Proteomic Interactions in the Mouse Vitreous-Retina Complex

Purpose

Human vitreoretinal diseases are due to presumed abnormal mechanical interactions between the vitreous and retina, and translational models are limited. This study determined whether nonstructural proteins and potential retinal biomarkers were expressed by the normal mouse vitreous and retina.

Methods

Vitreous and retina samples from mice were collected by evisceration and analyzed by liquid chromatography-tandem mass spectrometry. Identified proteins were further analyzed for differential expression and functional interactions using bioinformatic software.

Results

We identified 1,680 unique proteins in the retina and 675 unique proteins in the vitreous. Unbiased clustering identified protein pathways that distinguish retina from vitreous including oxidative phosphorylation and neurofilament cytoskeletal remodeling, whereas the vitreous expressed oxidative stress and innate immunology pathways. Some intracellular protein pathways were found in both retina and vitreous, such as glycolysis and gluconeogenesis and neuronal signaling, suggesting proteins might be shuttled between the retina and vitreous. We also identified human disease biomarkers represented in the mouse vitreous and retina, including carbonic anhydrase-2 and 3, crystallins, macrophage inhibitory factor, glutathione peroxidase, peroxiredoxins, S100 precursors, and von Willebrand factor.

Conclusions

Our analysis suggests the vitreous expresses nonstructural proteins that functionally interact with the retina to manage oxidative stress, immune reactions, and intracellular proteins may be exchanged between the retina and vitreous. This novel proteomic dataset can be used for investigating human vitreoretinopathies in mouse models. Validation of vitreoretinal biomarkers for human ocular diseases will provide a critical tool for diagnostics and an avenue for therapeutics.     

High Dose Rate versus Low Dose Rate Brachytherapy for Oral Cancer – A Meta-Analysis of Clinical Trials

Objective

To compare the efficacy and safety of high dose rate (HDR) and low dose rate (LDR) brachytherapy in treating early-stage oral cancer.

Data Sources

A systematic search of MEDLINE, EMBASE and Cochrane Library databases, restricted to English language up to June 1, 2012, was performed to identify potentially relevant studies.

Study Selection

Only randomized controlled trials (RCT) and controlled trials that compared HDR to LDR brachytherapy in treatment of early-stage oral cancer (stages I, II and III) were of interest.

Data Extraction and Synthesis

Two investigators independently extracted data from retrieved studies and controversies were solved by discussion. Meta-analysis was performed using RevMan 5.1. One RCT and five controlled trials (607 patients: 447 for LDR and 160 for HDR) met the inclusion criteria. The odds ratio showed no statistically significant difference between LDR group and HDR group in terms of local recurrence (OR = 1.12, CI 95% 0.62–2.01), overall mortality (OR = 1.01, CI 95% 0.61–1.66) and Grade 3/4 complications (OR = 0.86, CI 95% 0.52–1.42).

Conclusions

This meta-analysis indicated that HDR brachytherapy was a comparable alternative to LDR brachytherapy in treatment of oral cancer. HDR brachytherapy might become a routine choice for early-stage oral cancer in the future.     

Lens Subluxation after Plasmin and SF6 Injections in Rabbit Eyes

Purpose

To investigate the rate of lens subluxation following plasmin and/or SF₆ injections in eyes, and whether a subsequent elevated level of vascular endothelial growth factor (VEGF) and vitreous tap would aggravate subluxation.

Methods

Four groups of rabbits were used. Group 1 received an intravitreal injection (IVI) of plasmin and SF₆ in the right eye; group 2 received an IVI of plasmin in the right eye; group 3 received an IVI of SF₆ in the right eye; and group 4 received an IVI of balanced salt solution in the right eye. After treatment, IVIs of VEGF were given and vitreous tap was performed three times, followed by clinical observation of lens subluxation and scanning electronic microscope evaluation of the zonular fibers.

Results

After IVIs of plasmin and SF₆, and VEGF and vitreous tap had been performed one to three times, lens subluxation was noted in 0%, 43%, 71%, 71%, and 86% of the eyes in group 1. After IVIs of plasmin, VEGF, and vitreous tap had been performed one to three times, lens subluxation was noted in 11%, 22%, 44%, 44%, and 67% of the eyes in group 2. The eyes in group 3 and 4 did not show signs of lens subluxation after VEGF IVIs and vitreous tap. Histology confirmed zonular fiber damage in the eyes treated with plasmin.

Conclusions

The incidence of lens subluxation increased following plasmin injections in the eyes, and this was aggravated by the subsequent high VEGF level in the eyes and vitreous tapping. Zonular fibers were disrupted following plasmin treatment. These effects should be kept in mind when using plasmin enzymes in patients with vitreoretinal abnormalities.     

