Superior Quadrant Retinal Nerve Fiber Layer Thickness Research Articles

Retinal nerve fiber layer and ganglion cell layer changes on optical coherence tomography in early multiple sclerosis and optic neuritis cases.

Purpose:To study the retinal nerve fiber layer (RNFL) and ganglion cell layer (GCL) changes on optical coherence tomography in early multiple sclerosis (MS) patients.Methods:A prospective cohort study was conducted at a tertiary care center. Patients of early MS (expanded disability status scale <3) with or without optic neuritis (ON) and idiopathic ON were included. Twenty age-matched individuals were taken as controls. Changes in RNFL and GCL thickness were evaluated along with the correlation with visual function parameters such as visual acuity, contrast sensitivity, and visual evoked response at first visit and again at six months.Results:Forty-four patients of MS with or without ON (24 and 20 patients respectively), 29 patients with idiopathic ON, and 20 healthy controls constituted the cohorts. Mean LogMAR best-corrected visual acuity was found to be significantly reduced in all groups except fellow eyes (FE) of ON group. Mean values of average RNFL thickness and values in superior, temporal, and inferior quadrant were significantly reduced. Similarly, overall mean values of average GCL-inner plexiform layer (IPL) thickness and values in superior, superonasal, superotemporal, inferonasal, and inferotemporal quadrant were significantly reduced in all groups except FE of ON group (P < 0.05). All the visual parameters significantly correlated with GCL + IPL thickness.Conclusion:GCL + IPL thickness is a more sensitive clinical structural marker than RNFL in early MS with/without ON and ON patients and correlates with all the visual parameters better than RNFL thickness.

OCT Glaucoma Staging System: a new method for retinal nerve fiber layer damage classification using spectral-domain OCT.

PurposeTo describe a new method, the Optical Coherence Tomography (OCT) Glaucoma Staging System, for classifying retinal nerve fiber layer (RNFL) damage assessed with OCT.Patients and methodsThe OCT Glaucoma Staging System was created based on data obtained from Nidek RS 3000 spectral-domain (sd)-OCT. This system uses the superior and inferior quadrant RNFL thickness values, plotted on an x-y diagram for staging structural damage severity in glaucoma. A non-linear equation and two regression lines describe the boundary lines which separate the different sectors of the diagram. These mathematical formulas have been used to create a software, which provides a quick classification of the RNFL damage. Sensitivity and specificity of the system were assessed in a different cohort including 64 patients with early OAG, and 62 normal subjects.ResultsThree hundred and two OCT tests from 98 healthy controls and 284 patients affected by either ocular hypertension or chronic open-angle glaucoma were considered in order to design the new classification system. The OCT Glaucoma Staging System classifies RNFL defects into 6 stages of increasing severity ranging from borderline to stage 5, and 3 groups according to defect localization (superior, inferior, or diffuse). Sensitivity and specificity in discriminating between healthy and glaucomatous eyes were 95.2 and 91.9%, respectively, considering borderline results as abnormal.ConclusionsThe OCT Glaucoma Staging System appears to provide a standardized and objective classification of glaucomatous RNFL damage. It can be used in day-to-day clinical practice for an easy and fast interpretation of RNFL measurements obtained with OCT.

Anxiety During Pregnancy and Postpartum: Course, Predictors and Comorbidity with Postpartum Depression.

Previous findings on peripartum anxiety are inconsistent in respect to the prevalence and course of peripartum anxiety with comorbidity of depression. Our aim was threefold: (1) to examine the course of elevated anxiety during pregnancy, immediately after childbirth, and six weeks postpartum; (2) to establish comorbidity of postpartum anxiety and postpartum depression (PPD); and (3) to examine predictors of anxiety 6 weeks postpartum. A sample of women (N=272) who were below the cut-off score for clinical depression during pregnancy were assessed in the third trimester of pregnancy, then 2 days and 6 weeks postpartum. Questionnaires on anxiety, pregnancy specific distress, stress, coping styles, social support, and depression were administered at each assessment. Obstetric data were collected from the participants' medical records. The estimated rate of high anxiety was 35% during pregnancy, 17% immediately after childbirth, and 20% six weeks postpartum, showing a decrease in anxiety levels after childbirth. Comorbidity of anxiety and PPD was 75%. Trait anxiety and early postpartum state anxiety are significant predictors of postpartum anxiety. Anxiety is a common peripartum psychological disturbance. Anxiety symptoms overlap with PPD, but not com-pletely, indicating that screening for postpartum mental difficulties should include both depression and anxiety.

