Stratus Optical Coherence Tomography Research Articles

Evaluation of Visual Acuity, Macular Thickness, and Level of Proteinuria in Children with Nephrotic Syndrome.

Macular edema, serous retinal detachment, and retinal pigment epithelial detachment have been reported in patients with nephrotic syndrome. However, there is limited data about macular thickness in children with nephrotic syndrome. The aim of this study was to compare the mean macular thickness in children with nephrotic syndrome and in a control group and to correlate it with visual acuity and level of proteinuria. The comparative cross-sectional study included 66 children aged 6 to 17 years with nephrotic syndrome and healthy control seen in two tertiary centers in Malaysia. We recorded demographic data, as well as visual acuity, level of proteinuria, and the mean macular thicknesses in both groups. The mean macular thickness was measured using Stratus optical coherence tomography according to nine areas of the Early Treatment Diabetic Retinopathy Study map. The mean foveal thickness was 238.15 ± 22.98 µm for children with nephrotic syndrome and 237.01 ± 22.60 µm for the control group. There was no significant difference in the mean macular thickness between the groups (p = 0.843). A significant correlation with visual acuity was observed in the superior outer macula (r = -0.41, p = 0.019), the nasal outer macula (r = -0.41, p = 0.019), and the inferior outer macula (r = -0.40, p = 0.021). There was no significant correlation between the mean macular thickness and level of proteinuria (p = 0.338), although those with higher levels of proteinuria demonstrated a trend towards increased macular thickness. The mean macular thickness in children with nephrotic syndrome was similar to that of healthy children. A significant correlation between the mean thickness of the outer macular layer and the presenting visual acuity was observed. There was no correlation between the mean macular thickness and the level of proteinuria.

Macular Thickness Measurements Using Stratus Optical Coherence Tomography in Ahmadu Bello University Teaching Hospital, Zaria

Background: The need to establish the normal parameters of the macular is important for early detection of its changes in various causes of maculopathy. Objectives: To determine the normative values for macular thickness in healthy Nigerian adults in Ahmadu Bello University Teaching Hospital, Zaria and to correlate macular thickness values with gender, age, axial length, refractive errors, and intraocular pressure in adults using Stratus Optical Coherence Tomography. Material and Methods: Consenting 178 (101 males and 77 females) adult Nigerians with normal eyes were recruited and examined using Carl Zeiss Stratus Optical Coherence Tomography (OCT) machine Model 3000 software version 4.0 from December 2014 – December 2015. Results: One hundred and seventy-eight (178) eyes of 178 subjects were assessed. Mean age of subjects was 36.4 ± 11.7 years. Mean Total Macular Thickness (MTMT), was found to be 238.03 ± 16.83μm with an average of 240.45 ± 17.34μm in males and 234.84 ± 15.70μm in females. Significant correlation between MTMT with age (P = 0.000) and parity (0.043) was observed but not with ethnicity, axial length and refractive error (P = 0.315, 0.551 and 0.071 respectively).Mean Central Foveal Thickness (MCFT) was found to be 180.30 ± 19.22μm. However, it was 185.73 ± 18.06μm in males and 173.18 ± 18.46μm in females. MCFT was significantly higher in males than females (P = 0.000). Conclusion: Total macular thickness and central foveal thickness measurements in healthy Nigerian adult eyes in Zaria are presented in this study and results are comparable to that reported in previous studies. However, large population study is required in Nigeria six geopolitical zones in order to derive a reference value for the country. Keywords: Eye, Macular, Optical Coherence Tomography

