Smaller Disc Area Research Articles

Evaluation of optic nerve head in patients with small optic disc using oral isotretinoin

BackgroundIsotretinoin has a number of neurological and ocular side effects, but its effect on the optic nerve has not been demonstrated. PurposeTo investigate the effect of oral isotretinoin therapy on the peripapillary retinal nerve fibre layer thickness (RNFL) in patients with small optic disc area using optical coherence tomography (OCT). MethodsThis retrospective study included 55 patients taking 40 mg/day oral isotretinoin. The patients were grouped according to optic disc area. Patients with small optic disc area were included in group 1 and the others in group 2. RNFL thickness was measured by spectral domain OCT before the treatment, at the third month of the treatment, and at the third month after treatment. ResultsRNFL increased significantly in group1 in the third month of treatment compared to that before the treatment (P < 0.001); no significant change was observed in group 2 (P < 0.244). DiscussionOral isotretinoin treatment may be effective in patients with small optic nerve head. The presence of a small optic disc may increase the risk of adverse effects such as decreased dark adaptation, reduced vision, headache, or photophobia. ConclusionEvaluating the optic disc size before initiation of oral isotretinoin treatment may assist in planning patient treatment.

The Inferior, Superior, Temporal Rim Width Pattern (IST Rule) Detects Glaucoma in a Japanese Population.

Précis:The inferior>superior>temporal rim width rate (IST pattern) rather than inferior≥superior≥nasal≥temporal (ISNT) pattern was suited for screening glaucoma in Japanese subjects. Failure of the IST pattern was associated with several important risk factors for glaucoma.Purpose:The purpose of this study was to find a rim width rate pattern to yield the highest positive likelihood ratio (LR+) in detecting glaucoma eyes and to identify risk factors for glaucoma correlating with its failure in a population-based setting.Methods:Disc stereophotographs of 2474 eyes of 2474 normal subjects and 237 eyes of 237 glaucoma subjects found in the Kumejima Study were analyzed using computer-assisted planimetry. Among all combinations of the inferior (I), superior (S), nasal (N) and/or temporal (T) rim width rate, a pattern showing the highest LR+ was selected and risk factors for glaucoma correlating with its failure were determined using multiple logistic regression analysis.Results:The average I, S, N, and T rim widths (SD) were 0.45 (0.10), 0.39 (0.09), 0.47 (0.11), and 0.27 (0.07) mm. Among all combinations, the I>S>T rim width rate pattern (IST pattern) disregarding the N rim width showed the highest LR+ of 2.002 (95% confidence interval, 1.778–2.253). Failure of the IST pattern in normal eyes correlated with a smaller disc area (P<0.001) and disc ovality (P=0.005) and larger β-peripapillary area (P<0.001) and compliance with in glaucoma eyes with a smaller β-PPA area (P=0.027), thicker central corneal thickness (P=0.017), lower intraocular pressure (P=0.019), and higher body mass index (P=0.037).Conclusion:Among all combinations, the I>S>T rim width pattern, the IST pattern, yielded the highest LR+ in detecting glaucoma in Japanese glaucoma eyes and its failure of or compliance with the pattern significantly correlated with several known risk factors for glaucoma.

Associations of Optic Nerve Head and Anterior Segment Parameters in Normotensive Saudi Females

Objectives: To determine the relationship between anterior segment parameters and the optic nerve head (ONH) parameters of females. Methods: Anterior segment, optic nerve head parameters, Intraocular Pressure (IOP) and Axial Length (AL) of 99 participants (aged 20.1±1.3 years) were obtained. Differences between refraction groups and relationship between anterior segment and ONH parameters were assessed as well as linear regression for factors associated with ONH and anterior segment parameters after adjusting for cofounders. Results: SER (-0.12 Acknowledgements: The authors acknowledge the support of the Research Centre, of the Female Scientific and Medical Colleges, Deanship of Scientific Research at King Saud University.0.58D), AL (23.5±0.8 mm), IOP (17.8±2.0 mmHg), anterior segment parameters and optic disc parameters were similar between refraction groups (p&gt;0.20 for all). Age was correlated with anterior chamber volume (r=-0.19), while SER was correlated with AL (r=-0.26), anterior chamber volume (r=-0.25) and angle (r=- 0.19) and with the disc area (r=0.25; p&lt;0.02 for all). Myopes had wider anterior chamber depths than emmetropes (mean difference, 2.06, 95% confidence interval: 0.32/3.80 degs, p=0.02) with smaller disc area (-0.21mm², 95% CI: -0.38/-0.03mm²; p=0.021). After correcting for age and refraction, axial length was associated with corneal refractive power (r=-0.60, p&lt;0.001), and anterior segment parameters (p&lt;0.001 for all). Conclusions: The ONH structure was related to anterior segment morphology including corneal thickness, anterior chamber volume and depth, which is important when interpreting OCT imaging.

