammation of the posterior ethmoid and sphenoid sinuses was associated with optic nerve changes to a greater extent than that of the other paranasal sinuses.

Interocular Asymmetry of the Ganglion Cell-inner Plexiform Layer in Diabetic Retinopathy.

The interocular difference in the ganglion cell-inner plexiform layer thickness showed a significant correlation with the diabetic retinopathy (DR) severity. The purpose of this study was to analyze the interocular differences in the foveal, retinal nerve fiber layer (RNFL), and ganglion cell-inner plexiform layer (GC-IPL) thickness of DR patients using spectral-domain optical coherence tomography. A total of 508 eyes from 254 patients with different severities of DR and 184 eyes from 92 control subjects were included. The GC-IPL, foveal, and RNFL thicknesses were measured, and the interocular differences in these thicknesses were correlated in control subjects and DR patients. The interocular difference in the average GC-IPL thickness significantly increased with the severity of DR. The interocular differences in the average GC-IPL thicknesses of the severe nonproliferative DR (NPDR) and the proliferative DR patients were significantly higher than those of the control group. However, there was no significant difference in thickness between the control group and the group with mild to moderate NPDR. In the group with proliferative DR, the interocular difference in the average GC-IPL was greater than those in the central foveal and RNFL thicknesses. Multivariate regression analyses showed that the DR severity and the interocular difference in central foveal thickness were significantly correlated with the interocular difference in the average GC-IPL thickness. The interocular differences in the central foveal, RNFL, and GC-IPL thicknesses significantly increased with increased DR severity. However, there was no significant difference between the control group and the group with mild to moderate NPDR. The GC-IPL differences showed a significant correlation with DR severity. These findings may be an indicator of DR progression.

Optical coherence tomography analysis of the inner retinal layers in children

ObjectiveThe aim of this study was to determine a correlation between the optic nerve head (ONH) area, the peripapillary retinal nerve fibre layer (pRNFL), and the ganglion cell inner plexiform layer (GCIPL) thicknesses, measured by optical coherence tomography (OCT) in children. MethodsCross-sectional study of 358 eyes in 358 children, 187 belonging to males (52.2%), having a mean age of 6.41 ± 1.66 years and spherical equivalent 0.22 ± 0.50 D. All subjects were imaged with Cirrus HD-OCT. ONH parameters, pRNFL, and macula thicknesses maps for each subject were obtained. ResultsAverage pRNFL thickness was 100.19 ± 10.10 μm and average GCIPL thickness was 85.29 ± 5.54 μm. Thirty-eight eyes (10.6%) had megalopapilla. A positive correlation was found between pRNFL thickness and the ONH area, GCIPL thickness and the ONH area, and pRNFL and GCIPL thicknesses. ConclusionsIn children, a positive correlation was found between pRNFL and GCIPL thicknesses and the ONH area. As the ONH area increases, the pRNFL and GCIPL thicknesses measured by OCT increase, supporting the histological observations that large discs have a higher number of ganglion cells. Consequently, the fixed diameter of the OCT scan does not influence these measurements. We suggest that a future normative database of OCT measurements adapted to children adjust the pRNFL and GCIPL thicknesses with the ONH area.

Correlation between macular ganglion cell-inner plexiform layer thickness and visual acuity after resolution of the macular edema secondary to central retinal vein occlusion.

To examine the thickness of the ganglion cell-inner plexiform layer (GCIPL) in eyes with resolved macular edema (ME) in non-ischemic central retinal vein occlusion (CRVO), applying spectral-domain optical coherence tomography (SD-OCT), and its relationship with visual acuity. The retrospective observational case-control study included 30 eyes of non-ischemic CRVO patients with resolved ME (ME eyes) after treatment, and 30 eyes of non-ischemic CRVO patients without ME (non-ME eyes). The macular GCIPL thickness, peripapillary retinal nerve fiber layer (pRNFL) thickness and central macular thickness (CMT) were measured on a SD-OCT scan. Linear regression analyses were performed to determine the correlation between the thickness of each and the visual acuity (VA). No significant difference in average GCIPL thickness, mean pRNFL thickness and CMT were observed between ME group and non-ME group (P=0.296, 0.183, 0.846). But, minimum GCIPL thickness was reduced in ME eyes compared with non-ME eyes (P=0.022). Final VA significantly correlated with the minimum GCIPL thickness in ME eyes (r=-0.482, P=0.007), whereas no correlation was found with average GCIPL thickness, average pRNFL thickness and mean CMT. Minimum GCIPL thickness is reduced in ME eyes compared with non-ME eyes, and correlated with the VA in non-ischemic CRVO. These results propose that inner retinal damage occurring in patients with ME secondary to non-ischemic CRVO may lead to permanent visual defect after treatment.

