Normative database of retinal nerve fiber layer and macular retinal thickness in a Thai population

Five-year changes in macular thickness in the elderly population: A cohort study

BACKGROUND

The aim of this study is to determine the 5-year changes in macular thickness and related factors.

METHODS

Data were from the second (2014) and third (2019) phases of the Shahroud Eye Cohort Study. Examinations included measurement of uncorrected and best-corrected visual acuity, non-cycloplegic autorefraction, slit-lamp biomicroscopy, and funduscopy. Participants underwent Cirrus HD-OCT 4000 (Carl Zeiss Meditec, Dublin, CA).

IMAGING

RESULTS

The 5-year changes (95% confidence interval) of central and overall macular thicknesses were - 3.48 ± 8.16 μ (-3.92, -3.03) and - 0.79 ± 4.06 μ (-1.03, -0.54), respectively. The median and IQR of 5-year changes in the central subfield thickness were -3 and 10, although they were 0 and 5 in the overall macular thickness, respectively. Multiple regression model showed the central macular thickness (CMT) decreased with a U-shape pattern with increasing age. The 5-year changes in CMT were significantly lower in females compared to males β = -1.55; (-2.78, -0.32) and in smokers compared to non-smokers β = -1.92; (-3.55, -0.28). Moreover, higher body mass index β = -0.12; (-0.22, -0.02) and CMT at baseline β = -0.08; (-0.10, -0.06) were significantly associated with lower CMT changes. The average 5-year changes in overall macular thickness showed a non-linear decrease with age and was significantly higher in females β = 0.93; (0.4, 1.43). These changes were directly related to the anterior chamber depth β = 0.87; (0.10, 1.64) in the baseline.

CONCLUSIONS

The macular thickness decreased slightly after 5 years; however, this change is not clinically significant. Demographic factors such as age and sex and refractive errors were significantly related to macular thickness changes.

Macular thickness and its associated factors in a Chinese rural adult population: the Handan Eye Study

PURPOSE

To describe the normal macular thickness and assess its associations.

METHODS

The Handan Eye Follow-up Study was conducted between 2012 and 2013. Macular thickness was scanned by spectral-domain optical coherence tomography (OCT). The built-in software generated a retinal thickness (RT) map, which was divided into three regions (central, internal and external regions) and nine quadrants (one in central and four in internal and external regions each).

RESULTS

For 5394 subjects in the Handan Eye Follow-up Study, 4793 received OCT examination, 2946 of whom (accounting for 61.46% of the total subjects, mean age 58.91±10.95, 55.6% were women) were included for analysis. The mean RT in central macula, inner and outer rings were (237.38 µm±23.05 µm), (309.77 µm±18.36 µm) and (278.29 µm±14.38 µm), respectively (overall difference, p＜0.001). In inner ring, the RT in temporal was thinnest, followed by nasal, superior and inferior. In outer ring, the RT in superior was thinnest, with the next subfields being temporal, inferior and nasal, respectively. The RT in central macula, inner and outer rings were significantly thicker in men than in women. Multivariate linear regression analysis showed that in central macula, RT increased in subjects younger than 60 years and thinned above the age of 60. In inner and outer rings, RT thinned along with age (p＜0.001).

CONCLUSIONS

This study finds that RT in central macula is the thinnest, followed by the outer ring, the RT in the inner ring is the thickest. Age and gender are related to RT. These associated factors need to be considered when explaining RT.

Racial Differences in Detection of Glaucoma Using Retinal Nerve Fiber Layer Thickness and Bruch Membrane Opening Minimum Rim Width

PURPOSE

To compare the sensitivities and specificities of the retinal nerve fiber layer thickness (RNFLT) and Bruch membrane opening minimum rim width (BMO-MRW) reference database-based criteria for detection of glaucoma in individuals of European descent (ED) and individuals of African descent (AD).

DESIGN

Comparative diagnostic analysis by race METHODS: 382 eyes of 255 glaucoma patients (ED = 170, AD = 85) and 94 eyes of 50 healthy individuals (ED = 30, AD = 20) with global and sectoral RNFLT and BMO-MRW measured with Spectralis optical coherence tomography (OCT) were included. Six diagnostic criteria were evaluated: global measurement below the 5th or 1st percentile, ≥1 of the 6 sector measurements below the 5th or 1st percentile, and superotemporal (ST) and/or inferotemporal (IT) measurement below the 5th or 1st percentile. The sensitivities and specificities of these measurements for detection of glaucoma were compared using bootstrapping methods.

RESULTS

ST and/or IT RNFLT below the 5th percentile has the best performance for detection of glaucoma among RNFLT classifications with a sensitivity (95% CI) of 89.5% (86.1, 92.5) and specificity of 87.2% (77.8, 95.1). In AD individuals, sensitivities of ST and IT RNFLT and BMO-MRW measurements below the 5th percentile criteria were lower than in ED individuals (RNFLT: 83.7% vs 92.5%, and BMO-MRW: 72.1% vs 88.5%, respectively), as well as specificities (AD RNFLT: 73.7% and BMO-MRW: 89.5% vs ED RNFLT: 96.4% and BMO-MRW: 98.2%, respectively).

CONCLUSIONS

RNFLT and BMO-MRW had consistently lower diagnostic performance in AD individuals compared with ED individuals. BMO-MRW criteria might fail to detect as many as one-third of eyes with glaucoma, specifically in AD individuals. With the current reference database, RNFLT, and especially BMO-MRW, criteria are not adequate for diagnosing glaucoma in AD individuals.

Retinal nerve fibre layer thickness measured with SD-OCT in a population-based study: the Handan Eye Study

PURPOSE

To examine the normative profile of retinal nerve fibre layer (RNFL) thickness and ocular parameters based on spectral-domain optical coherence tomography (SD-OCT) and its associations with related parameters among the Chinese population.

METHODS

This population-based cohort Handan Eye Study (HES) recruited participants aged≥30 years. All subjects underwent a standardised ophthalmic examination. Peripapillary RNFL thickness was obtained using SD-OCT. Mixed linear models were adopted to evaluate the correlation of RNFL thickness with ocular parameters as well as systemic factors. R V.3.6.1 software was used for statistical analysis.

RESULTS

3509 subjects (7024 eyes) with the average age of 55.54±10.37 were collected in this analysis. Overall mean RNFL thickness measured was 113.46±10.90 µm, and the thickest quadrant of parapapillary RNFL was the inferior quadrant, followed by the superior quadrant, the nasal quadrant and the temporal quadrant. In the multivariate linear regression model, thinner RNFL thickness was remarkable association with male (p<0.001), older age (p<0.001), increased body mass index (>30, p=0.018), absence of diabetes (p=0.009), history of cataract surgery (p=0.001), higher intraocular pressure (p=0.007), lower spherical equivalent (p<0.001) and increased axial length (p=0.048).