Posterior staphyloma is associated with the microvasculature and microstructure of myopic eyes

ObjectiveTo investigate the microvasculature and structural characteristics of the eyes of myopic patients and their association with posterior staphyloma (PS).MethodsThis was a retrospective, case-control study comprising of 106 eyes from 72 individuals. Using 1:1 matching of axial length (AL) of their eyes, patients were allocated into a PS group or no posterior staphyloma (NPS) group. All patients were examined using ultra-widefield fundus imaging, optical coherence tomography angiography, and ocular biometry to acquire microvasculature and microstructure parameters.ResultsThe anterior chamber depth (ACD) of the PS group was significantly different from that of the NPS group (3.56 mm vs 3.76 mm, P < 0.001), as was 1ens thickness (3.72 mm vs 3.57 mm, P = 0.005) and spherical equivalent (SE)(-10.11D vs -8.80D, P = 0.014). The PS group had reduced choriocapillaris flow, subfoveal choroidal thickness (SFCT), and a thinner retinal layer compared with the NPS group. No difference in retinal blood flow between the two groups was observed. The PS group exhibited a smaller disc area (15082.89 vs 17,043.32, P = 0.003) and angle α between temporal retinal arterial vascular arcades (113.29°vs 128.39°, P = 0.003), a larger disc tilt ratio (1.41 vs 1.24, P < 0.001) and parapapillary atrophy (PPA) area (13840.98 vs 8753.86, P = 0.020), compared with the NPS group. Multivariate regression analysis indicated that disc tilt ratio (P = 0.031) and SFCT (P = 0.015) were significant predictors of PS. In addition, PS (P = 0.049), AL (P = 0.003), corneal refractive power (P < 0.001), ACD (P = 0.022), relative lens position (P = 0.045), and disc area (P = 0.011) were significant predictors of SE.ConclusionsPS was found to be closely linked to a reduction in choriocapillaris perfusion and anatomical abnormalities including posterior and anterior segments. Furthermore, PS exacerbated the progression of myopia.

Normative Values of Retinal Nerve Fibre Layer Thickness and Optic Nerve Head Parameters and Their Association with Visual Function in an African Population.

Purpose To determine normative values of retinal nerve fibre layer thickness (RNFL) and optic nerve head (ONH) parameters and their association with routine clinical tests such as refractive error (RE), stereoacuity (SA), and contrast sensitivity (CS) in an African population. Methods In a cross-sectional observational study, 100 normal subjects aged 20 to 78 years were evaluated using the Cirrus HD-OCT 5000 and matched with 200 glaucoma patients. Results Average (±SD) RNFL thickness for normal subjects was found to be 102.37 ± 7.45 (range, 82–119 microns) compared with 90.74 ± 14.50 found for glaucoma subjects. Females had higher average RNFL values (104.84 ± 6.90) compared with males (99.80 ± 7.18). Significant associations were calculated between quadrant RNFL thickness and SA, SE, and CS (all p < 0.05). The mean cup to disc ratio (CDR) was 0.49 ± 0.12, and mean optic disc area (DA) was 2.08 mm2 ± 0.40. Smaller DA was recorded for participants aged 60+ years (1.86 ± 0.25), followed by 40–59 age group (2.01 ± 0.41) and then 20–39 age group (2.19 ± 0.41). Significant associations were calculated between SA and ONH parameters, except rim area (all p < 0.05). The mean cup to disc ratio (CDR) was 0.49 ± 0.12, and mean optic disc area (DA) was 2.08 mm2 ± 0.40. Smaller DA was recorded for participants aged 60+ years (1.86 ± 0.25), followed by 40–59 age group (2.01 ± 0.41) and then 20–39 age group (2.19 ± 0.41). Significant associations were calculated between SA and ONH parameters, except rim area (all p < 0.05). The mean cup to disc ratio (CDR) was 0.49 ± 0.12, and mean optic disc area (DA) was 2.08 mm2 ± 0.40. Smaller DA was recorded for participants aged 60+ years (1.86 ± 0.25), followed by 40–59 age group (2.01 ± 0.41) and then 20–39 age group (2.19 ± 0.41). Significant associations were calculated between SA and ONH parameters, except rim area (all Conclusion RNFL thickness in healthy black Ghanaian population was significantly higher than that reported in other races. The values and associations reported in this study can inform clinical decision on the normal variation in RNFL and optic disc parameters.