LONGITUDINAL CHANGES IN THICKNESSES OF THE MACULA, GANGLION CELL-INNER PLEXIFORM LAYER, AND RETINAL NERVE FIBER LAYER AFTER VITRECTOMY: A 12-Month Observational Study.

To analyze longitudinal changes in the thicknesses of the macula, ganglion cell-inner plexiform layer (GC-IPL), and peripapillary retinal nerve fiber layer (RNFL) after vitrectomy. Thirty-eight patients diagnosed with intraocular lens (IOL) dislocation without evidence of other vitreoretinal diseases were included. They underwent conventional vitrectomy and IOL transscleral fixation, with a follow-up of 12 months. Using spectral domain optical coherence tomography, the thicknesses of the macula, GC-IPL, and peripapillary RNFL in the vitrectomized and fellow control eyes were measured. Various optic nerve head parameters were also determined. Optical coherence tomography showed that there were no significant differences in postoperative central macular thickness compared with baseline values. The average GC-IPL thickness increased 1 month after surgery from baseline (P = 0.038). The average RNFL thickness increased from baseline at 1 month (P = 0.001) and 3 months (P = 0.011) after vitrectomy. The mean foveal, GC-IPL, and RNFL thicknesses of the study eyes compared with the fellow control eyes increased at 1 month (P = 0.034), 1 month (P = 0.048), and 1 month (P = 0.013) to 3 months (P = 0.038), respectively, after surgery. However, no significant differences were found in intraocular pressure or optic nerve head parameters between the study and fellow control eyes at 12 months after surgery. Transient increases in the thickness of the macula and GC-IPL were observed at 1 month after vitrectomy, and the postoperative RNFL thickness increased until 3 months after surgery, after which it returned to preoperative levels. There was no significant change in intraocular pressure or optic nerve head parameters before and after surgery.

Peripapillary retina nerve fiber layer thickness and macular ganglion cell layer thickness in patients with obstructive sleep apnea syndrome.

PurposeTo investigate the association of the severity of obstructive sleep apnea syndrome (OSAS) with peripapillary retinal nerve fiber layer (RNFL) and macular ganglion cell-inner plexiform layer (GC-IPL).Materials and methodsIn this cross-sectional study, 145 patients with OSAS and 40 healthy subjects were enrolled. OSAS patients were further divided into mild (n=50), moderate (n=36), and severe (n=59) OSAS groups according to their apnea-hypopnea index (AHI) values. Spectral-domain optical coherence tomography was used to measure the peripapillary RNFL and GC-IPL thicknesses.ResultsThere was no statistical difference between the RNFL thickness in OSAS and control groups (P>0.05). Both average GC-IPL and minimum GC-IPL thicknesses were significantly lower in severe OSAS group than in healthy controls (P<0.05 for both). There was a significant negative correlation between AHI and both average GC-IPL (r=-0.232, P=0.005) and minimum GC-IPL (r=-0.233, P=0.005) thicknesses.ConclusionsOur study results suggest that although RNFL thickness did not differ significantly between OSAS and control groups, ganglion cell layer thickness in OSAS patients is much lower than in healthy population. Ganglion cell thickness showed a significant correlation with the severity of OSAS.

The Evaluation of Anatomic and Functional Changes in Unilateral Moderate Amblyopic Eyes Using Optical Coherence Tomography and Pupil Cycle Time

ABSTRACTPurpose: To investigate whether macular anatomic structure and afferent visual system function differ among amblyopic eyes, non-amblyopic fellow eyes, and controls, using spectral-domain optical coherence tomography (SD-OCT), and pupil cycle time (PCT).Methods: This observational, cross-sectional study included 30 patients with unilateral amblyopia and 30 healthy subjects. Optical coherence tomography (OCT) and pupil cycle time (PCT) were used to evaluate patients with unilateral amblyopia and were compared with their non-amblyopic fellow eyes and age- and gender-matched healthy eyes (30 participants). The amblyopic eyes were separated into two groups: anisometropic amblyopia (n = 16) and strabismic amblyopia (n = 14). OCT maps were used to calculate central macular thickness (CMT), retinal nerve fiber layer thickness (RNFLT), and ganglion cell-inner plexiform layer (GC-IPL) thickness.Results: The average RNFLT, GC-IPL thickness, and CMT did not show any significant differences among the amblyopic eyes, non-amblyopic fellow eyes and controls (p > 0.05, Kruskal–Wallis test). Mean PCT was 773.57 ± 64 msn in strabismic eyes, 771.25 ± 58 msn in anisometropic eyes, 778.00 ± 72 msn in non-amblyopic fellow eyes, and 774.75 ± 69 msn in control eyes. The differences among the amblyopic eyes, its fellow and control eyes were not statistically significant (p > 0.05, Kruskal–Wallis test).Conclusions: In this study, we investigated morphological and functional differences among amblyopic eyes, non-amblyopic fellow eyes and controls by using SD-OCT and PCT. We did not find anatomical or functional changes in amblyopic eyes.

