Non-invasive in vivo measurement of ocular rigidity: Clinical validation, repeatability and method improvement.

Ocular rigidity (OR) is thought to play a role in the pathogenesis of glaucoma, but the lack of reliable non-invasive measurements has been a major technical challenge. We recently developed a clinical method using optical coherence tomography time-lapse imaging and automated choroidal segmentation to measure the pulsatile choroidal volume change (ΔV) and calculate OR using Friedenwald's equation. Here we assess the validity and repeatability of this non-invasive technique. We also propose an improved mathematical model of choroidal thickness to extrapolate ΔV from the pulsatile submacular choroidal thickness change more accurately. The new mathematical model uses anatomical data accounting for the choroid thickness near the equator. The validity of the technique was tested by comparing OR coefficients obtained using our non-invasive method (OROCT) and those obtained with an invasive procedure involving intravitreal injections of Bevacizumab (ORIVI) in 12 eyes. Intrasession and intersession repeatability was assessed for 72 and 8 eyes respectively with two consecutive measurements of OR. Using the new mathematical model, we obtained OR values which are closer to those obtained using the invasive procedure and previously reported techniques. A regression line was calculated to predict the ORIVI based on OROCT, such that ORIVI = 0.655 × OROCT. A strong correlation between OROCT and ORIVI was found, with a Spearman coefficient of 0.853 (p < 0.001). The intraclass correlation coefficient for intrasession and intersession repeatability was 0.925, 95% CI [0.881, 0.953] and 0.950, 95% CI [0.763, 0.990] respectively. This confirms the validity and good repeatability of OR measurements using our non-invasive clinical method.

Transplantation of mesenchymal stem cells promotes tissue regeneration in a glaucoma model through laser-induced paracrine factor secretion and progenitor cell recruitment.

Among bone marrow cells, hematopoietic and mesenchymal components can contribute to repair damaged organs. Such cells are usually used in acute diseases but few options are available for the treatment of chronic disorders. In this study, we have used a laser-induced model of open angle glaucoma (OAG) to evaluate the potential of bone marrow cell populations and the mechanisms involved in tissue repair. In addition, we investigated laser-induced tissue remodeling as a method of targeting effector cells into damaged tissues. We demonstrate that among bone marrow cells, mesenchymal stem cells (MSC) induce trabecular meshwork regeneration. MSC injection into the ocular anterior chamber leads to far more efficient decrease in intraocular pressure (IOP) (p < .001) and healing than hematopoietic cells. This robust effect was attributable to paracrine factors from stressed MSC, as injection of conditioned medium from MSC exposed to low but not to normal oxygen levels resulted in an immediate decrease in IOP. Moreover, MSC and their secreted factors induced reactivation of a progenitor cell pool found in the ciliary body and increased cellular proliferation. Proliferating cells were observed within the chamber angle for at least 1 month. Laser-induced remodeling was able to target MSC to damaged areas with ensuing specific increases in ocular progenitor cells. Thus, our results identify MSC and their secretum as crucial mediators of tissue repair in OAG through reactivation of local neural progenitors. In addition, laser treatment could represent an appealing strategy to promote MSC-mediated progenitor cell recruitment and tissue repair in chronic diseases.

Denoising OCT videos based on temporal redundancy.

The identification of eye diseases and their progression often relies on a clear visualization of the anatomy and on different metrics extracted from Optical Coherence Tomography (OCT) B-scans. However, speckle noise hinders the quality of rapid OCT imaging, hampering the extraction and reliability of biomarkers that require time series. By synchronizing the acquisition of OCT images with the timing of the cardiac pulse, we transform a low-quality OCT video into a clear version by phase-wrapping each frame to the heart pulsation and averaging frames that correspond to the same instant in the cardiac cycle. Here, we compare the performance of our one-cycle denoising strategy with a deep-learning architecture, Noise2Noise, as well as classical denoising methods such as BM3D and Non-Local Means (NLM). We systematically analyze different image quality descriptors as well as region-specific metrics to assess the denoising performance based on the anatomy of the eye. The one-cycle method achieves the highest denoising performance, increases image quality and preserves the high-resolution structures within the eye tissues. The proposed workflow can be readily implemented in a clinical setting.

