Comparison of ganglion cell and retinal nerve fiber layer thickness in primary open-angle glaucoma and normal tension glaucoma with spectral-domain OCT

Background

The aim of this study was to evaluate the macular thickness (MT), ganglion cell complex (GCC), and circum-papillary retinal nerve fiber layer (RNFL) thickness in primary open-angle glaucoma (POAG) and normal tension glaucoma (NTG) with spectral domain optical coherence tomography (SD-OCT).

Methods

A total of 169 subjects were enrolled: 52 normal subjects, 61 with POAG, and 56 with NTG. Spectral-domain optical coherence tomography (SD-OCT) was used to analyze MT, GCC, and RNFL thickness. To compare the discrimination capabilities between the MT, GCC, and RNFL thickness measurements, we analyzed the areas under the receiver operating characteristic (ROC) curves (AUCs). The relationships between GCC and RNFL measurement and also the relationships of the groups, with age, gender, GCC, and RNFL thickness were assessed.

Results

Normal subjects showed the thickest superior and inferior GCC, followed by in order NTG and POAG (p?<?0.05). While there was a statistically difference in MT value of the normal subjects and the glaucoma patients (p?<?0.05), MT value did not differ between POAG and NTG (p?<?0.05). RNFL thickness parameters were significantly greater in normal subjects, followed in order by the NTG, and POAG (p?<?0.05). Between the normal and entire glaucoma groups, all GCC and RNFL parameters showed the similar discrimination power. RNFL thickness parameters correlated significantly with all GCC thickness (p?<?0.05). Superior RNFL thickness was the only independent variable between the POAG and NTG patients (odds ratio (OR) 0.942, p?=?0.004, 95 %CI 0.905–0.981).

Conclusions

SD-OCT evaluation results suggest higher GCC and RNFL parameters for NTG than POAG.     

Novel use of 3T MRI in assessment of optic nerve volume in glaucoma

Purpose

To measure optic nerve (ON) volume using 3 T magnetic resonance imaging (MRI), to correlate ON volume with retinal nerve fiber layer (RNFL) thickness, and to determine the viability of MRI as an objective tool in distinguishing glaucoma severity.

Methods

In this cross-sectional study, 30 severe glaucoma patients, 30 mild glaucoma patients and 30 age-matched controls were recruited. All subjects underwent standard automated perimetry, RNFL analysis and 3 T MRI examinations. Glaucoma patients were classified according to the Hodapp–Anderson–Parish classification. Pearson’s correlation coefficient was used to correlate ON volume with RNFL, and receiver operating curve (ROC) analysis was performed to determine the sensitivity and specificity of ON volume in detecting glaucoma severity.

Results

Optic nerve volume was significantly lower in both the left and right eyes of the severe glaucoma group (168.70?±?46.28 mm³; 167.40?±?45.36 mm³) than in the mild glaucoma group (264.03?±?78.53 mm³; 264.76?±?78.88 mm³) and the control group (297.80?±?71.45 mm³; 296.56?±?71.02 mm³). Moderate correlation was observed between: RNFL thickness and ON volume (r?=?0.51, p <0.001), and in mean deviation of visual field and optic nerve volume (r?=?0.60, p?<?0.001). ON volume below 236 mm³ was 96 % sensitive and 80 % specific for the detection of severe glaucoma.

Conclusions

MRI measured optic nerve volume is a reliable method of assessing glaucomatous damage beyond the optic nerve head. A value of 236 mm³ and below can be used to define severe glaucoma.     

Relationship between disc margin to fovea distance and central visual field defect in normal tension glaucoma

Background

To investigate the relationship between ocular geometric factors, including temporal disc margin to fovea distance (DFD) measured by optic disc stereophotography (ODP) and central visual field (VF) defect, in normal-tension glaucoma (NTG) patients.

Methods

This retrospective, single-center, cross-sectional study included 88 eyes of 88 NTG patients with mild VF defects (MD?>??6.0 dB). NTG patients were divided into two groups according to VF tests: central VF-invading and central VF-sparing groups. Optic nerve head (ONH) parameters including disc dimensions, peripapillary atrophy (PPA), and DFD were obtained by ODP, and retinal nerve fiber layer (RNFL) thickness was measured by Stratus optical coherence tomography (OCT).