Evaluation of retinal nerve fiber layer, ganglion cell layer and macular changes in patients with migraine.

The aim of this study was to investigate retinal nerve fiber layer (RNFL), ganglion cell layer (GCL) thickness, macular changes (central subfield thickness (CST), cube average thickness (CAT), cube volume (CV) in patients with migraine using spectral-domain optical coherence tomography (OCT) and to assess if there was any correlation with white matter lesions (WML). In this prospective case-control study, RNFL, GCL thickness and macular changes of 19 migraine patients with aura (MA), 41 migraine without aura (MO) and 60 age- and gender-matched healthy subjects were measured using OCT device. OCT measurements were taken at the same time of the day to minimize the effects of diurnal variation. The average, inferior and superior quadrant RNFL thickness were significantly thinner in patients with migraine (p=0.017, p=0.010, p=0.048). There was also a significant difference between patients with and without aura in the mean and superior quadrant RNFL thickness (p=0.02, p=0.043).While there was a significant thinning in CST and CAT in patients with migraine (p=0.020), there were no significant difference in GCL measurements (p=0.184). When the groups were compared to the control group, there were significant differences between MA and the control group regarding average, superior and inferior quadrant RNLF thickness (p<0.001, p=0.025, p<0.001). On the other hand, there were significant differences between MO and the control group regarding average and inferior faces (p=0.037, p=0.04). When OCT measurements were evaluated according to the frequency of attacks, CST and GCL thickness were significantly thinner in patients who had more than four attacks a month (p=0.024, p=0.014). In patients with WML, only CV measurements were significantly thinner than migraine patients without WML (p=0.014). The decreased RNFL, CST, CAT and CV of the migraine patients might be related to the vascular pathology of the disease. Because WML was not correlated with the same measurements except CV, we think that further studies are needed to evaluate the etiopathologic relationship between OCT measurements and WML in migraine patients.

Decreased retinal nerve fiber layer thickness in patients with obstructive sleep apnea syndrome: A meta-analysis.

Objective:To investigate the changes of retinal nerve fiber layer (RNFL) thickness in obstructive sleep apnea syndrome (OSAS) patients.Methods:Relevant studies were selected from 3 major literature databases (PubMed, Cochrane Library, and EMBASE) without language restriction. Main inclusion criteria is that a case-control study in which RNFL thickness was measured by a commercial available optical coherence tomography (OCT) in OSAS patients. Meta-analysis was performed using STATA 12.0 software. Efficacy estimates were evaluated by weighted mean difference with corresponding 95% confidence intervals (CIs). Primary outcome evaluations were: the average changes of RNFL thickness in total OSAS patients, subgroup analysis of RNFL thickness changes in patients of different OSAS stages, and subgroup analysis of 4-quadrant RNFL thickness changes in total OSAS patients.Results:Of the initial 327 literatures, 8 case-control studies with 763 eyes of OSA patients and 474 eyes of healthy controls were included (NOS scores ≥6). For the people of total OSAS, there had an average 2.92 μm decreased RNFL thickness compared with controls (95% CI: −4.61 to −1.24, P = 0.001). For subgroup analysis of OSAS in different stages, the average changes of RNFL thickness in mild, moderate, severe, and moderate to severe OSAS were 2.05 (95% CI: −4.40 to 0.30, P = 0.088), 2.32 (95% CI: −5.04 to 0.40, P = 0.094), 4.21 (95% CI: −8.36 to −0.06, P = 0.047), and 4.02 (95% CI: −7.65 to −0.40, P = 0.03), respectively. For subgroup analysis of 4-quadrant, the average changes of RNFL thickness in Superior, Nasal, Inferior, and Temporal quadrant were 2.43 (95% CI: −4.28 to −0.57, P = 0.01), 1.41 (95% CI: −3.33 to 0.51, P = 0.151), 3.75 (95% CI: −6.92 to −0.59, P = 0.02), and 0.98 (95% CI: −2.49 to 0.53, P = 0.203), respectively.Conclusion:Our study suggests that RNFL thickness in OSAS patients is much thinner than healthy population, especially in superior and inferior quadrant. The impact of OSAS disease on RNFL and visual function should be taken seriously in the further study.