Комбинированное лечение тяжелых форм диабетической ретинопатии

Purpose. To evaluate the efficacy and safety of combined treatment of proliferative diabetic retinopathy (PDR), including primary vitrectomy and delayed single-stage patterned panretinal retinal laser coagulation (PLC). Material and methods. The study included 28 patients (28 eyes) with newly diagnosed PDD complicated by hemophthalmos and / or local traction retinal detachment with or without 1-2 stage gliosis, against the background of sub- or decompensation of the course of diabetes mellitus (DM). At the initial examination, a standard ophthalmological examination was performed, as well as fundus photography (Visucam 500, Carl Zeiss, Germany), optical coherence tomography (OCT) (STRATUS OCT Carl Zeiss, Germany). The best corrected visual acuity (BCVA) at admission ranged from light projection to 0.4. All patients were undergone combined treatment. Results. 1-1.5 months after pattern PLC, patients showed regression of neovascularization, ischemic zones were completely blocked, in cases of iris neovascularization, its regression was noted. According to OCT data, the height of edema in the macular zone did not increase. In all cases, the removal of silicone oil was completed within 1-2 months. The indices of BCVA increased and varied from 0.1 to 0.7 after the removal of the silicone oil. According to OCT data, 17 patients showed a decrease in the height of retinal edema in the macular zone from 73 to 150 µm. Conclusion. In the postoperative period after vitreoretinated surgery in patients with PDR, one-stage patterned PLC allows to stabilize the course of the disease in a shorter time and shorten the time of silicone tamponade of the vitreous cavity. Key words: proliferative diabetic retinopathy, vitrectomy, silicone tamponade of the vitreous cavity, patterned panretinal laser coagulation of the retina.

Myopia and Regional Variations in Retinal Thickness in Healthy Eyes.

Purpose To investigate the effects of refraction on retinal thickness measurements at different locations and layers in healthy eyes of Saudi participants.MethodsThirty-six randomly selected adults aged 27.0 5.7 years who attended a Riyadh hospital from 2016 to 2017 were categorized into three groups: non-myopic (spherical equivalent refraction [SER], +1.00 to –0.50 diopters [D]), low myopic (SER, –0.75 to –3.00D), and moderate to high myopic (SER –3.25D). Full, inner, and outer retinal thicknesses were measured at nine locations by spectral-domain stratus optical coherence tomography (Optovue Inc., Fremont, CA, USA) and were compared according to refractive group and sex.ResultsThe mean SERs for the non-myopia, low myopia, and moderate to high myopia groups were 0.2 0.6, –1.5 0.5, and –7.5 1.9 D, respectively. Refractive error, but not sex, had significant effects on the retinal layer thickness measurements at different locations (P 0.05). The parafoveal and outer retinal layers were significantly thicker than the perifoveal and inner retina layers in all groups (P 0.05). The full foveal thickness was higher and the full parafoveal and perifoveal regions were thinner in moderate to high myopic eyes than in the non-myopic eyes (P 0.05), but were similar to those in the low myopic eyes (P 0.05). The foveal thicknesses measured in the inner and outer layers of the retina were higher but the thicknesses measured at the inner and outer layers of the parafoveal and perifoveal regions were lower in moderate to high myopic eyes.Conclusion There were regional differences in the retinal layer thicknesses of healthy Saudi eyes, which was dependent on the central refractions. This is important when interpreting retinal nerve fiber layer thicknesses in myopia and disease management in Saudi participants.

Eight-year multimodal follow-up of recurrent idiopathic acute exudative polymorphous vitelliform maculopathy

To describe and analyze clinical findings in a patient with recurrent idiopathic acute exudative polymorphous vitelliform maculopathy (AEPVM), followed in detail, and to propose the diagnostic and follow-up algorithm. Retrospective observational analysis. A young adult male patient diagnosed with idiopathic AEPVM who developed two relapses in a 12-month period eight years after the initial onset. Review of clinical charts, multimodal imaging, and electrophysiology findings. The patient repeatedly underwent complete ophthalmic examinations, including best-corrected visual acuity testing (BCVA), slit-lamp and fundus examinations; digital fundus photography, time-domain optical coherence tomography (OCT) in 2009 (Stratus OCT, Carl Zeiss Meditec, USA) and spectral-domain OCT in 2017-2018 (Spectralis-OCT, Heidelberg Engineering, Germany), together with fundus autofluorescence (FAF), fluorescein angiography (FA), and indocyanine green angiography (ICGA), all with HRA2 (Heidelberg Engineering, Germany); microperimetry (MP-1 microperimeter, Nidek, Japan). Laser flare photometry (Kowa FM-600, Japan) and electrophysiology testing were also performed. Clinical features of long-lasting recurrent idiopathic AEPVM, and diagnostic and follow-up algorithm in such rare cases. Case report of a 25-year-old male Caucasian patient with typical features of AEPVM, including serous neuroepithelial detachment with irregular retinal elevations, ophthalmoscopically resembling retinal folds, with subsequent subretinal accumulation of characteristic yellow-white vitelliform deposits. Features in this case rarely described, or even not yet reported, include indocyanine- and fluorescein-negative intraretinal cystic changes, optic disc hyperfluorescence on FA, serous retinal elevations mimicking retinal folds, increased choroidal thickness, lack of rapid visual recovery, and very slow anatomical improvement of the relapses. Bimonthly fundus autofluorescence evaluation together with SD-OCT were the most informative diagnostic methods, demonstrating the evolution of pathological signs. AEPVM may be a recurrent or even chronic condition with uncertain long-term visual outcomes. It may have variable clinical presentations depending on the stage of the disease, and both clinical manifestations and imaging features of different stages of the pathologic process may overlap. Patients should be made aware that visual improvement occurs very slowly, if at all. Bimonthly fundus autofluorescence evaluation together with SD-OCT should be recommended in such cases.