Optic Nerve Head Pulsatile Displacement in Open-Angle Glaucoma after Intraocular Pressure Reduction Measured by Optical Coherence Tomography: A Pilot Study.

This study investigated the effect of intraocular pressure (IOP) reduction on pulsatile displacement within the optic nerve head (ONH) in primary open-angle glaucoma (POAG) patients with and without axial myopia. Forty-one POAG patients (19 without myopia, 9 with axial myopia and 13 glaucoma with no intervention) participated. Swept-source optical coherence tomography (OCT) videos of the ONH were obtained before and after IOP-lowering treatment (medical or surgical) achieving a minimum IOP drop of 3 mmHg. A demons registration-based algorithm measured local pulsatile displacement maps within the ONH. Results demonstrated a significant 14% decrease in pulsatile tissue displacement in the non-myopic glaucoma cohort after intervention (p = 0.03). However, glaucoma patients with axial myopia exhibited no statistically significant change. There were no significant changes in the pulsatile ONH deformation in the control group. These findings suggest a potential link between IOP reduction and reduced pulsatile displacement within the ONH in POAG patients without myopia, offering new insights into the disease's pathophysiology and warranting further investigation into underlying mechanisms and clinical implications.

Ocular Rigidity and Current Therapy.

Purpose: Ocular rigidity (OR) is an important biomechanical parameter of the eye accounting for the material and geometrical properties of the corneoscleral shell.Methods: This study used a literature search to review the role of ocular rigidity and the application of potential therapies targeting this parameter in glaucoma and myopia.Conclusion: Biomechanical modeling and improved understanding of the biochemistry, and molecular arrangement of sclera and its constituents have yielded important insights. Recent developments, including that of a non-invasive and direct OR measurement method and improved ocular imaging techniques are helping to elucidate the role of OR in healthy and diseased eyes by facilitating large scale and longitudinal clinical studies. Improved understanding of OR at the initial stages of disease processes and its alterations with disease progression will undoubtedly propel research in the field. Furthermore, a better understanding of the determinants of OR is helping to refine novel therapeutic approaches which target and alter the biomechanical properties of the sclera in sight-threatening conditions such as glaucoma and myopia.

Ocular rigidity and neuroretinal damage in patients with vasospasticity: a pilot study.

OBJECTIVE: Evidence suggests that ocular blood flow dysregulation in patients with vasospasticity could occur in response to biomechanical stimuli, contributing to optic nerve head susceptibility in glaucoma. We evaluate the role of vasospasticity in the association between ocular rigidity (OR) and neuroretinal damage, hypothesizing that low OR correlates with greater glaucoma damage in patients with vasospasticity. DESIGN: Cross-sectional study. PARTICIPANTS: Patients with open-angle glaucoma (OAG), suspect discs, or no glaucoma. METHODS: OR was measured using a noninvasive, validated method developed by our group. Retinal nerve fibre layer (RNFL) and ganglion cell complex thicknesses were acquired using spectral domain optical coherence tomography. Vasospasticity was assessed by a standardized questionnaire that was based on existing validated questionnaires and adapted to our requirements. Atherosclerosis was evaluated based on Broadway and Drance's (1998) cardiovascular disease score. Correlations between OR and structural parameters were assessed in patients with vasospasticity and those with atherosclerosis. RESULTS: Of 118 patients with either OAG (n = 67), suspect discs (n = 26), or no glaucoma (n = 25) who were recruited consecutively, 10 were classified as having vasospasticity, and 37 as having atherosclerosis. In the vasospastic group, significant correlations were found between OR and the minimum ganglion cell complex thickness (rs = 0.681, p = 0.030), the average RNFL thickness (rs = 0.745, p = 0.013), and the RNFL in the temporal quadrant (rs = 0.772, p = 0.009), indicating more damage with lower OR. Similar trends were maintained when applying multiple testing correction; however, only the eighth RNFL clock hour corresponding to the inferior-temporal peripapillary region remained significantly correlated with OR in the vasospastic group (p = 0.015). In contrast, no correlation was found in the atherosclerotic group (p > 0.05). CONCLUSIONS: The findings of the current pilot study indicate a trend for more neuronal structural damage in less-rigid eyes of patients with vasospasticity, meaning that OR may play a greater role in glaucoma in vasospastic patients than in patients with atherosclerosis. Although these results provide interesting insight into the pathophysiology of OAG, further investigation is needed to confirm our observations.