Changes in retinal nerve fiber layer thickness in patients with cerebral infarction: evidence of transneuronal retrograde degeneration.

We aimed to evaluate the thicknesses of the retinal nerve fiber layer (RNFL) in patients with cerebral infarction (CI) by using optical coherence tomography. This cross-sectional study evaluated 45 patients with CI (patient group) and 45 healthy subjects (control group). All subjects underwent a complete ophthalmic examination including optical coherence tomography. The average, temporal, nasal, inferior, and superior quadrant RNFL thicknesses and in each of 12 sectors around the optic nerve head were obtained. The side with the infarction was compared to the contralateral side among the patients with cerebral infarction, and their measurements were also compared to those of the control group. Patients who had CI only in the middle cerebral artery (MCA) and posterior cerebral artery (PCA) were included in this study. Correlations between the RNFL thicknesses and infarction features were also evaluated. The mean age of the patients was 61.6±12.4years, and the mean age of the controls was 59.6±11.8years (p=0.65). Of the 45 patients with cerebral infarction, 35 (77.7%) had infarction in the MCA territory, 10 (22.2%) had infarction in the PCA territory and the mean duration of the disease was 20.2±29.1months. The average, superior, inferior, and nasal RNFL thicknesses were significantly thinner in both eyes of the patients with CI than in the eyes of the control group (p<0.05). The average and inferior RNFL thicknesses were significantly more affected in the ipsilateral eyes than in the contralateral eyes (p<0.031 and p<0.006, respectively). The amount of reduction in the RNFL thicknesses was not correlated with the infarction features. Significant thinning of the RNFL in patients with CI may result from transneuronal retrograde degeneration. Optical coherence tomography may provide useful information to confirm the process of trans-synaptic retrograde degeneration.

Assessment of Retinal Nerve Fiber Layer Thickness in Fellow Eye in Patients with Unilateral Optic Neuritis

Background: One of the main progressive consequences of optic neuritis is inflammatory axonal loss manifested by Retinal Nerve Fiber layer (RNFL) thinning on Optical Coherence Tomography. We assessed RNFL thickness in the fellow eye in patients with unilateral optic neuritis. Methods: Twenty nine patients with unilateral optic neuritis after three months of attack, were enrolled in the study and the RNFL thickness were measured by Optical Coherence Tomography in the quadrants of superior, nasal, inferior, and temporal at both involved and fellow eyes. Results: The mean RNFL thickness was significantly lower in the involved than in fellow eye in all quadrants except for temporal. Significant differences were only in women. Compared to fellow eyes, lower mean RNFL thickness in superior, inferior, and nasal quadrants in involved eyes was found mostly in the ages below 40. RNFL was less thickened in involved than in fellow eyes only in those patients with final diagnosis of isolated optic neuritis not in those with multiple sclerosis. Mean RNFL thickness was significantly lower in involved eyes in all quadrants (except for temporal) only in those who underwent Optical Coherence Tomography 13 to 24 months after optic neuritis. Conclusion: RNFL thinning occurs in involved eye compared to fellow eye in patients with unilateral optic neuritis. It is observed in women more than men and in those patients younger than 40. The abnormal change in RNFL thickness was also found in those patients underwent Optical Coherence Tomography 13 to 24 months after optic neuritis. The difference in mean RNFL thickness may be specified to inferior quadrant in MS patients.

Retinal Nerve Fiber Layer Thickness Changes in Migraine: A Meta-Analysis of Case–Control Studies