Detection of Functional Change in Preperimetric and Perimetric Glaucoma Using 10-2 Matrix Perimetry

To evaluate an effective functional strategy for detecting glaucomatous damage of the macula in preperimetric to perimetric glaucoma. Cross-sectional study. Preperimetric glaucoma patients (n=102) and perimetric glaucoma patients (n= 88) with isolated paracentral scotoma or combined paracentral scotoma were enrolled in this study. Global and sectoral mean sensitivities (MS) were evaluated using 10-2 standard automated perimetry (SAP) with a stimulus of sizes III (0.43-degree diameter) and V (1.72 degrees), and 10-2 Matrix perimetry with a stimulus of 2 degrees. Ganglion cell-inner plexiform layer (GCIPL) was measured using spectral-domain optical coherence tomography. The percentage of significantly depressed visual field (VF) points <5% and <1% in the pattern deviation plot was higher with frequency doubling technology (FDT) 10-2 than with SAP 10-2 III in patients with preperimetric glaucoma (both P < .001). Using FDT 10-2 tests, the global structure-function correlation was superior to SAP 10-2 (III or V) in both preperimetric and perimetric glaucoma. Topographic structure-function relationships for each VF test were more favorable with the FDT 10-2 test. The preperimetric glaucoma patients showing VF abnormalities on FDT 10-2 or SAP 10-2 (III) showed thinner average, minimum, superior, inferior, and inferotemporal GCIPL thicknesses than in those without VF abnormalities (all P < .05). FDT 10-2 was found to detect functional damage of the macula early in preperimetric glaucoma, and to perform better than with SAP 10-2 (size III or V) from preperimetric to perimetric glaucoma in the structure-function relationship. FDT 10-2 can be considered a useful tool to detect glaucomatous damage of the macula early and appropriately.

Macular ganglion cell-inner plexiform layer thickness for detection of early retinal toxicity of hydroxychloroquine.

This study evaluated the macular ganglion cell-inner plexiform layer (GC-IPL) thickness using spectral-domain (SD) optical coherence tomography (OCT) in patients with chronic exposure to hydroxychloroquine (HCQ). A total of 90 patients (90 eyes) treated with HCQ for at least 5years and normal controls were included in the study. A fundus examination, automated threshold perimetry, and GC-IPL thickness measurements using the Cirrus high-definition OCT ganglion cell analysis algorithm were performed in all patients treated with HCQ. Average, minimum, and sectorial macular GC-IPL thicknesses were compared between the patients and controls. There was no statistically significant difference in age or sex between the groups. The anterior segment and fundoscopy were normal in all patients and controls. Visual field (VF) testing was normal in all patients. The average, minimum, and sectorial macular GC-IPL thicknesses were significantly lower in patients than those in control subjects. There was significant thinning of the macular GC-IPL in the absence of clinically evident HCQ-related retinopathy and VF abnormalities. Measurements of the macular GC-IPL thickness using SD-OCT may therefore be useful in the early diagnosis and in monitoring the progression of retinal changes in patients receiving long-term HCQ therapy.

Usefulness of frequency doubling technology perimetry 24-2 in glaucoma with parafoveal scotoma.