Results

In the invading group, DFD was shorter (3.642?±?0.401 mm) than in the sparing group (3.877?±?0.278 mm; p?=?0.002). The sparing group had more vertically oval ONH (p?=?0.023) and wider temporal PPA width (p?=?0.031). The RNFL thickness in the invading group was thinner in the temporal and inferior quadrants, but thicker in the superior quadrant than that of the sparing group. In a multiple linear regression analysis, DFD was the only geometric factor associated with degree of central VF involvement (p?=?0.002). DFD was positively correlated with temporal RNFL thickness in the sparing group (r?=?0.484, p?<?0.001) but not in the invading group (r?=??0.080, p?=?0.631).

Conclusions

Eyes with a shorter DFD should be monitored carefully because central VF involvement appears to be related to shorter DFD in NTG patients with mild VF defects.     

Corneal biomechanics predict the outcome of selective laser trabeculoplasty in medically uncontrolled glaucoma

Purpose

To evaluate the predictive value of clinical parameters, including biomechanical properties on the outcome of selective laser trabeculoplasty (SLT) in medically uncontrolled open angle glaucoma (OAG).

Methods

Sixty-eight eyes from 68 patients with OAG and IOP insufficiently regulated by topical medications were enrolled. Patients’ follow-up occurred 6 and 12 months after the procedure. The recorded parameters intraocular pressure (IOP), angle characteristics, central corneal thickness (CCT) and biomechanical properties of the eyes, including corneal hysteresis CH and corneal resistance factor CRF measured with the Ocular Responses Analyzer (ORA, Reichert Ophthalmic Instruments) were tested on their predictive value of SLT-induced IOP lowering effect using correlation analyses and regression models.

Results

Mean IOP reduction 12 months after SLT was 4.2?±?5.7 mmHg (23.2 %, from baseline 18.1?±?5.2 mmHg). The preoperative IOP correlated significantly with IOP reduction (maximum Spearman’s correlation r?=?0.75, p?<?0.001). In linear regression analysis, the corneal biomechanical properties (CH and CRF) together with the baseline IOP revealed good modelling for the IOP lowering effect of SLT (R²?=?0.64, respectively).

Conclusions

In addition to the baseline IOP biomechanical properties (CH and CRF) are significant predictors of SLT induced IOP lowering effect in medically uncontrolled OAG.     

Relationship of change in central corneal thickness to visual field progression in eyes with glaucoma

Background

To assess the relationship between baseline central corneal thickness (CCT) and/or ongoing CCT change over time with subsequent visual field progression.

Methods

One hundred sixty three eyes of 163 patients with medically treated glaucoma were followed up for 6.8?±?1.8 years. Exclusion criteria was laser or intraocular surgery. Baseline and follow up CCT, confocal scanning laser tomography and visual fields were performed. CCT and CCT change related to visual field progression using Glaucoma Progress Analysis were assessed. Multivariate logistic regression analysis for predictive factors of glaucoma progression was used to analyze data.

Results

Thinner baseline CCT was associated with more advanced damage at presentation, mean deviation (MD) (r?=?0.17, p?=?0.02) and neuroretinal rim area (NRR) (r?=?0.20, p?=?0.02). Progressing eyes had significantly thinner (p?=?0.01) baseline CCT compared to non-progressing eyes. The slope of visual field change was significantly greater (p?=?0.05) for thinner (<540 μm) as compared to thicker eyes. A small but significant CCT reduction (12.78?±?13.35 μm, p?<?0.0001) was noted in all eyes; however, there was no significant difference (p?=?0.95) in the amount of change between progressing and non-progressing eyes. CCT change did not correlate with MD or NRR change. A thinner CCT (Odds ratio?=?1.80, p?=?0.02), but not CCT change (Odds ratio?=?1.07, p?=?0.69), was a significant risk factor for glaucoma progression.

Conclusions

CCT correlates significantly with the amount of glaucomatous damage at presentation. Thinner corneas may be associated with increased risk of visual field progression. CCT reduced slightly over time in eyes with glaucoma; but the magnitude of this change was not related to visual field progression.     

Pattern ERG and RNFL thickness in hypertensive eyes with normal blue-yellow visual field

Purpose

To evaluate the transient pattern electroretinogram (t-PERG) and the retinal nerve fiber layer (RNFL) thickness in eyes with ocular hypertension (OH) and normal short-wavelength automated perimetry (SWAP).