Background: The neurovascular dysfunction appears to be related to the development of migraines and it could be possible that hypoperfusion might also involve other areas besides brain, including the retina. Numerous studies have analyzed the ability of optical coherence tomography (OCT) to detect retinal nerve fiber layer (RNFL) thickness abnormalities and changes in migraine, but the results have not always been consistent. Therefore, we carried out a meta-analysis to evaluate the RNFL thickness measured with OCT in migraine.Methods: Case–control studies were selected through an electronic search of the Cochrane Controlled Trials Register, PUBMED and EMBASE. For the continuous outcomes, we calculated the weighted mean difference (WMD) and 95% confidence interval (CI). The statistical analysis was performed by RevMan 5.0 software.Results: Six case–control studies were included in the present meta-analysis, containing a total of 432 eyes in migraine patients and 288 eyes in healthy controls. The results of our study showed that there was a significant reduction in average RNFL thickness in patients with migraine compared to healthy controls (WMD = −3.67, 95% CI: −6.84 to −0.49, p = 0.02). Additionally, differences of RNFL thickness in superior quadrant (WMD = −9.23, 95% CI: −15.63 to −2.82, p = 0.005), inferior quadrant (WMD = −3.47, 95% CI: −6.73 to −0.22, p = 0.04), nasal quadrant (WMD = −3.86, 95% CI: −7.10 to −0.61, p = 0.02) and temporal quadrant (WMD = −3.10, 95% CI: −5.05 to −1.15, p = 0.002) were all significant between the two groups.Conclusions: Our meta-analysis found that RNFL thickness in the migraine patients was thinner than that in the healthy control group. Given the limited sample size, further investigations are needed to validate these findings.

Retinal Ganglion Cell Analysis Using High-Definition Optical Coherence Tomography in Patients with Mild Cognitive Impairment and Alzheimer's Disease

Alzheimer's disease (AD) is a neurodegenerative disorder with emerging evidence that it is associated with retinal ganglion cell loss; however, few data exist to establish this association. To determine whether macular ganglion cell-inner plexiform layer (GC-IPL) and retinal nerve fiber layer (RNFL), as quantitatively measured by non-invasive in vivo spectral-domain optical coherence tomography (SD-OCT), are altered in patients with AD and mild cognitive impairment (MCI). Patients with AD and MCI were recruited from dementia/memory clinics, and cognitively normal controls were selected from the Singapore Epidemiology of Eye Disease program. SD-OCT (Cirrus HD-OCT, software version 6.0.2, Carl Zeiss Meditec Inc, Dublin, CA) was used to measure the GC-IPL and RNFL thicknesses. Compared with cognitively normal controls (n = 123), patients with AD (n = 100) had significantly reduced GC-IPL thicknesses in all six (superior, superonasal, inferonasal, inferior, inferotemporal, and superotemporal) sectors (mean differences from -3.42 to -4.99 μm, all p < 0.05) and reduced RNFL thickness in superior quadrant (-6.04 μm, p = 0.039). Patients with MCI (n = 41) also had significantly reduced GC-IPL thicknesses compared with controls (mean differences from -3.62 to -5.83 μm, all p < 0.05). Area under receiver operating characteristic curves of GC-IPL were generally higher than that of RNFL to discriminate AD and MCI from the controls. Our data strengthens the link between retinal ganglion cell neuronal and optic nerve axonal loss with AD, and suggest that assessment of macular GC-IPL can be a test to detect neuronal injury in early AD and MCI.

Analysis of the Retinal Nerve Fiber Layer in Retinitis Pigmentosa Using Optic Coherence Tomography.

Aim. To evaluate the peripapillary retinal nerve fiber layer (RNFL) changes in retinitis pigmentosa (RP) patients using spectral domain optic coherence tomography (Sd-OCT). Methods. We retrospectively examined medical records of forty-four eyes of twenty-two RP patients. The results were also compared with those of previously reported forty-four eyes of twenty-two normal subjects (controls). Records of average and four quadrants peripapillary RNFL thickness measurements using Sd-OCT were assessed. Results. In RP patients the mean RNFL thickness was 97.57 ± 3.21 μm. The RNFL in the superior, temporal, nasal, and inferior quadrants was 119.18 ± 4.47 μm, 84.68 ± 2.31 μm, 75.09 ± 3.34 μm, and 113.88 ± 4.25 μm, respectively. While the thinning of RNFL was predominantly observed in the inferior quadrant, the thickening was mostly noted in temporal quadrant. The differences between mean, superior, and nasal quadrant RNFL thicknesses were not statistically significant when compared with control group. The RP patients had thinner inferior quadrant and thicker temporal quadrant than control group (p < 0.05). Conclusion. Sd-OCT is highly sensitive and effective instrument to detect RNFL changes in RP patients. RNFL measurements can provide information about the progression of retinitis pigmentosa and may provide prognostic indices for future treatment modalities.