The standard automated perimetry (SAP) 24-2 test cannot adequately test the paracentral region because test points are located sparsely in macular area where is crowded with retinal ganglion cells (RGCs), even though paracentral scotoma is clinically related to a risk of losing visual function. More sensitive visual field (VF) tests are needed to assess paracentral VF defects precisely. We investigated the structure–function relationship on the SAP 10-2 test and the frequency doubling technology (FDT) 24-2 test as well as the SAP 24-2 test in glaucoma with parafoveal scotoma (PFS). Glaucoma patients with PFS (134 patients) were included in this cross-sectional study. Sub-analysis was performed with isolated PFS (51 patients). Global and sectoral mean sensitivities (MS) were evaluated using SAP 24-2, 10-2, and FDT 24-2 program. MS was analyzed as dB or unlogged 1/lambert (SAP) or 1/Michelson contrast (FDT). Ganglion cell-inner plexiform layer (GCIPL) thickness was measured using spectral domain optical coherence tomography. Topographic relationships between the structure and the function were analyzed. In the total PFS group, good structure–function correlations were found in all zones with SAP 24-2, 10-2, and FDT 24-2 test. For glaucoma with isolated PFS, average GCIPL thickness was significantly correlated with central cluster MS (dB) using the SAP 10-2 test (r = 0.279, P = .047) and the FDT 24-2 test (r = 0.289, P = .039), but not the SAP 24-2 test (r = 0.264, P = .061). Topographically, the FDT 24-2 test showed significant correlations in all sectors between sectoral MS and corresponding GCIPL thickness. With regard to the SAP 10-2 test, there was significant topographical structure–function correlations for the superotemporal, inferotemporal, and inferonasal sectors. For SAP 24-2, only inferonasal GCIPL thickness was correlated with the corresponding VF sensitivity. Topographical structure–function on the macula was better with the SAP 10-2 test (superotemporal sector) and the FDT 24-2 test (superotemporal sector) than with the SAP 24-2 test in glaucoma with isolated PFS. In conclusion, FDT 24-2 and SAP 10-2 tests performed more favorably than the SAP 24-2 test in the structure–function relationship of glaucoma patients with isolated paracentral scotoma. FDT 24-2 tests can be another good option for detecting and monitoring RGC loss on the macular area while not missing VF defects outside the central 10°.

Ganglion Cell–Inner Plexiform Layer Change Detected by Optical Coherence Tomography Indicates Progression in Advanced Glaucoma

To examine the performance of Guided Progression Analysis (GPA; Carl Zeiss Meditec, Dublin, CA) in spectral-domain optical coherence tomography (OCT) in detecting progressive thinning of ganglion cell-inner plexiform layer (GCIPL) and retinal nerve fiber layer (RNFL) in glaucoma. Longitudinal, observational study. A total of 196 eyes of 123 primary open-angle glaucoma patients (mean follow-up, 5.0 years). Macular GCIPL and peripapillary RNFL thicknesses were measured by Cirrus HD-OCT (Zeiss, Dublin, CA), and progressive GCIPL and RNFL thinning were assessed by GPA. The reference standard of glaucoma progression was determined by visual field (VF) progression. Glaucomatous eyes were classified into mild (117 eyes) or moderate to advanced (79 eyes) groups based on VF defects. Ganglion cell-inner plexiform layer and RNFL thinning rates were compared between progressors and nonprogressors. Visual field survival estimates in eyes with and without progressive GCIPL and RNFL thinning were evaluated by Kaplan-Meier survival analysis and compared with the log-rank test. Progressive GCIPL and RNFL thinning assessed by OCT GPA. Seventy-six eyes (38.8%) and 43 eyes (21.9%) demonstrated progressive GCIPL and RNFL thinning, respectively, and 48 eyes (24.5%) were classified as progressors by reference standard. The rate of change in the average GCIPL thickness was significantly higher in progressors (-1.05±0.98 μm/year for mild glaucoma and-0.66±0.30 μm/year for moderate to advanced glaucoma) than in nonprogressors (-0.47±0.54 μm/year for mild glaucoma and-0.31±0.50 μm/year for moderate to advanced glaucoma), regardless of glaucoma severity (P < 0.05). Eyes with progressive GCIPL thinning had lower VF survival estimates than eyes without, regardless of glaucoma severity. However, the rate of change in the average RNFL thickness did not differ significantly in moderate to advanced glaucoma (P= 0.765; -0.26±0.55 μm/year for progressors and-0.33±0.92 μm/year for nonprogressors), and VF survival estimates did not differ significantly between eyes with and without progressive RNFL thinning in moderate to advanced glaucoma (P= 0.781). Ganglion cell-inner plexiform layer GPA provides a new approach for evaluating glaucoma progression. It may be more useful for detecting progression in the advanced stages of glaucoma than RNFL GPA.