Optical Coherence Tomography May Help Distinguish Glaucoma from Suprasellar Tumor-Associated Optic Disc.

Purpose This study aimed to differentiate patients with bilateral disc cupping associated with suprasellar tumor from patients with open-angle glaucoma by analyzing differences in optical coherence tomography (OCT) of the optic nerve. Methods In this retrospective cross-sectional study, we collected data from the eyes of 25 patients with suprasellar craniopharyngioma or pituitary macroadenomas (group 1) and 35 patients with primary open-angle glaucoma (POAG) (group 2), seen between 2001 and 2015, all with a visual acuity of ≥20/40, for whom Stratus Time-Domain (TD) optic nerve OCT scans were available. The main outcome measures were the retinal nerve fiber layer (RNFL) thickness, disc area, cup volume, cup/disc ratio, and rim area. Results A total of 31 patients met the inclusion criteria and were included in the study: 16 with suprasellar tumors and 15 with POAG. Both groups were similar in terms of gender and age (P > 0.05). The glaucoma group had a borderline greater total RNFL thickness (74.2 μm versus 62.8 μm, P=0.07), disc area (2.70 mm2 versus 2.16 mm2, P=0.004), and cup volume (0.20 mm3 versus 0.08 mm3, P=0.02). In multivariate, glaucoma was associated with increased total RNFL thickness (OR = 1.116 per μm, P=0.008), increased disc area (OR = 2.402 per 100 μm2, P=0.002), and decreased rim area (OR = 0.272 per 100 μm2, P=0.011). Of these, the parameter with the greatest AUC was the disc area (AUC = 0.79). Using the Youden index, the optimal cut-off point identified for stratification was a disc area greater than 2.33 μm2. Conclusions In patients with bilateral disc cupping, a decreased total RNFL thickness and smaller disc area seem to be associated with suprasellar tumors (when compared with open-angle glaucoma). These findings may aid in early diagnosis of cupping from suprasellar tumors, before compressive visual loss occurs.

Long-term evaluation of ocular hypertension withprimary angle closure and primary open angles.

To evaluate the long-term course of primary angle-closure ocular hypertension and primary open-angle ocular hypertension and possible risk factors for progression to glaucoma. A total of 109 eyes of 109 ocular hypertension (OHT) patients with a minimum follow-up period of 5years having complete ocular/medical records were evaluated. They were classified into primary angle closure or primary open angle based on gonioscopy at baseline. Baseline and review data of Humphrey field analyser, HFA, and Heidelberg retinal tomography, HRT, were recorded. Guided progression analysis (GPA) and univariate Cox regression were used for time to event analysis in identifying progression to glaucoma. Over a mean follow-up of 12.18 ± 4.8years, progression to glaucoma was 17.43% (19 eyes), out of whom 5.5% (6 eyes) showed ≥ 3 loci on GPA. Sub-classifying them, progression to primary angle-closure glaucoma was 19.72%, and that of primary open-angle glaucoma was 13.16%. The mean time to progression was 9.34 ± 3.6years. Significant risk factors included small disc area (≤ 1.99 sq.mm on HRT), requirement of ≥ 2 drugs to maintain target IOP and those engaged in activities yielding a Valsalva effect in daily life. Coronary artery disease (CAD) and systemic use of steroids were associated with increased severity. Overall progression of OHT to glaucoma was 17.43% over a mean of 9years, with target IOP of ≤ 18mm Hg. Patients with smaller discs, CAD, exercising Valsalva type activities and using ≥ 2 glaucoma medications or systemic steroids should be closely monitored.

A Small Disc Area Is a Risk Factor for Visual Field Loss Progression in Primary Open-Angle Glaucoma: The Glaucoma Stereo Analysis Study.