Peripapillary Retinal Nerve Fiber Layer Assessment of Spectral Domain Optical Coherence Tomography and Scanning Laser Polarimetry to Diagnose Preperimetric Glaucoma

PurposeTo compare the abilities of peripapillary retinal nerve fiber layer (RNFL) parameters of spectral domain optical coherence tomograph (SDOCT) and scanning laser polarimeter (GDx enhanced corneal compensation; ECC) in detecting preperimetric glaucoma.MethodsIn a cross-sectional study, 35 preperimetric glaucoma eyes (32 subjects) and 94 control eyes (74 subjects) underwent digital optic disc photography and RNFL imaging with SDOCT and GDx ECC. Ability of RNFL parameters of SDOCT and GDx ECC to discriminate preperimetric glaucoma eyes from control eyes was compared using area under receiver operating characteristic curves (AUC), sensitivities at fixed specificities and likelihood ratios (LR).ResultsAUC of the global average RNFL thickness of SDOCT (0.786) was significantly greater (p<0.001) than that of GDx ECC (0.627). Sensitivities at 95% specificity of the corresponding parameters were 20% and 8.6% respectively. AUCs of the inferior, superior and temporal quadrant RNFL thickness parameters of SDOCT were also significantly (p<0.05) greater than the respective RNFL parameters of GDx ECC. LRs of outside normal limits category of SDOCT parameters ranged between 3.3 and 4.0 while the same of GDx ECC parameters ranged between 1.2 and 2.1. LRs of within normal limits category of SDOCT parameters ranged between 0.4 and 0.7 while the same of GDx ECC parameters ranged between 0.7 and 1.0.ConclusionsAbilities of the RNFL parameters of SDOCT and GDx ECC to diagnose preperimetric glaucoma were only moderate. Diagnostic abilities of the RNFL parameters of SDOCT were significantly better than that of GDx ECC in preperimetric glaucoma.

The Foveal Position Relative to the Optic Disc and the Retinal Nerve Fiber Layer Thickness Profile in Myopia

To evaluate retinal nerve fiber layer (RNFL) thickness profiles according to the foveal position relative to the optic disc in myopia In 164 eyes of 164 healthy myopic subjects, the disc-foveal angle was defined as the angle between a horizontal line through the disc center and the line connecting the fovea and disc center in fundus photographs overlaid on Cirrus-HD optical coherence tomography (OCT) images. The quadrant/clock-hour based peripapillary RNFL thickness and differences between the inferior and superior (I-S) quadrant RNFL thicknesses were measured with OCT. RNFL thickness profiles were determined according to the disc-foveal angle and axial length (AL). As the disc-foveal angle increased (i.e., the fovea becomes more inferior to the optic disc), the superior RNFL decreased significantly (P = 0.003), whereas the inferior RNFL and I-S difference increased (P = 0.010 and P < 0.001, respectively). As the AL increased, the average and temporal RNFLs increased significantly (P = 0.013 and P < 0.001, respectively), and I-S difference was not affected (P = 0.231). The disc-foveal angle was significantly decreased with the distance between the fovea and the optic disc (P = 0.033). In multiple linear regression analysis, the disc-foveal angle was found to be a significant factor related to I-S differences, superior and inferior RNFL (all, P < 0.05) after adjusting for age, disc area, and AL. The intrinsic foveal position relative to the optic disc was an essential determinant of normal RNFL thickness in myopia. In particular, it was associated with the vertical asymmetry of RNFL distribution.

Retinal nerve fiber layer thickness changes in Parkinson disease: a meta-analysis.