Reproducibility of macular ganglion cell\u2013inner plexiform layer thickness in normal eyes determined by two different OCT scanning protocols

BackgroundTo investigate the reproducibility of macular ganglion cell-inner plexiform layer (GCIPL) thickness measurement in normal eyes determined by different operators and two different raster scanning protocols of Cirrus high-definition optical coherence tomography (HD-OCT).MethodsOne hundred and two eyes of 102 normal subjects were scanned three times using Cirrus HD-OCT with Macular Cube 512 × 128 protocol by two operators, respectively. Three extra scans were obtained using Macular Cube 200 × 200 protocol. The average, minimum, superotemporal, superior, superonasal, inferonasal, inferior, and inferotemporal GCIPL thickness was measured. The reproducibility of the measurements was evaluated with intraclass correlation coefficients (ICC) and coefficients of variation (CoV).ResultsThe intra-operator ICCs of macular GCIPL thickness were >0.875; and the inter-operator ICCs were 0.882 to 0.991. The intra-protocol ICCs of Macular Cube 512 × 128 and 200 × 200 protocol were 0.953 to 0.987 and 0.953 to 0.991, respectively; and the inter-protocol ICCs were 0.876 to 0.991. All CoVs were <1.5%.ConclusionsCirrus HD-OCT can measure macular GCIPL thickness in normal eyes with excellent reproducibility. The measurements determined by Macular Cube 512 × 128 and 200 × 200 protocol were highly consistent and both protocols were eligible for macular GCIPL thickness measurement.

Early inner retinal thinning and cardiovascular autonomic dysfunction in type 2 diabetes.

BackgroundTo investigate changes in the neural retina according to the presence of retinal nerve fiber layer (RNFL) defects in type 2 diabetes, and to determine the association between inner retina thickness and the severity of diabetic complications.MethodsWe studied non-glaucomatous patients with type 2 diabetes and control subjects Circumpapillary RNFL and macula ganglion cell-inner plexiform layer (GCIPL) thicknesses were measured by spectral-domain optical coherence tomography. In patients with type 2 diabetes, a cardiovascular autonomic function test (AFT) was performed, which included the heart rate parameter of beat-beat variation—with deep breathing, in response to the Valsalva maneuver, and on postural change from lying to standing. The results of each test were scored as 0 for normal and 1 for abnormal. A total AFT score of 1 was defined as early cardiovascular autonomic neuropathy (CAN), and an AFT score≥ 2 as definite CAN.ResultsWe compared control eyes (n = 70), diabetic eyes with RNFL defects (n = 47), and eyes without RNFL defects (n = 30). The average RNFL and GCIPL thicknesses were significantly different among groups (all, P<0.05). On post-hoc testing, diabetic eyes with RNFL defects had a significantly thinner average GCIPL thickness than those without RNFL defects. On multivariate analyses, significantly thinner average GCIPL was seen in early CAN staging (B = -4.32, P = 0.016) and in definite CAN staging (B = -10.33, P<0.001), compared with no CAN involvement, after adjusting for confounding parameters.ConclusionsCardiovascular autonomic dysfunction was associated with early neurodegenerative changes in type 2 diabetes.

Comparing the Rates of Retinal Nerve Fiber Layer and Ganglion Cell–Inner Plexiform Layer Loss in Healthy Eyes and in Glaucoma Eyes

To compare the rates of circumpapillary retinal nerve fiber layer (RNFL) and macular retinal ganglion cell-inner plexiform layer (GCIPL) change over time in healthy and glaucoma eyes. Cohort study. The rates of circumpapillary RNFL and macular GCIPL loss in 28 healthy subjects and 97 glaucoma subjects from the Diagnostic Innovations in Glaucoma Study (DIGS) were compared using mixed-effects models. The median follow-up time and number of visits were 1.7 years and 6 visits and 3.2 years and 7 visits for healthy and glaucoma eyes, respectively. Significant rates of loss of both global circumpapillary RNFL and average macular GCIPL thickness were detectable in early and moderate glaucoma eyes; in severe glaucoma eyes, rates of average macular GCIPL loss were significant, but rates of global circumpapillary RNFL loss were not. In glaucoma eyes, mean rates of global circumpapillary RNFL thickness change (-0.98μm/year [95% confidence interval (CI),-1.20 to-0.76]) and normalized global circumpapillary RNFL change (-1.7%/year [95% CI,-2.1 to-1.3]) were significantly faster than average macular GCIPL change (-0.57μm/year [(95% CI,-0.73 to-0.41]) and normalized macular GCIPL change (-1.3%/year [95% CI,-1.7 to-0.9]). The rates of global and inferior RNFL change were weakly correlated with global and inferior macular GCIPL change (r ranges from 0.16 to 0.23, all P < .05). In this cohort, the rate of circumpapillary RNFL thickness change was faster than macular GCIPL change for glaucoma eyes. Global circumpapillary RNFL thickness loss was detectable in early and moderate glaucoma, and average macular GCIPL thickness loss was detectable in early, moderate, and severe glaucoma, suggesting that structural changes can be detected in severe glaucoma.