CONCLUSIONS

In non-glaucoma individuals, this difference of RNFL thickness in Chinese population should be noted in making disease diagnoses. Meanwhile, multiple ocular and systemic factors are closely related to the thickness of RNFL. Our findings further emphasise the need to demonstrate ethnic differences in RNFL thickness and the specificity of associated ocular and systemic factors, as well as to develop better normative databases worldwide.

TRIAL REGISTRATION NUMBER

HES was registered in Chinese Clinical Trial Registry website, and the registry number was ChiCTR-EOC-17013214.

Evaluation of the Cirrus High-Definition OCT Normative Database Probability Codes in a Black American Population

PURPOSE

Race-adjusted interpretation of data from Cirrus high-definition OCT (HD-OCT) devices is not standard practice. The aim of this study is to evaluate differences in peripapillary retinal nerve fiber layer (RNFL) thickness between healthy Black Americans and the Cirrus HD-OCT normative database.

DESIGN

This is a cross-sectional observational study using control patients recruited from the greater Philadelphia, Pennsylvania, area.

PARTICIPANTS

A total of 466 eyes were included in this study. Subjects were retrospectively identified from the control cohort of the Primary Open-Angle African American Glaucoma Genetics (POAAGG) study.

METHODS

Using an age-stratified or linear regression method, we reclassified white-green-yellow-red color probability codes for RNFL thicknesses by quadrant.

MAIN OUTCOME MEASURES

The distribution of reclassified color codes was compared with the expected 5%-90%-4%-1% percentiles and to the original color codes by the Cirrus machine.

RESULTS

Average RNFL thickness in the POAAGG control cohort was thinner than in the Cirrus normative database in all except the nasal quadrant. The original color codes of the POAAGG cohort did not fall into the expected distributions, with more RNFL measurements assigned as white and red codes than expected (9.5% and 1.7%) and fewer measurements assigned as green and yellow codes than expected (85.3% and 3.5%) (P < 0.001). Compared with the original Cirrus machine, reclassification using linear regression produced color codes closest to the expected distributions (P = 0.09). The proportion of abnormal results shifted closer to the expected 5% in the nasal (1.3%, P < 0.001 vs. 3.0%, P = 0.048) and temporal (8.2%, P = 0.002 vs. 3.6%, P = 0.18) quadrants.

CONCLUSIONS

Results further establish the presence of structural differences in the RNFL of Black American patients. Color code reclassification suggests that the existing Cirrus database may not be accurately evaluating glaucomatous nerves in patients of African descent. This study addresses an unmet need to assess Cirrus HD-OCT color probability codes in a Black American population.

A normative database of A-scan data using the Heidelberg Spectralis Spectral Domain Optical Coherence Tomography machine

Purpose

To develop the first normative database of macular and circumpapillary scans with reference values at the level of the A-scan using the Heidelberg Spectralis Optical Coherence Tomography (OCT) machine.

Methods

This study is a retrospective cross sectional analysis of macular and circumpapillary OCT scans of healthy individuals. All participants had a full ophthalmic examination, including best corrected visual acuity, intraocular pressure, biomicroscopy, posterior segment examination and OCT scan. The volume and thickness of each of the nine Early Treatment Diabetic Retinopathy zones at the macula were analysed for the total retinal thickness, retinal nerve fibre layer (RNFL), ganglion cell layer (GCL) and inner plexiform layer (IPL). The thickness of the circumpapillary RNFL was analysed at the disc. Associations between age, gender, refractive error and OCT measurements were explored. De-identified A-scans were extracted from the OCT machine as separate tab-separated text file and made available according to the data sharing statement.

Results

Two-hundred eyes from 146 participants were included of which 69 (47%) were female. The mean age (SD) was 48.52 (17.52). Participants were evenly distributed across four age groups and represented nine broad ethnic groups in proportions comparable to the local distribution. All the macular scans were 20° x 20° (5.9 mm x 5.9 mm), with a total scan density between 12,800 and 49,152 A-scans. The peripapillary scans were all 12° (3.5 mm), at a scan density of 768 A-scans. The mean retinal, GCL and IPL volumes were significantly greater in males than females. Mean peripapillary RNFL thickness did not differ significantly between males and females. Age and total retinal volume (r = –0.2561, P = 0.0003), GCL volume (–0.2911, P < 0.0001) and IPL volume (–0.3194, P < 0.0001) were negatively correlated. The IPL had the strongest three significant negatively associated segments; superior inner IPL (r = –0.3444, P < 0.0001), nasal outer IPL (r = –0.3217, P < 0.0001) and inferior inner IPL (r = –0.3179, P < 0.0001). The temporal inner macular RNFL showed a statistically significant positive correlation (r = 0.1929, P = 0.0062) with age. The only significant association between age and thickness at the peripapillary disc scan was the superior temporal sector (r = –0.1910, P = 0.0067). All retinal layers were negatively correlated for refractive error, except for the central RNFL which was positively correlated (r = 0.1426, P = 0.044).

Conclusion

This study provides a normative database of macular and circumpapillary scans with reference values at the level of the A-scan using the Heidelberg Spectralis Optical Coherence Tomography (OCT) machine.

Ethnicity-Specific Database Improves the Diagnostic Ability of Peripapillary Retinal Nerve Fiber Layer Thickness to Detect Glaucoma

PURPOSE

To determine the changes in optical coherence tomography (OCT) color probability codes and diagnostic ability for peripapillary retinal nerve fiber layer (pRNFL) and ganglion cell complex (GCC) analysis after applying Chinese and white subjects normative databases.

DESIGN

Cross-sectional study.

METHODS

This study enrolled 219 healthy eyes (108 white and 111 Chinese patients) to construct an ethnicity-specific normative database for pRNFL and macular GCC thickness, which was tested then in 180 eyes with or without glaucoma (102 white and 78 Chinese patients). The percent of change of color probability codes were evaluated after applying the original built-in and the ethnicity-specific normative databases, respectively. Sensitivity and specificity were calculated to evaluate the change in diagnostic ability to detect glaucoma.

RESULTS

Healthy white subjects had a thinner pRNFL than Chinese subjects in the overall average thickness as well as the superior, inferior, and temporal quadrants (P < .001). Macular GCC did not differ between ethnicities. After applying an ethnicity-specific normative database, the percent of pRNFL abnormal color code labels decreased significantly for the overall average thickness in the white subjects. This resulted in a significant increase in the specificity to detect glaucoma in the white population (P < .001). No significant changes were seen when applying an ethnicity-specific normative database for macular GCC thickness.

CONCLUSIONS

After applying an ethnicity-specific normative database, the percent of pRNFL abnormal color codes decreased significantly, improving the specificity to detect glaucoma in the white population. These findings suggest there may be utility in having ethnicity-specific normative databases for pRNFL thickness.

Macular and choroidal thicknesses in a healthy Hispanic population evaluated by high-definition spectral-domain optical coherence tomography (SD-OCT)

Purpose

To report normal values of macular and choroidal thickness obtained from a healthy Hispanic population using Optovue (Optovue Inc, Freemont CA, USA) spectral domain optical coherence tomography (SD-OCT).