Quantification of Hypotony Maculopathy Using Spectral-Domain Optical Coherence Tomography.

PRCIS: We provide a free-to-use, open-source algorithm to quantify macular hypotony based on optical coherence tomography (OCT) images. This numerical approach calculates a metric that measures the deviations of Bruch's membrane from a smooth ideal retinal layer. PURPOSE: Hypotony maculopathy is a recurrent complication of glaucoma surgical interventions in which extremely low intraocular pressure triggers changes in the shape of retinal layers. Abnormal folds can often be observed in the retina using standard fundoscopy, but OCT is particularly important to appreciate the severity of symptoms at different depths. Despite the need for metrics that could be used for the informed clinical decision to evaluate the progression and resolution of macular hypotony, algorithms that quantify the retinal folds are not available in the literature or included in clinical imaging equipment. The purpose of this work is to introduce a simple algorithm that can be used to assess hypotony maculopathy from OCT B-Scans and volumes and a free, open-source implementation. METHODS: The pipeline we present is based on a straightforward segmentation of Bruch's membrane complex. The principal idea of quantification is to compute a smoothed version of this complex and analyze the deviations from an ideal interface. Such deviations are then measured and added to create a metric that characterizes each OCT B-Scan. A full OCT volume reconstruction is thus characterized by the average metric obtained from all planes. RESULTS: We tested the metric we proposed against the assessment of 3 experts and obtained a very good correspondence, with Pearson correlation coefficients higher than 0.8. Furthermore, agreement with automatic analysis seemed better than between experts. We describe the pipeline in detail and illustrate the results with a group of patients, comparing baseline images, severe hypotony maculopathy, and a variety of outcomes. CONCLUSION: The tool we introduce and openly provide fills a clinical gap to quantitatively grade hypotony maculopathy. It offers a metric of relatively simple interpretation that can be used to help clinicians in cases where the regression of symptoms is not obvious to the naked eye. Our pilot study demonstrates reliable results, and an open-source implementation facilitates easy improvements to our algorithm.

Ocular rigidity and choroidal thickness changes in response to microgravity: A case study.

Purpose: To evaluate ocular rigidity and choroidal thickness changes in response to microgravity and the Valsalva maneuver in a private astronaut. Methods: Ophthalmological examination and Optical Coherence Tomography were performed before, during, and after space flight. Choroidal thickness was measured at all time points at rest and during the Valsalva maneuver. Ocular rigidity was obtained before and after flight using a non-invasive method enhanced with deep learning-based choroid segmentation. Results: Ocular rigidity decreased after space flight compared to baseline. There was an increase in average choroidal thickness during the Valsalva maneuver compared to the resting condition before, during, and after space flight, and such increase was greater when the Valsalva maneuver was performed during space flight. Conclusions and importance: The data indicates biomechanical changes to ocular tissues because of space flight and greater choroidal thickness increase. The findings could lead to a better understanding of space flight-associated neuro-ocular syndrome and may have repercussions for short duration missions in a nascent industry.

Mapping Pulsatile Optic Nerve Head Deformation Using OCT.

