Anterior Lamina Cribrosa Depth Research Articles

Hemodialysis-induced positional changes in lamina cribrosa

This study is aimed to investigate the effect of hemodialysis (HD) on the lamina cribrosa (LC) of the optic nerve head (ONH) using swept-source optical coherence tomography (SS-OCT) and other ophthalmological parameters in patients with end-stage kidney disease (ESKD). This prospective observational study included 29 patients who underwent HD for ESKD. ONH parameters including neural canal diameter (NCD), peripapillary vertical height (PVH), and anterior LC depth (LCD), were assessed using SS-OCT. Changes in the ONH parameters before and after HD were statistically analysed. Correlations between changes in the LCD and other ocular and systemic measurements were identified using Pearson’s correlation analyses. The mean anterior LCD significantly decreased from 441.6 ± 139.8 μm before HD to 413.5 ± 141.7 μm after HD (P = 0.001). Mean NCD and PVH did not show significant changes after HD (P = 0.841 and P = 0.574, respectively). A significant correlation was found between changes in the anterior LCD and the mean ocular perfusion pressure (r = 0.397, P = 0.036). We observed a significant decrease in anterior LCD after HD. Our study suggests that HD can influence the ONH, especially in the LC.

Non-arteritic anterior ischemic and glaucomatous optic neuropathy: Implications for neuroretinal rim remodeling with disease severity.

Post-acute non-arteritic ischemic optic neuropathy (NAION) and glaucomatous optic neuropathy (GON) can be difficult to differentiate clinically. Our objective was to identify optical coherence tomography (OCT) parameters to help differentiate these optic neuropathies. We compared 12 eyes of 8 patients with NAION and 12 eyes of 12 patients with GON, matched for age and visual field mean deviation (MD). All patients underwent clinical assessment, automated perimetry (Humphrey Field Analyzer II; Carl Zeiss Meditec, Dublin, CA, USA), and OCT imaging (Spectralis OCT2; Heidelberg Engineering, Heidelberg, Germany) of the optic nerve head and macula. We derived the neuroretinal minimum rim width (MRW), peripapillary retinal nerve fibre layer (RNFL) thickness, central anterior lamina cribrosa depth, and macular retinal thickness. MRW was markedly thicker, both globally and in all sectors, in the NAION group compared to the GON group. There was no significant group difference in RFNL thickness, globally or in any sector, with the exception of the temporal sector that was thinner in the NAION group. The group difference in MRW increased with increasing visual field loss. Other differences observed included lamina cribrosa depth significantly greater in the GON group and significantly thinner central macular retinal layers in the NAION group. The ganglion cell layer was not significantly different between the groups. The neuroretinal rim is altered in a dissimilar manner in NAION and GON and MRW is a clinically useful index for differentiating these two neuropathies. The fact that the difference in MRW between the two groups increased with disease severity suggests distinct remodelling patterns in response to differing insults with NAION and GON.

Evaluation of the lamina cribrosa in different stages of diabetic retinopathy.

To evaluate the relationship of the peripapillary retina nerve fiber layer (RNFL) and lamina cribrosa (LC) with diabetic retinopathy (DR) in type 2 diabetes mellitus (DM) cases. Prospective comparative study. This study included 50 non-DR (Group 1), 55 non-proliferative diabetic retinopathy (NPDR) (Group 2), 28 DM cases with proliferative diabetic retinopathy (PDR) (Group 3) and 45 healthy volunteers (Group 4). All participants were evaluated with visual acuity, intraocular pressure (IOP) with Goldman applanation tonometry, anterior segment biomicroscopy, 24 - 2 visual field testing, and dilated fundus examination. Retinal nerve fiber layer (RNFL) thickness, lamina cribrosa thickness (LCT) and anterior lamina cribrosa depth (ALCD) were examined by spectral-domain optical coherence tomography (OCT). There was no difference between the groups in terms of age and gender. Visual acuity (p < 0.001) was significantly different between the groups, while IOP (p = 0.068) was similar. Mean (p = 0.010), superior-temporal (p = 0.024), and superior-nasal (p = 0.011) RNFL thickness decreased significantly in correlation with the stage of DR. LCT decreased significantly as the stage of DR progressed in both vertical and horizontal radial OCT scans (p < 0.001). ALCD was not different between groups (p = 0.954 for horizontal scan, p = 0.867 for vertical scan). Peripapillary RNFL and LCT significantly decreases as the DR stage progresses. The biomechanical effects of the LC may also be responsible for diabetes-induced neurodegeneration.