Design

Observational, cross-sectional, correlation study.

Methods

A total of 290 eyes (145 healthy subjects) were included; 69% of subjects were female. The median age was 39 ± 29 years (IQR), with a range between 18 and 89 years. The study sample was stratified into three age groups: Group 1, 18–40 years (50.3%), Group 2, 41–60 years (30.7%), and Group 3, older than 61 years (19%). Central macular, perifoveal (inner quadrants), and parafoveal (outer quadrants) thicknesses were estimated. In addition, central and peripheral choroidal thicknesses were estimated. Data analysis was performed to calculate the standardized mean difference according to the variance (Student’s t-test) and its differences with Epidat 4.1.

Results

Median macular central thickness was 250 ±30 µm (IQR) with Optovue. Median central choroidal thickness was 263 ± 48 µm (IQR). Median central choroidal thickness was greater than mean peripheral thickness. Macular evaluation showed a statistically significant difference in central, perifoveal, and parafoveal thicknesses, with lower values being recorded for the study sample compared with the manufacturer’s data.

Conclusions

SD-OCT has become a useful tool to obtain high-resolution images of the macula and choroid. This method allows precise assessment of the retinal and choroidal layers to diagnose and follow up posterior segment diseases. We are reporting normal cut-off values of macular and choroidal thicknesses in healthy Hispanic subjects evaluated with Optovue SD-OCT as new diagnostic normal parameters for research and clinical activities.

Normative Values of Peripapillary Retinal Nerve Fiber Layer Thickness in a Middle Eastern Population

Purpose

Peripapillary retinal nerve fiber layer (pRNFL) thickness is subject to high variability. Normative values of pRNFL thickness remain undocumented in the Middle East. The aim of our study is to assess the normative values of pRNFL thickness in a Middle Eastern population.

Methods

A retrospective chart review of 74 patients was conducted. Outpatients who had presented to the ophthalmology clinic at the Jordan University Hospital between January 2016 and July 2018 were consecutively sampled. Measurements had been recorded using Fourier-domain optical coherence tomography. Multivariable regression models were developed to generate predicted normative values with adjustments to candidate confounders.

Results

The mean global pRNFL thickness was 99 ± 11 μm. The mean quadrantic pRNFL thickness increased from the nasal quadrant (75 ± 16 μm) to the temporal (82 ± 20 μm), superior (114 ± 20 μm), and inferior (125 ± 20 μm) quadrants. Gender and eye sidedness did not contribute to the variability in pRNFL thickness. The relationship between aging and pRNFL thinning is independent of diabetes mellitus type 2 and systemic hypertension. Both systemic conditions significantly predicted pRNFL changes despite negative fundoscopic findings.

Conclusions

Our set of predicted normative data may be used to interpret measurements of pRNFL thickness in Middle Eastern patients. Our findings suggest that systemic conditions with potential ocular manifestations may require consideration in predictive models of pRNFL thickness, even in the absence of gross fundoscopic findings. Normative data from additional Middle Eastern populations are required to appraise our models, which adjust for common clinical confounders.

Assessment of inner and outer retinal layer metrics on the Cirrus HD-OCT Platform in normal eyes

Purpose

Ellipsoid zone (EZ) and outer retinal integrity are strongly linked to visual prognosis, but quantitative normative data is lacking. This study evaluates the EZ, outer retina, and inner retina in eyes without macular disease across a wide age spectrum.

Methods

An IRB-approved study was performed for eyes without macular pathology undergoing Spectral Domain Optical Coherence Tomography (SD-OCT) scans on the Cirrus HD-OCT system (Carl Zeiss Meditec, Oberkochen, Germany). Scans were analyzed using a previously described automated EZ mapping tool with line-by-line manual verification. Segmentation included internal limiting membrane (ILM), outer nuclear layer/Henle fiber layer complex (ONL/HFL), EZ, and the retinal pigment epithelium (RPE). The output included metrics for the inner retina (ILM-OPL/HFL), outer retina (ONL/HFL-RPE), EZ-RPE area and volume, and en face EZ mapping. EZ-RPE attenuation on en face mapping was defined as EZ-RPE thickness < 20 um, and total attenuation was 0 um. Imaging parameters were assessed for the group and compared to age, sex, visual acuity and spherical equivalent.

Results

167 eyes from 167 subjects were included. Mean age was 49.7 years (range 10–84 years). The mean foveal retinal thickness was 200.58 ± 19.22 um. Mean inner retinal thickness was 21.47 ± 13.60 um. Mean outer retinal thickness was 179.11 ± 18.52 um. Mean EZ-RPE thickness was 50.58 ± 6.01um. The mean EZ-RPE volume was 1.20 ± 0.10 mm³. Mean EZ attenuation percentage per macular map area was 0.87% ± 1.13% and mean percentage total attenuation was 0.12% ± 0.14%. Total and inner retinal thickness metrics decreased with age. Mean outer retinal thickness increased with age. EZ-RPE parameters were unchanged with age. However, EZ attenuation was negatively correlated with age.

Conclusion

This study provides important information for inner and outer retinal parameters. Future research on quantitative EZ integrity can utilize this data for comparison.

The development of a reference database with the Topcon 3D OCT-1 Maestro

Importance

The paper presents the range for measurements taken with a new spectral domain optical coherence tomography (OCT) device to establish a reference database for discrimination purposes.

Objective

To report the range of thickness values for the new Topcon Maestro 3D OCT device with 2 scan size settings: the 12×9 mm wide field and 6×6 mm scans.

Design

Prospective, multicenter cohort study conducted at 7 clinical sites across the USA.

Setting

Primary eyecare clinics within academic, hospital, and private practice locations.

Participants

Healthy volunteers; all enrolled participants underwent a complete ophthalmological examination to confirm healthy ocular status prior to being enrolled in the study.

Main outcome measure

Average and 1st, 5th, 95th, and 99th percentile ranges for OCT parameters Early Treatment Diabetic Retinopathy Study macula full retinal thickness, ganglion cell + inner plexiform layer thickness (GCL + IPL), ganglion cell complex (GCC) thickness, circumpapillary retinal nerve fiber layer (cpRNFL) thickness.

Results

Three hundred and ninety-nine eyes of 399 subjects were included in the analysis. Mean (SD) age was 46.3 (16.3) years (range 18–88 years). Forty-three percent of the subjects were male. Mean (SD) measurements (in μm) for the 12×9 mm wide scan were as follows: foveal thickness=237.079 (20.899), GCL + IPL=71.363 (5.924), GCC=105.949 (8.533), cpRNFL=104.720 (11.829); measurements for the 6×6 mm scans were as follows: foveal thickness=234.000 (20.657), GCL + IPL=71.726 (5.880), GCC=106.698 (9.094), cpRNFL=104.036 (11.341).