Objective: To develop a noninvasive technique to quantitatively assess the pulsatile deformation due to cardiac contractions of the optic nerve head (ONH). Design: Evaluation of a diagnostic test or technology. Participants: Healthy subjects with no history of refractive surgery, divided into 2 cohorts on the basis of their axial length (AL). Methods: We present a noninvasive technique to quantitatively assess the pulsatile deformation of the ONH tissue by combining high-frequency OCT imaging and widely available image processing algorithms. We performed a thorough validation of the approach, numerically and experimentally, evaluating the sensitivity of the method to artificially induced deformation and its robustness to different noise levels. We performed deformation measurements in cohorts of healthy (n = 9) and myopic (n = 5) subjects in different physiological strain conditions by calculating the amplitude of tissue displacement in both the primary position and abduction. The head rotation was measured using a goniometer. During imaging in abduction, the head was rotated 40° ± 3°, and subjects were instructed to direct their gaze toward the OCT visual target. Main Outcome Measures: Pulsatile tissue displacement maps. Results: The robustness of the method was assessed using artificial deformations and increasing noise levels. The results show acceptable absolute errors before the noise simulations grossly exaggerate image degradation. For the group of subjects with AL of < 25 mm (n = 9), the median pulsatile displacement of the ONH was 7.8 ± 1.3 µm in the primary position and 8.9 ± 1.2 µm in abduction. The Wilcoxon test showed a significant difference (P ≤ 0.005) between the 2 paired measures. Reproducibility was tested in 2 different sessions in 5 different subjects with the same intraocular pressure, and an intraclass correlation coefficient of 0.99 was obtained (P < 0.005). Conclusions: The computational pipeline demonstrated good reproducibility and had the capacity to accurately map the pulsatile deformation of the optic nerve. In a clinical setting, we detected physiological changes in normal subjects supporting its translation potential as a novel biomarker for the diagnosis and progression of optic nerve diseases.

Correlation of ocular rigidity with intraocular pressure spike after intravitreal injection of bevacizumab in exudative retinal disease.

BACKGROUND/AIMS: To evaluate the non-invasive measurement of ocular rigidity (OR), an important biomechanical property of the eye, as a predictor of intraocular pressure (IOP) elevation after anti-vascular endothelial growth factor (anti-VEGF) intravitreal injection (IVI). METHODS: Subjects requiring IVI of anti-VEGF for a pre-existing retinal condition were enrolled in this prospective cross-sectional study. OR was assessed in 18 eyes of 18 participants by measurement of pulsatile choroidal volume change using video-rate optical coherence tomography, and pulsatile IOP change using dynamic contour tonometry. IOP was measured using Tono-Pen XL before and immediately following the injection and was correlated with OR. RESULTS: The average increase in IOP following IVI was 19±9 mm Hg, with a range of 7-33 mm Hg. The Spearman correlation coefficient between OR and IOP elevation following IVI was 0.796 (p<0.001), showing higher IOP elevation in more rigid eyes. A regression line was also calculated to predict the IOP spike based on the OR coefficient, such that IOP spike=664.17 mm Hg·µL×OR + 4.59 mm Hg. CONCLUSION: This study shows a strong positive correlation between OR and acute IOP elevation following IVI. These findings indicate that the non-invasive measurement of OR could be an effective tool in identifying patients at risk of IOP spikes following IVI.

The Association Between Ocular Rigidity and Neuroretinal Damage in Glaucoma.

Purpose: Ocular rigidity (OR) is an important biomechanical property, thought to be relevant in the pathophysiology of open-angle glaucoma (OAG). This study aims to evaluate the relationship between OR and neuroretinal damage caused by glaucoma. Methods: One hundred eight subjects (22 with healthy eyes, 23 with suspect discs, and 63 with OAG) were included in this study. OR was measured using a noninvasive optical coherence tomography (OCT)-based method developed by our group. We also measured central corneal thickness (CCT), corneal hysteresis (CH), and corneal resistance factor (CRF). Pearson and partial correlations were performed to evaluate the relationship between OR and glaucomatous damage represented by ganglion cell complex (GCC), retinal nerve fiber layer (RNFL) thicknesses, and neuroretinal rim area. Results: Significant positive correlations were found between OR and minimum GCC thickness (r = 0.325, P = 0.001), average GCC thickness (r = 0.320, P = 0.002), rim area (r = 0.344, P < 0.001), and RNFL thickness in the superior (r = 0.225, P = 0.023), and inferior (r = 0.281, P = 0.004) quadrants. These correlations were generally greater than those found for CCT, CH, and CRF. Furthermore, no correlation was found between OR and corneal biomechanical parameters. After adjusting for age, sex, and ethnicity, significant correlations were found between OR and minimum and average GCC thickness (r = 0.357, P = 0.001 and r = 0.344, P = 0.001, respectively), rim area (r = 0.327, P = 0.001), average RNFL thickness (r = 0.331, P = 0.001), and RNFL thickness in the superior (r = 0.296, P = 0.003) and inferior (r = 0.317, P = 0.001) quadrants. Conclusions: In this study, we found a positive correlation between structural OCT-based parameters and OR, indicating more neuroretinal damage in eyes with lower OR. These findings could provide insight into the pathophysiology of OAG.

