Parapapillary Atrophy: Histological Gamma Zone and Delta Zone

Background

To examine histomorphometrically the parapapillary region in human eyes.

Methodology/Principal Findings

The histomorphometric study included 65 human globes (axial length:21–37 mm). On anterior-posterior histological sections, we measured the distance Bruch''s membrane end (BME)-optic nerve margin (“Gamma zone”), BME-retinal pigment epithelium (RPE) (“Beta zone”), BME-beginning of non-occluded choriocapillaris, and BME-beginning of photoreceptor layer. “Delta zone” was defined as part of gamma zone in which blood vessels of at least 50 µm diameter were not present over a length of >300 µm. Beta zone (mean length:0.35±0.52 mm) was significantly (P = 0.01) larger in the glaucoma group than in the non-glaucomatous group. It was not significantly (P = 0.28) associated with axial length. Beta zone was significantly (P = 0.004) larger than the region with occluded choriocapillaris. Gamma zone (mean length:0.63±1.25 mm) was associated with axial length (P<0.001;r² = 0.73) with an increase starting at an axial length of 26.5 mm. It was not significantly (P = 0.24) associated with glaucomatous optic neuropathy. Delta zone (present only in eyes with axial length of ≥27 mm) was associated with axial length (P = 0.001) and scleral flange length (P<0.001) but not with glaucoma (P = 0.73).

Conclusions/Significance

Parapapillary gamma zone (peripapillary sclera without overlying choroid, Bruch''s membrane and deep retinal layers) was related with axial globe elongation and was independent of glaucoma. Delta zone (no blood vessels >50 µm diameter within gamma zone) was present only in highly axially elongated globes and was not related with glaucoma. Beta zone (Bruch''s membrane without RPE) was correlated with glaucoma but not with globe elongation. Since the region with occluded choriocapillaris was smaller than beta zone, complete loss of RPE may have occurred before complete choriocapillaris closure.     

Clinical Assessment of Lamina Cribrosa Curvature in Eyes with Primary Open-Angle Glaucoma

Purpose

Quantitative evaluation of lamina cribrosa (LC) posterior bowing in primary open-angle glaucoma (POAG) eyes using swept-source optical coherence tomography.

Methods

Patients with POAG (n = 123 eyes) and healthy individuals of a similar age (n = 92 eyes) were prospectively recruited. Anterior laminar insertion depth (ALID) was defined as the vertical distance between the anterior laminar insertion and a reference plane connecting the Bruch’s membrane openings (BMO). The mean LC depth (mLCD) was approximated by dividing the area enclosed by the anterior LC, the BMO reference plane, and the two vertical lines for ALID measurement by the length between those two vertical lines. The LC curvature index was defined as the difference between the mLCD and the ALID. The factors influencing the LC curvature index were evaluated.

Results

The ALID and mLCD were significantly larger in POAG eyes than in healthy controls (P < 0.05). The LC curvature index was significantly larger in POAG eyes than in healthy controls on both the horizontal (85.8 ± 34.1 vs. 68.2 ± 32.3 μm) and vertical meridians (49.8 ± 38.5 vs. 32.2 ± 31.1 μm, all P < 0.001). Multivariate regression showed significant associations of greater disc area (P < 0.001), vertical C/D ratio (P < 0.001) and mLCD (P < 0.001), smaller rim area (P = 0.001), thinner average RNFLT (P < 0.001), and myopic refraction (P = 0.049) with increased LC curvature index. There was no difference in the LC curvature index between mild (MD > –6 dB) and moderate-to-advanced glaucoma (MD < –6 dB, P = 0.95).

Conclusions

LC posterior bowing was increased in POAG eyes, and was significantly associated with structural optic nerve head (ONH) changes but not with functional glaucoma severity. Quantitative evaluation of LC curvature can facilitate assessment of glaucomatous ONH change.     

Glaucomatous-Type Optic Discs in High Myopia

Purpose

To assess the prevalence of glaucoma in patients with high myopia defined as myopic refractive error of >-8 diopters or axial length ≥26.5 mm.

Methods

The hospital-based observational study included 172 patients (336 eyes) with a mean age of 61.9±12.3 years and mean axial length of 30.1±2.3 mm (range: 24.7–39.1mm). Glaucomatous-type optic discs were defined by glaucomatous optic disc appearance. Glaucoma was defined by glaucomatous optic disc appearance and glaucomatous Goldmann visual field defects not corresponding with myopic macular changes.

Results

Larger disc area (mean: 3.18±1.94 mm²) was associated with longer axial length (P<0.001; standardized correlation coefficient: 0.45). Glaucoma was detected in 94 (28%; 95% Confidence intervals: 23%, 33%) eyes. In multivariate analysis, glaucoma prevalence was 3.2 times higher (P<0.001) in megalodiscs (>3.79 mm²) than in normal-sized discs or small discs (<1.51 mm²) after adjusting for older age. Axial length was not significantly (P = 0.38) associated with glaucoma prevalence in that model. Glaucoma prevalence increased by a factor of 1.39 for each increase in optic disc area by one mm². Again, axial length was not significantly (P = 0.38) associated with glaucoma prevalence when added to this multivariate model.