Methods

In 26 patients with bilateral OH with normal SWAP, and in 26 age and sex matched healthy controls, t-PERG recording and RNFL thickness measurement were performed. Mean deviation (MD) and pattern standard deviation (PSD) of a reliable full threshold 24-2 SWAP were considered. RNFL thickness was determined by OCT3. Monocular PERG were recorded by using a black and white checkerboard pattern (check size 0.9°, contrast 100 %, mean luminance 80 cd/m2) generated on a monitor and reversed in contrast (four reversals per second, 2 Hz) at a distance of 70 cm. Patients had optimal correction at viewing distance; no mydriatic or miotic eye drops were used. Silver/silver chloride skin electrodes were placed over the lower eyelids in the stimulated eye (active electrode) and in the patched eye (reference electrode); ground electrode was in the Fpz scalp. Peak-to peak amplitude of P50 (N35-P50) and N95 (P50-N95) waves, and implicit time of P50, were considered.

Results

Compared to controls, in OH eyes, a reduction of N35-P50 amplitude (2.86?±?1.49 vs. 3.77?±?1.08 microvolts, ?24.1 %, t-test p?=?0.015), of average RNFL thickness (88?±?11 vs. 96?±?10 μm, ?9.5 %, t-test p?=?0.002), and of RNFL thickness in superior (p?=?0.015) and inferior quadrant (p?<?0.001), were found. Multivariate analysis showed that in OH eyes, N35-P50 amplitude was inversely related to intraocular pressure (IOP) (p?=?0.001); no correlation was found between N35-P50 amplitude and MD, PSD, CCT or RNFL thickness.

Conclusions

In OH eyes, both PERG and RNFL thickness changes occur in hypertensive eyes with undamaged SWAP; the correlation of PERG amplitude with IOP, but not with RNFL thickness, suggests that such PERG changes are an effect of the IOP on retinal ganglion cells, rather than a sign of their loss.     

Comparison of Spectralis-OCT, GDxVCC and GDxECC in assessing retinal nerve fiber layer (RNFL) in glaucomatous patients

Background

Glaucomatous optic neuropathy is characterized by a progressive loss of retinal ganglion cells (RGCs). The defects in the peripapillary retinal nerve fiber layer (RNFL) have been reported to be the earliest sign of glaucoma. We determined the agreement between RNFL thickness assessments from spectral-domain OCT (Spectarlis HRA?+?OCT; Heidelberg Engeneering, Heidelberg, Germany), scanning laser polarimetry (SLP) with variable cornea compensation (GDxVCC; Carl Zeiss Meditec, Dublin, CA, USA), and SLP with enhanced cornea compensation (GDxECC; Carl Zeiss Meditec, Dublin, CA, USA) in glaucomatous patients. Furthermore, we investigate the influence of typical scan score (TSS) on the results of GDx assessments.

Methods

The enrolled subjects were devided into different groups by modified HODAPP visual field criteria. The peripapillary RNFL thickness was assessed with the three devices . ANOVA test, Pearson and Spearman correlation coefficient, and Bland-Altman plots were used to analyse the RNFL thickness assessments.

Results

Ninety-two eyes from 92 glaucomatous subjects were analysed. These were divided into four groups: preperimetric glaucoma (n?=?26), mild glaucoma (n?=?18), moderate glaucoma (n?=?21), and severe glaucoma (n?=?27). For Spectralis-OCT, the average RNFL thickness (mean ± SD) was 99.25?±?26.31 μm, 80.52?±?16.63 μm, 71.59?±?21.15 μm, and 63.85?±?20.86 μm for preperimetric, mild, moderate, and severe glaucoma respectively. For GDxVCC, the corresponding assessments were 52.63?±?8.18 μm, 52.95?±?10.20 μm, 46.77?±?10.62 μm, and 49.70?±?13.34 μm. For GDxECC, the assessments were 49.35?±?6.52 μm, 45.92?±?7.21 μm, 42.19?±?8.00 μm, and 39.53?±?8.45 μm. All Spectralis-GDxVCC and Spectralis-GDxECC differences were statistically significant by ANOVA test. The differences between GDxVCC and GDxECC were statistically significant only for severe glaucoma. There was a highly significant correlation between Spectralis-OCT and GDxECC, as well as Spectralis-OCT and GDxVCC, in assessing the RNFL thickness. The best instrument agreement was found between GDxECC and Spectralis-OCT. The RNFL thickness assessed with Spectralis-OCT and GDxECC showed a better correlation to visual field defects than GDxVCC. Evaluating GDx assessments with typical retardation pattern GDxVCC and GDxECC showed very similar RNFL thickness results.

Conclusions

RNFL thickness assessments between GDxVCC, GDxECC, and Spectralis-OCT cannot be directly compared. The assessments are generally higher with Spectralis-OCT than with GDxVCC and GDxECC, because of differences in method of the devices. The atypical retardation pattern has a major impact on the RNFL thickness results of GDx devices. This must be taken into account when evaluating the assessed RNFL thickness results.     

