Retinal and optic nerve evaluation by optical coherence tomography in adults with obstructive sleep apnea–hypopnea syndrome (OSAHS)

Objective

To assess the peripapillary retinal nerve fiber layer (RNFL) thickness, optic nerve head (ONH) morphologic parameters, and macular thickness and volume in patients affected by obstructive sleep apnea–hypopnea syndrome (OSAHS).

Methods

This prospective, observational case-control study consisted of 96 eyes of 50 OSAHS patients (mean age of 50.9?±?12.4 years, best-corrected visual acuity ≥20/20, refractive error less than 3 spherocylindrical diopters, and intraocular pressure <21 mmHg) who were enrolled and compared with 64 eyes of 33 age-matched controls. Peripapillary RNFL thickness, ONH parameters, macular thickness and volume were measured by optical coherence tomography (OCT).

Results

OSAHS patients showed a significant reduction of the nasal quadrant RNFL thickness (74.7?±?15.8 μm) compared with those values observed in control patients (81.1?±?16.6 μm, p?=?0.047, Student's t-test). No differences in peripapillary RNFL thickness were observed when dividing the OSAHS group in accordance with disease severity. Vertical integrated rim area (VIRA) (0.67?±?0.41 mm³ in OSAHS vs 0.55?±?0.29 mm³ in controls; p?=?0.043, Student's t-test), horizontal integrated rim width (HIRW) (1.87?±?0.31 mm² in OSAHS vs 1.8?±?0.25 mm² in controls; p?=?0.039, Student's t-test) and disc area (2.74?±?0.62 mm² in OSAHS vs 2.48?±?0.42 mm² in controls; p?=?0.002, Student's t-test) showed significant differences, all of them being higher in the OSAHS group. Severe OSAHS had significant higher disc area (2.8?±?0.7 mm²) than controls (2.5?±?0.4 mm²; p?=?0.016, ANOVA test). Temporal inner macular thickness was significantly higher in mild–moderate OSAHS patients (270?±?12 μm) than in severe OSAHS patients (260?±?19 μm; p?=?0.021, ANOVA test).

Conclusions

OSAHS patients showed decreased peripapillary nasal RNFL thickness, and increased ONH area and volume parameters when they were evaluated by OCT. These findings suggest that neuronal degeneration might be present in the retina of OSAHS patients, as previously observed in some neurodegenerative disorders     

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.     

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.     

Comparison of OCT and HRT Findings Among Normal, Normal Tension Glaucoma, and High Tension Glaucoma

Purpose

To evaluate the relationship between optic disc and retinal nerve fiber layer (RNFL) measurements obtained with the optical coherence tomography (OCT) and the Heidelberg retina topography (HRT) in normal, normal tension glaucoma (NTG), and high tension glaucoma (HTG).

Methods

Normal, NTG and HTG subjects who met inclusion and exclusion criteria were evaluated retrospectively. One hundred seventy eyes of 170 patients (30 normal, 40 NTG, and 100 HTG) were enrolled. Complete ophthalmologic examination, HRT, OCT, and automated perimetry were evaluated.

Results

Disc area, cup area and cup/disc area ratio measured with HRT were significantly different between NTG and HTG (all p<0.05). Mean RNFL thickness measured by OCT with ascanning diameter of 3.4 mm was larger in NTG than HTG (84.97±24.20 µm vs. 73.53±27.17 µm, p=0.037). Four quadrant RNFL thickness measurements were not significantly different between NTG and HTG (all p>0.05). Mean deviation and corrected pattern standard deviation measured by automated perimetry was significantly correlated with mean and inferior RNFL thickness in both NTG and HTG (Pearson''s r, p<0.05). Mean RNFL thickness/disc area ratio was significantly larger in HTG than NTG (35.21±18.92 vs. 31.30±10.91, p=0.004).

Conclusions

These findings suggest that optic disc and RNFL damage pattern in NTG may be different from those of HTG.     

Optic disc rim area to retinal nerve fiber layer thickness correlation: comparison of diabetic and normal tension glaucoma eyes

Purpose

To compare the correlation between optic disc rim area and retinal nerve fiber layer thickness (rim-RNFL correlation) in diabetic eyes with non-progressive RNFL defects and normal tension glaucoma (NTG) eyes.

Methods

Seventy-three eyes of 73 patients with preperimetric or early NTG and 25 eyes of 25 type II diabetes patients with a non-progressive RNFL defect for ≥5 years were enrolled in this retrospective cohort study. Rim areas and RNFL thicknesses were measured by Heidelberg retina tomography (HRT II) and by optical coherence tomography (Cirrus OCT), in global and 12 clock-hour parameters. Diabetic eyes were evaluated whether they were above the 95 % prediction interval (PI) for the rim-RNFL correlation of NTG.

