Optic Cup Volume Research Articles

Preliminary clinical observation and analysis of structural changes of optic nerve head in glaucoma patients after visual training

Objective: To investigate the effect of virtual reality visual training on remodeling optic nerve structures of glaucoma patients and analyze the influencing factors of visual training effect. Methods: A prospective non-randomized controlled trial was conducted. Glaucoma patients who presented to the Department of Ophthalmology, Beijing Shijitan Hospital between October 2021 and October 2022 were collected and divided into the training group or the control group according to their intentions. The training group accepted 3 months of visual training, while the control group did not. Optical coherence tomography was used to examine the disc edge area, cup volume, disc area, cup-to-disc ratio, and other parameters of the optic disc of both eyes of the patients at enrollment and after 3 months, and the changes of each parameter in the two groups were analyzed. Multivariate analysis was performed in the training group to investigate the effects of sex, age, visual field index, and mean defect on visual disc structure changes during visual training. Results: A total of 53 glaucoma patients (101 eyes) were included in the final analysis, among which the training group consisted of 27 cases (51 eyes), with 19 males and 8 females, and the age range was 48.0 (40.0, 61.0) years old. The control group comprised 26 cases (50 eyes), with 26 males and 11 females, and the age range was 54.0 (38.0, 63.0) years old. Compared with the control group, the deviation of cup volume was -0.006(-0.050, 0.015)mm3 (P<0.05), and the deviation of disc edge area was 0.00(-0.04, 0.05)mm2 (P<0. 05)in the visual training group after 3 months of visual training. The gender (OR=4.217, 95%CI=1.188-14.966) may be the influence factor of rim area. While,the mean defect (OR=1.526, 95%CI=0.245-9.491) was not that influential on rim area change. Conclusions: Visual training can increase the disc area and decrease the optic cup volume of the optic nerve in glaucoma patients. The rim area may be increased more easily after visual training in male glaucoma patients.

Early detection of optic nerve head changes using optical coherence tomography after using mesenchymal stromal cells as intravitreal therapy in rabbit models of ocular hypertension.

Stem cell therapy is considered a promising treatment for several neurodegenerative diseases. However, there are very few studies on the use of this therapy in glaucoma models. By detecting the changes produced by glaucoma early, cell therapy could help prevent the events that lead to blindness. In this study, early changes in the optic nerve head (ONH) as detected by optical coherence tomography (OCT) after the application of human Wharton's jelly-derived mesenchymal stromal cells (hWJ-MSCs) in an experimental model of ocular hypertension (OH) were evaluated. Fifteen New Zealand rabbits were randomly divided into the following three groups: G1: OH, G2: hWJ-MSCs, and G3: OH + hWJ-MSCs. An OH model was constructed, and the intraocular pressure (IOP) was measured regularly. At week 7, 105/100 μL hWJ-MSCs were intravitreally injected. Retinography and OCT were used to evaluate structural changes in ONH. IOP increased significantly in G1 and G3 from week 3 onward. Retinography revealed more significant optic nerve changes, that is, papillary asymmetry suggestive of optic nerve excavation, vascular alterations, and irregular hypopigmentation peripheral to the optic disk margin, in G1 compared with G3. OH locates the hWJ-MSCs solution in the vitreous in front of the optic nerve. OCT revealed retinal nerve fiber layer (RNFL) reduction in all groups, reduced optic cup volume in G2 and G3 between weeks 1 and 9, and significant ganglion cell layer thickness reduction in G1 and a slight increase in G3. Intravitreal hWJ-MSCs injection produced changes in optic cup volume, which were detected early on by OCT; however, RNFL could not be restored in this OH model.

Optic disc edema during strict 6° head-down tilt bed rest is related to one-carbon metabolism pathway genetics and optic cup volume.