Comparative Evaluation of Lamina Cribrosa Anatomical Parameters with Retinal Nerve Fiber Layer Thickness Defects In Primary Open-angle Glaucoma Cases And Controls

OBJECTIVES To assess the lamina cribrosa (LC) anterior lamina cribrosa depth (ALCD), lamina cribrosa thickness (LCT) and retinal nerve fiber layer thickness (RNFLT) in primary open-angle glaucoma (POAG) cases and age-matched controls and to compare these anatomical variables among POAG cases and age-matched controls. METHODOLOGY The case-control study was researched at Al-Ain Eye Institute, Karachi, in four month’s duration (November 2018 till February 2019). Expert eye specialist recruited 57 POAG cases and 46 age-matched healthy controls. Observation of intraocular pressure (IOP) and open angle was done using Goldmann tonometry and Slit-lamp biomicroscopy with stereoscopic ophthalmoscopy respectively. Visual field parameters of mean deviation (MD) and pattern standard deviation (PSD) measured using Humphrey Field Analyzer. Highly sensitive spectral domain ocular coherence tomography with enhanced depth imaging (EDI-OCT) was used to determine ALCD, LCT and RNFLT. RESULTS Statistically significant results were produced by RNFLT defects when it is compared in groups of mild with moderate cases of POAG (P-value 0.037). ALCD and LCT did display an association with RNFLT defects but did not produced statistically significant results. CONCLUSION Assessments of ALCD and LCT can provide important prognostic evidence about RNFLT and can assist in future planning of mild and moderate cases suffering from POAG.

Effects of Acute Intracranial Pressure Changes on Optic Nerve Head Morphology in Humans and Pig Model

ABSTRACT Purpose The lamina cribrosa (LC) is a layer of fenestrated connective tissue tethered to the posterior sclera across the scleral canal in the optic nerve head (ONH). It is located at the interface of intracranial and intraocular compartments and is exposed to intraocular pressure (IOP) anteriorly and intracranial pressure (ICP) or Cerebrospinal fluid (CSF) pressure (CSFP) posteriorly. We hypothesize that the pressure difference across LC will determine LC position and meridional diameter of scleral canal (also called Bruch’s membrane opening diameter; BMOD). Methods We enrolled 19 human subjects undergoing a medically necessary lumbar puncture (LP) to lower CSFP and 6 anesthetized pigs, whose ICP was increased in 5 mm Hg increments using a lumbar catheter. We imaged ONH using optical coherence tomography and measured IOP and CSFP/ICP at baseline and after each intervention. Radial tomographic ONH scans were analyzed by two independent graders using ImageJ, an open-source software. The following ONH morphological parameters were obtained: BMOD, anterior LC depth and retinal thickness. We modeled effects of acute CSFP/ICP changes on ONH morphological parameters using ANOVA (human study) and generalized linear model (pig study). Results For 19 human subjects, CSFP ranged from 5 to 42 mm Hg before LP and 2 to 19.4 mm Hg after LP. For the six pigs, baseline ICP ranged from 1.5 to 9 mm Hg and maximum stable ICP ranged from 18 to 40 mm Hg. Our models showed that acute CSFP/ICP changes had no significant effect on ONH morphological parameters in both humans and pigs. Conclusion We conclude that ONH does not show measurable morphological changes in response to acute changes of CSFP/ICP. Proposed mechanisms include compensatory and opposing changes in IOP and CSFP/ICP and nonlinear or nonmonotonic effects of IOP and CSFP/ICP across LC.