Conclusion

Within highly myopic individuals, glaucoma prevalence increased with larger optic disc size beyond a disc area of 3.8 mm². Highly myopic megalodiscs as compared to normal sized discs or small discs had a 3.2 times higher risk for glaucomatous optic nerve neuropathy. The increased glaucoma prevalence in axial high myopia was primarily associated with axial myopia associated disc enlargement and not with axial elongation itself.     

Correlation of Aging and Segmental Choroidal Thickness Measurement using Swept Source Optical Coherence Tomography in Healthy Eyes

Purpose

To assess and compare choroidal thickness changes related to aging, we determined whether changes are due to thinning of the choriocapillaris plus Sattler''s (CS) layer and/or the large vessel layer in healthy eyes using swept-source optical coherence tomography (SS-OCT) at a wavelength of 1,050-nm.

Methods

We studied 115 normal eyes of 115 healthy volunteers, all with refractive errors of less than -6 diopters. All 115 eyes underwent analysis of choroidal thickness at the fovea, the CS layer and the large choroidal vessel layer. In 68 of the 115 eyes, choroidal thickness was determined at five sites (the fovea, and superior, inferior, nasal, and temporal sites) using SS-OCT with an Early Treatment of Diabetic Retinopathy grid scan.

Results

Total choroidal thicknesses at each of the five sites were related to subject age (P<0.0001). The choroid was thinnest at the nasal site, followed by the temporal, inferior, superior and finally the subfoveal site itself. The total choroidal thickness at the nasal site was significantly less than those at the other four sites (p<0.05). The CS layer showed thinning which correlated with age (P<0.0001). The thickness of the choroidal large vessel layer also decreased with age (p = 0.02). Subfoveal choroidal thickness was calculated as follows: 443.89–2.98×age (μm) (P<0.0001).

Conclusion

Subfoveal choroidal thickness decreases by 2.98 μm each year. Total choroidal thickness diminishes with age. The CS and large vessel layers of the choroid at the subfovea showed significant decreases, though only the former correlated strongly with age.     

Lamina Cribrosa Defects and Optic Disc Morphology in Primary Open Angle Glaucoma with High Myopia

Purpose

To investigate whether lamina cribrosa (LC) defects are associated with optic disc morphology in primary open angle glaucoma (POAG) eyes with high myopia.

Methods

A total of 129 POAG patients and 55 age-matched control subjects with high myopia were evaluated. Three-dimensional scan images obtained by swept source optical coherence tomography were used to detect LC defects. Radial B-scans and infrared images obtained by spectral domain optical coherence tomography were used to measure β-peripapillary atrophy (PPA) lengths with and without Bruch''s membrane (BM) (temporal, nasal, superior, and inferior), tilt angle (vertical and horizontal), and disc diameter (transverse and longitudinal). Peripapillary intrachoroidal cavitations (PICCs), disc area, ovality index, and cyclotorsion of the optic disc were analyzed as well.

Results

LC defects were found in 70 of 129 (54.2%) POAG eyes and 1 of 55 (1.8%) control eyes (P<0.001). Age, sex, spherical equivalent, axial length, intraocular pressure, and central corneal thickness were not significantly different among POAG eyes with LC defects, POAG eyes without LC defects, and control eyes. Temporal PPA lengths without BM in all three groups correlated significantly with vertical and horizontal tilt angles, although no PPA length with BM correlated significantly with any tilt angle. PICCs were detected more frequently in POAG eyes with LC defects than those without LC defects (P = 0.01) and control eyes (P = 0.02). POAG eyes with LC defects showed a smaller ovality index (P = 0.004), longer temporal PPA without BM (P<0.001), and larger vertical/horizontal tilt angles (vertical, P<0.001; horizontal, P = 0.01), and transverse diameter (P = 0.01). In multivariate analysis for the presence of LC defects, presence of POAG (P<0.001) and vertical tilt angle (P<0.001) were identified as significant.

Conclusions

The presence of LC defects was associated with myopic optic disc morphology in POAG eyes with high myopia.     

Retinal Nerve Fiber Layer Thickness. The Beijing Eye Study 2011

Purpose

To measure retinal nerve fiber layer (RNFL) thickness in a population-based setting.

Methods

In the population-based Beijing Eye Study 2011 with 3468 individuals, RNFL thickness was measured in a subgroup of 1654 (47.7%) study participants by spectral domain optical coherence tomography (iVue SD-OCT).