Conclusion

The overall normal thickness values reported with Topcon 3D OCT-1 Maestro were like those studies with OCT from different manufactures. The reference limits at the 1st, 5th, 95th, and 99th percentile points establish the thresholds for the quantitative comparison of the cpRNFL and the macula in the human retina to a database of known healthy subjects.

Impacts of age and sex on retinal layer thicknesses measured by spectral domain optical coherence tomography with Spectralis

Objective

To examine differences in individual retinal layer thicknesses measured by spectral domain optical coherence tomography (SD-OCT) (Spectralis^®) produced with age and according to sex.

Design

Cross-sectional, observational study.

Methods

The study was conducted in 297 eyes of 297 healthy subjects aged 18 to 87 years. In one randomly selected eye of each participant the volume and mean thicknesses of the different macular layers were measured by SD-OCT using the instrument's macular segmentation software.

Main outcome measures

Volume and mean thickness of macular retinal nerve fiber layer (mRNFL), ganglion cell layer (GCL), inner plexiform layer (IPL), inner nuclear layer (INL), outer plexiform layer (OPL), outer nuclear layer (ONL), retinal pigmentary epithelium (RPE) and photoreceptor layer (PR).

Results

Retinal thickness was reduced by 0.24 μm for every one year of age. Age adjusted linear regression analysis revealed mean GCL, IPL, ONL and PR thickness reductions and a mean OPL thickness increase with age. Women had significantly lower mean GCL, IPL, INL, ONL and PR thicknesses and volumes and a significantly greater mRNFL volume than men.

Conclusion

The thickness of most retinal layers varies both with age and according to sex. Longitudinal studies are needed to determine the rate of layer thinning produced with age.

Changes in macular parameters in different types of amblyopia: optical coherence tomography study

PURPOSE

The purposes of this study were to investigate the changes in macular parameters (thickness, volume) and peripapillary retinal nerve fiber layer (RNFL) thickness (RNFLT) in different cases of amblyopia versus the normal fellow eyes using optical coherence tomography (OCT) and to estimate the relationship of OCT changes with various defined patients' parameters.

DESIGN

This is a prospective, observational, cross-sectional case series.

METHODS

The method involved measuring the peripapillary RNFLT, macular thickness, and macular volume via spectral domain (OCT) in different types of amblyopia and comparing with the other fellow eyes. This study was conducted at the Mansoura Ophthalmic Center.

RESULTS

A total of 64 patients with different types of amblyopia were included. The mean central macular thickness (CMT) was 196.2±50.03 µm in the amblyopic eyes versus 167±12.76 µm in the fellow eyes (P=0.000), the mean average macular thickness was 265.80±12.77 µm in the amblyopic eyes versus 259.10±3.09 µm in the fellow eyes (P=0.000), the mean macular volume was 7.59±0.32 mm³ in the amblyopic eyes versus 7.34±0.071 mm³ in the fellow eyes (P=0.002), and the mean global RNFLT was 97.00±11.60 µm in the amblyopic eyes versus 78.50±13.05 µm in the fellow eyes (P=0.029). There was a discrepancy between the different amblyopic types. Age and the axial length were the only independent variables that statistically significantly correlated with the CMT.

CONCLUSION

The unilateral amblyopic eyes were prone to have a higher CMT and thicker global RNFL compared to those of the sound fellow eyes. Retinal variations between different types of the amblyopia differ from one type to another. The age could be considered as a predictor of the disease worsening and treatment prognosis. Further studies are required to emphasize these results.

Normative database for separate inner retinal layers thickness using spectral domain optical coherence tomography in Caucasian population

PURPOSE

Develop the first normative database of the thickness of every inner retinal layer in the macular area in a healthy, Caucasian population between 18 to 87 years old, using Spectralis Optical Coherence Tomography (OCT).

METHODS

On this transversal, observational study, 300 patients between 18 to 87 years old and without an ophthalmological condition were recruited. Macular OCT scans were performed on all patients (Spectralis OCT, Heidelberg Engineering). An axial length measurement, and keratometry were performed using an optical biometer. The volume and thickness of the different macular sectors of the inner retinal layers (retinal nerve fiber layer (RNFL), ganglion cells layer (CGL) and inner plexiform layer (IPL)) were analyzed with the Spectralis OCT segmentation software. An eye was randomly selected for each patient.

RESULTS

297 patients (179 females and 118 males) were included in the study. The mean age was 56.07 years (range: 40.50-72). The multivariate analysis showed a positive correlation between the RNFL thickness and the axial length (p < 0.001). The mean central retinal thickness was 278.2 μm (range: 266-291), the mean central RNFL thickness was 12.61 μm (range: 11-14), the mean central CGL thickness was 17.63 μm (range: 14-21) and the mean central IPL thickness was 22.02 μm (range: 20-25). The multivariate analysis showed a negative correlation between age and CGL thickness and inner IPL thickness (p< 0.001).

CONCLUSION

This study provides a normative database of the volume of each of the inner retinal layers on a Caucasian population.

The Distribution of Macular Thickness and Its Determinants in a Healthy Population

PURPOSE

To determine the distribution of macular thickness in a healthy Iranian population aged 45-69 years and its association with certain determinants.

METHODS

All participants underwent optometric examinations including measurement of uncorrected and corrected visual acuity, objective refraction by retinoscopy, and subjective refraction. Subsequently, all participants underwent slit-lamp biomicroscopy followed by fundus examination through direct and indirect ophthalmoscopy, and optical coherence tomography (OCT) imaging under pupil dilation.

RESULTS

Mean central macular thickness was 255.4 µm (95% confidence interval, CI, 254.5-256.3 µm), average inner macular thickness was 316.5 µm (95% CI 315.9-317.1 µm), average outer macular thickness was 275.3 µm (95% CI 274.8-275.8 µm), and overall average thickness was 278.6 µm (95% CI 278.1-279.1 µm). A linear multiple regression model showed that all indexes were significantly larger in male participants (p < 0.001). Central macular thickness increased with age (coef = 0.25, p < 0.001) while overall, inner and outer macular thickness decreased with age (coef = -0.18, -0.15, -0.19, respectively, all p < 0.001). Central and inner macular thickness had a positive correlation (coef = 3.8, 2.6, respectively, both p < 0.001) and outer macular thickness had a negative correlation (coef = -1.6, p < 0.001) with axial length.

CONCLUSION

Age, sex, refractive error, axial length, and keratometry were found to be associated with macular thickness. These factors should be taken into account when interpreting macular thickness measurements with spectral-domain OCT.

Macular thickness in healthy Saudi adults. A spectral-domain optical coherence tomography study

Objectives:

To determine the macular thickness in the eyes of healthy Saudi adults using spectral-domain optical coherence tomography (SD-OCT).