Purpose The Glaucoma Stereo Analysis Study, a cross-sectional multicenter collaborative study, used a stereo fundus camera (nonmyd WX) to assess various morphological parameters of the optic nerve head (ONH) in glaucoma patients. We compared the associations of each parameter between the visual field loss progression group and no-progression group. Methods The study included 187 eyes of 187 patients with primary open-angle glaucoma or normal-tension glaucoma. We divided the mean deviation (MD) slope values of all patients into the progression group (<−0.3 dB/year) and no-progression group (≧−0.3 dB/year). ONH morphological parameters were calculated with prototype analysis software. The correlations between glaucomatous visual field progression and patient characteristics or each ONH parameter were analyzed with Spearman's rank correlation coefficient. Results The MD slope averages in the progression group and no-progression group were −0.58 ± 0.28 dB/year and 0.05 ± 0.26 dB/year, respectively. Among disc parameters, vertical disc width (diameter), disc area, cup area, and cup volume in the progression group were significantly less than those in the no-progression group. Logistic regression analysis revealed a significant association between the visual field progression and disc area (odds ratio 0.49/mm2 disc area). Conclusion A smaller disc area may be associated with more rapid glaucomatous visual field progression.

Application of the ISNT rules on retinal nerve fibre layer thickness and neuroretinal rim area in healthy myopic eyes.

We determined the applicability of inferior>superior>nasal>temporal (ISNT) rules on retinal nerve fibre layer (RNFL) thickness and rim area and evaluated the impact of various ocular factors on the performance of the ISNT rules in healthy myopic eyes. A total of 138 eyes from 138 healthy myopic subjects were included in this cross-sectional observational study. The peripapillary RNFL and optic disc in each eye were imaged with Cirrus HD optical coherence tomography (OCT) and Heidelberg Retina Tomograph II (HRT2), respectively. The performance of the inferior>superior (IS), inferior>superior>nasal>temporal (IST) and ISNT rules on RNFL thickness and rim area was determined and compared between low-to-moderate myopia and high myopia. The effects of ocular factors [including axial length, disc area, disc tilt, disc torsion, disc-fovea angle (DFA) and retina artery angle] on the performance of ISNT rules were evaluated with logistic regression analysis. The mean axial length and refractive error were 25.57±1.09mm (range, 22.52-28.77mm) and -5.12±2.30D [range, -9.63 to -0.50dioptres (D)], respectively. Sixty-three per cent of the healthy eyes were compliant with the ISNT rule on rim area, while ISNT rule on RNFL thickness was followed in only 11.6% of the included eyes. For rim area, smaller disc area was significantly associated with increased compliance of the IS rule (odds ratio: 0.46, p=0.039), IST rule (odds ratio: 0.46, p=0.037) and ISNT rule (odds ratio: 0.44, p=0.030). For RNFL thickness, greater DFA was significantly associated with increased compliance of the IS and IST rules (odds ratio: 1.30, p<0.001; odds ratio: 1.19, p=0.006, respectively). In healthy myopic subjects, 88.4% and 37% of eyes did not comply with the ISNT rule on RNFL thickness and rim area, respectively. Due to significant low compliance in healthy eyes, the ISNT rule and its variants have limited potential utility in diagnosing glaucoma in myopic subjects.

Association of intraocular pressure-related factors and retinal vessel diameter with optic disc rim area in subjects with and without primary open angle glaucoma.

The data may support the notion that the intra-ocular pressure (IOP)-related factors and vascular factors were implicated concurrently in glaucomatous optic nerve damage. To study the association of intraocular pressure (IOP)-related factors, IOP, trans-lamina cribrosa pressure difference (TLCPD), cerebrospinal fluid pressure (CSFP) and retinal vessel diameters (RVD), central retinal arteriolar equivalent (CRAE), central retinal venular equivalent (CRVE) with neuro-retinal rim area (RA). A population-based, cross-sectional study. A total of 6830 people aged 30 years and over. All participants underwent a comprehensive eye examination, fundus photograph-based measurements of RVD and Heidelberg retinal tomogram (HRT) measurement of optic disc. RA, CRAE, CRVE, IOP, body mass index (BMI), CSFP and TLCPD. Primary open-angle glaucoma (POAG) was diagnosed using two separate methods: 67 from expert consensus, and 125 from the International Society of Geographical and Epidemiologic Ophthalmology (ISGEO) classification. After excluding of those with high myopia or without gradable HRT images, 4194 non-glaucoma and 40 POAG were analysed for determinants of RA. On multivariable analysis determinants of reduced RA were POAG (P < 0.001), higher IOP (P = 0.03), higher refractive error (P < 0.01), longer axial length (P = 0.01), CRVE (P < 0.001), lower BMI (P = 0.015), older age (P < 0.001) smaller disc area (P < 0.001) and higher TLCPD (P = 0.03). When age and/or BMI were omitted from the model, reduced RA was also associated with lower CSFP (P < 0.001). Reduced RA is associated with narrow CRVE and higher IOP or lower CSFP. The data supports the concurrent role of IOP-related and vascular factors in glaucomatous optic nerve damage.