Restoration of macular structure as the determining factor for macular hole surgery outcome

Objective

The aim of this work is to evaluate the preoperative and postoperative spectral domain optical coherence tomography (SD-OCT) findings as predictors of visual acuity for macular hole (MH) surgery.

Methods

Fifty eyes of 46 patients diagnosed with MH and that had undergone 25-g vitrectomy with internal limiting membrane peeling were included in this retrospective study. A complete clinical examination and SD-OCT were performed before and after surgery. Three groups were considered on the basis of the postoperative integrity of photoreceptor inner and outer segment (IS-OS) junction and the external limiting membrane (ELM): group A (11 eyes, both lines disrupted), group B (ten eyes, disrupted IS/OS line and complete ELM), and group C (29 eyes, both lines restored).

Results

LogMAR BCVA improved significantly after surgery from an average 0.60?±?0.29 to 0.19?±?0.19 (p?p≥0.18). Postoperative BCVA was significantly better in group C compared to groups A and B (p?≤?0.01). A significant correlation was found between ELM restoration and postoperative BCVA (r?=?–0.63, p?r?=?–0.55, p?Conclusions Outer retina restoration seems to be the best determining factor for a good visual rehabilitation after MH surgery.     

Relationship between retinal morphological findings and visual function in age-related macular degeneration

Background

We aimed to study the retinal morphological findings associated with exudative age-related macular degeneration (AMD) and their association with visual prognosis.

Methods

We retrospectively reviewed the medical records of 96 consecutive patients (96 eyes) with exudative AMD. Retinal structural changes were examined using optical coherence tomography (OCT).

Results

Initial OCT examination showed cystoid macular edema in 18 eyes (18.8%), fibrin exudate in 56 eyes (58.3%), and hyperreflective foci within the neurosensory retina in 78 eyes (81.3%). Upon initial examination, an external limiting membrane (ELM) line was detected under the fovea in 64 eyes (66.7%). Using Pearson’s correlation analyses, final visual acuity (VA) was correlated with initial VA (r?=?0.61, p?r?=?0.34, p?r?=?0.41, p?r?=?0.40, p?r?=?0.55, p?r?=?0.48, p?r?=?0.23, p?=?0.054), and detection of a foveal ELM line (r?=?0.36, p?=?0.008).

Conclusions

In eyes with exudative AMD, final VA was most correlated with initial VA. In addition, the initial integrity of the foveal outer retina was partially correlated with the visual prognosis. The initial ELM condition was associated with good final VA, while the initial presence of hyperreflective foci in the foveal neurosensory retina was associated with poor final VA.     

Correlation between optical coherence tomographic hyperreflective foci and visual outcomes after intravitreal bevacizumab for macular edema in branch retinal vein occlusion

Purpose

To investigate the correlation between hyperreflective foci (HF) on spectral-domain optical coherence tomography at baseline and visual outcomes after intravitreal bevacizumab injection (IVB) in branch retinal vein occlusion.

Methods

We retrospectively studied 97 eyes of 97 patients with macular edema secondary to BRVO, who were treated with IVB. The eyes were divided into three groups according to the location of HF on SD-OCT: HF in outer retinal layers, HF in inner retinal layers, and no HF. The baseline and final best-corrected visual acuity (BCVA), foveal thickness (FT), external limiting membrane (ELM) status, junction between photoreceptor inner and outer segments (IS/OS) status, and the number of HF were evaluated and compared among three groups.

Results

Baseline BCVA was correlated with baseline FT (R?=?0.366, p?R?=??0.008, p?=?0.942). Baseline BCVA was significantly better in eyes with intact ELM at baseline (p?=?0.006), and final BCVA was significantly better in eyes with intact ELM and IS/OS at final visit (p?p?=?0.003 respectively). At the final visit, 15 of 37 eyes (40.5 %) with HF in outer retinal layers had a disrupted ELM (p?=?0.001), while 28 of 37 eyes (75.7 %) with HF in outer retinal layers had a disrupted IS/OS (p?p?Conclusions HF on SD-OCT at baseline might predict the photoreceptor status and final VA after IVB in BRVO.     

Intraocular pressure correlates with optic nerve sheath diameter in patients with normal tension glaucoma

Purpose

1. Identify differences in optic nerve sheath diameter (ONSD) as an indirect measure of intracranial pressure (ICP) in glaucoma patients and a healthy population. 2. Identify variables that may correlate with ONSD in primary open-angle glaucoma (POAG) and normal tension glaucoma (NTG) patients.