Methods:

This is a prospective, cross-sectional study, including 158 healthy participants between August and December 2015. Mean subject age was 29.9 ± 7.85 years old. All participants underwent full ophthalmic evaluation, including SD-OCT imaging, and axial length measurement. Data from the right eye were included. Mean retinal thickness was determined. Correlations between retinal thickness and gender, age, axial length, and spherical equivalence were analyzed.

Results:

Mean central retinal thickness was 244.76 ± 23.62 µm, mean axial length was 23.8 ± 1.062 mm (range: 20.5-29 mm) and mean spherical equivalent was -0.31 ± 1.75 diopters (D) (range: -5.50 to +4.25 D). Central subfield (CSF) thickness and foveal volume were significantly lower in women than in men (both p<0.001). Data from the various age groups did not show statistically significant differences in the CSF thickness (p=0.389) or foveal volume (p=0.341). A positive correlation between CSF thickness and axial length (p<0.001) was observed.

Conclusion:

The normal macular thickness values in healthy Saudi individuals is different from that reported in other ethnic groups, as obtained by SD-OCT. Saudi men had thicker CSF than Saudi women and axial length was positively correlated to the central foveal thickness.

Retinal nerve fibre layer thickness in a general population in Iran

BACKGROUND

To determine retinal nerve fibre layer (RNFL) thickness distribution and its related factors in a general population of 45 to 69 year olds in Iran.

DESIGN

Population-based cross-sectional study.

PARTICIPANTS

Of the 5190 participants of phase one of Shahroud Eye Cohort Study, 4737 participated in Phase two (participation rate = 91.3%).

METHODS

All study participants underwent visual acuity measurement, refraction tests, slit lamp examination and ophthalmoscopic fundus exam. Tests also included imaging with Cirrus HD-OCT 4000 and its RNFL thickness data were used in this study.

MAIN OUTCOME MEASURES

The overall RNFL thickness and the average RNFL thickness in different quadrants.

RESULTS

Mean RNFL thickness in the superior, inferior, nasal and temporal quadrants were 92.47 µm [95% confidence interval (CI): 92.14-92.80], 111.22 µm (95% CI: 110.7-111.73), 118.93 µm (95% CI: 118.31-119.55), 74.83 µm (95% CI: 74.07-75.59) and 65.48 µm (95% CI: 65.06-65.90). Multiple linear regression models indicated that RNFL thickness in all quadrants decreased with ageing, was lower in females (coefficient:-0.87 and P = 0.015), decreased by 1.42 µm (P < 0.001) for each millimetre increase in axial length and decreased by 0.41 µm (P = 0.041) for each diopter decrease in spherical equivalent refraction of myopia.

CONCLUSION

RNFL thickness in the 45 to 69-year-old Iranian population is lower compared to other studies. This difference should be noted in making disease diagnoses, particularly glaucoma. Also, there is a significant relationship between ageing and RNFL thinning in all quadrants. Longer axial length, myopia and male gender are associated with reduced RNFL thickness.

Macular thickness and volume in the elderly: A systematic review

Ageing leads to a number of changes in the body including the macula. Detailed imaging using optical coherence tomography have enabled in vivo studies of how macula changes with age. Here we systematically review 49 studies (9115 participants and 11,577 eyes) to provide an overview of how ageing manifests in the macula of the elderly focusing on clinical relevant measures that are thicknesses and volumes of different macular areas. Ageing seems to increase center point foveal thickness. Ageing does not seem to change the center subfield thickness significantly. Ageing decreases the inner and outer macular thickness, and the overall macular thickness and volume. Studies find that specific retinal layers at specific locations seem to be the contributor to these changes. These findings confirm that age-related changes suggested in histological studies are measurable in vivo on thickness and volume and differ depending on location. Studies are needed to explore reasons for the large variance in measurements and how ageing by itself contributes to development of macular disease.

Normal Macular Thickness in Healthy Indian Eyes Using Spectral Domain Optical Coherence Tomography

PURPOSE

To determine macular thickness and its variation with age and sex in healthy Indian eyes using Zeiss spectral domain optical coherence tomography (SD-OCT).

DESIGN

A prospective, cross-sectional study.

METHODS

Four hundred healthy adult subjects (≥18 years) underwent macular cube scanning using Zeiss SD-OCT. Macular thickness from all 9 regions of the Early Treatment Diabetic Retinopathy Study map was documented for each subject. Variations in macular thickness by age and sex were determined.

RESULTS

The mean age of the subjects was 38.05 ± 12.13 (range, 18-78) years. The mean ages in men and women were 39.19 ± 12.16 and 37.13 ± 12.05 years, respectively (P > 0.05). The mean central subfield thickness (CST) of all subjects was 240.40 ± 18.26 μm, and mean macular thickness was 287.87 ± 18.07 μm. The mean CST in the right and left eyes were 240.40 ± 18.25 μm and 239.65 ± 17.73 μm, respectively (P = 0.55). Males were associated with greater mean CST and mean macular thickness compared with females (P < 0.05). There was an association of mean CST with sex (adjusted r = 0.095; P < 0.05) but not with age. Overall, the nasal quadrant was the thickest followed by the superior, inferior, and temporal subfields.

CONCLUSIONS

This is the normative data for macular thickness in healthy Indian eyes using Zeiss SD-OCT. This will serve as a baseline for diagnosing and treating macular pathologies in Indian eyes because such data using Zeiss SD-OCT in Indian eyes have previously been lacking.

Intraeye retinal nerve fiber layer and macular thickness asymmetry measurements for the discrimination of primary open-angle glaucoma and normal tension glaucoma

PURPOSE

The aim of this study was to evaluate the diagnostic capability of intraeye retinal nerve fiber layer (RNFL) thickness and macular thickness (MT) asymmetry measurements for the discrimination of normal tension glaucoma (NTG) and primary open-angle glaucoma (POAG) using spectral domain optical coherence tomography (SD-OCT).

METHODS

A total of 90 subjects were enrolled including 30 consecutive healthy subjects, 30 consecutive subjects with POAG, and 30 consecutive subjects with NTG. RNFL thicknesses around the optic disc as well as MT measurements were taken with circular and radial SD-OCT scans. Intraeye retinal and MT asymmetry were calculated as the absolute difference between superior and inferior hemispheres of the eye using posterior pole asymmetry analysis protocol. Analysis of variance was used for comparison and areas under the receiver operating characteristic (AROC) were obtained for different parameters among the three diagnostic groups.

RESULTS

There was a significant difference in MT asymmetry for all comparison groups (normal-NTG, p<0.05; normal-POAG, p<0.001; and NTG-POAG, p<0.001). Intraeye retinal nerve fiber thickness asymmetry measurements were not different between the groups (normal-NTG, p<0.187; normal-POAG, p<0.056; and NTG-POAG, p<0.837). The area under ROC curves exceeded 0.800 for all the studied parameters, including the MT asymmetry except for intraeye RNFL thickness asymmetry which had the lowest AROC as well as the least sensitivity for identifying subjects with NTG from normal (AROC=0.626, sensitivity=30%); POAG from normal (AROC=0.644, sensitivity=37%) and NTG from POAG (AROC=0.533, sensitivity=13%).

