Anterior Lamina Research Articles

Microvascular Density Is Associated With Retinal Ganglion Cell Axonal Volume in the Laminar Compartments of the Human Optic Nerve Head.

To quantify associations between microvascular density and retinal ganglion cell (RGC) axonal volume in the laminar compartments of the human optic nerve head (ONH). Eleven normal human ONHs were evaluated. Antibodies were used to label the vascular endothelium (factor VIII-related antigen/von Willebrand factor antibody) and RGC axons (neurofilament heavy antibody). Three-dimensional analysis of confocal scanning laser microscope images was used to study microvascular density and RGC axonal volume in the prelaminar, anterior lamina cribrosa, posterior lamina cribrosa, and retrolaminar compartments. Microvascular volume was significantly different between laminar compartments (P < 0.0083) and was greatest in the prelaminar region, occupying 11.7% of tissue volume. Microvascular volume per RGC axonal volume and cumulative capillary length per RGC axonal volume were significantly different between laminar compartments (all P < 0.0083). Both were significantly greater in the posterior laminar cribrosa (27.4% and 2.28 × 10-3 μm/μm3, respectively). Microvascular density is closely coupled to RGC axonal volume in the ONH. The posterior laminar cribrosa is a site of high blood supply as evidenced by a greater ratio of microvascular density to RGC axonal volume. The greater percentage of tissue volume occupied by microvasculature in the prelaminar region may implicate it as a site where significant connections between the central retinal artery and short posterior ciliary arteries occur.

Automatic Anterior Lamina Cribrosa Surface Depth Measurement Based on Active Contour and Energy Constraint

The lamina cribrosa is affected by intraocular pressure, which is the major risk of glaucoma. However, the capability to evaluate the lamina cribrosa in vivo has been limited until recently due to poor image quality and the posterior laminar displacement of glaucomatous eyes. In this study, we propose an automatic method to measure the anterior lamina cribrosa surface depth (ALCSD), including a method for detecting Bruch’s membrane opening (BMO) based on k-means and region-based active contour. An anterior lamina cribrosa surface segmentation method based on energy constraint is also proposed. In BMO detection, we initialize the Chan-Vese active contour model by using the segmentation map of the k-means cluster. In the segmentation of anterior lamina cribrosa surface, we utilize the energy function in each A-scan to establish a set of candidates. The points in the set that fail to meet the constraints are removed. Finally, we use the B-spline fitting method to obtain the results. The proposed automatic method can model the posterior laminar displacement by measuring the ALCSD. This method achieves a mean error of 45.34 μm in BMO detection. The mean errors of the anterior lamina cribrosa surface are 94.1% within five pixels and 76.1% within three pixels.

Quantitative analysis of neural tissues around the optic disc after panretinal photocoagulation in patients with diabetic retinopathy.

In this retrospective cross-sectional study, we quantitatively analyzed the tomographic features in the neural tissues around the optic disc in patients with diabetic retinopathy with and without panretinal photocoagulation. We analyzed 206 eyes, comprising 33 normal eyes in subjects without diabetes (group I), 30 eyes without diabetic retinopathy (group II), 66 eyes with non-proliferative diabetic retinopathy (group III), 45 eyes with panretinal photocoagulation (group IV), and 32 eyes with normal tension glaucoma (group V). Sequential images acquired using swept-source optical coherence tomography in three-dimensional mode were used to measure peripapillary retinal nerve fiber layer thickness, neuro-retinal rim thickness, anterior lamina cribrosa depth, prelaminar thickness, and thickness of the lamina cribrosa. The peripapillary retinal nerve fiber layer thickness and lamina cribrosa thickness were significantly thinner in group IV than in group III (p = 0.019 and p < 0.001). However, there was no significant difference in rim thickness, anterior lamina cribrosa depth, or prelaminar thickness between groups III and IV (p = 0.307, p = 0.877, and p = 0.212). Multivariate analysis revealed that time since panretinal photocoagulation and thickness of the lamina cribrosa had a significant effect on peripapillary retinal nerve fiber layer thickness (p < 0.001 and p = 0.014). In group IV, there was a negative correlation between time elapsed since panretinal photocoagulation and peripapillary retinal nerve fiber layer thickness, rim thickness, and thickness of the lamina cribrosa (r = -0.765, r = -0.490, and r = -0.419), but no correlation with prelaminar thickness or anterior lamina cribrosa depth (r = 0.104 and r = -0.171). Panretinal photocoagulation may be related to thinning of the peripapillary retinal nerve fiber layer, rim thickness, and lamina cribrosa, but not prelaminar thickness or anterior lamina cribrosa depth. These features are different from the peripapillary features of eyes with typical normal tension glaucoma.