Relationship between intraocular pressure and retinal nerve fibre thickness loss in a monkey model of chronic ocular hypertension

Chronic ocular hypertension (COHT) monkey models were established by destroying the trabecular meshwork, for investigating the relationship between intraocular pressure (IOP) and retinal nerve fibre layer (RNFL) thickness loss. IOP and RNFL thickness were measured before laser injury and weekly thereafter for 27 weeks using Tono Vet and Stratus optical coherence tomography (OCT). The quantitative relationship was as follows: (1) at 32-47 mmHg, the average damage rate was -3.08 ± 0.28 μm/week; (2) at 25-30 mmHg, it was -1.45 ± 0.19 μm/week. The inferior RNFL and superior RNFL turned out to be the most IOP-sensitive quadrants with the rate of RNFL change almost in parallel with IOP levels. The superior sector seemed to be resistant to high IOP conditions until a RNFL loss of ~20 μm was detected in the inferior sector. The rate of RNFL thickness loss was slowed with obvious turning points at RNFL thicknesses of ~75 μm, 65 μm, and 50 μm. The experimental results have achieved research significance. The COHT Monkey was an ideal animal model that can be used for evaluating the relationship between IOP and RNFL damage. Higher IOP was associated with faster RNFL thickness loss. The level of IOP was a vital factor for RNFL damage rate, and baseline/residual RNFL thickness was also important for subsequent RNFL damage. OCT was suitable for measuring RNFL thickness change in COHT monkey models.

Visual field defects and retinal nerve fiber imaging in patients with obstructive sleep apnea syndrome and in healthy controls

BackgroundTo assess the retinal sensitivity in obstructive sleep apnea hypopnea syndrome (OSAHS) patients evaluated with standard automated perimetry (SAP). And to correlate the functional SAP results with structural parameters obtained with optical coherence tomography (OCT).MethodsThis prospective, observational, case-control study consisted of 63 eyes of 63 OSAHS patients (mean age 51.7 ± 12.7 years, best corrected visual acuity ≥20/25, refractive error less than three spherical or two cylindrical diopters, and intraocular pressure < 21 mmHg) who were enrolled and compared with 38 eyes of 38 age-matched controls. Peripapillary retinal nerve fiber layer (RNFL) thickness was measured by Stratus OCT and SAP sensitivities and indices were explored with Humphrey Field Analyzer perimeter. Correlations between functional and structural parameters were calculated, as well as the relationship between ophthalmologic and systemic indices in OSAHS patients.ResultsOSAHS patients showed a significant reduction of the sensitivity for superior visual field division (p = 0.034, t-student test). When dividing the OSAHS group in accordance with the severity of the disease, nasal peripapillary RNFL thickness was significantly lower in severe OSAHS than that in controls and mild-moderate cases (p = 0.031 and p = 0.016 respectively, Mann-Whitney U test). There were no differences between groups for SAP parameters.We found no correlation between structural and functional variables. The central visual field sensitivity of the SAP revealed a poor Pearson correlation with the apnea-hipopnea index (0.284, p = 0.024).ConclusionsRetinal sensitivity show minor differences between healthy subjects and OSAHS. Functional deterioration in OSAHS patients is not easy to demonstrate with visual field examination.