Peripapillary choroidal vascular layers: the Beijing Eye Study

To assess thickness and associations of the peripapillary choroidal layers. The population-based Beijing Eye Study included 3468 participants with an age of 50+ years. Using spectral-domain optical coherence tomography, we measured the large vessel layer (LVL) and small-to-medium vessel layer (SMVL) of the peripapillary choroid in a circular scan with a diameter of 3.4mm around the optic nerve head centre at eight locations equidistant (45°) to each other. The ratio of SMVL thickness to LVL thickness was calculated. Measurements were available for 3000 (86.5%) study participants (mean age: 64.4±9.6years; range: 50-93years). SMVL (mean thickness: 31±7μm; range: 17-70μm) and LVL (103±48μm; range: 9-313μm) were thickest superiorly, followed by the temporal region, nasal region, and inferior region. Thicker SMVL was associated (regression coefficient r: 0.33) with younger age (p<0.001; standardized regression coefficient β: -0.26), higher cognitive function (p=0.02; β: 0.05), shorter axial length (p<0.001; β: -0.12), thicker lens (p<0.001; β: 0.07), smaller disc area (p<0.001; β: -0.08), smaller parapapillary β/γ zone (p<0.001; β: -0.10) and lower prevalence of angle-closure glaucoma (p=0.04; β: -0.04). Thicker LVL thickness was correlated (r: 0.45) with younger age (p<0.001; β: -0.34) and higher cognitive function (p=0.01; β: 0.05), shorter axial length (p<0.001; β: -0.09)), thicker lens (p=0.009; β: 0.06), smaller disc area (p<0.001; β: -0.09), smaller parapapillary alpha zone (p=0.04; β: -0.04), smaller β/γ zone (p<0.001; β: -0.14) and lower prevalence of angle-closure glaucoma (p=0.057; β: -0.04). A higher SMVL-to-LVL thickness ratio was related with older age (p<0.001; β: 0.36), longer axial length (p<0.001; β: 0.09), lower best-corrected visual acuity (BCVA) (p=0.002; β: 0.07), larger optic disc area (p<0.001; β: 0.10) and larger β/γ zone (p<0.001; β: 0.19). Small-to-medium vessel layer (SMVL) and LVL, thickest superiorly and thinnest inferiorly, increased with younger age and higher cognitive function after adjusting for axial length and prevalence of angle-closure glaucoma. With older age, longer axial length, larger optic disc area and larger β zone, LVL decreased more than SMVL in thickness. The association between thicker peripapillary choroidal thickness and better cognitive function may deserve further attention.

Peripapillary retinal nerve fibre layer thickness and its association with refractive error in Chinese children: the Anyang Childhood Eye Study.

To report the thickness of the peripapillary retinal nerve fibre layer (pRNFL) in Chinese children and examine its association with refractive error, axial length (AL) and optic disc parameters. Population-based cross-sectional study. A total of 2893 seven-year-old children from 11 randomly selected primary schools in Anyang, central China. Participants underwent ophthalmic examinations including optical biometry, cycloplegic autorefraction and spectral-domain ocular coherence tomography. Retinal nerve fibre layer thickness in 16 radial sections, cycloplegic spherical equivalent, AL. The mean (SD) average RNFL thickness was 102.01(8.02) µm. The average RNFL thickness decreased with smaller disc area (r = 0.18, R2 = 0.03, P < 0.0001), bigger cup area (r = -0.11, R2 = 0.01, P < 0.0001), smaller rim area (r = 0.28, R2 = 0.08, P < 0.0001), smaller nerve head volume (r = 0.27, R2 = 0.07, P < 0.0001), longer AL (r = -0.15, R2 = 0.02, P < 0.0001) and a negative spherical equivalent (r = 0.11, R2 = 0.01, P < 0.0001). Hyperopic children had a thicker RNFL than emmetropic children [102.45(8.13) µm vs. 100.81 (7.18) µm, P < 0.001]. Myopic children had thinner RNFL than emmetropic children [99.17 (7.69) µm vs. 100.81 (7.18) µm, P < 0.05]. Retinal nerve fibre layer thickness decreased with increasing AL, higher myopia, bigger cup area, smaller disc and rim area, and a smaller nerve head volume, but the coefficient of determination for all these associations was small. The RNFL in myopes was significantly thinner than emmetropes or hyperopes, but with small absolute differences. The study provides RNFL values for healthy 7-year-old Chinese children. Follow up of this cohort to observe the change of RNFL thickness with myopia and possible change in detected associations with age is planned.