Methods

Patients with NTG (n?=?46) and POAG (n?=?61), and healthy controls (n?=?42) underwent B-scan ultrasound measurement of ONSD by an observer masked to the patient diagnosis. Intraocular pressure (IOP) was measured in all groups, with additional central corneal thickness (CCT) and visual field defect measurements in glaucomatous patients. Only one eye per patient was selected. Kruskal–Wallis or Mann–Whitney were used to compare the different variables between the diagnostic groups. Spearman correlations were used to explore relationships among these variables.

Results

ONSD was not significantly different between healthy, NTG and POAG patients (6.09?±?0.78, 6.03?±?0.69, and 5.71?±?0.83 respectively; p?=?0.08). Visual field damage and CCT were not correlated with ONSD in either of the glaucoma groups (POAG, p?=?0.31 and 0.44; NTG, p?=?0.48 and 0.90 respectively). However, ONSD did correlate with IOP in NTG patients (r?=?0.53, p?<?0.001), while it did not in POAG patients and healthy controls (p?=?0.86, p?=?0.46 respectively). Patient’s age did not relate to ONSD in any of the groups (p?>?0.25 in all groups).

Conclusions

Indirect measurements of ICP by ultrasound assessment of the ONSD may provide further insights into the retrolaminar pressure component in glaucoma. The correlation of ONSD with IOP solely in NTG patients suggests that the translaminar pressure gradient may be of particular importance in this type of glaucoma.     

Long-term anatomical and functional outcomes of idiopathic macular hole surgery. The yield of spectral-domain OCT combined with microperimetry

Background

To evaluate the correlations between anatomical and functional changes studied with microperimetry (MPM) and spectral-domain OCT (SD-OCT) in patients after successful repair of idiopathic macular hole (MH).

Methods

Monocentric, retrospective, interventional study in 23 eyes of 23 patients who underwent successful surgery for MH defined as closure of the hole, at least 1 year before. Reported data were pre- and postoperative best-corrected visual acuity (BCVA), retinal sensitivity values on MPM, macular and foveal thicknesses, and retinal anatomic lesions on SD-OCT.

Results

Macular sensitivity (MS) and foveal sensitivity (FS) were lower and the number of lesions of the outer retinal layers was higher in patients with a poorer postoperative VA (P?=?0.029, P?=?0.011 and P?=?0.003 respectively). Preoperative MH size was lower and MS and FS were better in patients with a preserved junction line between the inner and outer segments of photoreceptors (IS/OS) (P?=?0.045, P?=?0.001, and P?=?0.001 respectively). Better postoperative VA was correlated with better preoperative VA (P?=?0.012, r?=?0.513). Postoperative VA was correlated with MS and FS (P?=?0.032, r?=?0.449, and P?=?0.019, r?=?0.483 respectively). Greater foveal thickness was associated with better postoperative VA (P?=?0.020, r?=?0.482).

Conclusion

Postoperative outer retinal layer integrity is associated with better final retinal sensitivity. Further studies are warranted to assess the role of SD-OCT and microperimetry in the pre- and postoperative evaluation of idiopathic macular holes.     

Correlation between early retinal nerve fiber layer loss and visual field loss determined by three different perimetric strategies: white-on-white,frequency-doubling,or flicker-defined form perimetry

Purpose

To compare the significance of white-on-white standard automated perimetry (SAP), matrix frequency doubling technology (FDT), and flicker-defined form perimetry (FDF) for early detection of nerve fiber layer loss in early glaucoma patients.

Methods

Fifty-one healthy controls and 40 patients with early glaucomatous nerve fiber loss were enrolled in this study. Patients had retinal nerve fiber layer (RNFL) imaging and visual field testing by SAP, FDT matrix, and FDF perimetry at the same visit. Visual field defects were confirmed with two or more consecutive examinations by the same types of perimetry. Significant retinal nerve fiber layer loss and thus early glaucoma was defined with the reference to the RNFL thickness deviation map. The sensitivity, specificity, correlation, MD (mean deviation) and PSD (pattern standard deviation) visual field indexes, and area under the receiver operating characteristic curve (AUC) of MD and PSD of the perimetries were compared.

Results

There was a significant difference in nerve fiber layer thickness between healthy patients (97.7 ± 1.34 μm and patients with early glaucoma (84.1 ± 1.58 μm) (p?p?0.6. AUCs of PSD were not reliable in all of the three VF devices.