CONCLUSION

The intraeye MT asymmetry holds significant potential as a distinguishing parameter for NTG and POAG.

Influence of Clinical Factors and Magnification Correction on Normal Thickness Profiles of Macular Retinal Layers Using Optical Coherence Tomography

PURPOSE

To identify the factors which significantly contribute to the thickness variabilities in macular retinal layers measured by optical coherence tomography with or without magnification correction of analytical areas in normal subjects.

METHODS

The thickness of retinal layers {retinal nerve fiber layer (RNFL), ganglion cell layer plus inner plexiform layer (GCLIPL), RNFL plus GCLIPL (ganglion cell complex, GCC), total retina, total retina minus GCC (outer retina)} were measured by macular scans (RS-3000, NIDEK) in 202 eyes of 202 normal Asian subjects aged 20 to 60 years. The analytical areas were defined by three concentric circles (1-, 3- and 6-mm nominal diameters) with or without magnification correction. For each layer thickness, a semipartial correlation (sr) was calculated for explanatory variables including age, gender, axial length, corneal curvature, and signal strength index.

RESULTS

Outer retinal thickness was significantly thinner in females than in males (sr2, 0.07 to 0.13) regardless of analytical areas or magnification correction. Without magnification correction, axial length had a significant positive sr with RNFL (sr2, 0.12 to 0.33) and a negative sr with GCLIPL (sr2, 0.22 to 0.31), GCC (sr2, 0.03 to 0.17), total retina (sr2, 0.07 to 0.17) and outer retina (sr2, 0.16 to 0.29) in multiple analytical areas. The significant sr in RNFL, GCLIPL and GCC became mostly insignificant following magnification correction.

CONCLUSIONS

The strong correlation between the thickness of inner retinal layers and axial length appeared to result from magnification effects. Outer retinal thickness may differ by gender and axial length independently of magnification correction.

Normative spectral domain optical coherence tomography data on macular and retinal nerve fiber layer thickness in Indians

Aim:

To provide the normative data of macular and retinal nerve fiber layer (RNFL) thickness in Indians using spectral domain OCT (Spectralis OCT, Heidelberg Engineering, Germany) and to evaluate the effects of age, gender, and refraction on these parameters.

Design:

Observational, cross-sectional study.

Materials and Methods:

The eyes of 105 healthy patients aged between 20-75 years, with no ocular disease and best corrected visual acuity of 20/20, were scanned using standard scanning protocols by a single examiner. Exclusion criteria included glaucoma, retinal diseases, diabetes, history of prior intraocular surgery or laser treatment. The mean macular and RNFL thickness were recorded, and the effects of age, gender, and refraction on these parameters were evaluated. This data was compared with published literature on Caucasians to assess the ethnic variations of these parameters.

Results:

The normal central foveal thickness in healthy Indian eyes measured using Spectralis OCT was 260.1 ± 18.19 μm. The nasal inner quadrant showed maximum retinal thickness (338.88 ± 18.17 μm). The mean RNFL thickness was 101.43 ± 8.63 μm with maximum thickness in the inferior quadrant. The central foveal thickness showed a gender-based difference (P = 0.005) but did not correlate significantly with age (P = 0.134), whereas the parafoveal, perifoveal thickness, macular volume, and RNFL thickness showed significant negative correlation with age.

Conclusions:

Our study provides the normative database for Indians on Spectralis OCT. It also suggests that age should be considered while interpreting the macular thickness and RNFL, whereas gender should also be given consideration in central foveal thickness.

Retinal thickness measured by spectral-domain optical coherence tomography in eyes without retinal abnormalities: the Beaver Dam Eye Study

PURPOSE

To examine relationships of age, sex, and systemic and ocular conditions with retinal thickness measured by spectral-domain ocular coherence tomography (SD OCT) in participants without retinal disease.

DESIGN

Longitudinal study.

METHODS

setting: Population-based cohort. study population: Persons aged 43-86 years living in Beaver Dam, Wisconsin in 1988-1990. observation procedures: Retinal thickness was measured via SD OCT at the Beaver Dam Eye Study examination in 2008-2010. Retinal disease was determined by ophthalmoscopy, fundus photography, or SD OCT. main outcome measures: Retinal thickness from the inner limiting membrane to the Bruch membrane.

RESULTS

The retina was thickest in the inner circle (mean 334.5 μm) and thinnest in the center subfield (285.4 μm). Mean retinal thickness decreased with age in the inner circle (P < .0001) and outer circle (P < .0001). Adjusting for age, eyes in men had thicker retinas than eyes in women in the center subfield (P < .001) and inner circle (P < .001). Sex, axial length/corneal curvature ratio, and peak expiratory flow rate were associated with center subfield thickness. Sex and peak expiratory flow rate were associated with retinal thickness in the inner circle. Alcohol consumption, age, axial length/corneal curvature ratio, cataract surgery, ocular perfusion pressure, and peak expiratory flow rate were associated with retinal thickness in the outer circle.

CONCLUSIONS

This study provides data for retinal thickness measures in eyes of individuals aged 63 years and older without retinal disease. This information may be useful for clinical trials involving the effects of interventions on retinal thickness and for comparisons with specific retinal diseases affecting the macula.

Peripapillary retinal nerve fiber layer and foveal thickness in hypermetropic anisometropic amblyopia

Purpose

To evaluate whether there was a difference in peripapillary retinal nerve fiber layer (RNFL) and foveal thickness between amblyopic and normal individuals with optical coherence tomography.

Materials and methods

Sixty patients, 30 patients with hypermetropic anisometropic amblyopia and 30 normal emmetropic subjects, were enrolled in this study. The eyes of the participants were divided into three groups: 30 eyes of 30 patients with amblyopia (A), 30 fellow eyes of the amblyopic patients (B), and 30 eyes of 30 normal subjects (C). Emmetropic normal subjects included cases with normal visual acuity and unremarkable ocular examinations. After routine ophthalmic examination, peripapillary retinal nerve fiber layer and foveal thickness measurements were measured by time-domain optical coherence tomography and compared among the three groups.

Results

The difference in RNFL thickness between amblyopic eyes, fellow eyes of the amblyopic patients, and normal eyes of the emmetropic subjects was not clinically significant. However, the mean foveal thickness was significantly thicker in amblyopic eyes versus the fellow eyes and normal subjects’ eyes.

Conclusion

Our results suggest that amblyopia seems to have an effect on the foveal thickness, but not on the RNFL thickness.

Effect of age on individual retinal layer thickness in normal eyes as measured with spectral-domain optical coherence tomography

PURPOSE

To determine the effect of age on the thickness of individual retinal layers, measured with spectral-domain optical coherence tomography (SD-OCT), in a population of healthy Caucasians.