Evaluation of Lamina Cribrosa by Using Enhanced Depth Imaging Optical Coherence Tomography in Ocular Sarcoidosis during Quiescent Phase.

Enhanced depth imaging optical coherence tomography is a useful method to allow for the evaluation of deep ocular structures, such as choroid and lamina cribrosa (LC), which are affected by ocular diseases. We hypothesized that choroidal and optic nerve inflammation in patients with ocular sarcoidosis (OS) might affect the LC structure. This study aimed to evaluate changes in the LC and anterior LC depth (ALCD) in patients with OS. Forty-eight eyes of 26 patients with OS who received the treatment of panuveitis and were in the quiescent phase for at least 6 months were included in the study. Thirty healthy subjects' randomly selected eyes were selected as a control group. Eyes with OS were divided into two subgroups according to the presence (OS eyes with glaucoma [OSWG], n = 23) or absence of glaucoma (OS eyes without glaucoma [OSWOG], n = 25). The LC thickness, ALCD, and peripapillary choroidal thickness were measured using enhanced depth imaging optical coherence tomography in eyes with OS and in controls. The mean LC thickness was found significantly thinner in both OSWG and OSWOG eyes compared with the healthy controls (P < .001 and P = .001, respectively). The mean ALCD was found significantly higher in OSWG eyes (462 ± 65 μm) compared with OSWOG eyes (417 ± 58 μm) and the healthy control eyes (397 ± 59 μm; P = .03 and P = .001, respectively). The average peripapillary choroidal thickness was found to be significantly thinner in OSWG eyes compared with the control eyes (P = .05). The present study revealed that OS is associated with a thinned LC independent of the presence of glaucoma. The degenerative changes in the LC, which is the transition point of the retinal nerve fibers, may cause long-term visual dysfunction in OS. These degenerative changes should be prevented by controlling inflammation with early diagnosis and treatment in patients with OS.

Longitudinal assessment of optic nerve head changes using optical coherence tomography in a primate microbead model of ocular hypertension

In humans, the longitudinal characterisation of early optic nerve head (ONH) damage in ocular hypertension (OHT) is difficult as patients with glaucoma usually have structural ONH damage at the time of diagnosis. Previous studies assessed glaucomatous ONH cupping by measuring the anterior lamina cribrosa depth (LCD) and minimal rim width (MRW) using optical coherence tomography (OCT). In this study, we induced OHT by repeated intracameral microbead injections in 16 cynomolgus primates (10 unilateral; 6 bilateral) and assessed the structural changes of the ONH longitudinally to observe early changes. Elevated intraocular pressure (IOP) in OHT eyes was maintained for 7 months and serial OCT measurements were performed during this period. The mean IOP was significantly elevated in OHT eyes when compared to baseline and compared to the control eyes. Thinner MRW and deeper LCD values from baseline were observed in OHT eyes with the greatest changes seen between month 1 and month 2 of OHT. Both the mean and maximum IOP values were significant predictors of MRW and LCD changes, although the maximum IOP was a slightly better predictor. We believe that this model could be useful to study IOP-induced early ONH structural damage which is important for understanding glaucoma pathogenesis.

Association of lamina cribrosa morphometry with retinal nerve fiber layer loss and visual field defects in primary open angle glaucoma.

Objectives:To calculate the anterior lamina cribrosa depth (ALCD) and lamina cribrosa thickness (LCT) in primary open angle glaucoma (POAG) patients and controls and to correlate lamina cribrosa (LC) parameters to retinal nerve fiber layer thickness (RNFLT) and visual field (VF) defects.Methods:The study was conducted from November 2018 to March 2019. A total of 60 correspondents (30 cases and 30 controls) were assessed for general ophthalmological investigations including intraocular pressure (IOP), axial length AXL, ophthalmoscopy, visual field (VF) testing and spectral domain ocular computed tomography (SDOCT).Results:The mean age of subjects was 62 years (Cases 67.30±1.2, controls 57.32±1.1) with more male participants. Intraocular pressure [IOP (19.85 ±1.4)], AXL (22.85 ± 1.6), VF defects (8.30 ± 4.5), RNFLT (72.58 ± 13.2) and LCT (162.51 ± 64.62) were statistically significant in POAG patients as compared to the controls.Conclusion:A thinner LC in POAG correlated significantly with the RNFLT and VF defects. LC anatomical parameters can be estimated with precision using SDOCT with enhanced depth imaging (EDI).