Some astronauts on International Space Station missions experience neuroophthalmological pathologies as part of spaceflight associated neuro-ocular syndrome (SANS). Strict head-down tilt bed rest (HDTBR) is a spaceflight analog that replicates SANS findings and those who had 3-4 risk alleles (G and C alleles from the methionine synthase reductase [MTRR] A66G and serine hydroxymethyltransferase [SHMT1] C1420T, respectively) as compared to 1-2 risk alleles, had a greater increase in total retinal thickness (TRT). The objective of this study was to identify factors that contribute to the individual variability of the development of SANS in a 60d HDTBR at the German Aerospace Center's:envihab facility, Cologne Germany. 22 of 24 subjects who participated in the HDTBR study provided blood samples for genetic analysis. Total retinal thickness and optic cup volume were measured before and after bed rest. Subjects with 3-4 versus 0-2 risk alleles had greater ΔTRT during and after bed rest, and the model improved with the addition of baseline optic cup volume. This bed rest study confirms that variants of MTRR and SHMT1 are associated with ocular pathologies. Subjects with more risk alleles had the greatest HDTBR-induced ΔTRT, reaffirming that genetics predispose some individuals to developing SANS. Preflight optic cup volume and genetics better predict ΔTRT than either one alone. Whether nutritional supplements can override the genetic influences on biochemistry, physiology, and pathophysiology remains to be tested. These findings have significant implications for both aerospace and terrestrial medicine.

Retinal Neurodegeneration as a Potential Biomarker of Accelerated Aging in Schizophrenia Spectrum Disorders.

Several biological markers are believed to reflect accelerated aging in schizophrenia spectrum disorders; however, retinal neural changes have not yet been explored as potential CNS biomarkers of accelerated aging in this population. The aim of this study was to determine whether retinal neural layer thinning is more strongly related to age in schizophrenia and schizoaffective disorder patients (SZ) than in a psychiatrically healthy control group (CON). Schizophrenia (n = 60) and CON participants (n = 69) underwent spectral domain optical coherence tomography (OCT) scans to examine the following variables in both eyes: retinal nerve fiber layer (RNFL) thickness, macula central subfield (CSF) thickness, macula volume, ganglion cell layer-inner plexiform layer (GCL-IPL) thickness, optic cup volume, and cup-to-disc ratio. Eleven participants in each group had diabetes or hypertension. Significant negative relationships between age and RNFL thickness, macula volume, and GCL-IPL thickness were observed in the SZ group, while no significant relationships were observed in the CON group. However, many of the findings in the SZ group lost significance when participants with diabetes/hypertension were removed from analyses. A notable exception to this was that the age × SZ interaction accounted for a unique proportion of variance in GCL-IPL thinning over and above the effect of diabetes/hypertension. The results suggest that retinal atrophy occurs at an increased rate in schizophrenia spectrum disorders, potentially reflecting accelerated aging inherent to these conditions, with considerable contributions from systemic medical diseases closely linked to this population.

Identification of Factors Associated With the Development of Optic Disc Edema During Spaceflight

Approximately 70% of crew members who complete long-duration missions to the International Space Station develop signs of optic disc edema, a hallmark finding of spaceflight-associated neuro-ocular syndrome. The onset and magnitude of edema differ across individuals, and the reason for this variability remains unknown. Identifying risk factors for spaceflight-induced disc edema is important because this condition may become more severe during extended-duration missions to the moon and Mars and could be associated with irreversible vision loss. To assess whether preflight indicators of crowded optic nerve head morphology, other ocular measures (such as choroid thickness and axial length), body weight, body mass index, sex, age, and previous flight experience are associated with optic disc edema development. This cohort study analyzed ocular, body weight, and demographic data collected from 31 US and international crew members before, during, and after spaceflight at the NASA Johnson Space Center and International Space Station. Ocular factors assessed included preflight and in-flight peripapillary total retinal thickness, minimum rim width, optic cup volume, mean cup depth, mean cup width, cup-disc ratio, Bruch membrane opening area, retinal nerve fiber layer thickness, choroid thickness, axial length, and refractive error. In addition, body weight, body mass index, sex, age, and previous spaceflight experience were assessed for associations with optic disc edema development. The data were analyzed from August 2021 to June 2022. Approximately 6 to 12 months of spaceflight. In-flight increases in peripapillary total retinal thickness. Linear mixed models were used to assess for associations between a wide range of risk factors and in-flight increases in peripapillary total retinal thickness, which is a sensitive objective measure for detecting optic disc edema. This study included 31 International Space Station crew members with a mean (SD) age of 46.9 (6.0) years (25 men [80.6%]). During spaceflight, mean (SE) peripapillary total retinal thickness increased from 392.0 (5.8) μm to 430.2 (9.6) μm (P < .001), and greater individual changes were associated with smaller preflight cup volume (slope [SE], -62.8 [18.9]; P = .002), shallower preflight cup depth (slope [SE], -0.11 [0.03]; P < .001), and narrower preflight cup width (slope [SE], -0.03 [0.01]; P = .03). No associations were observed between changes in peripapillary total retinal thickness and any other variable evaluated. Findings of this cohort study suggest that smaller optic cup morphology may be associated with optic disc edema development during spaceflight. Crew members with this cup profile may benefit from enhanced ophthalmic monitoring during spaceflight and use of countermeasures against spaceflight-associated neuro-ocular syndrome.