Positional and shape changes of lamina cribrosa after trabeculectomy in pseudoexfoliative and primary open angle glaucoma

PurposeTo evaluate positional and shape changes of anterior lamina cribrosa (LC) after trabeculectomy and compare them between eyes with pseudoexfoliative (PEXG) and primary open angle glaucoma (POAG).MethodsThe prospective study included 99 eyes (78 PEXG and 21 POAG) planned for trabeculectomy. The morphological parameters of LC and intraocular pressure (IOP) were measured pre‐ and postoperatively (1 week and 1, 3, 6 and 9 months after the surgery). LC was imaged using enhanced depth imaging spectral domain optical coherence tomography. The mean and sectoral LC depth (LCD), global shape index (GSI), curvedness and curvatures in main meridians were calculated using Morphology 1.0 software. LC parameters were compared across the follow‐up visits and in‐between PEXG and POAG groups.ResultsThe mean IOP reduced in PEXG and POAG eyes after the trabeculectomy at all follow‐up visits (p &lt; 0.001). There was a decrease in mean and sectoral LCD (p &lt; 0.001), curvedness (p &lt; 0.001), nasal‐temporal (N‐T) and superior‐inferior (S‐I) curvatures (p &lt; 0.001, p = 0.045, respectively) during whole postoperative period. LC GSI did not change significantly postoperatively and stayed in‐between a trough and rut shape (p = 0.065). There were no differences in the changes of LC morphology between PEXG and POAG eyes (p &gt; 0.05); however a tendency of greater reduction in LCD and curvature was observed. The decrease in LCD, N‐T and S‐I curvatures correlated positively with IOP reduction(ρ = 0.326, ρ = 0.3, ρ = 0.261, p &lt; 0.01 after 1 week, respectively).ConclusionsTrabeculectomy induced a long term mean and sectoral anterior displacement as well as flattening of LC. However, the overall shape of LC was not affected postoperatively. Despite a potential elastinopathy of pseudoexfoliative syndrome PEXG and POAG eyes did not show differences in positional and shape behaviour of LC after the surgery.

Biomechanical Responses of Lamina Cribrosa to Intraocular Pressure Change Assessed by Optical Coherence Tomography in Glaucoma Eyes.

The purpose of this study was to measure change in anterior lamina cribrosa depth (ALD) globally and regionally in glaucoma eyes at different intraocular pressures (IOP). Twenty-seven glaucoma patients were imaged before and after IOP-lowering procedures using optical coherence tomography. The anterior lamina was marked in approximately 25 locations in each of six radial scans to obtain global and regional estimates of ALD. ALD and its change with IOP were compared with optic disc damage, nerve fiber layer thickness, and visual field loss. Variables associated with deeper baseline ALD included larger cup/disc ratio, thinner rim area, larger cup volume, thinner central corneal thickness, and male sex (all P ≤ 0.02). When IOP was lowered, ALD position became more anterior, more posterior, or was unchanged. The mean ALD change after lowering was 27 ± 142 μm (P = 0.3). The mean absolute value of ALD change was 112 ± 90 μm (P = 0.002). Change in ALD was greater in eyes with lower IOP in paired comparisons (P = 0.006) but was not associated with the magnitude of IOP lowering between imaging sessions (P = 0.94). Eyes with no significant change in ALD tended to have more visual field loss than those with significant anterior ALD displacement (P = 0.07). Areas within each optic nerve head that corresponded to zones with thicker nerve fiber layer had greater ALD positional change (P = 0.0007). The lamina can move either anteriorly or posteriorly with IOP decrease, with greater displacement at lower IOP. Glaucoma eyes and regions within glaucoma eyes associated with greater glaucoma damage exhibited smaller responses.