Results

Mean RNFL thickness was significantly (P<0.001) higher in the inferior sector (131.4±20.6 µm) than the superior sector (126.1±19.1 µm), where it was higher than in the temporal sector (79.8±12.2 µm;P<0.001), where it was higher than in the nasal sector (75.1±12.6 µm;P<0.001). In multivariate analysis, mean global RNFL thickness (103.2±12.6 µm) increased significantly with younger age (standardized correlation coefficient beta:−0.30;P<0.001), larger neuroretinal rim area (beta:0.26;P<0.001), shorter axial length (beta:−0.21;P<0.001), thicker subfoveal choroidal thickness (beta:0.15;P<0.001), larger optic disc area (beta:0.10;P<0.001), less refractive lens power (beta:0.10;P<0.001), flatter anterior cornea (beta:0.07;P = 0.01) and female gender (beta:0.05;P = 0.03). In this population with an age of 50+ years, the age-related decline in RNFL thickness was 0.5 µm per year of life or 0.36% of an original RNFL thickness of 137 µm at baseline of the study at 50 years of age. Mean global RNFL thickness decreased by 2.4 µm for each mm enlargement of axial length.

Conclusions

The RNFL profile shows a double hump configuration with the thickest part in the inferior sector, followed by the superior sector, temporal sector and nasal sector. Factors influencing global RNFL thickness were younger age, larger neuroretinal rim, shorter axial length, thicker subfoveal choroid, larger optic disc, less refractive lens power, flatter anterior cornea and female gender. Beyond an age of 50+ years, RNFL decreased by about 0.3% per year of life at an age of 50+ years and by 2.4 µm per mm of axial elongation. These findings may be of interest for the knowledge of the normal anatomy of the eye and may be of help to diagnose diseases affecting the RNFL.     

Acoustic Radiation Force Impulse Imaging for Noninvasive Evaluation of Renal Parenchyma Elasticity: Preliminary Findings

Objective

To evaluate the diagnostic value of acoustic radiation force impulse (ARFI) to test the elasticity of renal parenchyma by measuring the shear wave velocity (SWV) which might be used to detect chronic kidney disease (CKD).

Methods

327 healthy volunteers and 64 CKD patients were enrolled in the study. The potential influencing factors and measurement reproducibility were evaluated in the healthy volunteers. Correlations between SWV and laboratory tests were analyzed in CKD patients.?Receiver-operating characteristic curve (ROC) analyses were performed to assess the diagnostic performance of ARFI.

Results

The SWV of healthy volunteers correlated significantly to age (r = −0.22, P<0.001, n = 327) and differed significantly between men and women (2.06±0.48 m/s vs. 2.2±0.52 m/s, P = 0.018, n = 327). However, it did not correlate significantly to height, weight, body mass index, waistline, kidney dimension and the depth for SWV measurement (n = 30). Inter- and intraobserver agreement expressed as intraclass coefficient correlation were 0.64 (95% CI: 0.13 to 0.82, P = 0.011) and 0.6 (95% CI: 0.31 to 0.81, P = 0.001) (n = 40). The mean SWV in healthy volunteers was 2.15±0.51 m/s, while was 1.81±0.43 m/s, 1.79±0.29 m/s, 1.81±0.44 m/s, 1.64±0.55 m/s, and 1.36±0.17 m/s for stage 1, 2, 3, 4 and 5 in CKD patients respectively. The SWV was significantly higher for healthy volunteers compared with each stage in CKD patients. ARFI could not predict the different stages of CKD except stage 5. In CKD patients, SWV correlated to e-GFR (r = 0.3, P = 0.018), to urea nitrogen (r =  −0.3, P = 0.016), and to creatinine (r =  −0.41, P = 0.001). ROC analyses indicated that the area under the ROC curve was 0.752 (95% CI: 0.704 to 0.797) (P<0.001). The cut-off value for predicting CKD was 1.88 m/s (sensitivity 71.87% and specificity 69.69%).

Conclusion

ARFI may be a potentially useful tool in detecting CKD.     

Peripapillary Arterial Circle of Zinn-Haller: Location and Spatial Relationships with Myopia

Purpose

To measure histomorphometrically the location of the peripapillary arterial circle of Zinn-Haller (ZHAC) and assess its associations with axial length.

Methods

Using a light microscope, we measured the distance from the ZHAC to the peripapillary ring (optic disc border), the merging point of the dura mater with the posterior sclera (“dura-sclera point”), and the inner scleral surface. In the parapapillary region, we differentiated between beta zone (presence of Bruch''s membrane, absence of retinal pigment epithelium) and gamma zone (absence of Bruch''s membrane). The peripapillary scleral flange as roof of the orbital cerebrospinal fluid space was the connection between the end of the lamina cribrosa and the posterior full-thickness sclera starting at the dura-sclera point.