Changes in Optic Nerve Head and Retinal Morphology During Spaceflight and Acute Fluid Shift Reversal

Countermeasures that reverse the headward fluid shift experienced in weightlessness have the potential to mitigate spaceflight-associated neuro-ocular syndrome. This study investigated whether use of the countermeasure lower-body negative pressure during spaceflight was associated with changes in ocular structure. To determine whether changes to the optic nerve head and retina during spaceflight can be mitigated by brief in-flight application of 25-mm Hg lower-body negative pressure. In the National Aeronautics and Space Administration's "Fluid Shifts Study," a prospective cohort study, optical coherence tomography scans of the optic nerve head and macula were obtained from US and international crew members before flight, in-flight, and up to 180 days after return to Earth. In-flight scans were obtained both under normal weightless conditions and 10 to 20 minutes into lower-body negative pressure exposure. Preflight and postflight data were collected in the seated, supine, and head-down tilt postures. Crew members completed 6- to 12-month missions that took place on the International Space Station. Data were analyzed from 2016 to 2021. Spaceflight and lower-body negative pressure. Changes in minimum rim width, optic cup volume, Bruch membrane opening height, peripapillary total retinal thickness, and macular thickness. Mean (SD) flight duration for the 14 crew members (mean [SD] age, 45 [6] years; 11 male crew members [79%]) was 214 (72) days. Ocular changes on flight day 150, as compared with preflight seated, included an increase in minimum rim width (33.8 μm; 95% CI, 27.9-39.7 μm; P < .001), decrease in cup volume (0.038 mm3; 95% CI, 0.030-0.046 mm3; P < .001), posterior displacement of Bruch membrane opening (-9.0 μm; 95% CI, -15.7 to -2.2 μm; P = .009), and decrease in macular thickness (fovea to 500 μm, 5.1 μm; 95% CI, 3.5-6.8 μm; P < .001). Brief exposure to lower-body negative pressure did not affect these parameters. Results of this cohort study suggest that peripapillary tissue thickening, decreased cup volume, and mild central macular thinning were associated with long-duration spaceflight. Acute exposure to 25-mm Hg lower-body negative pressure did not alter optic nerve head or retinal morphology, suggesting that longer durations of a fluid shift reversal may be needed to mitigate spaceflight-induced changes and/or other factors are involved.

Retinal layers and associated clinical factors in schizophrenia spectrum disorders: a systematic review and meta-analysis.