Hyperfractionated high-dose rate brachytherapy in the treatment of oral tongue cancer

Background

Low-dose rate brachytherapy is a well established treatment modality of oral cancer. Data about high-dose rate (HDR) brachytherapy are still sparse with various fractionation schedules and heterogeneous results.

Aim

The aim of our retrospective study was to evaluate the results of HDR brachytherapy with doses of 3 Gy twice daily.

Patients and methods

Twenty patients with squamous cell tongue cancer were treated in the years 2001–2009 by exclusive HDR BT 18 × 3 Gy twice daily. The plastic tube technique was used. Median follow up was 47 months (7.8–118) since brachytherapy.

Results

The local and locoregional control was 85% and 68%, respectively. Bone necrosis developed in one case treated without mandibular shielding and soft tissue necrosis in 2 cases.

Conclusion

It can be concluded that HDR brachytherapy with 18 × 3 Gy twice daily is safe with promising local control. The risk of nodal recurrences is substantial.     

The histopathologic evaluation of soft tissue changes in rabbit extremity after different dose-fractionation schemes of interstitial high dose rate (HDR) brachytherapy

Background

The use of HDR in the treatment of soft tissue sarcoma had been on the rise. However, there was limited study to evaluate the effect of different fractionation schemes on soft tissue and the optimal HDR scheme.

Aims

We aimed to assess the histopathologic changes on soft tissue after different HDR brachytherapy doses.

Methods

The subjects were divided into three groups. Each group included 10 limbs. Group A had only an applicator without radiation, group B received a total of 24 Gy at 6 Gy per fraction, twice a day, and group C received a total of 13.5 Gy in a single fraction. The histopathologic findings were grouped into soft tissue pathology-1 (edema, inflammation, endothelial proliferation, necrosis) and soft tissue pathology-2 (atrophy, calcification, vascular hyalinization, fibrosis) (STP-1–2).

Results

The highest mean grade values of STP-1 and STP-2 were observed in group C (0.95 and 1.45) in comparison to group A (0.45 and 0.85) and group B (0.65 and 0.9). The difference in STP-1 was found significant only between groups A and C and the difference in STP-2 was found both between groups A and C and groups B and C.

Conclusion

In our experimental study it was shown that the fractionated interstitial HDR had both lower rate and severity of toxicity in comparison to a single high dose fraction. Before using a single fractionated regimen in the clinic, the increased morbidity related to the irreversible early toxicities or progressive late toxicities should be kept in mind.     

Clinical Features and Course of Ocular Toxocariasis in Adults

Purpose

To investigate the clinical features, clinical course of granuloma, serologic findings, treatment outcome, and probable infection sources in adult patients with ocular toxocariasis (OT).

Methods

In this retrospective cohort study, we examined 101 adult patients diagnosed clinically and serologically with OT. Serial fundus photographs and spectral domain optical coherence tomography images of all the patients were reviewed. A clinic-based case-control study on pet ownership, occupation, and raw meat ingestion history was performed to investigate the possible infection sources.

Results

Among the patients diagnosed clinically and serologically with OT, 69.6% showed elevated immunoglobulin E (IgE) levels. Granuloma in OT involved all retinal layers and several vitreoretinal comorbidities were noted depending on the location of granuloma: posterior pole granuloma was associated with epiretinal membrane and retinal nerve fiber layer defects, whereas peripheral granuloma was associated with vitreous opacity. Intraocular migration of granuloma was observed in 15 of 93 patients (16.1%). Treatment with albendazole (400 mg twice a day for 2 weeks) and corticosteroids (oral prednisolone; 0.5–1 mg/kg/day) resulted in comparable outcomes to patients on corticosteroid monotherapy; however, the 6-month recurrence rate in patients treated with combined therapy (17.4%) was significantly lower than that in patients treated with corticosteroid monotherapy (54.5%, P = 0.045). Ingestion of raw cow liver (80.8%) or meat (71.2%) was significantly more common in OT patients than healthy controls.

Conclusions

Our study discusses the diagnosis, treatment, and prevention strategies for OT. Evaluation of total IgE, in addition to anti-toxocara antibody, can assist in the serologic diagnosis of OT. Combined albendazole and corticosteroid therapy may reduce intraocular inflammation and recurrence. Migrating feature of granuloma is clinically important and may further suggest the diagnosis of OT. Clinicians need to carefully examine comorbid conditions for OT. OT may be associated with ingestion of uncooked meat, especially raw cow liver, in adult patients.     

Impact of Robotic Assistance on Precision of Vitreoretinal Surgical Procedures

Purpose

To elucidate the merits of robotic application for vitreoretinal maneuver in comparison to conventional manual performance using an in-vitro eye model constructed for the present study.