Conclusions

The sensitivity for detection of RNFL loss in early glaucoma seems to be higher in FDF and FDT matrix than SAP perimetry, while specifity was highest in SAP. Thus, simultaneous performance of FDF/FDT matrix and SAP perimetry seems beneficial for the correct diagnosis of early glaucoma in patients.     

Ranibizumab as adjuvant in the treatment of rubeosis iridis and neovascular glaucoma—results from a prospective interventional case series

Background

To evaluate the capability of adjuvant intraocular ranibizumab (Lucentis®) injections in the treatment of rubeosis and intraocular pressure in patients with rubeosis and neovascular glaucoma.

Methods

Ten eyes with rubeosis (R) and ten eyes with neovascular glaucoma (NVG) received Lucentis® injections (ranibizumab 0.5 mg/0.05 ml) in this prospective, monocenter, 12-months, interventional case series. The primary efficacy outcome measure was the change of degree of iris rubeosis as documented by iris fluorescein angiography measured after 12 months. Secondary outcomes were intraocular pressure (IOP), best-corrected visual acuity (BCVA, logMAR), numbers of additional interventions or antiglaucoma medications administered after injection, the gonioscopic status of the anterior chamber angle, and central retinal thickness.

Results

In the R group, 3.6 injections and in the NVG group 2.3 injections of Lucentis® were administered. Additional treatments were photocoagulation (n?=?19), cyclodestructive procedures (n?=?9), cryopexy (n?=?3), and vitrectomy (n?=?1). The mean stage of rubeosis was 3.4?±?0.7 in the R group and 3.6?±?0.8 in the NVG group at baseline. At month 12, the rubeosis was almost resolved in the R group (0.1?±?0.3, p?<?0.001), and decreased significantly in the NVG group (0.7?±?1.1, p?<?0.001). In the NVG subgroup, mean IOP was 41.4?±?13.4 mmHg at baseline, which decreased rapidly (18.2?±?12.3, day-14, p?=?0.005) and stabilized during the follow-up (15.6?±?2.0 mmHg, p?<?0.05). BCVA improved significantly in both groups (p?<?0.05, at month 12).

Conclusions

Injection of 0.5 mg ranibizumab appears to be beneficial as an adjuvant treatment in neovascular glaucoma and rubeosis due to its anti-angiogenic properties and its ability to prevent establishment or progression of anterior chamber angle obstruction. Conventional therapeutic procedures addressing the retinal ischemia are still required in a stage-wise treatment approach.     

Biometry and spectral domain optical coherence tomography parameters in children with large cupping

Purpose

The purpose of this study is to investigate optic nerve head using spectral domain optical coherence tomography (SD-OCT) in children with large cupping.

Methods

111 eyes (4–10 years) were divided into three groups according to the cup to disc ratio: group 1, ≤0.3; group 2, 0.4–0.6; and group 3, ≥0.7. The rim area, disc area, average cup to disc ratio, vertical cup to disc ratio, and cup volume were investigated using SD-OCT (Cirrus HD-OCT, Carl Zeiss, Jena, Germany), and the axial length and anterior chamber depth (ACD) were measured by IOL master (IOL master 500, Carl Zeiss, Jena, Germany). Next, we compared ocular biometry and SD-OCT between the three groups.

Results

The mean age of group1 was 6.48?±?1.42 years, 7.00?±?1.75 years in group 2, and 6.63?±?1.82 years in group 3 (p?=?0.370). A significant difference was seen in the spherical equivalent between the groups (p?=?0.001). Group 2 had the most myopic refractive errors. As the cup to disc ratio increases, disc area, average cup to disc ratio, vertical cup to disc ratio, and cup volume increase significantly. When the results of ocular biometry and SD-OCT are adjusted for axial length, only disc area showed a significant correlation with cup to disc ratio (ACD: p?=?0.473, rim area: p?=?0.639, disc area: p?=?0.005, and cup volume: p?=?0.325).

Conclusion

Axial length is the key factor determining disc size, which in turn is important for determining cup to disc ratio. Normal children with large cupping should be examined for axial length, myopic refractive errors, and disc size.     

Frequency-doubling technology and retinal measurements with spectral-domain optical coherence tomography in preperimetric glaucoma

Background

To determine the relationship between visual fields and retinal structures measured with spectral-domain optical coherence tomography in preperimetric glaucoma (PPG).