The retina shares structural and functional similarities with the brain. Furthermore, structural changes in the retina have been observed in patients with schizophrenia spectrum disorders (SSDs). This systematic review and meta-analysis investigated retinal abnormalities and their association with clinical factors for SSD. Studies related to retinal layers in SSD patients were retrieved from PubMed, Scopus, Web of Science, Cochrane Controlled Register of Trials, International Clinical Trials Registry Platform, and PSYNDEX databases from inception to March31, 2021. We screened and assessed the eligibility of the identified studies. EZR ver.1.54 and the metafor package in R were used for the meta-analysis and a random-effects or fixed-effects model was used to report standardized mean differences (SMDs). Twenty-three studies (2079 eyes of patients and 1571 eyes of controls) were included in the systematic review and meta-analysis. The average peripapillary retinal nerve fiber layer (pRNFL) thickness, average macular thickness (MT), and macular ganglion cell layer-inner plexiform layer (GCL-IPL) thickness were significantly lower in patients than in controls (n = 14, 6, and 3, respectively; SMD = -0.33, -0.49, and -0.43, respectively). Patients also had significantly reduced macular volume (MV) compared to controls (n = 7; SMD = -0.53). The optic cup volume (OCV) was significantly larger in patients than in controls (n = 3; SMD = 0.28). The meta-regression analysis indicated an association between several clinical factors, such as duration of illness and the effect size of the pRNFL, macular GCL-IPL, MT, and MV. Thinning of the pRNFL, macular GCL-IPL, MT, and MV and enlargement of the OCV in SSD were observed. Retinal abnormalities may be applicable as state/trait markers in SSDs. The accumulated evidence was mainly cross-sectional and requires verification by longitudinal studies to characterize the relationship between OCT findings and clinical factors.

The changes in retinal nerve fiber layer and macular thickness in Chinese patients with alcohol dependency

ObjectivesThis study examined the changes in the retinal nerve fiber layer (RNFL) thickness and the macular thickness in Chinese patients with alcohol dependency and ascertaining the influence of optic cup volume on cognitive functioning. MethodsA total of 26 alcohol-dependent patients and 53 age- and gender-matched healthy controls were enrolled in the study. All subjects underwent Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) measurement and were scanned via spectral-domain optical coherence tomography (OCT). ResultsCompared with the healthy controls, the alcohol-dependent patients returned lower scores across all subscales and total RBANS scores. The total thickness of the RNFL of the left eye, temporal and nasal RNFLthickness of both eyes were thinner in the alcohol-dependent patients (all p < 0.05). In terms of macular thickness, eight macular regions and the average thickness of the right eye and three of the left eye were thinner in the alcohol-dependent patients than in the healthy controls. The linear regression analysis indicated that a higher alcohol consumption was associated with thinner RNFL and macular thickness especially in temporal and inferior quadrant region after controlling for smoker status, age, BMI, cholesterol level and AKT level. ConclusionsA higher alcohol consumption was significantly associated with thinner RNFL and macular thickness, indicating that alcohol is a potential risk factor affecting RNFL thickness and macular thickness. Meanwhile, the increase in optic cup volume was associated with the reduced cognitive functioning of the alcohol-dependent patients.

T168. MACULAR THINNING IN FEMALE PATIENTS WITH PSYCHOSIS SPECTRUM DISORDERS: PRELIMINARY OPTICAL COHERENCE TOMOGRAPHY FINDINGS