Anterior lamina cribrosa surface depth in healthy Saudi females.

PurposeThis study was conducted to determine normative profile of anterior lamina cribrosa surface depth (ALCSD) in healthy Saudi females using Topcon Three-Dimensional (3D) Optical Coherence Tomography (OCT) 2000 – Spectral Domain (SD-OCT). In addition, the correlation between ALCSD and other clinical factors such as age, refractive error, intraocular pressure (IOP), central corneal thickness, anterior chamber depth, axial length, retinal nerve fiber layer thickness, and disk area was also assessed.DesignThis study was a prospective, nonrandomized, cross-sectional, observational, and quantitative study.MethodsThis study included 191 eyes of 191 healthy Saudi females from the College of Applied Medical Sciences of King Saud University. Stereoscopic disk photographs were reconstructed using Topcon 3D OCT-2000 for all subjects. ALCSD was measured at three planes (superior, middle, and inferior) and defined as the distance from Bruch’s membrane opening level (reference line) to anterior lamina cribrosa surface. Average of ALCSD at all planes was defined as mean ALCSD of the eye. Correlation between ALCSD and all the clinical factors was performed by linear regression analysis. Paired t-test was performed in order to compare ALCSD at all planes.ResultsIn this study, the average ALCSD was 371.88±114.62 μm (range, 155–647.6 μm). Paired t-test showed a significant difference between superior and middle planes (P=0.004) and middle and inferior planes (P=0.013). Using the same test, no significant difference between superior and inferior planes (P=0.820) was observed. Generally, the largest ALCSD was in the middle plane. In addition, linear regression analysis showed no significant correlation between ALCSD and associated clinical factors.ConclusionThis work is the first to provide the normative profile of ALCSD in Saudi females using Topcon 3D OCT-2000. Further studies are recommended for males, different ethnic populations, high myopic eyes, and different age groups using advanced imaging techniques such as enhanced depth imaging OCT.

Relationship Between Anterior Lamina Cribrosa Surface Tilt and Glaucoma Development in Myopic Eyes.

To evaluate the anterior lamina cribrosa (LC) surface tilt angle in myopic eyes and associate it with glaucoma development. In this retrospective study, medical records of myopic patients referred for glaucoma examination from July 1, 2012 to March 30, 2016 were reviewed. Comprehensive ophthalmic examination including spectral-domain optical coherence tomography were performed. We measured the angle of anterior LC surface tilt against Bruch's membrane opening from optical coherence tomography images at the center of the clinical optic disc margin. In horizontal and vertical sections, the angles were defined as α and β, respectively. Patients were grouped according to the presence of glaucomatous damage and factors including optic nerve head morphologic parameters and LC tilt angles were compared between the 2 groups. Among 138 patients originally enrolled, 102 patients were finally analyzed. One eye from 1 patient was randomly chosen. Fifty-five eyes had glaucoma and 47 were normal. The degree of myopia and all optic nerve head morphologic parameters were not significantly different between the 2 groups. However, |α| and |β| were significantly larger in the glaucoma group (all P<0.001), and significances were maintained in multivariate analysis (P<0.001). Larger anterior LC surface tilt angles were related to the presence of glaucoma in normal-pressure myopic eyes. Angulation of the LC against Bruch's membrane opening plane might be associated with increased glaucoma susceptibility in myopic eyes. Further investigations are warranted before clinical utilization of LC tilt as glaucoma susceptibility biomarker.

Circumpapillary retinal nerve fiber layer thickness, anterior lamina cribrosa depth, and lamina cribrosa thickness in neovascular glaucoma secondary to proliferative diabetic retinopathy: a cross-sectional study