Methods

Capability to accurately approach the target on the fundus, to stabilize the manipulator tip just above the fundus, and to perceive the contact of the manipulator tip with the fundus were tested. The accuracies were compared between the robotic and manual control, as well as between ophthalmologists and engineering students.

Results

In case of manual control, ophthalmologists were superior to engineering students in all the 3 test procedures. Robotic assistance significantly improved accuracy of all the test procedures performed by engineering students. For the ophthalmologists including a specialist of vitreoretinal surgery, robotic assistance enhanced the accuracy in the stabilization of manipulator tip (from 90.9 µm to 14.9 µm, P = 0.0006) and the perception of contact with the fundus (from 20.0 mN to 7.84 mN, P = 0.046), while robotic assistance did not improve pointing accuracy.

Conclusions

It was confirmed that telerobotic assistance has a potential to significantly improve precision in vitreoretinal procedures in both experienced and inexperienced hands.     

Volumetric Breast Density Estimation from Full-Field Digital Mammograms: A Validation Study

Objectives

To objectively evaluate automatic volumetric breast density assessment in Full-Field Digital Mammograms (FFDM) using measurements obtained from breast Magnetic Resonance Imaging (MRI).

Material and Methods

A commercially available method for volumetric breast density estimation on FFDM is evaluated by comparing volume estimates obtained from 186 FFDM exams including mediolateral oblique (MLO) and cranial-caudal (CC) views to objective reference standard measurements obtained from MRI.

Results

Volumetric measurements obtained from FFDM show high correlation with MRI data. Pearson’s correlation coefficients of 0.93, 0.97 and 0.85 were obtained for volumetric breast density, breast volume and fibroglandular tissue volume, respectively.

Conclusions

Accurate volumetric breast density assessment is feasible in Full-Field Digital Mammograms and has potential to be used in objective breast cancer risk models and personalized screening.     

Evaluation of Gafchromic EBT2 film for the measurement of anisotropy function for high-dose-rate 192Ir brachytherapy source with respect to thermoluminescent dosimetry

Aim

The aim of this work was to assess the suitability of the use of a Gafchromic EBT2 film for the measurement of anisotropy function for microSelectron HDR ¹⁹²Ir (classic) source with a comparative dosimetry method using a Gafchromic EBT2 film and thermoluminescence dosimeters (TLDs).

Background

Sealed linear radiation sources are commonly used for high dose rate (HDR) brachytherapy treatments. Due to self-absorption and oblique filtration of radiation in the source capsule material, an inherent anisotropy is present in the dose distribution around the source which can be described by a measurable two-dimensional anisotropy function, F(r, θ).

Materials and methods

Measurements were carried out in a specially designed and locally fabricated PMMA phantom with provisions to accommodate miniature LiF TLD rods and EBT2 film dosimeters at identical radial distances with respect to the ¹⁹²Ir source.

Results

The data of anisotropy function generated by the use of the Gafchromic EBT2 film method are in agreement with their TLD measured values within 4%. The produced data are also consistent with their experimental and Monte Carlo calculated results for this source available in the literature.

Conclusion

Gafchromic EBT2 film was found to be a feasible dosimeter in determining anisotropy in the dose distribution of ¹⁹²Ir source. It offers high resolution and is a viable alternative to TLD dosimetry at discrete points. The method described in this paper is useful for comparing the performances of detectors and can be applied for other brachytherapy sources as well.     

Effects of a Seven Day Overload-Period of High-Intensity Training on Performance and Physiology of Competitive Cyclists

Objectives

Competitive endurance athletes commonly undertake periods of overload training in the weeks prior to major competitions. This investigation examined the effects of two seven-day high-intensity overload training regimes (HIT) on performance and physiological characteristics of competitive cyclists.

Design

The study was a matched groups, controlled trial.

Methods

Twenty-eight male cyclists (mean ± SD, Age: 33±10 years, Mass 74±7 kg, VO₂ peak 4.7±0.5 L·min⁻¹) were assigned to a control group or one of two training groups for seven consecutive days of HIT. Before and after training cyclists completed an ergometer based incremental exercise test and a 20-km time-trial. The HIT sessions were ∼120 minutes in duration and consisted of matched volumes of 5, 10 and 20 second (short) or 15, 30 and 45 second (long) maximal intensity efforts.

Results

Both the short and long HIT regimes led to significant (p<0.05) gains in time trial performance compared to the control group. Relative to the control group, the mean changes (±90% confidence limits) in time-trial power were 8.2%±3.8% and 10.4%±4.3% for the short and long HIT regimes respectively; corresponding increases in peak power in the incremental test were 5.5%±2.7% and 9.5%±2.5%. Both HIT (short vs long) interventions led to non-significant (p>0.05) increases (mean ± SD) in VO₂ peak (2.3%±4.7% vs 3.5%±6.2%), lactate threshold power (3.6%±3.5% vs 2.9%±5.3%) and gross efficiency (3.2%±2.4% vs 5.1%±3.9%) with only small differences between HIT regimes.