Methods

Twenty-six eyes of 26 patients with PPG and 20 healthy eyes of 20 volunteers were included. All patients underwent Heidelberg retina tomography-2 (HRT2), standard automated perimetry (SAP), frequency-doubling technology (FDT) perimetry, and RTVue-100. SAP and FDT indices, HRT parameters, and circumpapillary retinal nerve fiber layer (cpRNFL) and macular ganglion cell complex (mGCC) thicknesses were correlated using Pearson’s test. Areas under the receiver operating characteristic curves (AUROCs) and sensitivity/specificity based on each parameter’s definition of abnormalities were compared between parameters.

Results

Significant differences were found in FDT-MD, FDT-PSD, SAP-PSD, cpRNFL, and mGCC parameters (p?<?0.001–0.015), but not in SAP-MD or HRT parameters, between PPG and control groups. Significant correlations were not found between visual field indices and structural parameters, except between FDT-MD and HRT rim area (r?=?0.450, p?=?0.021) and between FDT-PSD and temporal cpRNFL thickness (r?=?0.402, p?=?0.021). AUROCs for cpRNFL (p?=?0.0047–0.033) and mGCC (p?=?0.0082–0.049) parameters were significantly better than those of HRT parameters, whereas significant differences were not found between FDT indices and cpRNFL or mGCC parameters or between cpRNFL and mGCC parameters. Adding average cpRNFL or mGCC thickness to FDT-MD significantly increased sensitivity compared to single parameters (p?=?0.016–0.031).

Conclusions

Structural and functional parameters were poorly correlated but complementary for glaucoma detection in PPG. Combining these parameters may improve PPG diagnosis.     

Retinal neurovascular coupling in patients with glaucoma and ocular hypertension and its association with the level of glaucomatous damage

Purpose

To analyze neurovascular coupling in the retina of untreated primary open-angle glaucoma (POAG) and ocular hypertension (OHT) patients.

Patients and methods

Maximal vessel dilation in response to flicker light was analyzed with Retinal Vessel Analyzer (RVA) in temporal superior/inferior arterioles and veins in 51 POAG patients, 46 OHT and 59 control subjects. RVA parameters were compared between groups, between contralateral POAG eyes, and correlated to intraocular pressure, visual field mean defect and retinal nerve fiber layer thickness.

Results

POAG eyes demonstrated generally smaller response of all vessels to flicker light than the other two groups (ANOVA p?=?0.026; mean arterial flicker response in percent of baseline, averaged superior and inferior was 3.48?±?2.22 % for controls , 2.35?±?2.06 % for POAG patients , and 2.97?±?2.35 % for OHT patients; corresponding values for venules were 3.88?±?1.98 %, 2.89?±?1.72 %, 3.45?±?2.77 %). There was no difference in flicker response between the eye with more and less advanced damage in each patient of the POAG group (ANOVA p?=?0.79). Correlation of flicker response to intraocular pressure (IOP) was borderline at best, correlations to the level of glaucomatous damage were not significant. Correlation of flicker response of superior and inferior vessels of the same eye was significant for the arteries (Pearson r?=?0.23, p?=?0.004), as well as venules (r?=?0.52, p?<?0.001).

Conclusion

General vessel response to flicker light was decreased in POAG patients, compared to normal controls and OHT patients. In contrast to significant correlation between the two contralateral eyes of the flicker response itself, only its borderline correlation to IOP was seen. There was no correlation to the level of damage, altogether indicating a systemic dysregulation phenomenon.

Grants

Swiss National Foundation Grant 3200B0-113685, Velux Stiftung Grant, Freie Akademische Gesellschaft (FAG) Grant, Pfizer Inc. Grant

Clinical trial registration reference number

ClinicalTrials.gov NCT00430209     

Measurement of macular ganglion cell layer and circumpapillary retinal nerve fiber layer to detect paracentral scotoma in early glaucoma

Background

Glaucoma patients with paracentral scotoma are at higher risk of losing central vision than those without glaucoma. The purpose of this study was to determine whether macular inner retinal layer (MIRL) measurements with spectral-domain optical coherence tomography (SD-OCT) outperform circumpapillary retinal nerve fiber layer (cpRNFL) measurements in discriminating between eyes with and without paracentral scotoma.