METHODS

One hundred and twenty subjects with an age ranging between 18 and 81 years were examined with SD-OCT. Mean layer thickness was calculated for seven retinal layers, in the fovea (region 1 of the 9 Early Treatment Diabetic Retinopathy Study [ETDRS] regions); in the pericentral ring (ETDRS regions 2 to 5); and the peripheral ring (ETDRS regions 6 to 9) following automated segmentation using the Iowa Reference Algorithm. In addition, mean peripapillary retinal nerve fiber layer (RNFL) thickness was measured. The partial correlation test was performed on each layer to determine the effect of age on layer thickness, while correcting for spherical equivalent, sex, and Topcon image quality factor as confounders, followed by Bonferroni corrections to adjust for multiple testing.

RESULTS

The thickness of the peripapillary RNFL (R = -0.332; P < 0.001); pericentral ganglion cell layer (R = -0.354, P < 0.001); peripheral inner plexiform layer (R = -0.328, P < 0.001); and foveal outer segment layer (R = -0.381, P < 0.001) decreased significantly with increasing age. Foveal RPE thickness (R = 0.467, P < 0.001) increased significantly with increasing age; other layers showed no significant differences with age.

CONCLUSIONS

Several macular layers and the peripapillary RNFL thickness showed significant changes correlated with age. This should be taken into consideration when analyzing macular layers and the peripapillary RNFL in SD-OCT studies of retinal diseases and glaucoma.

Total macular volume and foveal retinal thickness alterations in healthy pregnant women

ABSTRACT Purpose: To evaluate whether there are alterations in total macular volume (TMV) and foveal retinal thickness (FT) values during pregnancy.

METHODS

This study included 60 healthy pregnant women in their first, second, and third trimester (groups 1, 2, and 3) and 20 nonpregnant women (group 4). TMV and FT values were measured by optical coherence tomography (OCT) in each group.

RESULTS

Mean TMV was 1.43 ± 0.56 mm(3), 1.88 ± 0.54 mm(3), 2.04 ± 0.66 mm(3) and 1.35 ± 0.41 mm(3) in groups 1, 2, 3, and 4, respectively. Mean FT was 199.20 ± 64.35 µ, 274.35 ± 67.45 µ, 287.95 ± 95.50 µ and 192.100 ± 58.61 µ in groups 1, 2, 3, and 4, respectively. There was statistical significance among group 1-2 (p1 = 0.014, p2 = 0.001), group 1-3 (p1 = 0.003, p2 = 0.002), group 2-4 (p1 = 0.001, p2 = 0.001), and group 3-4 (p1 = 0.001, p2 = 0.001) for both TMV and FT, respectively.

CONCLUSION

The increase of fluid in the body, in particular in the second and last trimester, may cause an increase of TMV and FT.

Retinal nerve fiber layer thickness in children <18 years by spectral-domain optical coherence tomography

OBJECTIVES

To establish a normative database for retinal nerve fiber layer (RNFL) thickness in children<18 years by spectral-domain optical coherence tomography (SD-OCT).

METHODS

Children <18 years, who were consecutively enrolled from July-August 2011 in this cross-sectional hospital study, underwent Cirrus SD-OCT. Recorded demographics and clinical characteristics included age, sex, axial length, spherical equivalent, intraocular pressure (by Perkins tonometry) and cup disc ratio. The RNFL thickness full circle (RNFL-FC), superior, (RNFL-S), inferior (RNFL-I), temporal (RNFL-T), and nasal (RNFL-N) and the influence of clinical and demographic factors on the RNFL thickness were assessed using linear regression analysis.

RESULTS

148 eyes of 74 children were analyzed (females: males = 37: 37) with a mean age of 10 ± 3.4 years (range 4-17 years) and a mean spherical equivalent of -0.6 ± 1.2 dioptres. The mean RNFL-FC was 94 ± 10.9 and 93 ± 10.6 µm in the right and left eyes, respectively, with maximum thickness found in the superior quadrant. The RNFL-FC and RNFL-S decreased by 1.9 µm for every 1 dioptre increase in myopic shift, p < 0.001, and by 1.9 µm for every mm increase in axial length, p < 0.001. There was no effect of age on RNFL thickness in females or males.

CONCLUSIONS

The RNFL thickness in children was influenced most by axial length and refractive error while it was independent of age. The normative data from this study could serve as reference for further studies on pediatric glaucoma using newer imaging devices.

Relationship between macular ganglion cell complex thickness and macular outer retinal thickness: a spectral-domain optical coherence tomography study

BACKGROUND

To assess the relationship between macular ganglion cell complex and macular outer retinal thicknesses.

DESIGN

Case-control study.

PARTICIPANTS

Forty-two normal eyes and 91 eyes with primary open-angle glaucoma were studied.

METHODS

Spectral-domain optical coherence tomography (RTVue-100) was used to measure the macular ganglion cell complex and macular outer retinal thickness. Ganglion cell complex to outer retinal thickness ratio was also calculated.

MAIN OUTCOME MEASURES

The relationships between the ganglion cell complex and outer retinal thicknesses and between the ganglion cell complex to outer retinal thickness ratio and outer retinal thickness were evaluated.

RESULTS

There was a positive correlation between ganglion cell complex and outer retinal thicknesses in the normal group and the glaucoma group (r = 0.53, P < 0.001 and r = 0.42, P < 0.001, respectively). In that respect, there was no correlation between ganglion cell complex to outer retinal thickness ratio and outer retinal thickness in the both groups (r = -0.07, P = 0.657, and r = 0.04, P = 0.677, respectively). The ganglion cell complex to outer retinal thickness ratio was 55.65% in the normal group, 45.07% in the glaucoma group. This difference was statistically significant.

CONCLUSIONS

The ganglion cell complex thickness may be affected by outer retinal thickness, and there is individual variation in the outer retinal thickness. Therefore, when determining the ganglion cell complex, it seems necessary to consider the outer retinal thickness as well. We propose the ratio as a suitable parameter to account for individual variations in outer retinal thickness.

Macular thickness and volume of myopic eyes measured using spectral-domain optical coherence tomography

PURPOSE

The aim was to evaluate macular thickness and volume of young myopic eyes measured using Cirrus HD spectral-domain optical coherence tomography (Cirrus HD-OCT; Carl Zeiss Meditec, Dublin, CA, USA).

METHODS

Three hundred and thirty-six eyes of 336 healthy young subjects (aged 19 to 25) with various degrees of refractive error and axial length were recruited. Average macular thickness, foveal thickness, inner/outer macular thickness and macular volume were measured using Cirrus HD-OCT. The association between refractive error/axial length and retinal thickness/volume was analysed.

RESULTS

The mean average macular thickness, foveal thickness, inner/outer macular thickness and macular volume were 280.7 ± 10.9 µm, 258.1 ± 18.4 µm, 320.6 ± 12.7/277.3 ± 12.3 µm and 10.1 ± 0.4 mm(3), respectively. Average macular thickness, inner/outer macular thickness and macular volume decreased and foveal thickness increased as the degree of myopia/axial length increased (p-values less than 0.01). The correlation between axial length and macular measurements remained significant when refractive error was controlled (p ≤ 0.017); however, when axial length was controlled, the association between refractive error and macular thickness/volume was no more significant (p ≥ 0.084).