BackgroundParkinson disease (PD) is a neurodegenerative process that leads to a selective loss of dopaminergic neurons, mainly in the basal ganglia of the brain. Numerous studies have analyzed the ability of optical coherence tomography (OCT) to detect retinal nerve fiber layer (RNFL) thickness abnormalities and changes in PD, but the results have not always been consistent. Therefore, we carried out a meta-analysis to evaluate the RNFL thickness measured with OCT in PD.Methods and FindingsCase-control studies were selected through an electronic search of the Cochrane Controlled Trials Register, PUBMED and EMBASE. For the continuous outcomes, we calculated the weighted mean difference (WMD) and 95% confidence interval (CI). The statistical analysis was performed by RevMan 5.0 software. Thirteen case-control studies were included in the present meta-analysis, containing a total of 644 eyes in PD patients and 604 eyes in healthy controls. The results of our study showed that there was a significant reduction in average RNFL thickness in patients with PD compared to healthy controls (WMD = −5.76, 95% CI: −8.99 to −2.53, P = 0.0005). Additionally, differences of RNFL thickness in superior quadrant (WMD = −4.44, 95% CI: −6.93 to −1.94, P = 0.0005), inferior quadrant (WMD = −7.56, 95% CI: −11.33 to −3.78, P<0.0001), nasal quadrant (WMD = −3.12, 95% CI: −5.63 to −0.61, P = 0.01) and temporal quadrant (WMD = −4.63, 95% CI: −7.20 to −2.06, P = 0.0004) were all significant between the two groups.ConclusionIn view of these results and the noninvasive nature of OCT technology, we surmise that OCT could be a useful tool for evaluating the progression of the Parkinson disease.Trial RegistrationClinicalTrials.gov NCT01928212

Retinal Nerve Fiber Layer Thickness in Patients With Alzheimer Disease

The aim of this study was to investigate retinal nerve fiber layer (RNFL) thickness in patients with Alzheimer disease (AD) without visual impairment using spectral domain optical coherence tomography (SD-OCT) and to compare the results with healthy controls. A total of 80 subjects, including 40 patients with early untreated AD (mean age, 69.3 ± 4.9 years) and 40 healthy controls (mean age, 68.9 ± 5.1 years) were enrolled. Both eyes of patients with AD and controls were imaged using SD-OCT. The average RNFL thickness was significantly less in the AD patients than in controls (65 ± 6.2 μm vs 75 ± 3.8μm; P = 0.001). There was selective thinning of the RNFL in the superior quadrant, the mean superior quadrant RNFL thickness being 76 ± 6.7 μm in AD patients and 105 ± 4.8 μm in controls (P = 0.001). In our study, the thickness of RNFL in patient with AD was lower than that of controls. This suggests that SD- OCT has the potential to be used in the early diagnosis of AD as well as in the study of therapeutic agents. Further studies are needed to validate this technology as a viable ocular biomarker over time in AD.

Retinal nerve fiber layer and ganglion cell layer thickness in patients receiving systemic isotretinoin therapy

To evaluate the effect of oral isotretinoin therapy on retinal nerve fiber layer (RNFL) and ganglion cell layer (GCL) thickness by spectral domain optical coherence tomography (OCT). This prospective study included newly diagnosed nodulocystic acne patients about to receive isotretinoin treatment. Macular average GCL thickness and peripapillary average, temporal, nasal, inferior, and superior quadrant RNFL thickness were measured by OCT before and after isotretinoin treatment. Pre- and post-treatment measurements were compared with paired t test. Fifty-six eyes of 28 patients were included. The mean duration of the treatment was 6.5 ± 1.3 months. The mean average GCL thickness was 90.04 ± 5.87 (80-96) μm at baseline and 90.75 ± 6.34 (81-96) μm after treatment. The mean average RNFL thickness was 93.25 ± 6.06 μm (84-107) before treatment and 93.05 ± 5.54 μm (82-106) after treatment. There were no statistically significant differences between pre- and post-treatment values (all p > 0.05). A 6-month course of systemic isotretinoin therapy seems to have no unfavorable effect on retinal ganglion cells; however, larger studies with longer follow-up periods are needed to be conclusive.

The attenuation of retinal nerve fiber layer thickness and cognitive deterioration

Thinner retinal nerve fiber layer (RNFL) has been reported in Alzheimer’s disease (AD) patient. However, whether changes in RNFL thickness can predict the cognitive deterioration remains unknown. We therefore set out a prospective clinical investigation to determine the potential association between the attenuation of RNFL thickness and the deterioration of cognitive function over a period of 25 months. We assessed cognitive function using the Repeatable Battery for the Assessment of Neuropsychological Status and measured RNFL thickness employing optical coherence tomography in 78 participants (mean age 72.31 ± 3.98 years, 52% men). The participants were categorized as stable participants whose cognitive status remained no change (N = 60) and converted participants whose cognitive status deteriorated (N = 18). We found that there was an association between the attenuation of superior quadrant RNFL thickness and the deterioration of cognitive function in the stable participants. In the converted participants, however, there was an inverse association between the reduction of inferior quadrant RNFL thickness and decline of cognitive functions [scores of list recall (R = -0.670, P = 0.002), adjusted (R = -0.493, P = 0.031)]. These data showed that less reduction in the inferior quadrant of RNFL thickness might indicate a higher risk for the patients to develop cognitive deterioration. These findings have established a system to embark a larger scale study to further test whether changes in RNFL thickness can serve as a biomarker of AD, and would lead to mechanistic studies to determine the cellular mechanisms of cognitive deterioration.