Results

The study included 101 human globes (101 patients) with a mean axial length of 26.7±3.7 mm (range: 20.0–39.0 mm). The distance between the ZHAC and the peripapillary ring increased significantly with longer axial length (P<0.001; correlation coefficient r = 0.49), longer parapapillary gamma zone (P<0.001;r = 0.85), longer (P<0.001;r = 0.73) and thinner (P<0.001;r = −0.45) peripapillary scleral flange, and thinner sclera posterior to the equator (P<0.001). ZHAC distance to the peripapillary ring was not significantly associated with length of parapapillary beta zone (P = 0.33). Including only non-highly myopic eyes (axial length <26.5 mm), the ZHAC distance to the disc border was not related with axial length (P = 0.84). In non-highly myopic eyes, the ZHAC was located close to the dura-sclera point. With increasing axial length and decreasing thickness of the peripapillary scleral flange, the ZHAC was located closer to the inner scleral surface.

Conclusions

The distance between the ZHAC and the optic disc border is markedly enlarged in highly myopic eyes. Since the ZHAC is the main arterial source for the lamina cribrosa blood supply, the finding may be of interest for the pathogenesis of the increased glaucoma susceptibility in highly myopic eyes.     

Enhanced Insight into the Autoimmune Component of Glaucoma: IgG Autoantibody Accumulation and Pro-Inflammatory Conditions in Human Glaucomatous Retina

Background

There is accumulating evidence that autoimmune components, such as autoantibodies and autoantibody depositions, play a role in the pathogenesis of neurodegenerative diseases like Alzheimeŕs disease or Multiple Sclerosis. Due to alterations of autoantibody patterns in sera and aqueous humor, an autoimmune component is also assumed in the pathogenesis of glaucoma, a common reason for irreversible blindness worldwide. So far there has been no convincing evidence that autoantibodies are accumulated in the retina of glaucoma patients and that the local immune homeostasis might be affected.

Methods and Results

Six human glaucomatous donor eyes and nine samples from donors with no recorded ocular disease were included. Antibody microarrays were used to examine the patterns of pro-inflammatory proteins and complement proteins. Analysis of TNF-α and interleukin levels revealed a slight up-regulation exclusively in the glaucomatous group, while complement protein levels were not altered. IgG autoantibody accumulations and/or cellular components were determined by immunohistology (n = 4 per group). A significantly reduced number of retinal ganglion cells was found in the glaucomatous group (healthy: 104±7 nuclei/mm, glaucoma: 67±9 nuclei/mm; p = 0.0007). Cell loss was accompanied by strong retinal IgG autoantibody accumulations, which were at least twice as high as in healthy subjects (healthy: 5.0±0.5 IgG deposits/100 cells, glaucoma: 9.4±1.9 IgG deposits/100 cells; p = 0.004). CD27⁺ cells and CD27⁺/IgG⁺ plasma cells were observed in all glaucomatous subjects, but not in controls.

Conclusion

This work provides serious evidence for the occurrence of IgG antibody deposition and plasma cells in human glaucomatous retina. Moreover, the results suggest that these IgG deposits occurred in a pro-inflammatory environment which seems to be maintained locally by immune-competent cells like microglia. Thereby, glaucoma features an immunological involvement comparable to other neurodegenerative diseases, but also shows a multifactorial pathomechanism, which diverges and might be linked to the specific nature of both eye and retina.     

The Morphology of Corneal Cap and Its Relation to Refractive Outcomes in Femtosecond Laser Small Incision Lenticule Extraction (SMILE) with Anterior Segment Optical Coherence Tomography Observation

Purpose

To investigate the morphology of corneal caps in femtosecond laser small incision lenticule extraction (SMILE) and its relation to the refractive outcomes.

Methods

A prospective study of fifty-four corneal caps created with VisuMax femtosecond laser were examined using an Fourier-domain optical coherence tomography at 1 day, 1 week, 1 month and 6 months after SMILE. The cap thickness at nine points on each of the four meridians (0°, 45°, 90°, 135°) and the diameter were measured. Cap morphology, changes over time and its correlation with refractive outcomes were assessed.

Results

The mean achieved central cap thickness were (108.74±5.06) µm at 6 months and (107.32±4.81 ) µm at 1 month postoperatively, significantly thinner than that at 1 day (110.81±7.95) µm and 1 week (109.58±7.48 ) µm (P<0.05). The mean diameter on 0° meridian was (7.61±0.07) mm, significantly larger than that on 90° meridian (7.57±0.06) mm (P = 0.001). Cap morphology showed good regularity, except that the differences of points in two pairs were significant at 1 day postoperatively. The uniformity was consistent over time and the central cap thickness was thinner than those in the paracentral and peripheral areas. The refractive outcomes stabilized within 1 month. Uncorrected distance visual acuity (UDVA) was correlated to the central cap thickness at 1 day and 1 week (both r_s = 0.33, p<0.05). The uniformity index was correlated with UDVA (r_s = 0.34, p<0.05) and corrected distance visual acuity (r_s = 0.32, p<0.05) at 1 week postoperatively.

Conclusions

Corneal caps of SMILE are predictable with good reproducibility, regularity and uniformity. Cap morphology might have a mild effect on refractive outcomes in the early stage. Further study should focus on the impact on the visual quality.     