Quantitative and regional measurement of retinal blood flow in rats using N-isopropyl-p-[14C]-iodoamphetamine ([14C]-IMP).

Quantitative and regional measurement of retinal blood flow in rodents is of prime interest for the investigation of regulatory mechanisms of ocular circulation in physiological and pathological conditions. In this study, a quantitative autoradiographic method using N-isopropyl-p-(14)C-iodoamphetamine ([(14)C]-IMP), a diffusible radioactive tracer, was evaluated for its ability to detect changes in retinal blood perfusion during hypercapnia. Findings were compared to cerebral blood flow values measured simultaneously. Hypercapnia was induced in awaken Wistar rats by inhalation of 5% or 8% CO(2) in medical air for 5 min. [(14)C]-IMP (100 microCi/kg) was injected in the femoral vein over a 30 s period and the rats were sacrificed 2 min later. Blood flow was calculated from whole-mount retinae and 20 microm thick brain sections in discrete regions of interest by quantitative autoradiography or from digested samples of retina and brain by liquid scintillation counting. Retinal blood flow values measured with quantitative and regional autoradiography were higher in the central (108 +/- 20 ml/100 g/min) than in peripheral (84 +/- 15 ml/100 g/min) retina. These values were within the same range as cortical blood flow values (97 +/- 4 ml/100 g/min). The retinal blood flow values obtained on whole-mount retinae were validated by the sampling method. Hypercapnia significantly increased overall blood flow in the retina (24-53%) with a maximal augmentation in the peripheral region and in the brain (22-142%). The changes were stronger in the brain compared to retina (p = 0.016). These results demonstrate that retinal blood flow can be quantified using [(14)C]-IMP and compared with cerebral blood flow. This technique is a powerful tool to study how retinal blood flow is regulated in different regions of the rat retina.

Effectiveness and safety of dorzolamide-timolol alone or combined with latanoprost in open-angle glaucoma or ocular hypertension.

BACKGROUND: Treatment of glaucoma is aimed at reducing intraocular pressure (IOP) to prevent further damage to the optic nerve. For patients who do not respond to monotherapy, combination treatment may be effective in achieving therapeutic reduction or target IOP. OBJECTIVE: To evaluate the effectiveness and safety of dorzolamide 2% with timolol 0.5% alone or combined with latanoprost in reducing IOP in a real-world setting. METHODS: A prospective, open-label, multicenter, nonrandomized interventional study was designed. Three hundred fifty patients with primary open-angle glaucoma or ocular hypertension and uncontrolled IOP after latanoprost monotherapy for 4 or more weeks were treated with combination dorzolamide-timolol twice daily added to their existing latanoprost therapy (D/T-Add-On; n = 280) or dorzolamide-timolol twice daily monotherapy (D/T-Switch; n = 70). The primary effectiveness outcome measure was the change in IOP after 6 and 12 weeks of treatment. RESULTS: Of the total population, 313 patients completed this trial (248 D/T-Add-On; 65 D/T-Switch). After 12 weeks, the mean +/- SD IOP decrease was -6.3 +/- 3.6 mm Hg (-28.1%) and -5.8 +/- 4.9 mm Hg (-23.5%) in the D/T-Add-On and D/T-Switch groups, respectively (both p < 0.001). Therapeutic response rates (defined as IOP reduction >20%) after 12 weeks of treatment for the D/T-Add-On and the D/T-Switch groups were 66.4% (186/280) and 52.9% (37/70), respectively. There were 116 predominantly mild, nonserious adverse events attributed to the study drugs, reported by 86 (24.6%) patients. The most frequent adverse events were eye irritation (n = 42; 12.0%) and taste perversion (n = 15; 4.3%). No serious adverse events related to the study medications were reported. CONCLUSIONS: In patients with primary open-angle glaucoma or ocular hypertension and elevated IOP while on monotherapy with latanoprost, switching to dorzolamide-timolol or combining dorzolamide-timolol with latanoprost are effective and safe treatment options for reducing IOP and achieving therapeutic response.