A hierarchical cluster analysis of normal-tension glaucoma using spectral-domain optical coherence tomography parameters.

Normal-tension glaucoma (NTG) is a heterogenous disease, and there is still controversy about subclassifications of this disorder. On the basis of spectral-domain optical coherence tomography (SD-OCT), we subdivided NTG with hierarchical cluster analysis using optic nerve head (ONH) parameters and retinal nerve fiber layer (RNFL) thicknesses. A total of 200 eyes of 200 NTG patients between March 2011 and June 2012 underwent SD-OCT scans to measure ONH parameters and RNFL thicknesses. We classified NTG into homogenous subgroups based on these variables using a hierarchical cluster analysis, and compared clusters to evaluate diverse NTG characteristics. Three clusters were found after hierarchical cluster analysis. Cluster 1 (62 eyes) had the thickest RNFL and widest rim area, and showed early glaucoma features. Cluster 2 (60 eyes) was characterized by the largest cup/disc ratio and cup volume, and showed advanced glaucomatous damage. Cluster 3 (78 eyes) had small disc areas in SD-OCT and were comprised of patients with significantly younger age, longer axial length, and greater myopia than the other 2 groups. A hierarchical cluster analysis of SD-OCT scans divided NTG patients into 3 groups based upon ONH parameters and RNFL thicknesses. It is anticipated that the small disc area group comprised of younger and more myopic patients may show unique features unlike the other 2 groups.

Effect of age and disc size on rim order rules by Heidelberg Retina Tomograph.

The ISNT rule for nonglaucomatous eyes suggests that the neuroretinal rim is thickest at the inferior quadrant (I), followed by the superior (S), nasal (N), and temporal (T) quadrants. This study aimed to use Heidelberg Retina Tomograph (HRT III) measurements to assess (a) fulfillment of the ISNT rule and its derivatives in a large normative database and (b) effect of disc size and age on rule fulfillment. A multicenter, prospective, cross-sectional study of a Caucasian normative database consisting of 280 subjects with normal comprehensive biomicroscopic examination, intraocular pressure <21 mm Hg, and normal automated visual field testing was conducted. Right eye neuroretinal rim and disc area, measured by HRT III, for each of the 4 quadrants were analyzed. Compliance of the rim area to the ISNT rule (I≥S≥N≥T) and its derivates was determined. Effect of age and disc area on rule compliance was further determined. Only 18% of normal eyes had rim areas that complied with the ISNT rule; however, a majority complied to IS (77%) and IST (73%) rules. The temporal quadrant had the smallest rim area [(I,S,N)>T] in 91% of patients. The likelihood of ISNT rule violation was increased in larger discs (χ², P=0.003) but was not affected by age. The ISNT rule does not apply to neuroretinal rim area as measured by HRT, as only 18% of the eyes complied with the ISNT rule in this normative database. Although the ISNT rule may be more applicable to normal eyes with a smaller disc area, the IS and IST rules seem to better represent the normative database.

Diagnostic Classification of Macular Ganglion Cell and Retinal Nerve Fiber Layer Analysis: Differentiation of False-Positives from Glaucoma