Assessment of retinal nerve fiber layer thickness in migraine patients measured with optical coherence tomography

Background: Headache is one of the most disturbing symptoms with common neurological signs. Variations in optic nerve perfusion quality or retinal microcirculation may end up in peripapillary retinal nerve fiber layer (RNFL) thickness in patients with migraine. The aim of this study was to investigate the retinal nerve fiber layer (RNFL) thickness in patients with migraine.Methods: This cross-sectional study was conducted by including thirty patients diagnosed with migraine and thirty normal individuals. Patients were evaluated in groups including migraine with and without aura and controls. Retinal nerve fiber layer (RNFL) thickness was measured using stratus optical coherence tomography (OCT) and then was compared in case and control groups. All data were analyzed using SPSS software version 16.Results: RNFL thickness was significantly thinner in migraine patients compared to the control group. Symmetricity of RNFL showed significantly reduction in patients with migraine compared to standard value (95% vs 68%). Comparison of NRR area between patients and standard value showed significantly reduced values (P=0.0001). Mean value of optic disc area showed significantly reduced value compared to standard value about 2.35 m2 (P=0.0001).Conclusions: This study suggests that migraine leads to a reduction in the peripapillary RNFL thickness and to thinning in choroidal structures. These findings can be explained by a chronic ischemic insult related to migraine pathogenic mechanisms.

Новые возможности мониторинга пациентов с миопией

Purpose: to study the changes of axial length and distension of the posterior pole retina of the eye in patients with myopia, using two optical methods: contactless biometrics and optical coherence tomography (OCT). Material and methods. We conducted a combined clinical and instrumental examination of 83 patients (166 eyes) with low and moderate myopia aged 10-19 (ave. 13.8 ± 2.5 years). The examination included the measurement of axial length, using a Lenstar contactless laser biometer Lenstar, and retinal nerve fiber layer (RNFL) thickness using optical coherent tomography (OCT Stratus). 32 patients (64 eyes) with emmetropia aged 7 to 18 (ave. 11.7 ± 2.6 years) served as control. Results. The analysis of contactless biometrics and OCT results collected for 1 year helped specify four clinical groups: Myopia progression, Latent myopia progression, Myopic refractogenesis, and Stable myopia. It was also found that RNFL thickness in different retinal sectors is decreasing unevenly in latent myopia progression. To facilitate the evaluation of myopia progression, a structural indicator of progression was proposed. Conclusion. Progressing myopia monitoring by two modern optical methods: biometrics (for AL) and OCT (for RNFL thickness) enables the detection of changes in the fibrous eye capsule and identification of individual features of myopic progression. For citation: Strakhov V.V., Makhova M.V., Klimova O.N. New opportunities of monitoring patients with myopia. Russian ophthalmological journal. 2018; 11 (3): 30-5 (In Russian). doi: 10.21516/2072-0076-2018-11-3-30-35

Validate the Correlation between Macular Thickness and Temporal Retinal Nerve Fiber Layer Thickness in Normal Eyes with Age and Refractive Status Using Stratus Optical Coherence Tomography

Validate the Correlation between Macular Thickness and Temporal Retinal Nerve Fiber Layer Thickness in Normal Eyes with Age and Refractive Status Using Stratus Optical Coherence Tomography

Diagnostic capability of peripapillary retinal nerve fiber layer parameters in time-domain versus spectral-domain optical coherence tomography for assessing glaucoma in high myopia.

To evaluate and compare the diagnostic capabilities of peripapillary retinal nerve fiber layer (p-RNFL) parameters of Spectralis optical coherence tomography (OCT) versus Stratus OCT to detect glaucoma in patients with high myopia. This is a retrospective, cross-sectional study. Sixty highly myopic eyes of 60 patients were enrolled, with 30 eyes in the glaucoma group and 30 eyes in the control group. All eyes received peripapillary imaging of the optic disc using Stratus and Spectralis OCT. Areas under the receiver operating characteristic curve (AUROC) and the sensitivity at specificity of >80% and >95% for p-RNFL parameters obtained using the two devices to diagnose glaucoma were analysed and compared. In Spectralis OCT, p-RNFL thickness parameters with the largest AUROC were the temporal-inferior sector (0.974) and the inferior quadrant (0.951), whereas in Stratus OCT, the best parameters were the 7-o'clock sector (0.918) and the inferior quadrant (0.918). Compared to the Stratus OCT parameters, the Spectralis OCT parameters demonstrated generally higher AUROC; however, the difference was not statistically significant. The best p-RNFL parameters for diagnosing glaucoma in patients with high myopia were the temporal-inferior sector on Spectralis OCT and the 7-o'clock sector on Stratus OCT. There were no significant differences between the AUROCs for Spectralis OCT and Stratus OCT, which suggest that the glaucoma diagnostic capabilities of these two devices in patients with high myopia are similar.