Results

A significant linear rim-RNFL correlation was observed in NTG eyes globally and at all clock-hours, except in the 4 and 9 o’clock areas, (0.08 < r ² < 0.56, P < 0.05). Eighty-four percent of the diabetic eyes were above the 95 % PI of the rim-RNFL correlation of NTG in ≥2 clock-hours, as compared with 36 % of the eyes in the global parameter.

Conclusions

The eyes of diabetic patients with non-progressive RNFL were well-differentiated from NTG eyes by the rim-RNFL correlation.     

A comparison of false positives in retinal nerve fiber layer,optic nerve head and macular ganglion cell-inner plexiform layer from two spectral-domain optical coherence tomography devices

Background

The incidence of false positive (FP) results of optic coherence tomography (OCT) retinal nerve fiber layer (RNFL) color code in healthy subjects can be very high with Cirrus OCT. Recent evidence has shown that OCT parameters derived from macular ganglion cell-inner plexiform layer (GCIPL) have excellent ability to discriminate between normal eyes and eyes with early glaucoma.

Methods

This was a prospective, cross-sectional study. One hundred eyes from 50 healthy volunteers underwent circumpapillary scanning by Cirrus and Spectralis OCT and macular scanning using Cirrus OCT. FP rates for each of the OCT parameters, using predefined criteria for an abnormal test were calculated. Comparative analysis was performed using the McNemar test. A generalized estimating equations model (GEE) was used to compare demographic and clinical factors between the eyes with normal findings and eyes with abnormal results.

Results

The overall RNFL color-code FP rate was significantly higher for Cirrus (39 %) than for Spectralis (18 %) (P?=?0.000). The Spectralis RNFL FP rate showed no significant difference when compared to the FP rate by Cirrus GCIPL (13 %) and ONH (11 %) analysis. Axial length, mean spherical equivalent, presence of peripapillary atrophy, and tilted disc were significantly related to the RNFL FP occurrence displayed by both devices.

Conclusions

Spectralis might be more specific than Cirrus when evaluating the RNFL thickness for Caucasians and moderate myopic population. GCIPL and ONH analysis might be more useful than RNFL thickness to evaluate this population using Cirrus OCT.     

Relationship between corneal hysteresis and optic nerve parameters measured with spectral domain optical coherence tomography

Background

Corneal hysteresis (CH) has been associated with visual field damage in glaucoma and is related to the velocity of perimetric glaucoma progression. We undertook this investigation to determine whether CH is associated with structural markers of glaucoma damage on spectral domain optical coherence tomography (SD-OCT).

Methods

In this retrospective study, 131 patients under glaucoma evaluation were evaluated with SD-OCT (Cirrus; Carl Zeiss Meditec, Dublin, CA) and had CH measurements with the ocular response analyzer (Reichert, Inc., Buffalo, NY). Pearson and partial correlation adjusting for age were preformed to examine the association between CH and variables of interest. Generalized estimating equations were used to construct simple and multiple linear models.

Results

While Pearson correlations were modest overall, CH best correlated with mean deviation (MD; r?=?0.19) followed by average retinal nerve fiber layer (RNFL) thickness (r?=?0.18) and vertical cup to disc ratio (r?=??0.11) in the open angle glaucoma group. In univariable models, CH varied as a function of MD (ß?=?0.1, 95 % CI 0.03, 0.1; p?<?0.001) and of average RNFL thickness (ß?=?0.2, 95 % CI 0.1, 0.4; p?=?0.001). In a multivariable analysis including MD, age, average RNFL thickness, and glaucoma status, MD (p?=?0.001) and age (p?<?0.001) retained significant associations with CH.

Conclusions

In patients under evaluation and treatment for glaucoma, CH was more closely related to visual field MD than to structural markers of glaucoma damage as measured by SD-OCT.     

Effect of myopia and age on optic disc margin anatomy within the parapapillary atrophy area

Purpose

To evaluate the effect of myopia and age on temporal optic disc margin anatomy within the parapapillary atrophy (PPA) area by use of spectral-domain optical coherence tomography (OCT).

Methods

Fifty young myopic eyes with PPA (myopic PPA group), 50 aged non-myopic eyes with PPA (aged PPA group), and 50 young non-myopic eyes without PPA (control group) were enrolled. High-definition OCT scanning was used to obtain horizontal cross-sectional optic nerve head (ONH) images. By use of these OCT scans we investigated three temporal optic disc margin structures: the configuration of the border tissue of Elschnig; the cross-sectional ONH structure coinciding with the clinically detected optic disc margin; and the integrity of the retinal layers within the PPA area.