To investigate the rate and associated factors of false-positive diagnostic classification of ganglion cell analysis (GCA) and retinal nerve fiber layer (RNFL) maps, and characteristic false-positive patterns on optical coherence tomography (OCT) deviation maps. Prospective, cross-sectional study. A total of 104 healthy eyes of 104 normal participants. All participants underwent peripapillary and macular spectral-domain (Cirrus-HD, Carl Zeiss Meditec Inc, Dublin, CA) OCT scans. False-positive diagnostic classification was defined as yellow or red color-coded areas for GCA and RNFL maps. Univariate and multivariate logistic regression analyses were used to determine associated factors. Eyes with abnormal OCT deviation maps were categorized on the basis of the shape and location of abnormal color-coded area. Differences in clinical characteristics among the subgroups were compared. (1) The rate and associated factors of false-positive OCT maps; (2) patterns of false-positive, color-coded areas on the GCA deviation map and associated clinical characteristics. Of the 104 healthy eyes, 42 (40.4%) and 32 (30.8%) showed abnormal diagnostic classifications on any of the GCA and RNFL maps, respectively. Multivariate analysis revealed that false-positive GCA diagnostic classification was associated with longer axial length and larger fovea-disc angle, whereas longer axial length and smaller disc area were associated with abnormal RNFL maps. Eyes with abnormal GCA deviation map were categorized as group A (donut-shaped round area around the inner annulus), group B (island-like isolated area), and group C (diffuse, circular area with an irregular inner margin in either). The axial length showed a significant increasing trend from group A to C (P=0.001), and likewise, the refractive error was more myopic in group C than in groups A (P=0.015) and B (P=0.014). Group C had thinner average ganglion cell-inner plexiform layer thickness compared with other groups (group A=B>C, P=0.004). Abnormal OCT diagnostic classification should be interpreted with caution, especially in eyes with long axial lengths, large fovea-disc angles, and small optic discs. Our findings suggest that the characteristic patterns of OCT deviation map can provide useful clues to distinguish glaucomatous changes from false-positive findings.

Influence of the disc-fovea angle on limits of RNFL variability and glaucoma discrimination.

To determine factors affecting the disc-fovea angle (DFA), and to test the hypotheses that adjusting for DFA improves limits of retinal nerve fiber layer (RNFL) variability in normal subjects or enhances performance of RNFL measures for glaucoma detection. Disc-fovea angle was measured on scanning laser ophthalmoscope fundus images from 170 eyes (110 normal and glaucoma subjects). The DFA measurements were repeated in 24 eyes. The relationship between DFA and various anatomic variables was explored. Main outcome measures were changes in 95% RNFL prediction limits or glaucoma discrimination after adjusting for DFA. We also explored the angle between temporal raphe and horizontal meridian in 19 eyes with nasal field defects limited to one hemifield. Average mean deviation and DFA were -0.1 (±1.2) dB and -6.6° (±3.4°) and -4.1 (±3.3) dB and -7.9° (±3.9°) in the control and glaucoma groups, respectively (P < 0.001 and = 0.029). The average difference between DFA repeat measurements was 2.0° (±1.8°). Predictors for DFA were female sex (P = 0.004), smaller disc area (P = 0.006), and glaucoma diagnosis (P = 0.019). The absolute change in sectoral RNFL thickness was 6.1 (±3.9) and 4.6 (±3.1) μm in control and glaucoma subjects, respectively. Retinal nerve fiber layer prediction limits improved in 5, 9, and 10 o'clock sectors (P < 0.02). Discrimination ability for the best-performing RNFL sector did not improve (P = 0.936). The average angle between temporal raphe and horizontal meridian was 0.8° (±0.8°). Disc-fovea angle measurements demonstrated fair intersession repeatability. While adjusting for DFA improved RNFL prediction limits in some sectors, it did not enhance glaucoma detection.

Retinal nerve fiber layer and optic disc measurements by spectral domain OCT: normative values and associations in young adults

To determine normative values and associations of retinal nerve fiber layer (RNFL) and optic disc parameters in normal eyes measured by spectral domain optical coherence tomography (OCT). In a population-based setting, 1521 young adults were examined as part of the Sydney Adolescent Vascular and Eye Study (SAVES). Their mean age was 17.3±0.6 years. RNFL and optic disc parameter measurements were made using Cirrus HD-OCT 4000. The average RNFL was found to be 99.4±9.6 μm. RNFL thickness was least for the temporal quadrant (69.9±11.2 μm), followed by the nasal (74.3±12.8 μm), superior (124.7±15.7 μm) and inferior (128.8±17.1 μm) quadrants. The mean disc area in this population was 1.98±0.38 mm(2) with a mean rim area of 1.50±0.30 mm(2) and a mean cup/disc ratio of 0.44±0.18. Multivariate-adjusted RNFL thickness was marginally greater in East Asian than in white participants (100.1 μm vs 99.5 μm; P=0.0005). The RNFL was thinner with greater axial length (P<0.0001), less positive spherical equivalent refractions (P<0.0001), smaller disc area and rim area (P<0.0001). This study documents normative values for the RNFL and optic disc measured using Cirrus HD-OCT in young adults. The values and associations reported in this study can inform clinicians on the normal variation in RNFL and optic disc parameters.