Evaluation of the retinal changes in patients with chronic migraine

The aim of this study was to investigate retinal nerve fiber layer (RNFL) thickness and macular changes (central subfield thickness, cube average thickness, cube volume) in patients with chronic migraine (CM) without visual impairment using spectral-domain optical coherence tomography (SD-OCT) and to compare the results to healthy controls. A total of 80 subjects, including 40 CM patients (24 females, 16 males, [corrected] at 19-36 years of age) with no migraine prophylactic treatment and 40 healthy controls (22 females, 18 males, [corrected] at 20-40 years of age) were enrolled. Both eyes of patients with CM and controls were imaged using Cirrus HD SD-OCT (Carl Zeiss Meditec, Dublin, CA, USA). The average RNFL thickness was not significantly thinner in patients with CM. The mean average RNFL thickness was 83 ± 10.5 μm in CM patients and 85 ± 9.6 μm in healthy controls (p = 0.648), but superior quadrant RNFL thickness in the CM patients was significantly lower than healthy controls. The mean superior RNFL thickness was 86 ± 6.7 μm in CM patients and 108 ± 7.3 μm in controls (p < 0.001). Illness duration and frequency of the attacks were not affected by RNFL thickness. No significant differences were detected in macular changes between CM patients and healthy controls. In our study, the thickness of superior RNFL was found to be thinner in CM patients. This implies that longitudinal follow-up is needed to clarify whether RNFL thinning, in migraine patients, is related to a progressive loss of axons and retinal ganglion cells.

LONG-TERM TEMPORAL CHANGES OF PERIPAPILLARY RETINAL NERVE FIBER LAYER THICKNESS BEFORE AND AFTER PANRETINAL PHOTOCOAGULATION IN SEVERE DIABETIC RETINOPATHY

To analyze the long-term changes of peripapillary retinal nerve fiber layer (RNFL) thickness before and after panretinal photocoagulation (PRP) in patients with severe diabetic retinopathy. In this retrospective observational case series, we reviewed the records of 46 patients (68 eyes) with severe diabetic retinopathy, who were treated with PRP and could be followed for more than 6 months. Peripapillary RNFL thickness and foveal thickness were measured at baseline, 3-month intervals until 1 year post-PRP, and 6- to 12-month intervals after 1 year post-PRP using optical coherence tomography. Long-term changes of peripapillary RNFL thickness and foveal thickness as well as the correlation between the two parameters were analyzed. The average RNFL thickness (360° measurement) decreased significantly from 108.4 μm to 103.5 μm at 2 years post-PRP. The average RNFL thickness increased slightly during the initial 3 months post-PRP and thereafter gradually decreased, showing statistically significant reductions at 2 years post-PRP (false discovery rate adjusted P = 0.0051). The superior and inferior quadrant RNFL thicknesses were significantly decreased at 2 years post-PRP (false discovery rate adjusted P = 0.0119 and 0.0051, respectively). The decrease in the nasal quadrant RNFL thickness showed borderline significance at 2 years post-PRP (false discovery rate adjusted P = 0.0854). However, there was no significant decrease in RNFL thickness for the temporal quadrant at any follow-up time. In addition, there was no significant difference in the foveal thickness. But, the pattern of temporal changes in foveal thickness showed a similar pattern with that of temporal RNFL thickness. This study shows that average RNFL thickness after PRP undergoes early thickening and subsequent progressive thinning throughout the 2 years post-PRP. This temporal change varies according to the peripapillary RNFL quadrant. Our results also indicate that temporal RNFL and foveal thickness have a similar pattern of long-term change after PRP.