Correlation between Lamina Cribrosa Tilt Angles,Myopia and Glaucoma Using OCT with a Wide Bandwidth Femtosecond Mode-Locked Laser

Purpose

To measure horizontal and vertical lamina cribrosa (LC) tilt angles and investigate associated factors using prototype optical coherence tomography (OCT) with a broad wavelength laser light source.

Design

Cross sectional study.

Methods

Twenty-eight no glaucoma eyes (from 15 subjects) and 25 glaucoma eyes (from 14 patients) were enrolled. A total of 300 optic nerve head B-scans were obtained in 10 µm steps and the inner edge of Bruch''s membrane opening (BMO) was identified as the reference plane. The vertical and horizontal angles between BMO line and approximate the best-fitting line for the surface of the LC were measured and potential associated factors were estimated with univariate and multivariate logistic regression analyses.

Results

The median (interquartile range) horizontal and vertical tilt angles were 7.10 (2.43–11.45) degrees and 4.15 (2.60–6.85) degrees in eyes without glaucoma and 8.50 (4.40–14.10) degrees and 9.30 (6.90–14.15) degrees in glaucoma eyes, respectively. The refractive errors had a statistically significant association with horizontal LC tilt angles (coefficients, −1.53 per diopter) and glaucoma had a significant correlation with vertical tilt angles (coefficients, 6.56) using multiple logistic regression analysis (p<0.001).

Conclusions

OCT allowed evaluation of the internal tilting of the LC compared with the BMO. The horizontal internal LC tilt angle was correlated with refractive errors, corresponding to myopic physiological changes, and vertical internal LC tilt was correlated with glaucoma, corresponding to glaucomatous pathological changes. These parameters have important implications for investigation of the correlation between myopia, glaucoma and LC morphological features.     

Pattern of Pseudoexfoliation Deposits on the Lens and Their Clinical Correlation- Clinical Study and Review of Literature

Purpose

To study the clinical correlates of pattern of deposits over the lens in patients with pseudoexfoliation syndrome (PXF) or pseudoexfoliation glaucoma.

Methods

This retrospective observational study screened 346 patients with PXF seen in glaucoma clinic of a tertiary hospital from 2011–2013. Details like pattern of deposits, location on the lens surface and pupillary abnormalities in slit lamp photographs and their correlation with clinical and demographic variables, were analysed.

Results

A total of 84 eyes of 42 patients with bilateral PXF were included for the study. Glaucoma was seen in 30 eyes with baseline IOP of 24+3.8 mm Hg. Comparing the type of deposits, namely classical (n = 39 eyes), radial pigmentary (RP) form (n = 39 eyes) and combined classical and radial pigmentary (CR) forms (n = 6 eyes) of deposits, pupillary ruff atrophy was common in all forms while poor dilatation was rare in the RP type (n = 5 vs n = 25 in classical forms, p<0.001). Mean deviation (MD) was worse in the classical and CR form as compared to RP type with the latter presenting much earlier, 43±3.2 years vs 48±4.1 years in CR and 56±5.7 years in classical form, p<0.001. The baseline IOP in the RP group (18±2.3 mm Hg) was significantly lower than the other two forms (CR 20±3.2 mm Hg, classical 28±2.3 mm Hg), p<0.001, with only 2 eyes on anti-glaucoma drugs at presentation.

Conclusion

Pattern of exfoliation deposits may indicate the stage and severity of the disease process in evolution with the RP representing an earlier/less severe form of pseudoexfoliation syndrome.     

Vitamin D and Exercise Performance in Professional Soccer Players

Aim

The current study had two aims. The primary purpose was to examine the association between serum vitamin D levels and the ergometric evaluation of muscle strength, aerobic capacity, and speed in professional soccer players. The secondary aim was to evaluate the effects of the soccer off-season period on serum vitamin D levels.

Methods

Sixty-seven Caucasian male soccer players (age 25.6±6.2 and height 1.81±0.08 m), members of two Greek Superleague Soccer teams and one Football-league championship team participated in this study. Exercise performance testing for the determination of squat jump (SJ), countermovement jump (CMJ), 10 (10 m) and 20 meters (20 m) sprint performance, maximal oxygen consumption (VO₂max), anthropometry, and blood sampling were performed before (pre) and after (post) the six-week off-season period.

Results

Analysis of our results showed the following: (a) a significant correlations between serum vitamin D levels and performance parameters in both pre (SJ; P<0.001, CMJ; P<0.001, VO₂max; P<0.001, 10 m; P<0.001, and 20 m; P<0.001) and post (SJ; P<0.001, CMJ; P<0.001, VO₂max; P = 0.006, 10 m; P<0.001, and 20 m; P<0.001) experimental sessions. (b) Vitamin D concentration increased significantly (P<0.001) following the six-week off-season period compared to baseline, while at the same time all measured performance parameters decreased (SJ; P<0.001, CMJ; P<0.001, 10 m; P<0.001, 20 m; P<0.001, VO₂max; P<0.001).