CONCLUSIONS

In healthy young myopic eyes, thinner macular thickness, lower macular volume and thicker foveal thickness were associated with longer axial length.

Optical coherence tomography measurements of retinal nerve fiber layer thickness in chinese children and teenagers

PURPOSE

To establish a reference range of retinal nerve fiber layer (RNFL) thickness by optical coherence tomography (OCT) in Chinese children and teenagers, and to investigate its relationship with sex, age, eye side, and refractive error.

METHODS

A total of 398 eyes from 199 normal Chinese aged 5 to 18 years (a mean of 10.4 ± 2.7 y), who were undergoing physical examination in the Department of Ophthalmology, were recruited for this study. Their RNFL thicknesses were measured by OCT [OCT, Stratus OCT (OCT3); Carl Zeiss Meditec, Dublin, Calif], and 7 parameters associated with the RNFL thickness were analyzed by the RNFL thickness average analysis program. The influences of several factors (such as sex, age, eye side, and refractive error) on RNFL thickness were also analyzed.

RESULTS

We found that the global average RNFL thickness (±SD) was 112.36 ± 9.21 μm in the present cohort. The thickest RNFL was located at the superior (148.73 ± 17.06 μm) and inferior (142.08 ± 16.03 μm) quadrants of the retina, followed by the temporal (83.82 ± 13.53 μm) quadrant and the nasal (74.84 ± 15.03 μm) quadrant. There was no significant difference in the measurements between boys and girls, however, the eye side had significant influence on RNFL thickness (P<0.01). We also found that the average RNFL thickness was positively correlated with the age and refractive error (P<0.01).

CONCLUSIONS

This study has established a standard reference of RNFL thickness measurements in Chinese aged 5 to 18 years by OCT, which may help to identify the changes of RNFL thickness in children and teenagers in Chinese and other parts of East Asia countries.

Glaucomatous eye macular ganglion cell complex thickness and its relation to temporal circumpapillary retinal nerve fiber layer thickness

PURPOSE

To clarify the correlation between temporal circumpapillary retinal nerve fiber layer (RNFL) thickness and macular ganglion cell complex (mGCC) thickness in glaucomatous eyes.

METHODS

Seventy-seven eyes of 77 subjects were categorized as normal, early glaucoma and moderate-to-advanced (moderate) glaucoma. After the circumpapillary RNFL thickness and mGCC thickness were measured, the temporal mean RNFL and mean mGCC were compared within the three groups. The study also investigated whether there was any correlation between the temporal RNFL and mGCC thicknesses.

RESULTS

In the glaucoma groups, significant thinning of the temporal RNFL and mGCC thicknesses was noted. With the exception of the papillomacular bundle (r = -0.078), correlations were seen in each of the early glaucoma mGCC and temporal RNFL sectors (r = 0.38-0.753). Correlations were also noted for the mGCC and all temporal RNFL sectors in the moderate glaucoma group (r = 0.425-0.809).

CONCLUSIONS

From the early stage of glaucoma, similar decreases of the mGCC and RNFL occured, and a high correlation existed between the two. Therefore, like RNFL, mGCC can potentially be used to detect the early stages of glaucoma. However, in early glaucoma eyes, the papillomacular bundle of the RNFL may be spared, even though mGCC thinning is present.

Retinal nerve fiber layer defect patterns in primary angle-closure and open-angle glaucoma: a comparison using optical coherence tomography

PURPOSE

To compare the patterns of retinal nerve fiber layer (RNFL) thickness loss in primary angle-closure glaucoma (PACG) and primary open-angle glaucoma (POAG) using optical coherence tomography (OCT).

METHODS

Forty-three participants with PACG and 60 with POAG underwent fast RNFL thickness measurement by OCT. Eyes were classified according to the visual field mean deviation (VF-MD) into mild (>-8 dB), moderate (-8 dB to >-16 dB), and advanced (≤ -16 dB) glaucoma subgroups. The raw RNFL thickness data were compared with data from the Thai normative database.

RESULTS

Mean (SD) age was 67.0 (9.6) and 64.1 (11.6) years in the PACG and POAG groups, respectively (P = 0.19). In the mild subgroups, a focal RNFL thickness loss was found in the inferior area in the POAG group, but not in the PACG group. The RNFL defect involved sectors 1, 6, and 7 in the moderately advanced disease subgroups of both PACG and POAG and extended through almost all sectors in the advanced disease subgroups. The deepest RNFL defect, -17.25 μm, was found in sector 6 of the mild POAG subgroup, compared with -8.78 μm in the PACG group (P = 0.04). The number of affected points in each sector in the mild subgroups was greater in the POAG group than in the PACG group.

CONCLUSION

Participants with mild POAG had deeper and more localized RNFL defects than did participants with PACG. The pattern was similar in participants with moderate or advanced disease.

Retinal thickness analysis by race, gender, and age using Stratus OCT

PURPOSE

To detect differences in retinal thickness among patients of different race, gender, and age using Stratus OCT.

DESIGN

Cross-sectional study.

METHODS

In a multicenter, university-based study, 126 patients with no history of ocular disease were enrolled (78 diabetics without retinopathy and 48 nondiabetics). Optical coherence tomography measurements were performed using Stratus OCT. Statistical comparisons of center point foveal thickness and mean foveal thickness were made using generalized estimating equations adjusting for diabetic status, race, age, and gender.

RESULTS

The study population consisted of 36% male subjects, 39% Caucasian, 33% African-American, and 28% Hispanic. Mean foveal thickness was 191.6 +/- 2.7 microm and 194.5 +/- 2.7 microm for diabetics and nondiabetics, respectively (P = .49). Mean foveal thickness in male subjects was significantly larger than in female (201.8 +/- 2.7 microm and 186.9 +/- 2.6 microm, respectively; P < .001). Mean foveal thickness was 200.2 +/- 2.7 microm for Caucasian, 181.0 +/- 3.7 microm for African-American, and 194.7 +/- 3.9 microm for Hispanic subjects. Mean foveal thickness was significantly less for African-American than Caucasian (P < .0001) or Hispanic subjects (P = .005). Center point foveal thickness and mean foveal thickness showed a significant increase with age.

CONCLUSIONS

There are statistically significant differences in retinal thickness between subjects of different race, gender, and age. When compared to Caucasian and Hispanic subjects, African-American race is a predictor of decreased mean foveal thickness; and male sex (regardless of race) is a significant predictor of increased mean foveal thickness. Mean foveal thickness is similar among diabetics and nondiabetics when data are controlled for age, race, and sex. These results suggest that studies comparing OCT measurements should carefully control for age-based, race-based, and gender-based variations in retinal thickness.