In Vivo anterior Optic Nerve Head changes as a function of Visual Field loss in Glaucoma

AbstractPurposeTo correlate regional measures of prelamina (preL) depth and thickness, anterior lamina cribrosa (LC) depth and nerve fibre layer (NFL) thicknesses with change in visual field sensitivity in primary open angle glaucoma, using enhanced depth imaging optical coherence tomography (OCT).MethodsThree‐dimensional image datasets were acquired as 20° scans centred on the optic nerve head (ONH) of glaucoma (n=111) and control (n=39) eyes, using a custom built OCT at 1040nm (spectral bandwidth 70nm). ONH measurements of regional (superior [S], inferior [I], nasal [N], temporal [T], and central [C]) preL and anterior LC depth were performed using Bruch’s membrane opening as a reference plane. PreL thickness was calculated from these surface measures. Border (above BMO) and peripapillary (pp) NFL were also measured. Intraclass correlation coefficients (ICC) were used to determine intra‐session repeatability.ResultsPreL depth (S: r=0.339, I: r=0.363, and N: r=0.317; p&lt;0.001, T: r=0.219, p=0.007, central: r=0.202, p=0.013) and anterior LC depth (S: r=0.232, p=0.006, I: r=0.229, p=0.006, N: r=0.246, p=0.009, T: r=0.169, p=0.04, central: r=0.226, p=0.006) significantly increased with increasing VF loss in all ONH regions. PreL thickness significantly decreased with increasing VF loss in all ONH regions, (S: r=‐0.295 and I: r=‐0.346; p&lt;0.001, N: r=‐0.218, p=0.026, temporal: r=‐0.177, p=0.031), except for the centre (r=‐0.106, p=0.199). ICCs &gt;0.9 were calculated for all ONH measures and intra‐session differences in the ONH parameters were not identified within triplicate image datasets (p&gt;0.05). BNFL and ppNFL thicknesses significantly decreased with VF loss (p&lt;0.001).ConclusionsSignificant correlations were found between preL depth and thickness, and anterior LC depth with VF function, indicating that these quantitative (and repeatable) measures are useful in monitoring glaucomatous optic neuropathy.

Evaluation of lamina cribrosa in angioid streaks using spectral-domain optical coherence tomography enhanced depth imaging

To investigate retinal nerve fiber layer (RNFL) thickness, anterior lamina cribrosa depth (ALD) and laminar thickness (LT) in eyes with angioid streaks (AS) in comparison with healthy eyes. Patients with AS (n=32 eyes) and age-matched healthy subjects (n=42 eyes) underwent enhanced depth imaging with spectral domain optical coherence tomography of the optic nerve head. RNFL thickness was obtained automatically by using the Heidelberg software. The ALD was defined as the vertical distance between the Bruch's membrane openings as reference plane and the anterior border of the lamina cribrosa. The LT was measured as the distance between the anterior and posterior borders of the lamina cribrosa. RNFL thickness, ALD and LT were compared between the AS and healthy eyes adjusting for axial length. The mean age was 51.7±8.0 years for AS patients and 53.8±10.2 years for control subjects (P=0.34). The mean RNFL thickness was 88.6±17.6μm in AS eyes and 102.1±8.3μm in control eyes; the difference between the groups was significantly significant. ALD was 350.9±70.8μm in AS eyes and 432.5±82.1μm in control eyes, while LT was 166.3±41.0μm in AS eyes and 241.3±43.2μm in control eyes. ALD and LT were also significantly thinner in AS eyes than control eyes (P=0.003, P<0.001; respectively). Enhanced depth imaging revealed that eyes with AS demonstrate thinner RNFL, ALD and LT compared with normal eyes. Further studies with a larger sample size are needed to understand the relationship between these findings and the morphologic changes and pathogenesis of AS.