BackgroundTo compare the lamina cribrosa between eyes with and without neovascular glaucoma (NVG) using enhanced depth imaging spectral-domain optical coherence tomography.MethodsForty-six patients with proliferative diabetic retinopathy were enrolled in this cross-sectional study. The patients were divided into two groups based on the absence or presence of NVG (the non-NVG group and the NVG group, respectively). The intraocular pressure (IOP), circumpapillary retinal nerve fiber layer (cpRNFL) thickness, anterior lamina cribrosa depth (ALD), and laminar thickness (LT) were compared between the groups.ResultsIn the non-NVG group, the mean age was 66.2 ± 2.4 (mean ± standard error) years, mean maximum IOP was 18.8 ± 1.8 mmHg, mean cpRNFL thickness was 91.2 ± 3.9 μm, mean ALD was 407.0 ± 22.9 μm, and mean LT was 155.0 ± 4.7 μm. In the NVG group, the mean age was 61.4 ± 2.1 years, mean maximum IOP was 33.1 ± 1.6 mmHg, mean cpRNFL thickness was 73.6 ± 3.4 μm, mean ALD was 403.9 ± 20.1 μm, and mean LT was 156.9 ± 4.2 μm. The IOP was significantly higher and the cpRNFL was significantly thinner in the NVG group (P < 0.001 and P = 0.002, respectively). However, the age, ALD, and LT were not statistically different between the groups (P = 0.151, 0.919, and 0.757, respectively).ConclusionsAlthough the cpRNFL was thinner, the structure of the lamina cribrosa was unchanged in the NVG eyes. Axonal loss of the retinal ganglion cells in NVG patients was prior to lamina cribrosa deformation.

Origin of the Lateral Wall of the Mammalian Skull: Fossils, Monotremes and Therians Revisited

To interpret the fundamental differences in the structure and origin of the braincase sidewalls of monotremes, multituberculates, and therians, we examined MicroCT scans of a mammaliaform, Morganucodon; two non-mammalian cynodonts, Massetognathus and Probainognathus; a stem therian, Vincelestes; a juvenile and adult monotreme, Ornithorhynchus; and two marsupials, Monodelphis and Didelphis. The skull of Morganucodon resembles the pattern predicted for an early mammal: the descending flanges of the frontal and parietal cover the lateral surface of the orbitosphenoid and the palatine forms most of the medial wall of the orbit. In monotremes, the lateral region of the chondrocranium ossifies to form a long presphenoid/orbitosphenoid complex. During the transition from early mammals to extant mammals the height of the alisphenoid decreased drastically, the anterior lamina extended anteriorly to form part of the sidewall while the lateral surface of the orbitosphenoid was exposed by the dorsal withdrawal of the frontal and parietal. By contrast, in multituberculates and therians the lateral edges of the frontals extended further ventrally and the orbitosphenoid was reduced to a smaller orbital exposure below the frontals. In multituberculates the alisphenoid decreased in height, replaced by an anterior extension of the anterior lamina. The palatine withdrew from the orbital wall, replaced by a dorsally directed expansion of the maxilla. Extant therians have lost the anterior lamina. The inferior edges of the frontal followed the further ventral migration of the orbitosphenoid. The alisphenoid and parietal form most of the braincase sidewall.

Impact of Rates of Change of Lamina Cribrosa and Optic Nerve Head Surface Depths on Visual Field Progression in Glaucoma.

To investigate the impact of the rates of change of anterior lamina cribrosa surface depth (ALCSD) and optic nerve head surface depth (ONHSD) on visual field (VF) progression in glaucoma. One hundred forty-six eyes of 95 glaucoma patients had optical coherence tomography ONH imaging and VF testing at approximately 4-month intervals for greater than or equal to 5 years. Anterior lamina cribrosa surface depth and ONHSD were measured with reference to (1) Bruch's membrane opening (BMO), and (2) choroid-sclera interface (CSI). The rates of change of ALCSD and ONHSD of individual eyes were measured with linear regression analysis. The hazard ratios (HRs) of the rates of change of ALCSD/ONHSD for prediction of VF progression as per Early Manifest Glaucoma Trial criteria were determined by joint longitudinal and survival models. Using the BMO reference, 23.3% and 28.1% of eyes showed a significant positive trend (posterior displacement), whereas 29.5% and 24.0% showed a significant negative trend (anterior displacement) of ALCSD and ONHSD, respectively. Using the CSI reference, the proportions with a significant negative trend decreased to 11.6% and 14.4%, respectively; and the proportions with a significant positive trend increased to 37.7% and 38.4%, respectively. The HRs of VF progression were 1.06 and 1.11 for each micrometer per year increase in the rates of change of ALCSDBMO and ONHSDBMO, respectively; and 1.07 and 1.09 for each micrometer per year increase in the rates of change of ALCSDCSI and ONHSDCSI, respectively. Identifying fast progressors of posterior ALCS/ONHS displacement is relevant to the management of glaucoma patients as they have a higher risk of VF progression.