The effects of systemic medications on ocular blood flow.

This article reviews the effects of systemic medications and some native vasoactive molecules on ocular blood flow (OBF). Some evidence exists for a positive effect of centrally acting calcium-channel blockers, nitric oxide precursors, adenosine, histamine, estrogens, and ginkgo biloba extract, while evidence for a negative effect on OBF exists for endothelin-1 and indomethacin. Some other molecules appear to have mixed effects, depending on the ocular vascular bed studied or the study protocol. In addition, medically induced changes in systemic blood pressure (BP) have an important impact on OBF, and the direction and magnitude of this effect may depend on the disease status of the patient and of the eye, as well as the absolute level of BP achieved. There are relatively few studies of the effects of systemic medications on OBF in glaucoma patients, and little is known of the long-term impact of such therapies on the preservation of optic nerve structure and function.

Surgical Outcome of Replacing a Failed Ahmed Glaucoma Valve by a Baerveldt Glaucoma Implant in the Same Quadrant in Refractory Glaucoma.

PURPOSE: The purpose of this study was to describe the surgical technique and outcomes in eyes that underwent surgery to replace a failed Ahmed valve by a Baerveldt glaucoma implant in the same quadrant. METHODS: This study was a retrospective case series of 9 patients. Parameters analyzed include age, glaucoma type, prior surgery, complications, intraocular pressure (IOP), visual acuity, and number of glaucoma medications before and after the surgery. Surgical success was defined as having either an IOP below 21 mm Hg or a 20% IOP reduction, with or without hypotensive agent. RESULTS: The mean follow-up duration was 47 months. After surgery, at the time of final follow-up, the mean IOP decreased from 29.9 mm Hg to 16.7 mm Hg (36% of mean IOP reduction; P=0.008). There was a significant reduction of hypotensive agents from a mean of 4.33 to 2.22 (P=0.02). The visual acuity did not have a significant deterioration (P=0.07). In the final visit, 5 of 9 patients met total success criteria and 2 patients were qualified successes. Two cases failed totally after 69 and 125 months of follow-up. The cumulative probability of total success after 6 months was 76% and this rate remained stable until the sixth year. One patient had bullous keratopathy. Two patients had early postoperative pressure spikes: the first patient was treated by trabeculectomy, and the second by vitrectomy. CONCLUSIONS: A replacement of the failed Ahmed glaucoma valve by a new Baerveldt glaucoma implant in the same quadrant can be a reasonable choice to control refractory glaucoma.

Patch graft using collagen matrix (Ologen) for glaucoma drainage device exposure in a patient with Boston Keratoprosthesis type 1.

PURPOSE: To report the first successfully treated case of recurrent tube exposure in a patient with the Boston Keratoprosthesis type 1 with a collagen matrix patch graft (Ologen). OBSERVATIONS: A 50 year-old female with a Boston Keratoprosthesis type 1 and a history of Axenfeld-Reiger syndrome presents to our department with recurrent glaucoma drainage device exposure in her left eye. After failed spontaneous closure with topical antibiotics and lubricants, she undergoes tube exposure repair using an Ologen patch graft. Surgery was successful and the patient did not have any recurrence up to last follow-up two years post-operatively. CONCLUSION: Collagen matrix patch graft seems to be advantageous in treating glaucoma tube exposure in the Boston KPro eye, which is often a more challenging entity to treat. IMPORTANCE: Collagen matrix patch graft could be considered as a primary patch graft in treating tube exposure in eyes with the Boston KPro.

Small-Gauge Endoscopy-Guided Pneumatic Anterior Hyaloid Detachment: A New Surgical Technique for Combined Pars Plana Vitrectomy and Pars Plana Glaucoma Drainage Implant.