Changes in the Anterior Lamina Cribrosa Morphology with Glaucoma Severity

This study was designed to evaluate if primary open angle glaucoma (POAG) and its severity are associated with the shape of the lamina cribrosa (LC) as measured by a global shape index (LC-GSI), or other indices of LC curvature or depth. Optical coherence tomography (OCT) scans of the optic nerve head (OHN) were obtained from subjects with POAG (n = 99) and non-glaucomatous controls (n = 76). ONH structures were delineated, the anterior LC morphology reconstructed in 3D, and the LC-GSI calculated (more negative values denote greater posterior concavity). Anterior LC depth and 2D-curvature were also measured. Severity of glaucoma was defined by the extent of visual field loss, based on the Hodapp-Parrish-Anderson grading. Linear regression analyses compared LC characteristics between controls, mild-moderate, and advanced POAG groups. After adjusting for age, gender, ethnicity, intraocular pressure, axial length and corneal curvature, the LC-GSI was most negative in the advanced POAG group (mean [standard error] = −0.34 [0.05]), followed by the mild-moderate POAG group (−0.31 [0.02]) and then controls (−0.23 [0.02], PTrend = 0.01). There was also a significant trend of increasing LC depth and greater LC horizontal curvature with increasing severity of glaucoma (PTrend = 0.04 and 0.02, respectively). Therefore, with more severe glaucoma, the LC-GSI was increasingly more negative, and the anterior LC depth and curvature greater. These observations collectively correspond to greater cupping of the ONH at the level of the LC. As the LC-GSI describes the 3D anterior LC morphology, its potential usage may be complementary to existing ONH parameters measured on OCT.

Swept-Source OCT for Evaluating the Lamina Cribrosa: A Report by the American Academy of Ophthalmology

To review the published literature on the use of swept-source (SS) OCT for evaluating the lamina cribrosa in glaucoma. A PubMed and Cochrane Library literature search initially conducted on March 3, 2017, and updated on June 26, 2018, yielded a total of 64 articles. Articles that were reviews or that were not published in English were excluded, and 29 were found to fit the inclusion criteria. The panel methodologist then assigned a level of evidence rating to each study. Fifteen studies were rated level III, 14 studies were rated level II, and no studies were rated level I. Different aspects of the lamina cribrosa were studied using SS-OCT, including the anterior lamina cribrosa curvature, anterior lamina cribrosa depth, anterior lamina cribrosa insertions, laminar thickness, focal lamina cribrosa defects (FLCDs), and lamina cribrosa microarchitecture. In general, imaging of the anterior lamina can be achieved reliably, although shadowing from blood vessels at the neuroretinal rim remains an issue. Imaging of the posterior lamina can be achieved with varying levels of success. In glaucoma, there is posterior migration of the anterior lamina cribrosa insertions as well as increased thinning and posterior curvature of the lamina cribrosa. Focal lamina cribrosa defects appear more commonly in glaucoma, and this may hint at the pathogenesis of axonal damage. In addition, there may be remodeling of the microarchitecture of the lamina, resulting in more variable laminar pores. There are limited studies comparing SS-OCT with spectral-domain (SD) OCT with regard to imaging of the lamina, but the difference in image quality between enhanced depth imaging (EDI) with SD-OCT and SS-OCT seems minimal. Imaging of the lamina cribrosa using SS-OCT has demonstrated that the lamina cribrosa is likely biomechanically active and that significant changes occur in glaucoma. The diagnostic utility of SS-OCT for lamina cribrosa imaging is promising, but standardized nomenclature, automated measurements, and longitudinal studies with larger and more diverse sample sizes are needed.