A Digital Staining Algorithm for Optical Coherence Tomography Images of the Optic Nerve Head.

PurposeTo digitally stain spectral-domain optical coherence tomography (OCT) images of the optic nerve head (ONH), and highlight either connective or neural tissues.MethodsOCT volumes of the ONH were acquired from one eye of 10 healthy subjects. We processed all volumes with adaptive compensation to remove shadows and enhance deep tissue visibility. For each ONH, we identified the four most dissimilar pixel-intensity histograms, each of which was assumed to represent a tissue group. These four histograms formed a vector basis on which we ‘projected' each OCT volume in order to generate four digitally stained volumes P1 to P4. Digital staining was also verified using a digital phantom, and compared with k-means clustering for three and four clusters.ResultsDigital staining was able to isolate three regions of interest from the proposed phantom. For the ONH, the digitally stained images P1 highlighted mostly connective tissues, as demonstrated through an excellent contrast increase across the anterior lamina cribrosa boundary (3.6 ± 0.6 times). P2 highlighted the nerve fiber layer and the prelamina, P3 the remaining layers of the retina, and P4 the image background. Further, digital staining was able to separate ONH tissue layers that were not well separated by k-means clustering.ConclusionWe have described an algorithm that can digitally stain connective and neural tissues in OCT images of the ONH.Translational RelevanceBecause connective and neural tissues are considerably altered in glaucoma, digital staining of the ONH tissues may be of interest in the clinical management of this pathology.

Factors Associated with the Retinal Nerve Fiber Layer Loss after Acute Primary Angle Closure: A Prospective EDI-OCT Study.

PurposeTo determine the factors associated with retinal nerve fiber layer (RNFL) loss in eyes with acute primary angle-closure (APAC), particularly focusing on the influence of the change in the anterior lamina cribrosa surface depth (LCD).MethodsAfter the initial presentation, 30 eyes with unilateral APAC were followed up at the following specific time points over a 12-month period: 1 week, 1~2 months, 2~3 months, 5~6 months, and 11~12 months. These follow-ups involved intraocular pressure measurements, enhanced depth-imaging spectral-domain optical coherence tomography (SD-OCT) scanning of the optic disc, and measurements of the circumpapillary RNFL thickness. The prelaminar tissue thickness (PLT) and LCD were determined in the SD-OCT images obtained at each follow-up visit.ResultsRepeated measures analysis of variance revealed a significant pattern of decrease in the global RNFL thickness, PLT, and LCD (all p<0.001). The global RNFL thickness decreased continuously throughout the follow-up period, while the PLT decreased until 5~6 months and did not change thereafter. The LCD reduced until 2~3 months and then also remained steady. Multivariable regression analysis revealed that symptoms with a longer duration before receiving laser peripheral iridotomy (LI) (p = 0.049) and a larger LCD reduction (p = 0.034) were significant factors associated with the conversion to an abnormal RNFL thickness defined using OCT normative data.ConclusionEarly short-term decreases in the PLT and LCD and overall long-term decrease in the peripapillary RNFL were observed during a 12-month follow-up after an APAC episode. A longer duration of symptoms before receiving LI treatment and larger LCD reduction during follow-up were associated with the progressive RNFL loss. The LCD reduction may indicate a prior presence of significant pressure-induced stress that had been imposed on the optic nerve head at the time of APAC episode. Glaucomatous progression should be suspected in eyes showing LCD reduction after the APAC remission.

Transoral screw and wire fixation for unstable anterior ½ atlas fracture.