Discussion

Our findings suggest that vitamin D levels are associated with the ergometric evaluation of muscle strength, as expressed by SJ and CMJ, sprinting capacity, and VO₂max in professional soccer players, irrespective the levels of performance. Furthermore, our data reaffirm the importance of UVB on serum vitamin D levels. Moreover, reductions in exercise training stress may also have beneficial effects on vitamin D levels, suggesting a possible association of its levels and the training-induced stress. Our results indicate a possibly bidirectional interaction between soccer performance indices and vitamin D levels.     

Trans-Lamina Cribrosa Pressure Difference and Open-Angle Glaucoma. The Central India Eye and Medical Study

Purpose

To assess associations of the trans-lamina cribrosa pressure difference (TLCPD) with glaucomatous optic neuropathy.

Methods

The population-based Central India Eye and Medical Study included 4711 subjects. Based on a previous study with lumbar cerebrospinal fluid pressure (CSFP) measurements, CSFP was calculated as CSFP[mmHg] = 0.44 Body Mass Index[kg/m2]+0.16 Diastolic Blood Pressure[mmHg]−0.18×Age[Years] −1.91. TLCPD was IOP–CSFP.

Results

Mean TLCPD was 3.64±4.25 mm Hg in the non-glaucomatous population and 9.65±8.17 mmHg in the glaucomatous group. In multivariate analysis, TLCPD was associated with older age (P<0.001; standardized coefficient beta:0.53; regression coefficient B:0.18; 95% confidence interval (CI):0.17, 0.18), lower body mass index (P<0.001; beta: −0.28; B: −0.36; 95%CI: −0.38, −0.31), lower diastolic blood pressure (P<0.001; beta: −0.31; B: −0.12; 95%CI: −0.13, −0.11), higher pulse (P<0.001; beta:0.05; B:0.02; 95%CI:0.01,0.2), lower body height (P = 0.02; beta: −0.02; B: −0.01; 95%CI: −0.02,0.00), higher educational level (P<0.001; beta:0.04; B:0.15; 95%CI:0.09,0.22), higher cholesterol blood concentrations (P<0.001; beta:0.04; B:0.01; 95%CI:0.01,0.01), longer axial length (P = 0.006; beta:0.03; B:0.14; 95%CI:0.04,0.24), thicker central cornea (P<0.001; beta:0.15; B:0.02; 95%CI:0.02,0.02), higher corneal refractive power (P<0.001; beta:0.07; B:0.18; 95%CI:0.13,0.23) and presence of glaucomatous optic neuropathy (P<0.001; beta:0.11; B:3.43; 95%CI:2.96,3.99). Differences between glaucomatous subjects and non-glaucomatous subjects in CSFP were more pronounced for open-angle glaucoma (OAG) than for angle-closure glaucoma (ACG) (3.0 mmHg versus 1.8 mmHg), while differences between glaucomatous subjects and non-glaucomatous subjects in IOP were higher for ACG than for OAG (8.5 mmHg versus 3.0 mmHg). Presence of OAG was significantly associated with TLCPD (P<0.001; OR:1.24; 95%CI:1.19,1.29) but not with IOP (P = 0.08; OR:0.96; 95%CI:0.91,1.00). Prevalence of ACG was significantly associated with IOP (P = 0.04; OR:1.19; 95%CI:1.01,1.40) but not with TLCPD (P = 0.92).

Conclusions

In OAG, but not in ACG, calculated TLCPD versus IOP showed a better association with glaucoma presence and amount of glaucomatous optic neuropathy. It supports the notion of a potential role of low CSFP in the pathogenesis of open-angle glaucoma.     

Multimodal Retinal Vessel Analysis in CADASIL Patients

Purpose

To further elucidate retinal findings and retinal vessel changes in Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) patients by means of high resolution retinal imaging.

Methods

28 eyes of fourteen CADASIL patients and an equal number of control subjects underwent confocal scanning laser ophthalmoscopy (cSLO), spectral-domain optical coherence tomography (SD-OCT), retinal nerve fibre layer (RNFL) measurements, fluorescein and indocyanine angiography. Three vessel measurement techniques were applied: RNFL thickness, a semiautomatic software tool based on cSLO images and manual vessel outlining based on SD-OCT.

Results

Mean age of patients was 56.2±11.6 years. Arteriovenous nicking was present in 22 (78.6%) eyes and venous dilation in 24 (85.7%) eyes. Retinal volume and choroidal volume were 8.77±0.46 mm³ and 8.83±2.24 mm³. RNFL measurements showed a global increase of 105.2 µm (Control group: 98.4 µm; p = 0.015). Based on semi-automatic cSLO measurements, maximum diameters of arteries and veins were 102.5 µm (106.0 µm; p = 0.21) and 128.6 µm (124.4 µm; p = 0.27) respectively. Manual SD-OCT measurements revealed significantly increased mean arterial 138.7 µm (125.4 µm; p<0.001) and venous 160.0 µm (146.9; p = 0.003) outer diameters as well as mean arterial 27.4 µm (19.2 µm; p<0.001) and venous 18.3 µm (15.7 µm; p<0.001) wall thicknesses in CADASIL patients.