BackgroundStructural retinal architecture in living organisms became measurable with the development of optical coherence tomography (OCT) scanners. Recent investigations identified thinning of individual retinal layers in psychosis spectrum disorders (PSD) [1]. Previous reports have shown that structural sex dimorphism of normal brain development is disturbed in psychosis [2]. To the best of our knowledge, no study has examined sex differences in retinal architecture in PSD.MethodsA total of 39 patients with psychosis spectrum disorders and 35 healthy controls matched by age and sex were included. The groups were further divided according to sex: male patients (MP; n=21), female patients (FP; n=18), male controls (MC; n=18), female controls (FC; n=17).A spectral-domain OCT device (Cirrus 4000, Carl Zeiss Inc.) was used to assess the thickness of retinal nerve fiber layer (RNFL), macular volume (MV), total macular thickness, mean and minimal ganglion cell-inner plexiform layer thickness (GC-IPL), optic cup volume and cup-to-disk ratio. Daily dosage of antipsychotic medication was calculated through chlorpromazine equivalents (CPZeq). Comparisons between the groups were performed with one-way ANOVA (Tukey post hoc), Student’s t-test, and chi-squared test.ResultsSociodemographic/clinical characteristics of the groups were as follows: MC – age 29.6 ± 6.4 years; FC – age 32.8 ± 12.1 years; MP – age 33.2 ± 6.0 years (duration of illness 7.3 ± 4.0 years, CPZeq 254.1 ± 153.19 mg) and FP – age 30.6 ± 6.9 year (duration of illness 5.3 ± 3.7 years, CPZeq 201.6 ± 96.2 mg). There were no significant differences in any of the given parameters.Assessment of retinal parameters showed: lower macular central subfield thickness in the right eye when FP and FC were compared (243.75 vs. 260.52 µm, respectively; p=0.03), while in the left eye it showed a similar trend (FP vs. FC, 246.00 vs. 261.11 µm, respectively; p=0.06). MV was lower when FP and FC were compared both in the right (10.00 vs. 10.40 mm3, respectively; p=0.03) and in the left eye (9.94 vs. 10.40 mm3, respectively; p=0.00). Differences were found in total macular thickness in FP vs. FC in both right (277.81 vs. 288.94 µm, respectively; p=0.02) and left eye (276.00 vs. 288.88 µm, respectively; p=0.00). No significant differences in any of the retinal parameters were found when MP were compared with MC.In MP negative correlations were observed between mean antipsychotic dose and the following retinal parameters: inferior RNFL quadrant in the left eye (r=-0.76, p=0.00), macular volume in the right eye (r=-0.60, p=0.03), total macular thickness in the right (r=-0.61, p=0.03) and left eye (r=-0.59, p=0.04) and minimum GC-IPL thickness in the right eye (r=-0.63, p=0.02). In FP, no associations between any of the parameters and antipsychotic dosages were found.DiscussionTo the best of our knowledge, relatively greater macular thinning in female patients with psychosis has not been reported before. Preclinical studies have shown that variability in individual retinal parameters could be influenced by the estrus cycle [3]. In this context, it has been suggested that women who are vulnerable to the development of PSD may have lower levels of endogenous estrogen in comparison to healthy women [4]. The importance of the menstrual phase in the interpretation of retinal thickness measurements in women during reproductive age is an important issue and should be taken into further consideration. Heterogeneous associations between antipsychotic dosages and retinal parameters need additional exploration. Further investigations of sex differences in PSD trough OCT-based measurements are needed in order to confirm and further clarify retinal sex differences in psychosis.

Retinal structural abnormalities in young adults with psychosis spectrum disorders

BackgroundStructural retinal architecture in living organisms became measurable with the development of optical coherence tomography (OCT) scanners. Single-layer analysis with spectral-domain OCT, among other techniques, may provide further insight into pathological changes in complex brain disorders such as psychosis spectrum disorders (PSD). MethodsThis study investigated potential thinning of retinal layers (retinal nerve fiber layer - RNFL, macular volume, macular thickness, ganglion cell-inner plexiform layer- GC-IPL, optic cup volume and cup-to-disk ratio) using a spectral-domain OCT device in 33 non-acute PSD patients (illness duration 5.9 ± 3.9 years) and 35 healthy controls. ResultsIn comparison to age and gender matched controls, patients had bilateral reductions in GC-IPL layer thickness and macular volume. Macular central subfield thinning was found in the right eye, while average macular thickness was lower in the left eye only. RNFL thinning was not observed in patients in comparison to controls, but we noticed that status of this layer could be affected by daily dose of antipsychotics and by illness duration. ConclusionTaken together, our results reveal that retinal thinning is present in young adults with PSDs, but in comparison to the literature we found more prominent changes in both GC-IPL and macular volume/thickness, than in RNFL. Our findings may reflect synaptic loss and neuronal atrophy in non-acute young patients with psychosis.

Optical coherence tomography represents a sensitive and reliable tool for routine monitoring of idiopathic intracranial hypertension with and without papilledema.