Results

The distribution of the configuration of the border tissue of Elschnig and the cross-sectional ONH structure coinciding with the clinically detected optic disc margin of the myopic PPA group differed significantly from those of the control group (P < 0.01) whereas those of the aged PPA group did not (P > 0.05). Other than the photoreceptor layer, the retinal layers within the PPA area were more commonly impaired in the myopic PPA group than in the aged PPA group (P < 0.001).

Conclusions

Myopia and aging led to different structural changes in temporal optic disc margin anatomy within the PPA area. This finding implies that different mechanisms may underlie myopic and age-related PPA development.     

Farbduplexsonographie der retrobulb?ren Gef??e und Hyperkapnie bei Normaldruckglaukom

Purpose

The aim of the study was to investigate retrobulbar flow velocities during hypercapnia in patients with normal tension glaucoma (NTG) without systemic vasospasm and jn controls.

Methods

A total of 16 NTG patients (mean age 58?±?14 years) and 16 control subjects (mean age 50?±?13 years, p?=?0.10) were enrolled in this study. Flow velocities, peak systolic velocity (PSV), end-diastolic velocity (EDV) and resistive indices (RI) of the ophthalmic (OA) and central retinal arteries (CRA) were assessed using color Doppler imaging. Blood flow velocities were measured under normocapnic and hypercapnic conditions (increasing the end-tidal pCO₂ by 15%). Blood pressure, ventilation rate and oxygen saturation were monitored simultaneously.

Results

During hypercapnia, velocity responses of the PSV (p?=?0.044) and EDV (p?=?0.037) of the CRA were significantly different in NTG patients and healthy controls, showing a greater increase of flow velocities in control subjects. Flow velocities of the OA increased significantly in both groups (PSV p?=?0.039, EDV p?=?0.003) during hypercapnia. Blood pressure, oxygen saturation and intraocular pressure changed similarly in both study groups with carbon dioxide provocation.

Conclusions

Velocity response to hypercapnia was reduced in the CRA of NTG patients compared to controls. This may indicate a faulty vasodilatory response in NTG patients without vasospastic disease.     

Scanning laser ophthalmoscopic parameters of eyes with exfoliation syndrome

Purpose

To evaluate optic nerve head (ONH) characteristics in patients with exfoliation syndrome (EXS).

Methods

This was a cross-sectional, observational study in which 73 eyes from 73 patients with EXS and 93 eyes from 93 age-matched healthy subjects who met the inclusion criteria were included. Topographic measurements of the ONH and peripapillary retinal nerve fiber layer (RNFL) thickness were performed by confocal scanning laser ophthalmoscopy, using a Heidelberg retina tomograph. Outcomes of interest were studied by Student t test and χ-squared test.

Results

EXS patients and age-matched controls did not differ in ONH parameters. Nevertheless, the mean cup depth and height variation contour values were higher in the normal subjects (P = 0.07, P = 0.056, respectively). Mean RNFL thickness was 0.22 ± 0.06 mm in the EXS group and 0.26 ± 0.06 mm in the control group, (P = 0.001). Likewise, the RNFL cross-sectional area was significantly lower in exfoliative eyes (1.16 ± 0.35 mm²) than in those of the control group (1.31 ± 0.33 mm²) (P = 0.006).

Conclusions

No significant differences in ONH parameters between EXS patients and age-matched healthy subjects were observed; however, RNFL measurements in eyes with EXS showed lower values.     

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.     

Depth and Area of Retinal Nerve Fiber Layer Damage and Visual Field Correlation Analysis

Purpose

To evaluate the relationship between the structural damage as assessed by time-domain optical coherence tomography (OCT) and functional changes in glaucoma.

Methods

In total, 190 patients with normal tension glaucoma or primary open angle glaucoma were included in this study. The thickness of retinal nerve fiber layer (RNFL) around the optic disc and the area of RNFL defect were determined using OCT scans. The relationships between the RNFL thickness or area of the defect and visual field (VF) indices were assessed using the Lowess function, regression analysis and partial Spearman correlation. The differences between these associations depending on the stage of VF damage were further analyzed. Age, optic disc size, refraction, central corneal thickness and the presence of systemic disease were corrected for in order to exclude confounding factors.