Ganglion cell-inner plexiform layer and retinal nerve fiber layer thickness according to myopia and optic disc area: a quantitative and three-dimensional analysis

BackgroundTo determine the influences of myopia and optic disc size on ganglion cell-inner plexiform layer (GCIPL) and peripapillary retinal nerve fiber layer (RNFL) thickness profiles obtained by spectral domain optical coherence tomography (OCT).MethodsOne hundred and sixty-eight eyes of 168 young myopic subjects were recruited and assigned to one of three groups according to their spherical equivalent (SE) values and optic disc area. All underwent Cirrus HD-OCT imaging. The influences of myopia and optic disc size on the GCIPL and RNFL thickness profiles were evaluated by multiple comparisons and linear regression analysis. Three-dimensional surface plots of GCIPL and RNFL thickness corresponding to different combinations of myopia and optic disc size were constructed.ResultsEach of the quadrant RNFL thicknesses and their overall average were significantly thinner in high myopia compared to low myopia, except for the temporal quadrant (all Ps ≤0.003). The average and all-sectors GCIPL were significantly thinner in high myopia than in moderate- and/or low-myopia (all Ps ≤0.002). The average OCT RNFL thickness was correlated significantly with SE (0.81 μm/diopter, P < 0.001), axial length (-1.44 μm/mm, P < 0.001), and optic disc area (5.35 μm/mm2, P < 0.001) by linear regression analysis. As for the OCT GCIPL parameters, average GCIPL thickness showed a significant correlation with SE (0.84 μm/diopter, P < 0.001) and axial length (-1.65 μm/mm, P < 0.001). There was no significant correlation of average GCIPL thickness with optic disc area. Three-dimensional curves showed that larger optic discs were associated with increased average RNFL thickness and that more-myopic eyes were associated with decreased average GCIPL and RNFL thickness.ConclusionMyopia can significantly affect GCIPL and RNFL thickness profiles, and optic disc size has a significant influence on RNFL thickness. The current OCT maps employed in the evaluation of glaucoma should be analyzed in consideration of refractive status and optic disc size.

Comparing ganglion cell-inner plexiform layer thickness with focal and global responses on multifocal electroretinogram in glaucoma.

BACKGROUND:The aim of this study was to evaluate responses on multifocal electroretinogram (mfERG) with ganglion cell-inner plexiform layer (GCIPL) thickness on cirrus spectral-domain optical coherence tomography (SD-OCT) in glaucoma.METHODS:All diagnosed glaucoma patients attending glaucoma services at our institute from November 2012 to April 2013 were screened for this observational hospital-based study. Controls included patients attending our outpatient services for general eye checkup. Structural parameters on SD-OCT including GCIPL and retinal nerve fiber layer (RNFL) thickness were compared with functional parameters on mfERG in early (mean deviation <−6 dB), moderate (−6 to − 12 dB), and controls.RESULTS:A total of 54 cases and 33 controls fulfilling inclusion criteria were recruited for the study. The average and minimum GCIPL thickness did not vary significantly between early and control eyes while moderate glaucoma eyes had marginally lower GCIPL thickness than early glaucoma eyes. The GCIPL minimum thickness on univariate regression was found to be influenced by N2 amplitudes (β = −0.5, P = 0.012) and global N2P1amplitudes (β =0.6, P = 0.01) in moderate glaucoma. In early glaucoma, these were influenced only by RNFL parameters with no association with functional mfERG responses. Multivariate logistic regression identified global N2P1 amplitude to be significantly influencing GCIPL average and minimum thickness (P = 0.01 and 0.02, R2 = 47.8% and 52.3%, respectively) in moderate glaucoma. Maximum area under the curve was found for GCIPL minimum (95% confidence interval [CI] 0.53–0.81) and N2P1 amplitude (95% CI 0.55–0.80).CONCLUSIONS:The second order responses N2P1 and N2 amplitude on mfERG predict function that correlated with structural GCIPL thickness in moderate glaucoma. Early glaucoma may be best predicted by RNFL thickness rather than on mfERG responses.