Structure-function relationships in glaucoma using enhanced depth imaging optical coherence tomography-derived parameters: a cross-sectional observational study

BackgroundTo investigate structural and functional correlations in glaucoma patients using enhanced depth imaging spectral-domain optical coherence tomography (EDI OCT)-derived parameters.MethodsWe prospectively enrolled healthy participants and glaucomatous patients with a wide range of disease stages. All participants underwent visual field (VF) testing (SITA - Standard 24–2; Carl Zeiss Meditec, Dublin, CA) and EDI OCT imaging (Spectralis; Heidelberg Engineering Co., Heidelberg, Germany). The following optic nerve head parameters were measured on serial vertical EDI OCT B-scans by two experienced examiners masked to patients clinical data: lamina cribrosa (LC) thickness and area, prelaminar neural tissue thickness and area, anterior LC depth, Bruch’s membrane opening (BMO) and average, superior, and inferior BMO-minimum rim width (BMO-MRW). Only good quality images were considered, and whenever both eyes were eligible, one was randomly selected for analysis. Scatter plots were constructed to investigate correlations between each anatomic parameter and patient’s VF status (based on VF index [VFI] values).ResultsA total of 73 eyes of 73 patients were included. All EDI OCT parameters evaluated differed significantly between glaucomatous and control eyes (P ≤ 0.045). A secondary analysis, in which glaucomatous patients were divided according to VF mean deviation index values into 3 groups (mild [G1; > − 6 dB], moderate [G2; − 6 to − 12 dB] and advanced [G3; <− 12 dB] glaucoma), revealed that average BMO-MRW was the EDI OCT parameter that presented more significant differences between the different stages of glaucoma. Significant structure-function correlations were found between VFI values and prelaminar neural tissue area (R2 = 0.20, P = 0.017), average BMO-MRW (R2 = 0.35, P ≤ 0.001), superior BMO-MRW (R2 = 0.21, P = 0.012), and inferior BMO-MRW (R2 = 0.27, P = 0.002). No significant correlations were found for LC area and anterior LC depth (P ≥ 0.452).ConclusionsEvaluating the distribution pattern and structure-function correlations of different laminar and prelaminar EDI OCT-derived parameters in glaucomatous patients, we found better results for neural tissue-based indexes (compared to LC-derived parameters). The diagnostic utility of each parameter deserves further investigations.

Increased prelaminar tissue thickness in patients with open-angle glaucoma and type 2 diabetes.

BackgroundThe characteristics of the optic nerve head (ONH) in open angle glaucoma (OAG) patients with diabetes have not been reported. This study aimed to characterize the ONH structures and glaucomatous damage in diabetic OAG patients, using age-matched non-diabetic OAG patients and control subjects.MethodsThe locations of visual field defects of OAG patients were classified and the prelaminar thickness and lamina cribrosa depth were measured in 64 OAG patients with type 2 diabetes (OAG+DM), 68 OAG patients without diabetes (OAG-DM), and 36 controls. All participants were scanned by spectral domain-optical coherence tomography. The anterior prelaminar depth and lamina cribrosa depth were measured at the center of the reference line (the Bruch’s membrane opening plane). The prelaminar tissue thickness was obtained by subtracting the anterior prelaminar depth from the anterior lamina cribrosa depth.ResultsThe visual field defects in the OAG+DM group were more commonly found in the inferior hemifield (P = 0.010), and tended to involve the central visual field compared to the OAG-DM group (P = 0.044). In the comparison of ONH parameters, the prelaminar thickness was highest in the OAG+DM group, followed by the control subjects and the OAG-DM group (P = 0.035). Post-hoc testing showed that prelaminar thickness was significantly greater in the OAG+DM group than in the OAG-DM group (P = 0.033). The lamina cribrosa depth was deepest in the OAG+DM group, followed by the OAG-DM group and the control subjects (P = 0.006).ConclusionsDiabetic and non-diabetic OAG patients exhibit different characteristics of glaucoma, particularly increased prelaminar thickening in diabetics.