Results

A logarithmic scale of RNFL thickness showed a negative linear relationship with VF indices. The area of the RNFL defect showed a weak correlation with the pattern of standard deviation, whereas the remnant RNFL thickness was moderately correlated with the pattern of standard deviation (partial Spearman correlation coefficient, 0.39, -0.47, respectively; p < 0.0001). Many outliers were detected in the Lowess-plotted graphs. Multiplication of the area and the inverted RNFL thickness showed a moderately correlated logarithmic relationship with the VF indices (partial Spearman correlation coefficient, 0.46; 95% confidence interval, 0.34 to 0.57; p < 0.0001). In the severe stage of VF damage, correlation between the area of the RNFL defect and mean deviation was significantly greater than in other stages (partial Spearman correlation coefficient, -0.66; p = 0.02).

Conclusions

The thickness of the RNFL had a negative logarithmic correlation with the VF indices and was more relevant to the VF indices than the area of the RNFL defect, as measured by OCT.     

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.     

Visual and anatomical outcomes of non-arteritic anterior ischemic optic neuropathy with high-dose systemic corticosteroids

Background

To evaluate the visual and anatomic outcomes after systemic steroid treatment in non-arteritic anterior ischemic optic neuropathy (NAION).

Methods

Ten eyes from ten patients diagnosed with NAION and treated during the acute phase with 80 mg daily, tapering-down dose of corticosteroids were compared with a non-contemporary cohort of 27 patients that received no treatment. The visual outcomes of treated and untreated group were compared. Patients underwent complete ophthalmic examination including determination of Snellen visual acuity (VA), visual fields (VFs) (standard automated perimetry, Swedish Interactive Testing Algorithm 24–2 strategy), and optical coherence tomography (OCT) scanning of the optic nerve head at diagnosis, 6–8 weeks and 6 months after presentation.

Results

No statistical differences were found between steroid-treated and untreated NAION for the median change in VA (Mann–Whitney P?=?0.28), median change in VF mean deviation (MD) and median change in VF pattern standard deviation (PSD) (Mann–Whitney P?=?0.213 and P?=?0.07 respectively). Statistical analysis showed no differences when comparing average RNFL loss (P?=?0.871) and RNFL loss for superior, nasal, inferior and temporal optic disc quadrants between both groups. Complications occurred in three of the ten treated patients (30%); in one of them, steroid therapy had to be discontinued. Another two patients developed a NAION in their fellow eye after 2 and 3 months while on low-dose prednisone. No complications developed in the control group. The study was interrupted early due to a significantly higher rate of complications observed in the treated group (P?=?0.002)

Conclusion

High-dose systemic steroid treatment did not show any beneficial effect in visual and anatomic outcomes when given during the acute phase of NAION. Furthermore, it caused serious complications in a third of the patients treated.     

Comparison of visual field progression between temporally tilted disc and nontilted disc,in patients with normal tension glaucoma

Purpose

To investigate the long-term visual field (VF) progression of temporally tilted disc and nontilted disc in normal tension glaucoma (NTG).

Methods

Retrospective, observational case series. Forty-seven patients with temporally tilted disc (47 eyes), 44 patients with nontilted disc in NTG (44 eyes) patients, who were examined by at least 5 VF tests, and were followed-up over a 5-year period, at the Department of Ophthalmology of the Samsung Medical Center, from May 1998 to 2013. VF progression was defined by modified Anderson–Hodapp criteria, and Glaucoma Progression Analysis (GPA). Multivariate analysis was used to identify the risk factors for VF progression in the temporally tilted disc.

Results

According to the Anderson–Hodapp criteria, progression rates of the temporally tilted disc and nontilted disc at 60 months were 19% and 72%, respectively (P<0.0001). According to GPA, they were 25% and 53%, respectively (P<0.0001). Twenty of 47 patients in the temporally tilted disc did not show progression. Among them, the more tilted disc showed the more VF defects. The hazard ratio of retinal nerve fiber layer (RNFL) defect type was 3.08 (95% CI, 1.17–8.14; P=0.02). The simultaneous superior and inferior RNFL defect type was the most common in progressors in the temporally tilted disc (P=0.04).

Conclusion

Through long-term follow-up, the cumulative survival rate of temporally tilted disc was higher than that of nontilted disc. Caution is required in the treatment of the temporally tilted disc. New treatment policy for the temporally tilted disc may follow.     

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.     

Evaluation of relationship between retinal nerve fiber layer thickness progression and visual field progression in patients with glaucoma

Purpose

To evaluate the capability of optical coherence tomography (OCT), retinal nerve fiber layer (RNFL) thickness, and visual field (VF) measurements in glaucoma progression detection.

Methods

The study examined 62 eyes of 37 glaucoma patients observed over a 3-year period. All eyes underwent at least four serial RNFL measurements performed by Cirrus OCT, with the first and last measurements separated by at least 3 years. VF testing was performed by using the Swedish interactive threshold algorithm (SITA) Standard 30-2 program of the Humphrey field analyzer (HFA) on the same day as the RNFL imaging. Both serial RNFL thicknesses and VF progression were assessed by the guided progression analysis (GPA) software program. RNFL thickness progression was evaluated by event analysis. Total deviation (TD) in the superior or inferior hemifield was also examined.