Comparison of retinal nerve fiber layer thickness in relation to optic nerve head size and average retinal nerve fiber layer thickness using optical coherence tomography in glaucomatous optic neuropathy

Context: This study is conducted to determine the correlation between retinal nerve fiber layer (RNFL) thickness and optic nerve head (ONH) size in normal and glaucomatous subjects by optical coherence tomography (OCT). Objective: The objective of this study is to compare the thickness of RNFL in relation to ONH size and average retinal nerve fiber thickness in glaucomatous optic neuropathy using OCT. Subjects and Methods: A prospective study was carried out on one hundred and fifty eyes of 75 patients with 39 normal and 36 glaucoma patients aged between 20 and 60 years. Results: Stratus OCT, values were correlated with the data obtained by ONHs analysis. The values of RNFL thickness showed a high correlation with the ONH size. The RNFLA values were also positively correlated with the *2.27 value. Mean RNFL in glaucoma patients is 72.20 ± 18.79 (standard deviation [SD]) and in *2.27 is 63.57 ± 17.3 (SD) (calculated Z value is 2.58 and P ≤ 0.004) and is highly significant at 4% level in glaucoma patients. Besides correlation coefficient of RNFLA*2.27 in glaucoma patients found positive correspondence with the correlation coefficient 0.867. In normal subject, mean RNFL is 92.16 ± 9.80 and in *2.27, 85.16 ± 10.21 (calculated Z value is 4.34 and P ≤ 0.007) and significant at 3% level in normal subjects. A negative correlation was seen with the value of correlation coefficient − 0.21. Conclusions: RNFL thickness *2.27 measurement has high correlation with each other as obtained by Stratus OCT; moreover, it decreased significantly with an increase in optic disc size. Statistical Analysis Used: To test the difference between two means, Z-test was used. “Z” distribution with population variance not known at that point of time because no normative-based population data were available for Indian population to find out the correlation between two variance correlation coefficient at that point of time.

Effect of chronic alcohol and tobacco use on retinal nerve fibre layer thickness: a case–control study

ObjectiveTo identify the effects of chronic alcohol and/or tobacco use on retinal nerve fibre layer (RNFL) thickness and to find the association between severity of addiction with RNFL thinning.MethodologyA case–control...

Relationship between macular thickness measurement and signal strength using Stratus optical coherence tomography.

PurposeTo examine the relationship between signal strength and macular thickness as measured by Stratus optical coherence tomography (OCT)’s fast macular thickness protocol in healthy subjects.MethodsIn this prospective cross-sectional study 79 eyes of 42 healthy subjects were enrolled. The age, gender, and eye (right vs left) of each subject were recorded. The Stratus OCT fast macular thickness scan protocol was used and the macular thickness was measured with retinal thickness map analysis. Each eye was imaged at least six times to acquire images with signal strengths of 4, 5, 6, 7, 8, and 9 out of 10 via adjustment of the focusing knob. The OCT parameters included in the analysis were thickness in the central 1 mm and in the different quadrants in the 3-mm area.ResultsOverall 79 eyes of 42 patients with a mean age of 38.4±12.4 were included. There was no significant difference between the signal strength measurements obtained with different signal strengths in the central thickness (P=0.20). In the superior, nasal, inferior, and temporal quadrants, a signal strength of 8 demonstrated up to 3 µm thicker measurements than a signal strength of 5 (P<0.05). In general linear regression analysis, after accounting for age and gender, signal strength did not remain a significant predictor of thickness in any quadrant.ConclusionsWhen using fast map macular measurements, a signal strength of 5 is clinically as efficient as a signal strength of 8 in measuring macular thickness in all quadrants. Insisting on higher signal strength may not be necessary.

Surgically induced changes in retinal vessel diameter, retinal nerve fibre layer thickness, and the optic disc after 23-gauge pars plana vitrectomy.