Retinal Nerve Fiber Layer Analysis with Scanning Laser Polarimetry and RTVue-OCT in Patients of Retinitis Pigmentosa

Purpose: To measure the thickness of the retinal nerve fiber layer (RNFL) of patients with retinitis pigmentosa (RP) and that of normal controls by scanning laser polarimetry with enhanced corneal compensation (GDxECC) and RTVue-optical coherence tomography (OCT). Methods: Fifty-two eyes of 26 patients were included. All patients underwent complete ophthalmological examinations and testing with GDxECC. Twenty-eight of 52 eyes of RP patients underwent RTVue-OCT measurements. A group of 50 eyes of 25 normal subjects (controls) was also included. GDxECC measured RNFL thickness in the peripapillary area in all subjects as well as temporal-superior-nasal-inferior-temporal (TSNIT) parameters, including TSNIT means, superior and inferior region means, TSNIT standard deviation (SD), inter-eye symmetry and nerve fiber indicator (NFI). RTVue-OCT measured the mean, superior, inferior, temporal and nasal quadrant RNFL thickness. Result: In RP patients and controls, TSNIT means by GDxECC were, respectively, 65.00 ± 7.35 and 55.32 ± 5.20. Mean superior quadrant thicknesses were80.56 ± 10.93 and 69.54 ± 7.45. Mean inferior thicknesses were 80.58 ± 9.34 and 69.12 ± 7.78. SDs were 27.92 ± 5.21 and 28.23 ± 4.01. Inter-eye symmetries were 0.82 ± 0.17 and 0.87 ± 0.09. NFIs were 9.74 ± 8.73 and 16.81 ± 8.13. The differences between mean TSNIT, mean superior and mean inferior quadrant thicknesses and NFIs were statistically significant (p < 0.001). In RTVue-OCT measurements, the differences between mean, superior, inferior and temporal quadrant RNFL thicknesses were statistically significant (p = 0.0322, 0.0213, 0.0387, 0.0005). Conclusions: The RNFL measured by GDxECC was significantly thicker in RP patients than in controls. RNFL thickness measured by RTVue-OCT was significantly greater in RP patients than in controls in the superior, inferior and temporal regions. This contribution provides information on RNFL thickness and discusses the mechanism underlying this phenomenon.

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

To evaluate the transient pattern electroretinogram (t-PERG) and the retinal nerve fiber layer (RNFL) thickness in eyes with ocular hypertension (OH) and normal short-wavelength automated perimetry (SWAP). In 26 patients with bilateral OH with normal SWAP, and in 26 age and sex matched healthy controls, t-PERG recording and RNFL thickness measurement were performed. Mean deviation (MD) and pattern standard deviation (PSD) of a reliable full threshold 24-2 SWAP were considered. RNFL thickness was determined by OCT3. Monocular PERG were recorded by using a black and white checkerboard pattern (check size 0.9°, contrast 100 %, mean luminance 80 cd/m2) generated on a monitor and reversed in contrast (four reversals per second, 2 Hz) at a distance of 70 cm. Patients had optimal correction at viewing distance; no mydriatic or miotic eye drops were used. Silver/silver chloride skin electrodes were placed over the lower eyelids in the stimulated eye (active electrode) and in the patched eye (reference electrode); ground electrode was in the Fpz scalp. Peak-to peak amplitude of P50 (N35-P50) and N95 (P50-N95) waves, and implicit time of P50, were considered. Compared to controls, in OH eyes, a reduction of N35-P50 amplitude (2.86 ± 1.49 vs. 3.77 ± 1.08 microvolts, -24.1 %, t-test p = 0.015), of average RNFL thickness (88 ± 11 vs. 96 ± 10 μm, -9.5 %, t-test p = 0.002), and of RNFL thickness in superior (p = 0.015) and inferior quadrant (p < 0.001), were found. Multivariate analysis showed that in OH eyes, N35-P50 amplitude was inversely related to intraocular pressure (IOP) (p = 0.001); no correlation was found between N35-P50 amplitude and MD, PSD, CCT or RNFL thickness. In OH eyes, both PERG and RNFL thickness changes occur in hypertensive eyes with undamaged SWAP; the correlation of PERG amplitude with IOP, but not with RNFL thickness, suggests that such PERG changes are an effect of the IOP on retinal ganglion cells, rather than a sign of their loss.