Glaucoma Diagnostic Capabilities of Optic Nerve Head Parameters as Determined by Cirrus HD Optical Coherence Tomography

To compare the glaucoma diagnostic capabilities of optic nerve head (ONH) parameters with retinal nerve fiber layer thickness (RNFLT) using Cirrus spectral-domain optical coherence tomography (Carl Zeiss Meditec Inc, Dublin, CA; version 5.0.0.326). Two hundred twenty-nine glaucomatous patients, 405 preperimetric glaucoma patients, and 109 healthy individuals were imaged by Cirrus optical coherence tomography optic disc cube mode. Correlations were sought between RNFLT and ONH parameters (disc and rim area, average and vertical cup-to-disc ratio, and cup volume). Areas under receiver operating characteristic curves (AUCs) of average RNFLT were compared with those of ONH parameters with respect to discrimination between glaucomatous patients and healthy individuals. Subgroup analysis was performed in early, moderate-to-advanced glaucomatous groups, glaucoma patients with a small disc area and a large disc area. Rim area showed the strongest correlation with average RNFLT (r=0.663) and the highest AUC (0.871). The overall AUC for discrimination between healthy individuals and glaucomatous patients was higher for average RNFLT than for rim area (0.957 vs. 0.871, P<0.001). In the early and small disc area subgroup, the AUC of average RNFLT was significantly greater than those of all ONH parameters. In moderate-to-advanced glaucomatous groups' patients, the AUCs of average RNFLT and rim area, in large disc area group patients, the AUC of average RNFLT and vertical cup-to-disc ratio, did not differ significantly. RNFLT was better than any tested ONH parameter when used for glaucoma discrimination, especially in patients with early-stage glaucoma and in glaucomatous patients with small optic discs.

Factors affecting the sensitivity and specificity of the Heidelberg Retina Tomograph parameters to glaucomatous progression in disc photographs

To evaluate the factors affecting the sensitivity and specificity of the stereometric optic nerve head (ONH) parameters of the Heidelberg Retina Tomograph (HRT) to glaucomatous progression in stereoscopic ONH photographs. The factors affecting the sensitivity and specificity of the vertical cup : disc ratio, the cup : disc area ratio, the cup volume, the rim area and a linear discriminant function to progression were analysed. These parameters were the best indicators of progression in a retrospective study of 476 eyes. The reference standard for progression was the masked evaluation of stereoscopic ONH photographs. The factors having the most significant effect on the sensitivity and specificity of the stereometric ONH parameters were the reference height difference and the mean topography standard deviation (TSD), indicating image quality. Also, the change in the TSD and age showed consistent, but variably significant, influence on all parameters tested. The sensitivity and specificity improved when there was little change in the reference height, the image quality was good and stable, and the patients were younger. The sensitivity and specificity of the vertical cup : disc ratio was improved by a large disc area and high baseline cup : disc area ratio. The rim area showed a better sensitivity and specificity for progression with a small disc area and low baseline cup : disc area ratio. The factors affecting the sensitivity and specificity of the stereometric ONH parameters to glaucomatous progression in disc photographs are essentially the same as those affecting the measurement variability of the HRT.

Factors Associated with False Positives in Retinal Nerve Fiber Layer Color Codes from Spectral-Domain Optical Coherence Tomography

To determine the factors that contribute to false-positive retinal nerve fiber layer (RNFL) color code results from spectral-domain optical coherence tomography (OCT). A prospective, cross-sectional study. This study included 149 eyes from 77 healthy participants. Participants, who were consecutively enrolled from June 2009 to December 2009, underwent Cirrus OCT. Recorded demographic and clinical factors included age, gender, eye side, intraocular pressure, central corneal thickness, spherical equivalent, axial length, anterior chamber depth, disc area, and the extent of retinal vasculature. An abnormal finding in RNFL color codes was defined as ≥1 yellow or red sectors by quadrant and clock-hour maps and a wedge-shaped color pattern represented by yellow or red in the deviation map. The incidence of false-positive color codes was determined. The influence of clinical and demographic factors on the incidence of false-positive RNFL color codes was assessed using generalized linear mixed model analysis. The false-positive rate for ≥1 of the quadrant, clock-hour, and deviation maps was 26.2%. Longer axial length and smaller disc area were significantly associated with an increased incidence of false-positives when other factors were controlled (odds ratios, 2.422 and 0.165; P = 0.008 and 0.035, respectively). The factors that significantly affected the false-positive RNFL color code results using spectral-domain OCT were axial length and disc area, which may significantly affect the specificity of spectral-domain OCT. Therefore, axial length and disc area should be considered during RNFL thickness profile analysis.