The association between prelaminar tissue thickness and peripapillary choroidal thickness in untreated normal-tension glaucoma patients.

To evaluate the association between prelaminar tissue thickness (PLT) and peripapillary choroidal thickness (PCT) in untreated normal-tension glaucoma (NTG) patients.A cross-sectional study was conducted in 65 untreated NTG patients. All of the subjects were imaged with swept-source optical coherence tomography (SS-OCT, DRI OCT; Topcon, Tokyo, Japan) to obtain the horizontal scan crossing the optic nerve head center. The PLT was calculated by subtracting the anterior prelaminar depth (APLD) from the anterior lamina cribrosa depth (ALCD). The retinal nerve fiber layer thickness and PCT were measured automatically using the in-built automated software of the OCT device. Spearman correlation analysis was conducted to investigate the ocular factors that were associated with PLT.The average PLT, APLD, ALCD, and PCT values were 134.05 ± 55.54, 314.59 ± 113.59, 448.64 ± 125.69, and 121.23 ± 59.56 μm, respectively. PLT was correlated with the axial length, visual field index (VFI), ALCD, and PCT. When the subjects were divided into 2 groups according to their PLT values (median value, 125.114 μm), the thin PLT group showed worse mean deviation, VFI values, and thinner PCT when compared to the thick PLT group.The PLT was significantly associated with the PCT, and the thinner PLT showed the greater glaucomatous damage in untreated NTG. The thickness of the prelaminar tissue may be related with the choroidal blood flow in untreated NTG patients.

Lamina Cribrosa and Choroid Features and Their Relationship to Stage of Pseudoexfoliation Glaucoma.

PurposeTo better understand the relationship of lamina cribrosa (LC) and choroid features to the severity of pseudoexfoliation glaucoma (PXG).MethodsIn this cross-sectional study, 137 eyes of 122 subjects (47 eyes with moderate/advanced PXG [mean deviation (MD), −15.0 ± 7.7 dB], 34 eyes with mild PXG [MD, −2.7 ± 1.5 dB], 32 aged-matched pseudoexfoliation syndrome [PXS] eyes, and 24 aged-matched control eyes) were investigated. Optic discs, LC thickness, and anterior LC depth (ALD; midsuperior, center, and midinferior) as well as peripapillary choroidal thickness were determined. Linear mixed modeling was used to adjust for age, sex, and axial length.ResultsA progressive decrease in LC thickness was found when comparing controls (271.9 ± 61.3 μm), PXS (212.6 ± 51.5 μm), mild PXG (180.8 ± 24.6 μm), and moderate/advance PXG (138.9 ± 37.5 μm) (P < 0.001). ALD was greater (P < 0.001) in moderate/advance glaucoma (306.7 ± 105.3 μm) and mild PXG (209.5 ± 79.7 μm) compared with PXS (155 ± 86.7 μm) and healthy controls (149.2 ± 103 μm). Although eyes with moderate/advance PXG had the thinnest choroid (117.2 ± 36.6 μm), choroidal thickness was comparable in mild PXG, PXS, and controls (150.0 ± 46.1, 159.7 ± 65.5, and 157.5 ± 51.1 μm, respectively; P = 0.002). Worse MD was the only factor associated with thinner LC (β = 2.344, P < 0.001) and choroid (β = 1.717, P = 0.009 μm) in PXG eyes. Higher IOP (β = 4.305, P = 0.013) and worse MD (β = −6.390, P < 0.001) were associated with deeper ALD in PXG.ConclusionsIn pseudoexfoliation, LC thinning is an early sign, and there is progressive thinning with advancing glaucoma. Choroidal thinning is observable only with moderate/advanced glaucoma. In PXG eyes, LC thickness, depth, and peripapillary choroidal thickness are associated with glaucoma severity.