We previously reported that certain optical coherence tomography (OCT) measures were sensitive and reliable in identifying idiopathic intracranial hypertension (IIH). This prospective study aimed to define OCT measures that allow differentiation of IIH with and without papilledema, thereby helping clinical decision-making. Eight patients with IIH with papilledema, nine without papilledema and 19 with other neurological diseases were included. OCT measures were obtained before lumbar puncture and within 2h, 1, 3 and 6months after lumbar puncture with cerebrospinal fluid (CSF) removal. All patients with papilledema had increased retinal nerve fiber layer (RNFL) thickness and elevated CSF pressure. All patients without papilledema had normal RNFL but elevated CSF pressure. After CSF removal, reduced RNFL thickness was registered in all eight patients with IIH with papilledema. No significant change in RNFL thickness after CSF removal was observed in IIH without papilledema or in patients with other neurological diseases, although reduced CSF pressure was documented. RNFL thickness tended to be normal in patients with IIH with papilledema at 3-6months after CSF removal. All patients with IIH showed increased rim area and rim thickness, but reduced optic cup volume regardless of RNFL thickness or papilledema. Retinal nerve fiber layer thickness is sensitive for monitoring acute IIH and evaluating treatment effect. Increased rim area and rim thickness and decreased optic cup volume are reliable parameters that indicate persistently increased CSF pressure and risk of relapse. OCT measures are sensitive and reliable for diagnosing subtle IIH even in the absence of papilledema.

OCT measurements of optic nerve head changes in idiopathic intracranial hypertension

ObjectiveSeverity of papilledema and vision loss constitute a basis for therapeutic intervention in idiopathic intracranial hypertension (IIH), but both are often subjective and insensitive in guiding clinical management. The aim of this study was to identify reliable and sensitive measurements of optic nerve head (ONH) and macula, to provide objective guidance for prognostic evaluation and treatment in IIH. We analyzed potential of spectral domain optical coherence tomography (SD-OCT), to measure neuro-retinal rim thickness and area, optic cup-to-disc ratio (C/D) and cup volume of ONH which have not previously been reported in IIH. In parallel, thickness of peripapillary retinal nerve fiber layer (RNFL) and macular ganglion cell layer (GCL) together with inner plexiform layer (IPL) (GCL–IPL) were examined. ResultsAll 7 enrolled IIH patients had increased neuro-retinal rim thickness (p<0.01 for both eyes) and rim area (p<0.05), decreased C/D (p<0.01) and optic cup volume (p<0.01) when compared to findings in 18 sex- and age-matched healthy controls (HC). In a longitudinal study, two IIH patients were followed repetitively by SD-OCT before and after measurement of intracranial pressure (ICP) and removal of cerebrospinal fluid (CSF) by lumbar puncture. Rim thickness and area, C/D and optic cup volume remained altered. RNFL thickness may change with very high ICP, but not immediately after CSF removal. GCL–IPL thickness was unchanged irrespective of ICP change or CSF removal. ConclusionSD-OCT allows detection of ONH changes even in subtle IIH without papilledema and has potential for routine use in IIH.

Valsalva manoeuver, intra‐ocular pressure, cerebrospinal fluid pressure, optic disc topography: Beijing intracranial and intra‐ocular pressure study

To assess whether a Valsalva manoeuver influences intra-ocular pressure (IOP), cerebrospinal fluid pressure (CSF-P) and, by a change in the trans-laminar cribrosa pressure difference, optic nerve head morphology. In the first part of the study, 20 neurological patients (study group 'A') underwent measurement of IOP and lumbar CSF-P measurement in a lying position before and during a Valsalva manoeuver. In the second study part, 20 healthy subjects (study group 'B') underwent ocular tonometry and confocal scanning laser tomography of the optic nerve head before and during a Valsalva manoeuver. During the Valsalva manoeuver in study group 'A', the increase in CSF-P by 10.5±2.7mmHg was significantly (p<0.001) higher than the increase in IOP by 1.9±2.4mmHg. The change in CSF-P was not significantly (p=0.61) correlated with the change in IOP. During the Valsalva manoeuver in study group 'B', IOP increased by 4.5±4.2mmHg and optic cup volume (p<0.001), cup/disc area ratio (p=0.02), cup/disc diameter ratio (p=0.03) and maximum optic cup depth (p=0.01) significantly decreased, while neuroretinal rim volume (p=0.005) and mean retinal nerve fibre layer thickness (p=0.02) significantly increased. The Valsalva manoeuver-associated short-term increase in CSF-P was significantly larger than a simultaneous short-term increase in IOP. It led to a Valsalva manoeuver-associated decrease or reversal of the trans-laminar cribrosa pressure difference, which was associated with a change in the three-dimensional optic nerve head morphology: optic cup-related parameters decreased and neuroretinal rim-related parameters enlarged. These findings may be of interest for the pathogenesis of glaucomatous optic neuropathy.