The aim of the study is to investigate the retinal vascular calibre, retinal nerve fibre layer's thickness, and optic disc changes in patients after pars plana vitrectomy. We examined 40 eyes in 40 patients who had undergone unilateral pars plana vitrectomy at three time points: prior to surgery, and at 3 and 6months after the operation. The diameters of central retinal arteries and veins were measured using retinal photographs. The central retinal arteriolar equivalent (CRAE) and central retinal venular equivalent (CRVE) were calculated using the revised Parr-Hubbard formula. Retinal nerve fibre layer thickness was obtained using Stratus optical coherence tomography. The cup-to-disc vertical ratio of the optic disc was evaluated using stereo optic disc photography. There were no significant differences between the eyes of individual patients before the operation. Cup-to-disc vertical ratios of the optic disc were significantly increased 3 and 6months postoperatively (p<0.01, p<0.01), and there was a significant difference between the operative eye and fellow eye at the same time points (p<0.01, p<0.01). Changes in CRAE and CRVE in the operative eyes were significantly larger than the fellow eyes 6months postoperatively (p<0.01, p<0.01). The retinal nerve fibre layer thickness showed no significant changes. While there were no changes in retinal nerve fibre layer thickness, vitrectomy induced changes in the cup-to-disc vertical ratio of the optic disc and retinal vessel diameter for at least 6months after surgery.

Three-dimensional image reconstruction of macula from stratus optical coherence tomography (OCT) for diagnosis of macular degeneration

Diagnosis of macular degeneration using a Stratus OCT with a fast macular thickness map (FMTM) method produced six B-scan images of macula from different angles. The images were converted into a retinal thickness chart to be evaluated by normal distribution percentile of data so that it can be classified as normal thickness of macula or as experiencing abnormality (e.g. thickening and thinning). Unfortunately, the diagnostic images only represent the retinal thickness in several areas of the macular region. Thus, this study is aims to obtain the entire retinal thickness in the macula area from Status OCT's output images. Basically, the volumetric image is obtained by combining each of the six images. Reconstruction consists of a series of processes such as pre-processing, segmentation, and interpolation. Linear interpolation techniques are used to fill the empty pixels in reconstruction matrix. Based on the results, this method is able to provide retinal thickness maps on the macula surface and the macula 3D image. Retinal thickness map can display the macula area which experienced abnormalities. The macula 3D image can show the layers of tissue in the macula that is abnormal. The system built cannot replace ophthalmologist in decision making in term of diagnosis.

Between-Subject Variability in Healthy Eyes as a Primary Source of Structural-Functional Discordance in Patients With Glaucoma.

PurposeTo test with an independent data set the finding that between-subject variability in healthy eyes is the primary source of structural–functional discordance in patients with glaucoma.MethodsNeuroretinal rim area, retinal nerve fiber layer thickness, and perimetric data were analyzed for one eye in each of 55 control subjects and for 245 right eyes of patients in the United Kingdom Glaucoma Treatment Study. Data were gathered with the Heidelberg Retina Tomograph (HRT), Stratus Optical Coherence Tomograph (OCT), and Humphrey Field Analyzer (HFA). Discordance was quantified as width of the limits of agreement from a Bland-Altman analysis of depth of defect. The ratio of variances (F test) for the patient and control groups was computed for comparisons of HFA-OCT, HFA-HRT, and OCT-HRT. Bonferroni adjustment required P less than 0.017 for statistical significance. The discordance in the patients was also quantified as the 95% prediction interval computed from the discordance in controls using the Hood-Kardon model for the HFA-OCT comparison.ResultsThe F ratio comparing discordance in patients and controls was 0.77, 1.43, and 1.32 for the HFA-OCT, HFA-HRT, and OCT-HRT comparisons with P values 0.88, 0.06, and 0.11, respectively. For the Hood-Kardon model, 4.7% of the patients had discordance outside the 95% prediction interval computed from the discordance in controls. Similar results were obtained when all comparisons were repeated for left eyes of patients.ConclusionsThese results confirm previous findings that between-subject variability in healthy eyes is the primary source of structural–functional discordance in patients with glaucoma, and extends this finding to a structural–structural comparison.

Retinal nerve fiber layer thickness measurements of normal Northern Nigerian adults using optical coherence tomography.