Results

A total of 295 OCT scans and 295 VFs were analyzed. Five eyes exhibited progression by OCT only and 8 eyes exhibited progression by VF GPA only. When the analysis was based on the combined measurement findings, progression was noted in 6 eyes. The average of the progressive hemifield TD at baseline for combined RNFL and VF progression was ?3.21 ± 1.38 dB, while it was ?2.17 ± 1.14 dB for RNFL progression and ?9.12 ± 3.75 dB for VF progression. The average of the progressive hemifield TD indicated a significant advancement of VF progression as compared to RNFL progression (P = 0.002).

Conclusions

When a mild VF defect is present, OCT RNFL thickness measurements are important in helping discern glaucoma 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.     

The glaucoma detection capability of spectral-domain OCT and GDx-VCC deviation maps in early glaucoma patients with localized visual field defects

Purpose

To evaluate and compare the glaucoma detection capabilities afforded by retinal nerve fiber layer (RNFL) thickness and deviation maps obtained using Cirrus spectral domain optical coherence tomography (Cirrus OCT), and GDx employing variable corneal compensation (GDx-VCC) in glaucoma patients with early, localized visual field (VF) loss.

Methods

This prospective controlled, comparative study was performed on 42 eyes with localized VF defects, and 42 age/refractive error-matched healthy eyes. All participants were imaged by both imaging devices at the same visit. The area of the RNFL defect in each deviation map, corresponding to a VF defect, was analyzed by direct counting of color-coded superpixels in each device. Receiver operating characteristic (ROC) curves were constructed and compared between Cirrus OCT and GDx-VCC.

Results

The areas under the ROCs (AUCs) of RNFL quadrant thicknesses in hemifields with visual field (VF) defects did not differ significantly (Cirrus OCT; 0.961, GDx-VCC; 0.919, P?=?0.07). However, Cirrus OCT afforded a better diagnostic ability, by deviation map analysis, than did GDx-VCC (0.972 vs 0.887, P?=?0.02).

Conclusions

The RNFL thicknesses assessed by either Cirrus OCT or GDx-VCC were comparable in terms of early glaucoma diagnostic capability. However, when areas containing RNFL defects were analyzed via deviation mapping, Cirrus OCT was better than GDx-VCC.     

Restoration of the photoreceptor layer and improvement of visual acuity in successfully treated optic disc pit maculopathy: a long follow-up study by optical coherence tomography

Purpose

To investigate by optical coherence tomography (OCT) the evolution of the photoreceptor layer and its association with best-corrected visual acuity (BCVA) in optic disc pit (ODP) maculopathy after successful surgical treatment.

Methods

Fourteen eyes of 14 patients were included in this study, and followed up from 36 to 95?months (mean 57.36 ± 18.32?months). The follow-up period started at the time of complete subretinal fluid absorption. Examination was performed by time-domain OCT before and after treatment. Spectral-domain OCT was used after treatment. Parameters assessed were type of elevation, central foveal thickness, time elapsed from onset to treatment, type of treatment, BCVA, and inner segment outer segment (IS/OS) junction line. The IS/OS junction was characterized after treatment as intact, interrupted, or absent (not distinguishable).

Results

Significant restoration of the IS/OS junction line was first noticed between 6 and 12?months after fluid absorption (p?=?0.02; Wilcoxon signed rank test). Restoration was continuous up to the 24th month of postoperative examination after fluid absorption (p?=?0.14; Wilcoxon signed rank test). BCVA was 0.99 ± 0.38 logMar before treatment, 0.81 ± 0.26 logMar (p?=?0.011; paired t-test) immediately after fluid absorption and 0.61 ± 0.33 logMar (p?=?0.026; one-way ANOVA) 24?months after fluid resolution. BCVA was significantly positively correlated with the integrity of the IS/OS junction line during follow-up (Pearson r?=?0.775; p?<?0.001).

Conclusions

The IS/OS junction restoration cannot be detected immediately after fluid resolution in the majority of cases. It became evident 6–12?months later and was completed 24?months after fluid absorption. Improvement in BCVA was noticed only during the first 2?years of follow-up. No significant changes were noticed in BCVA or the IS/OS line after 2?years. Among the studied variables, the final photoreceptor layer condition and BCVA immediately after fluid absorption are the main factors predicting final BCVA after successful surgical treatment of ODP maculopathy.