Conclusions

The findings reflect current knowledge on pathophysiologic changes in vessel morphology in CADASIL patients. SD-OCT may serve as a complementary tool to diagnose and follow-up patients suffering from cerebral small-vessel diseases.     

Endothelial Function and Serum Concentration of Toxic Metals in Frequent Consumers of Fish

Background

Endothelial dysfunction is involved in the pathogenesis of atherosclerosis. Consumption of fish is associated with reduced cardiovascular risk, but there is paucity of data concerning its effect on endothelial function. Furthermore, investigation of the effects of fish consumption on health must take into account the ingestion of contaminants, including transition metals and some metalloids, which may have unfavorable effects on health, including those on the cardiovascular system. We investigated the association between fish consumption, endothelial function (flow mediated dilation of the brachial artery), and serum concentration of some toxic metals in apparently healthy people.

Methods

Twenty-nine high fish consumers (at least 3 portions a week) were compared with 25 low fish consumers (less than 1 portion a week). All participants were free of diabetes, cardiovascular or other systemic diseases. Serum metal (antimonium, arsenic, mercury, lead, cobalt, copper, zinc, selenium, strontium) concentrations were measured in subgroups of 24 high fish consumers and 19 low fish consumers.

Results

Both groups exhibited similar habitual dietary patterns, age and anthropometric characteristics. The high fish consumers had higher flow mediated dilation (9.7±1.8 vs. 7.3±1.9%; P<0.001), but also higher serum concentrations of mercury (5.87±2.69 vs. 1.65±1.10 mcg/L; P<0.001) and arsenic (6.04±3.25 vs. 2.30±1.58 mcg/L; P<0.001). The fasting plasma glucose concentrations were significantly correlated with both mercury (r = 0.39; P = 0.01) and arsenic concentrations (r = 0.55; P<0.001).

Conclusions

Habitual consumption of high amounts of fish is associated with better endothelial function despite higher serum concentrations of mercury and arsenic.     

Distribution of Central Corneal Thickness and its Association with Ocular Parameters in a Large Central European Cohort: The Gutenberg Health Study

Main objective

To evaluate the distribution of central corneal thickness (CCT) in a large German cohort and to analyse its relationship with intraocular pressure and further ocular factors.

Design

Population-based, prospective, cohort study.

Methods

The Gutenberg Health Study (GHS) cohort included 4,698 eligible enrollees of 5,000 subjects (age range 35–74 years) who participated in the survey from 2007 to 2008. All participants underwent an ophthalmological examination including slitlamp biomicroscopy, intraocular pressure measurement, central corneal thickness measurement, fundus examination, and were given a questionnaire regarding glaucoma history. Furthermore, all subjects underwent fundus photography and visual field testing using frequency doubling perimetry.

Results

Mean CCT was 557.3±34.3 µm (male) and 551.6±35.2 µm in female subjects (Mean CCT from right and left eyes). Younger male participants (35–44 years) presented slightly thicker CCT than those older. We noted a significant CCT difference of 4 µm between right and left eyes, but a high correlation between eyes (Wilcoxon test for related samples: p<0.0001). Univariable linear regression stratified by gender showed that IOP was correlated with CCT (p<0.0001). A 10 µm increase in CCT led to an increase in IOP between 0.35–0.38 mm Hg, depending on the eye and gender. Multivariable linear regression analysis revealed correlations between gender, spherical equivalent (right eyes), and CCT (p<.0001 and p = 0.03, respectively).

Conclusions

We observed positive correlations between CCT and IOP and gender. CCT was not correlated with age, contact lens wear, positive family history for glaucoma, lens status, or iris colour.     

Correlation Analysis between Central Corneal Thickness and Intraocular Pressure in Juveniles in Northern China: The Jinan City Eye Study

Purpose

To determine the distributions and relation of central corneal thickness (CCT) and intraocular pressure (IOP) by NT-530P in Chinese juveniles, and the effect of gender, age, height, weight and refractive errors on the CTT and IOP.

Methods

CCT and IOP of 982 eyes in 514 juveniles aged from 7 to 18 years were measured with NT-530P. Multi-linear regression and ANOVA analysis were used to analyze the relation of CCT and IOP, and the effect of gender, age, height, weight, refractive condition on CCT and IOP respectively.