Methods

This retrospective study included 63 early glaucomatous eyes of 63 patients with (PSI group) or without (PSF group) paracentral visual field (VF) defects. MIRL thicknesses, including macular ganglion cell complex (mGCC), macular ganglion cell layer + inner plexiform layer (mGCL+), macular RNFL (mRNFL), and cpRNFL thickness were measured using a SD-OCT instrument (3D OCT-2000). The MIRL and cpRNFL were divided into 50 grid cells and 36 sectors, respectively, which were numbered from center/temporal to periphery/nasal. Discriminating ability of the methods for number of cells/sectors with abnormal thickness (<5 % of normal) and average thickness in the hemisphere corresponding to the VF defects (termed hemi-thickness) was compared by area under the receiver operating characteristics curves (AROCs).

Results

The number of abnormal nearest sectors of cpRNFL and all MIRL parameters were significantly smaller in the PSI group than in the PSF group (P?≤?0.001–0.047), whereas no significant differences were found for average or hemi-cpRNFL thickness. The AROCs of the number of abnormal nearest cells for mGCC and mGCL+ and average hemi-thickness for mGCC, mGCL+, and mRNFL were comparable and significantly higher than those of the number of abnormal nearest sectors/cells for cpRNFL (P?=?0.0002–0.0063) and mRNFL (P?=?0.0003–0.0267) parameters.

Conclusions

Regional assessment of MIRL thickness as measured by SD-OCT may potentially be an effective method for predicting central involvement of VF defects in early glaucoma.     

The effect of cataract surgery on blue–yellow and standard-pattern visual-evoked potentials

Purpose

Blue–yellow visual-evoked potentials (BY-VEPs) may be used for diagnostics of functional ganglion cell damage in glaucoma and other ocular diseases. In this study we investigated the impact of lenticular opacities on BY- and standard pattern reversal VEPs by examining patients before and after cataract surgery.

Methods

Eighteen patients with moderate cataract were included in a prospective study. Transient on/off isoluminant blue–yellow 2° checks were used for short-wavelength stimulation (BY-VEP), transient large 1° (M1) and small 0.25° (M2) black-white checks for standard pattern reversal VEPs. VEPs were acquired before (24?±?30 days) and after cataract surgery (14?±?16 days). The contralateral eye was used as a control.

Results

Amplitude and latency of M1 and M2 peaks did not change significantly from before to after surgery. The amplitude of the BY-VEPs did not change significantly after cataract surgery (pre-surgery, ?7.42?±?3.43 μV, post-surgery, ?7.93?±?3.65 μV, p?=?0.42), yet the latency of the main negative peak showed a significant decrease (pre-surgery, 143.9?±?12.9 ms, post-surgery, 133.2?±?7.7 ms, p?=?0.0006). The BCVA improvement was significant from before to after cataract surgery (pre-surgery, 0.344?±?0.125 LogMAR, post-surgery, 0.224?±?0.179 LogMAR, p?=?0.013) yet not correlated to the absolute decrease in latency of the BY-VEP after surgery (r?=?0.309, p?=?0.22). No significant changes were found in the contralateral eye.

Conclusions

The BY-VEP is sensitive to lenticular opacities of the human lens, presumably due to the increased short-wavelength absorption in the aging eye. This fact should be considered when applying BY-VEPs for diagnostics.     

Retinal vessel diameter in normal-tension glaucoma patients with asymmetric progression

Purpose

To investigate the longitudinal changes in the central retinal vessel diameter in asymmetric progressive normal-tension glaucoma (NTG) patients.

Methods

This study included 27 patients with bilateral NTG without any systemic vascular disease who showed glaucomatous progression in one eye at the mean follow-up of 24.3 months (range, 18–29 months). Progression was determined by the development of new retinal nerve fiber layer (RNFL) defects or widening of pre-existing defects on red-free RNFL photographs. The central retinal arteriolar equivalent (CRAE) and the central retinal venular equivalent (CRVE) were measured at baseline and at the mean follow-up of 24.3 months. We classified the eyes of each patient as either progressed or stable eyes, and compared the differences and changes in the CRAE and CRVE.

Results

No significant inter-eye difference was observed at baseline in the mean CRAE (167.5?±?22.2 μm vs. 168.2?±?15.5 μm, p?=?0.809) and in the mean CRVE (276.3?±?18.2 μm vs. 281.6?±?21.9 μm, p?=?0.267) between the progressed and stable eyes. There were significant changes in CRAE in the progressed eyes between baseline and 2 years after baseline (from 167.5?±?22.2 μm to 146.9?±?18.0 μm, p?p?=?0.084).

Conclusions

In our series of NTG patients with asymmetric progression, central retinal artery diameter decreased over time in the progressed eyes, whereas no significant decrease in the central retinal artery diameter was seen in the stable eyes.