Factors associated with lamina cribrosa displacement after trabeculectomy measured by optical coherence tomography in advanced primary open-angle glaucoma

To investigate the relationship of lamina cribrosa displacement to corneal biomechanical properties and visual function after mitomycin C-augmented trabeculectomy. Eighty-one primary open-angle eyes were imaged before and after trabeculectomy using an enhanced depth spectral domain optical coherence tomography (SDOCT). Corneal biomechanical properties were measured with the ocular response analyzer before the surgery. The anterior lamina cribrosa (LC) was marked at several points in each of the six radial scans to evaluate LC displacement in response to intraocular pressure (IOP) reduction. A Humphrey visual field test (HVF) was performed before the surgery as well as 3 and 6months, postoperatively. Factors associated with a deeper baseline anterior lamina cribrosa depth (ALD) were cup-disc ratio (P= 0.04), baseline IOP (P= 0.01), corneal hysteresis (P= 0.001), and corneal resistance factor (P= 0.001). After the surgery, the position of LC became more anterior (negative), posterior (positive), or remained unchanged. The mean LC displacement was - 42μm (P= 0.001) and was positively correlated with the magnitude of IOP reduction (regression coefficient = 0.251, P= 0.02) and negatively correlated with age (regression coefficient = - 0.224, P= 0.04) as well as baseline cup-disk ratio (Regression coefficient = - 0.212, P= 0.05). Eyes with a larger negative LC displacement were more likely to experience an HVF improvement of more than a 3dB gain in mean deviation (P= 0.002). A larger IOP reduction and younger age was correlated with a larger negative LC displacement and improving HVF. The correlation between lower SDOCT cup-disc ratio and postoperative negative LC displacement was borderline (P = 0.05). Corneal biomechanics did not predict LC displacement.

Evaluation of the lamina cribrosa in patients with diabetes mellitus using enhanced depth imaging spectral-domain optical coherence tomography

To compare the lamina cribrosa thickness and anterior lamina cribrosa depth between patients with and without diabetes mellitus and to investigate the effect of metabolic control and duration of diabetes mellitus on lamina cribrosa thickness and anterior lamina cribrosa depth using enhanced depth imaging spectral-domain optical coherence tomography. A total of 70 patients were enrolled in this cross-sectional study and were divided into the diabetes and control groups. Intraocular pressure, circumpapillary retinal nerve fibre layer thickness, anterior lamina cribrosa depth and lamina cribrosa thickness were compared between the groups. In the control group, the mean intraocular pressure was 14.6 ± 3.1 (mean ± standard deviation) mmHg, mean circumpapillary retinal nerve fibre layer thickness was 105.41 ± 5.86 μm, mean anterior lamina cribrosa depth was 420.3 ± 90.2 μm and mean lamina cribrosa thickness was 248.5 ± 5.4 μm. In the diabetes group, the mean intraocular pressure was 13.9 ± 2.2 mmHg, mean circumpapillary retinal nerve fibre layer thickness was 101.37 ± 10.97 μm, mean anterior lamina cribrosa depth was 351.4 ± 58.6 μm and mean lamina cribrosa thickness was 271.6 ± 33.9 μm. Lamina cribrosa thickness was significantly higher ( p < 0.001) and anterior lamina cribrosa depth was significantly lower ( p = 0.003) in the diabetes group. There was no statistical difference between the groups with regard to age, spherical equivalent, axial length, circumpapillary retinal nerve fibre layer thickness and intraocular pressure ( p = 0.69, 0.26, 0.47, 0.06 and 0.46, respectively). Lamina cribrosa thickness and anterior lamina cribrosa depth were not significantly correlated with duration of diabetes mellitus (lamina cribrosa thickness: r = -0.078, p = 0.643; anterior lamina cribrosa depth: r = -0.062, p = 0.710) or HbA1c levels (lamina cribrosa thickness: r = -0.078, p = 0.596; anterior lamina cribrosa depth: r = -0.228, p = 0.169). The results of this study showed that the optical coherence tomography measurement of lamina cribrosa revealed thicker and more anteriorly positioned lamina cribrosa for patients with diabetes mellitus compared with those for healthy controls.

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.

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.