Study Design:Atlas fractures are evaluated according to the fracture type and ligamentous injury. External immobilization may result in fracture nonunion.Objective:The ideal treatment method for non-stabilized atlas fractures is limited fixation without restricting the range of motion of the atlantoaxial and atlantooccipital joints.Summary of Background Data:Such a result can be established by using either anterior fixation or posterior lateral mass fixation. However, none of these techniques can fully address anterior 1/2 atlas fractures such as in this case.Materials and Methods:A transoral technique in which bilateral screws were placed intralaminarly and connected with wire was used to reduce and stabilize an anterior 1/2 fracture of C1.Result:Radiological studies after the surgery showed good cervical alignment, no screw or wire failure and good reduction with fusion of anterior arcus of C1.Conclusions:Internal immobilization by this screw and wire osteosynthesis technique protects the mobility of the atlanto-occipital and atlantoaxial joints. The main advantage is that neither the twisted wires inserted under the anterior lamina, nor the laterally placed screw heads interfere with midline wound closure; unlike the plate/cage and rod systems used together with anterior screws. A computer navigation system with intraoperative 3D imaging facilities will be of benefit for safe placement of the screw, however we preferred a free-hand technique, as the starting point was at the fracture line along the trajectory of the routinely accessible anterior lamina.

Comparing the lamina cribrosa in eyes with primary open angle glaucoma and chronic primary angle closure glaucoma

Objective To compare the lamina cribrosa parameters between primary open angle glaucoma (POAG) and chronic primary angle closure glaucoma (CPACG) eyes. Methods A total of 73 POAG eyes (73 subjects), 64 CPACG eyes (64 subjects), and 40 normal control eyes (40 subjects) with matched ages were included in this cross-sectional observational study. No significant difference was found in sex (χ2=2.07) and age (F=0.38) among three groups (P>0.05). The intraocular pressure, average retinal nerve fiber layer (RNFL) thickness and average visual field defect were not significantly different between POAG and CPACG patients (F=15.67, 21.15, 44.40, 27.99; P<0.05). All subjects underwent spectral-domain optical coherence tomography (SD-OCT) with enhanced depth imaging (EDI). The optic nerve head was scanned radially at the angle of 20; six high resolution B-scan images were obtained from each eye. The center and para-center lamina cribrosa thickness (LCT) and anterior lamina cribrosa surface depth (ALCSD) were measured in each image. The mean LCT and ALCSD were recorded as the average of the LCT and ALCSD of the 6 images and compared among POAG, CPACG and normal control eyes. Results The average LCT of normal control eyes were (211.48±12.07) μm, while those of the POAG eyes were (145.43±34.33) μm, CPACG eyes were (156.79±33.66) μm. The mean LCT of the POAG and CPACG eyes were thinner than those of the control eyes (t=-11.76, -9.88; P<0.01). All LCT of the POAG eyes were significantly thinner than those of the CPACG eyes (t=-1.96, P=0.03). The average ALCSD of normal control eyes were (390.73±84.40) μm, while those of the POAG eyes were (558.51±176.66) μm, CPACG eyes were (539.39±177.30) μm, respectively. The average ALCSD of the POAG and CPACG eyes were deeper than those of the control eyes (t=5.65, 4.96; P<0.01). But no significantly different ALCSD was shown between POAG and CPACG eyes (t=0.63, P=0.49). Conclusions POAG and CPACG eyes have thinner LCT and deeper ALCSD than normal eyes. POAG eyes have thinner LCT than CPACG eyes when their visual field defect and damage of RNFL were in the same degree. Key words: Glaucoma, open-angle/diagnosis; Glaucoma, angle-closure/diagnosis; Tomography, optical coherence

Effect of fishmeal and fish oil replacement by vegetable meals and oils on gut health of European sea bass (Dicentrarchus labrax)

The main objective of this study was to assess the effects of graded levels of replacement of fishmeal (FM) and fish oil (FO) by terrestrial meals (TM) and vegetable oils (VO) on gut health of European sea bass (Dicentrarchus labrax) based on gut morphology, gut-associated immune system (GALT) and gut microbiota composition. Reducing the dietary FM and FO levels down to 10 and 3%, respectively did not affect the growth of European sea bass. Increase in TM and VO markedly affected anterior and posterior gut morphology and fatty acid composition, which mirrored the dietary fatty acid profile. FO replacement by VO increased lipid deposition in anterior gut lamina propria, denoting an effect in lipid metabolism and lipoprotein synthesis. In posterior gut, FM replacements by TM induced an engrossment of the submucosa, an up-regulation of the proinflammatory cytokines IL-1β and TNFα genes, a relatively high mucus production and changes in mucosal microbiota profiles. Finally, supplementation of 0%FM-0%FO diets with LC-PUFA contributed to maintain gut homeostasis in terms of GALT response and microbiota profiles alterations. Statement of relevanceFM and FO appropriate dietary levels for European seabass

Optic Nerve Head Biomechanic and IOP Changes Before and After the Injection of Aflibercept for Neovascular Age-Related Macular Degeneration.