Results

The mean CCT and IOP were 554.19±35.46 µm and 15.31±2.57 mmHg. There were significant correlations between the CCT and IOP values. Linear regression analysis revealed a positive correlation between CCT and IOP (r = 0.44, P<0.05). Linear regression equation: IOP = −2.35+0.032CCT, which means the IOP will increase 0.32 mm Hg for every 10-µm increase in CCT. The mean of Corrected IOP (CIOP) was 15.32±2.38 mmHg and had no relation with CCT. There was a negative correlation between refraction degree and CCT (P<0.05), but no correlation between refraction degree and IOP. Multi-linear regression model revealed that the height, weight, age and gender have no effect on the distribution of CCT and IOP respectively.

Conclusions

There is a 0.32 mmHg increase in IOP for every 10-µm increase in CCT. The height, weight, age and gender has no effect on the distribution of CCT and IOP. CCT will become thinner with myopia diopters increases in juveniles. The measurement of CCT is helpful in evaluating the actual IOP correctly.     

Quantification of Mineralized Bone Response to Prostate Cancer by Noninvasive In Vivo μCT and Non-Destructive Ex Vivo μCT and DXA in a Mouse Model

Background

To compare nondestructive in vivo and ex vivo micro-computed tomography (μCT) and ex vivo dual-energy-X-ray-absorptiometry (DXA) in characterizing mineralized cortical and trabecular bone response to prostate cancer involving the skeleton in a mouse model.

Methodology/Principal Findings

In vivo μCT was performed before and 10 weeks after implantation of human prostate cancer cells (MDA-PCa-2b) or vehicle into SCID mouse femora. After resection, femora were imaged by nondestructive ex vivo specimen μCT at three voxel sizes (31 µ, 16 µ, 8 µ) and DXA, and then sectioned for histomorphometric analysis of mineralized bone. Bone mineral density (BMD), trabecular parameters (number, TbN; separation, TbSp; thickness, TbTh) and mineralized bone volume/total bone volume (BV/TV) were compared and correlated among imaging methods and histomorphometry. Statistical tests were considered significant if P<0.05. Ten weeks post inoculation, diaphyseal BMD increased in the femur with tumor compared to the opposite femur by all modalities (p<0.005, n = 11). Diaphyseal BMD by in vivo μCT correlated with ex vivo 31 and 16 µm μCT and histomorphometry BV/TV (r = 0.91–0.94, P<0.001, n = 11). DXA BMD correlated less with bone histomorphometry (r = 0.73, P<0.001, n = 11) and DXA did not distinguish trabeculae from cortex. By in vivo and ex vivo μCT, trabecular BMD decreased (P<0.05, n = 11) as opposed to the cortex. Unlike BMD, trabecular morphologic parameters were threshold-dependent and when using “fixed-optimal-thresholds,” all except TbTh demonstrated trabecular loss with tumor and correlated with histomorphometry (r = 0.73–0.90, P<0.05, n = 11).

Conclusions/Significance

Prostate cancer involving the skeleton can elicit a host bone response that differentially affects the cortex compared to trabeculae and that can be quantified noninvasively in vivo and nondestructively ex vivo.     

3D Evaluation of the Lamina Cribrosa with Swept-Source Optical Coherence Tomography in Normal Tension Glaucoma

Purpose

Although the lamina cribrosa (LC) is the primary site of axonal damage in glaucoma, adequate methods to image and measure it are currently lacking. Here, we describe a noninvasive, in vivo method of evaluating the LC, based on swept-source optical coherence tomography (SS-OCT), and determine this method’s ability to quantify LC thickness.

Methods

This study comprised 54 eyes, including normal (n = 18), preperimetric glaucoma (PPG; n = 18), and normal tension glaucoma (NTG; n = 18) eyes. We used SS-OCT to obtain 3 x 3 mm cube scans of an area centered on the optic disc, and then synchronized reconstructed B- and en-face images from this data. We identified the LC in these B-scan images by marking the visible borders of the LC pores. We marked points on the anterior and posterior borders of the LC in 12 B-scan images in order to create a skeleton model of the LC. Finally, we used B-spline interpolation to form a 3D model of the LC, including only reliably measured scan areas. We calculated the average LC thickness (avgLCT) in this model and used Spearman''s rank correlation coefficient to compare it with circumpapillary retinal nerve fiber layer thickness (cpRNFLT).

Results

We found that the correlation coefficient of avgLCT and cpRNFLT was 0.64 (p < 0.01). The coefficient of variation for avgLCT was 5.1%. AvgLCT differed significantly in the groups (normal: 282.6 ± 20.6 μm, PPG: 261.4 ± 15.8 μm, NTG: 232.6 ± 33.3 μm). The normal, PPG and NTG groups did not significantly differ in age, sex, refractive error or intraocular pressure (IOP), although the normal and NTG groups differed significantly in cpRNFLT and Humphrey field analyzer measurements of mean deviation.

Conclusion

Thus, our results indicate that the parameters of our newly developed method of measuring LC thickness with SS-OCT may provide useful and important data for glaucoma diagnosis and research.