Objective:To assess retinal nerve fiber layer (RNFL) thickness measurements of normal Northern Nigerian adults using optical coherence tomography (OCT).Subjects and Methods:The OCT procedure was carried out with the Carl Zeiss Stratus OCT Model 3000 software version 4.0 (Carl Zeiss Meditec AG, Jena, Germany). The fast RNFL scan protocol was used to obtain RNFL thickness measurements. Student's t-test was used to compare mean RNFL thickness values. P ≤ 0.05 was considered as statistically significant. Average RNFL thickness was correlated with age.Results:Two hundred and twenty eyes of 110 subjects aged 18–51 years were examined. The average RNFL thickness was 104.17 ± 10.71 μm. The mean values for the RNFL thickness were 129.15 ± 16.87 μm, 135.34 ± 20.40 μm, 85.10 ± 23.60 μm, and 67.19 ± 13.27 μm for the inferior, superior, nasal, and temporal quadrants, respectively. A statistically significant difference was found between males and females for the mean RNFL thickness (t = 3.30, P = 0.001) and for the mean superior and inferior RNFL thickness. There was a statistically significant difference between right and left eyes (t = 3.73, P = 0.001) for the mean RNFL thickness. A negative correlation was found between RNFL thickness and age (r = −0.313, P = 0.002).Conclusion:Normal RNFL thickness measurements in healthy Nigerian adults are presented. The RNFL was found to be thicker in females and in right eyes. The values were comparable to those of the Indian population but higher than some Caucasian values.

Comparison and interchangeability of macular thickness measured with Cirrus OCT and Stratus OCT in myopic eyes.

To investigate the difference of macular thickness measurements between stratus optical coherence tomography (OCT) and Cirrus OCT (Carl Zeiss Meditec, Dublin, CA, USA) in the same myopic patient and to develop a conversion equation to interchange macular thickness obtained with these two OCT devices. Eighty-nine healthy Chinese adults with spherical equivalent (SE) ranging from -1.13 D to -9.63 D were recruited. The macular thickness was measured by Cirrus OCT and Stratus OCT. The correlation between macular thickness and axial length and the agreement between two OCT measurements were evaluated. A formula was generated to interchange macular thickness obtained with two OCT devices. Average macular thickness measured with Stratus OCT (r=-0.280, P=0.008) and Cirrus OCT (r=-0.224, P=0.034) were found to be negatively correlated with axial length. No statistically significant correlation was found between axial length and central subfield macular thickness (CMT) measured with Stratus OCT (r=0.191, P=0.073) and Cirrus OCT (r=0.169, P=0.113). The mean CMT measured with Cirrus OCT was 53.63±7.94 µm thicker than with Stratus OCT. The formula CMTCirrus OCT=78.328+0.874×CMTStratus OCT was generated to interchange macular thickness obtained with two OCT devices. Macular thickness measured with Cirrus OCT were thicker than with Stratus OCT in myopic eyes. A formula can be used to interchange macular thickness measured with two OCT devices in myopic eyes. Studies with different OCT devices and larger samples are warranted to enable the comparison of macular values measured with different OCT devices.

Investigating Tissue Optical Properties and Texture Descriptors of the Retina in Patients with Multiple Sclerosis.

PurposeTo assess the differences in texture descriptors and optical properties of retinal tissue layers in patients with multiple sclerosis (MS) and to evaluate their usefulness in the detection of neurodegenerative changes using optical coherence tomography (OCT) image segmentation.Patients and Methods38 patients with MS were examined using Stratus OCT. The raw macular OCT data were exported and processed using OCTRIMA software. The enrolled eyes were divided into two groups, based on the presence of optic neuritis (ON) in the history (MSON+ group, n = 36 and MSON- group, n = 31). Data of 29 eyes of 24 healthy subjects (H) were used as controls. A total of seven intraretinal layers were segmented and thickness as well as optical parameters such as contrast, fractal dimension, layer index and total reflectance were measured. Mixed-model ANOVA analysis was used for statistical comparisons.ResultsSignificant thinning of the retinal nerve fiber layer (RNFL), ganglion cell/inner plexiform layer complex (GCL+IPL) and ganglion cell complex (GCC, RNFL+GCL+IPL) was observed between study groups in all comparisons. Significant difference was found in contrast in the RNFL, GCL+IPL, GCC, inner nuclear layer (INL) and outer plexiform layer when comparing MSON+ to the other groups. Higher fractal dimension values were observed in GCL+IPL and INL layers when comparing H vs. MSON+ groups. A significant difference was found in layer index in the RNFL, GCL+IPL and GCC layers in all comparisons. A significant difference was observed in total reflectance in the RNFL, GCL+IPL and GCC layers between the three examination groups.ConclusionTexture and optical properties of the retinal tissue undergo pronounced changes in MS even without optic neuritis. Our results may help to further improve the diagnostic efficacy of OCT in MS and neurodegeneration.