We investigated the early effects of intravitreal aflibercept injection (IAI) on optic nerve head (ONH) morphology. All of the participants underwent applanation tonometry and enhanced depth imaging by spectral-domain optical coherence tomography immediately before injection, and within 5 and 30 minutes after IAI. Changes in the anterior lamina cribrosa surface depth, prelaminar tissue thickness (PTT), optic cup width, optic cup depth, and Bruch's membrane opening (BMO) were assessed. The study included 30 eyes of 30 subjects with a mean age of 77.4 ± 6.8 years (range, 65-89 years) following IAI (2 mg in 0.05 ml). Within 5 minutes after injection, the mean cup depth, mean cup width, and BMO were significantly increased (P = 0.013, P = 0.000, and P = 0.004, respectively), whereas the mean PTT was thinned (P = 0.009). These morphologic changes returned to near baseline values 30 minutes after injection. Cup widening and BMO expansion (P = 0.000; r, 0.668), as well as cup deepening and prelaminar thinning (P = 0.000; r, -0.838), were significantly correlated. The magnitude of cup deepening and prelaminar tissue thinning correlated with the IOP change in the opposite direction than expected (P = 0.039; r, -0.379 and P = 0.377; r, 0.040). A significant widening and deepening of the optic cup, BMO expansion, and prelaminar tissue thinning occurred following IAI for neovascular AMD. Eyes having greater optic disc cup deepening and prelaminar tissue condensation after IAI, associated with a lower IOP increase after injection, suggesting that ONH compliance might buffer the effect of additional intravitreal fluid injection on IOP values.

Intra- and Inter-Rater Agreement of Anterior Lamina Cribrosa Depth Measurements Using Enhanced-Depth Imaging Optical Coherence Tomography

Purpose: To determine intra- and inter-rater agreement of anterior lamina cribrosa depth (ALCD) manual measurements using enhanced-depth imaging optical coherence tomography (EDI-OCT). Methods: Observational study. EDI-OCT of the optic nerve head was performed in healthy subjects. ALCD was defined as the perpendicular distance between the line connecting both edges of Bruch's membrane opening and the anterior border of the lamina cribrosa (LC), at the maximum depth point. Two experienced operators performed manual ALCD measurements of the LC independently, and one of the observers performed the same measurements twice. Intra- and inter-rater agreement was evaluated using intraclass correlation coefficients (ICC) and concordance correlation coefficients (CCC) for the right eye vertical (REV) and horizontal (REH) scans and left eye vertical (LEV) and horizontal (LEH) scans. Results: 120 eyes of 61 subjects, with a mean age of 62.1 ± 15.0 years. The mean REV, REH, LEV and LEH ALCD were 456.2 ± 84.3, 444.5 ± 92.2, 436.7 ± 81.6, 427.6 ± 82.7 μm, respectively. ALCD intra- and inter-rater ICC and intra- and inter-rater CCC varied between 0.85-0.95, 0.84-0.93, 0.85-0.95 and 0.84-0.93, respectively. Conclusions: ALCD manual intra- and inter-rater measurements with EDI-OCT showed high agreement. EDI-OCT is a reliable tool for ALCD measurement, which can provide potentially useful information for integrated glaucoma management.

A New Giant Titanosauria (Dinosauria: Sauropoda) from the Late Cretaceous Bauru Group, Brazil.