BACKGROUND AND OBJECTIVE: Pars plana glaucoma drainage implant (GDI) occlusion is mainly related to entrapment of residual anterior vitreous gel in the implant. The aim of the present report is to describe a new surgical technique to induce pneumatic anterior hyaloid detachment in eyes with GDI. PATIENTS AND METHODS: This is a description of the surgical technique used to induce pneumatic anterior hyaloid detachment. RESULTS: The technique was used in two cases. The first patient had secondary Ahmed valve (New World Medical, Rancho Cucamonga, CA) obstruction secondary to anterior vitreous entrapment; the second patient had neovascular glaucoma secondary to proliferative diabetic retinopathy and underwent pars plana GDI implantation. CONCLUSION: Endoscopy-assisted anterior hyaloid detachment allows for complete removal of anterior hyaloid and decreases the risk of secondary implant obstruction. [Ophthalmic Surg Lasers Imaging Retina. 2018;49:48-50.].

Relationship between central corneal thickness and changes of optic nerve head topography and blood flow after intraocular pressure reduction in open-angle glaucoma and ocular hypertension.

OBJECTIVES: To investigate changes in optic nerve head topography and blood flow after therapeutic intraocular pressure reduction and to correlate them with central corneal thickness. METHODS: Sixteen patients with open-angle glaucoma and 16 patients with ocular hypertension underwent Heidelberg retina tomography and scanning laser Doppler flowmetry in 1 eye before and at least 2 months after a mean 35% sustained therapeutic reduction in intraocular pressure. Patients were assigned to a thin or thick group based on their median central corneal thickness. RESULTS: Compared with 16 patients with thick corneas (mean +/- SD central corneal thickness, 587 +/- 31 microm), the 16 patients with thin corneas (518 +/- 32 microm) had greater reductions in mean (36 +/- 32 vs 4 +/- 36 microm, P = .003) and in maximum cup depth (73 +/- 107 vs 4 +/- 89 microm, P = .02). These changes were not statistically significantly different between the patients with open-angle glaucoma and those with ocular hypertension. Smaller mean +/- SD improvements in neuroretinal rim blood flow were seen in patients with thinner corneas compared with those with thicker corneas (35 +/- 80 vs 110 +/- 111 arbitrary units, P = .04). CONCLUSION: Patients with open-angle glaucoma and ocular hypertension with thinner corneas show significantly greater shallowing of the cup, a surrogate marker for lamina cribrosa displacement (compliance), and smaller improvements of neuroretinal rim blood flow after intraocular pressure reduction.

Maladaptive coping strategies and glaucoma progression.

The identification of modifiable risk factors for glaucoma progression is needed. Our objective was to determine whether maladaptive coping styles are associated with recent glaucoma progression or worse visual field mean deviation.A hospital-based case-control study was conducted in the Glaucoma Service of Maisonneuve-Rosemont Hospital in Montreal, Canada. Patients with primary open angle glaucoma or normal tension glaucoma with ≥4 years of follow-up and ≥5 Humphrey visual fields were included. Cases had recent visual field progression as defined according to the Early Manifest Glaucoma Trial pattern change probability maps. Controls had stable visual fields. The Brief Cope questionnaire, a 28-item questionnaire about 14 different ways of coping with the stress of a chronic disease, was asked. Questions were also asked about demographic and medical factors, and the medical chart was examined. Outcomes included glaucoma progression (yes, no) and visual field mean deviation. Logistic and linear regressions were used.A total of 180 patients were included (82 progressors and 98 nonprogressors). Although none of the 14 coping scales were associated with glaucoma progression (P > 0.05), higher denial was correlated with worse visual field mean deviation (r = -0.173, P = 0.024). In a linear regression model including age, sex, education, depression, intraocular pressure, and family history of glaucoma, greater levels of denial (ß = -1.37, 95% confidence interval [CI] -2.32, -0.41), Haitian ethnicity (ß = -7.78, 95% CI -12.52, -3.04), and the number of glaucoma medications (ß = -1.20, 95% CI -2.00, -0.38) were statistically significantly associated with visual field mean deviation.The maladaptive coping mechanism of denial was a risk factor for worse visual field mean deviation. Further prospective research will be required to verify the pathways by which denial may exert an effect on glaucomatous visual field loss.