Cup to disc ratio by optical coherence tomography is abnormal in multiple sclerosis

Objective To identify and characterize cup to disc ratio (CDR) and related optic nerve head abnormalities in multiple sclerosis (MS) using spectral domain optical coherence tomography (OCT). Background While CDR is routinely assessed by ophthalmologists in the evaluation of glaucoma, CDR and related optic nerve head metrics remain largely unexplored in MS. Design/methods Cirrus-HD (high density) OCT was used to evaluate average CDR, vertical CDR, optic disc area, optic cup volume, and neuro-retinal rim area in 105 MS patients and 88 age-matched healthy individuals. High-contrast (100%) visual acuity, 2.5% low-contrast letter acuity and 1.25% low-contrast letter acuity were assessed in 77 MS patients. Two-sample t-tests were used in the analysis of OCT-derived optic nerve head measures between healthy controls and MS patients. Multivariate regression (accounting for age and gender) was used to assess relationships between optic nerve head measures and visual function. Results Average CDR (p = 0.007) and vertical CDR (p = 0.005) were greater in MS patients compared to healthy controls, while neuro-retinal rim area was decreased in MS patients (p = 0.001). CDR increased with retinal nerve fiber layer (RNFL) thinning (r = −0.29, p = 0.001). 2.5% low-contrast (p = 0.005) and 1.25% low-contrast letter acuity (p = 0.03) were lower in MS patients with higher vertical CDR. Conclusions/relevance CDR (as determined by spectral domain OCT) is abnormal in MS and correlates with visual function. OCT-derived CDR and related optic nerve head metrics may represent an objective measure by which to monitor disease progression, and potentially neuroprotection, in therapeutic MS trials.

Comparison of Photographic Techniques and Films Used in Stereophotogrammetry of the Optic Disk

We compared photogrammetric measurements of optic cup volume, area, and depth made from two types of stereophotography and two types of film to determine their effect on the precision of the measurements. We found that measurements from simultaneous stereophotography (Donaldson stereoscopic fundus camera) had a smaller range of values and a smaller mean percent error than measurements from consecutive stereophotography (Zeiss Fundus Flash II camera). However, a Student's t-test for related measures showed no significant difference. The measurements from Kodachrome 25 film and Kodak Photomicrography film varied in range and mean percent error without a pattern. The Student's t-test for related measures showed no significant difference.

Photogrammetric Analysis of Volume Asymmetry of the Optic Nerve Head Cup in Normal, Hypertensive, and Glaucomatous Eyes

Recent studies of optic cup volume, depth, and orifice area demonstrated a large overlap of the range of these factors for normal and glaucomatous eyes, suggesting that it is usually not possible to distinguish abnormal disks on the basis of a particualr set of geometric quantifiers. Because of the knowledge that qualitative asymmetry of a person's optic cups may be a sign of glaucoma, calculation of the quantity of cup asymmetry using the aforementioned geometric parameters was undertaken in 90 patients. Results indicated that 90% of the bilaterally normal subjects who were studied and 80% of the ocular hypertensives had less than 0.20 mm3 cup volume asymmetry. In contrast, however, all of the unilateral glaucoma patients in this sample exceeded that value. It therefore appears that measurement of the amount of, volume asymmetry between a person's optic cups may be a useful tool in the diagnosis of glaucoma.