Titanosaurian dinosaurs include some of the largest land-living animals that ever existed, and most were discovered in Cretaceous deposits of Argentina. Here we describe the first Brazilian gigantic titanosaur, Austroposeidon magnificus gen. et sp. nov., from the Late Cretaceous Presidente Prudente Formation (Bauru Group, Paraná Basin), São Paulo State, southeast Brazil. The size of this animal is estimated around 25 meters. It consists of a partial vertebral column composed by the last two cervical and the first dorsal vertebrae, all fairly complete and incomplete portions of at least one sacral and seven dorsal elements. The new species displays four autapomorphies: robust and tall centropostzygapophyseal laminae (cpol) in the last cervical vertebrae; last cervical vertebra bearing the posterior centrodiapophyseal lamina (pcdl) bifurcated; first dorsal vertebra with the anterior and posterior centrodiapophyseal laminae (acdl/pcdl) curved ventrolaterally, and the diapophysis reaching the dorsal margin of the centrum; posterior dorsal vertebra bearing forked spinoprezygapophyseal laminae (sprl). The phylogenetic analysis presented here reveals that Austroposeidon magnificus is the sister group of the Lognkosauria. CT scans reveal some new osteological internal features in the cervical vertebrae such as the intercalation of dense growth rings with camellae, reported for the first time in sauropods. The new taxon further shows that giant titanosaurs were also present in Brazil during the Late Cretaceous and provides new information about the evolution and internal osteological structures in the vertebrae of the Titanosauria clade.

Shape Changes of the Anterior Lamina Cribrosa in Normal, Ocular Hypertensive, and Glaucomatous Eyes Following Acute Intraocular Pressure Elevation.

The purpose of this study was to estimate and compare changes in anterior lamina cribrosa (LC) morphology in normal, ocular hypertensive (OHT), and glaucomatous eyes following acute elevations in intraocular pressure (IOP). The optic nerve heads (ONHs) of 97 subjects (17 OHT, 19 primary open-angle glaucoma [POAG], 31 primary angle-closure glaucoma [PACG], and 30 normal subjects) were imaged using optical coherence tomography (OCT). Intraocular pressure was raised twice by applying forces to the anterior sclera, using an ophthalmodynamometer. After each IOP elevation, IOP was held constant and measured; each ONH was rescanned with OCT. In each OCT volume, the anterior LC was enhanced, delineated, and its global shape index (GSI) calculated and compared across groups. The baseline IOP was 17.5 ± 3.5 mm Hg and was increased to 38 ± 5.9 mm Hg and then to 46.5 ± 5.9 mm Hg. At the first IOP increment, mean GSI was significantly smaller than that at baseline in normal subjects and glaucoma subjects (P < 0.05) but not in OHT subjects (P = 0.12). For the second IOP increment, the mean GSI was significantly smaller than that at baseline in normal subjects and in OHT eyes (P < 0.05). After adjusting for age, sex, and baseline IOP, the LC of POAG eyes was found to be significantly more posteriorly curved than that of normal subjects (P = 0.04). Acute IOP elevations altered anterior LC shape in a complex nonlinear fashion. The LC of POAG eyes was more cupped following acute IOP elevations compared to that of normal subjects.

Relationship between intraocular pressure and anterior lamina cribrosa depth: a cross-sectional observational study in a healthy Portuguese population.

To investigate the association between anterior lamina cribrosa depth (ALCD), determined with enhanced depth imaging spectral-domain optical coherence tomography (EDI-OCT), and intraocular pressure (IOP) in a healthy Portuguese population. In this cross-sectional observational study conducted between January and July 2015, 2 optic nerve head (ONH)-centered EDI-OCT cross-scans were performed and ALCD was defined as the perpendicular distance between the line connecting both edges of Bruch's membrane opening and the anterior border of the lamina cribrosa at the maximum depth point. A multivariate regression model was performed to assess the association of IOP and ALCD. The studied population included 59 subjects (35 women) with a mean age of 61.7 ± 15.1 years. Mean vertical and horizontal maximum ALCD was 444.5 ± 92.2 μm and 427.6 ± 82.7 μm, respectively. When controlling for age and spherical equivalent, maximum vertical and horizontal ALCD were positively correlated with intraocular pressure (R2>0.20) by 8.58 μm (95% confidence interval [CI] 2.80-14.36 μm; p<0.01) and 8.25 μm (95% CI 2.71-13.78 μm; p<0.01) per mm Hg of IOP, respectively. Our sample of healthy subjects presented a statistically significant positive correlation between IOP and ALCD when controlling for possible confounding factors. These results may trigger further studies to better elucidate the role of IOP in the morphologic and functional dynamics of the ONH.