Conclusions

Seven days of overload HIT induces substantial enhancements in time-trial performance despite non-significant increases in physiological measures with competitive cyclists.     

Histone Deacetylase Inhibitors Selectively Target Homology Dependent DNA Repair Defective Cells and Elevate Non-Homologous Endjoining Activity

Background

We have previously used the ATAD5-luciferase high-throughput screening assay to identify genotoxic compounds with potential chemotherapeutic capabilities. The successful identification of known genotoxic agents, including the histone deacetylase inhibitor (HDACi) trichostatin A (TSA), confirmed the specificity of the screen since TSA has been widely studied for its ability to cause apoptosis in cancer cells. Because many cancers have acquired mutations in DNA damage checkpoints or repair pathways, we hypothesized that these cancers may be susceptible to treatments that target compensatory pathways. Here, we used a panel of isogenic chicken DT40 B lymphocyte mutant and human cell lines to investigate the ability of TSA to define selective pathways that promote HDACi toxicity.

Results

HDACi induced a DNA damage response and reduced viability in all repair deficient DT40 mutants although ATM-nulls were least affected. The most dramatic sensitivity was observed in mutants lacking the homology dependent repair (HDR) factor BLM or the non-homologous end-joining (NHEJ) and HDR factors, KU/RAD54, suggesting an involvement of either HDR or NHEJ in HDACi-induced cell death. To extend these findings, we measured the frequencies of HDR and NHEJ after HDACi treatment and monitored viability in human cell lines comparably deficient in HDR or NHEJ. Although no difference in HDR frequency was observed between HDACi treated and untreated cells, HDR-defective human cell lines were clearly more sensitive than wild type. Unexpectedly, cells treated with HDACis showed a significantly elevated NHEJ frequency.

Conclusions

HDACi targeting drugs induced significant increases in NHEJ activity in human cell lines but did not alter HDR frequency. Moreover, HDR is required for cellular resistance to HDACi therapy; therefore, NHEJ does not appear to be a critical axis for HDACi resistance. Rather, HDACi compounds induced DNA damage, most likely double strand breaks (DSBs), and HDR proficiency is correlated with cell survival.     

Long term results of HDR brachytherapy in men older than 75 with localized carcinoma of the prostate

Background

Prostate cancer is an illness with a high incidence, especially among older men. The choice of a treatment option among men above 75 years is, however, not clear. Radical prostatectomy in this age group is connected with a relatively high morbidity. A further possibility of curative treatment is radiotherapy which can be administered in the form of external beam or in combination with high dose rate (HDR) brachytherapy.

Aim

The aim of our work was to evaluate how HDR brachytherapy is tolerated among men older than 75 and how associated diseases can influence the tolerance to this treatment. Of interest to us were the treatment results and mortality from other diseases.

Materials and methods

We analyzed a sample of 20 men above 75 years old (median 77 years) who were undergoing treatment by a combination of external radiotherapy and brachytherapy. Sixteen (80%) of them had prostate cancer with an intermediate and high risk of recurrence, four had low risk prostate cancer. Most patients, 14 (70%), had less than two comorbidities.

Results

The median observation period was 57 months. No perioperative complications were recorded. Acute genitourinary toxicity (GU) to a maximum grade of 1–2 manifested in 60% of cases. Acute gastrointestinal toxicity (GIT) was observed only at grade 1 and in 25% of cases. Late GU toxicity occurred in 35% of patients, with only one showing grade 3; late GIT toxicity was recorded at grade 1 only in 3 patients (15%). 70% of the men lived longer than 3 years after treatment, at present, 50% lived more than 5 years. Long-term biochemical remission was achieved in 18 patients (90%).

Conclusions

HDR BRT is possible and well-tolerated in older men above 75 years in good condition and without serious intercurrence.Well-selected older patients with higher-risk tumours and without serious comorbidities undoubtedly benefit from radical treatment when compared with watchful waiting.     

Angiogenic Potential of Vitreous from Proliferative Diabetic Retinopathy and Eales' Disease Patients

Purpose

Proliferative Diabetic Retinopathy (PDR) and Eales'' Disease (ED) have different aetiologies although they share certain common clinical symptoms including pre-retinal neovascularization. Since there is a need to understand if the shared end-stage angiogenic pathology of PDR and ED is driven by common stimulating factors, we have studied the cytokines contained in vitreous from both patient groups and analyzed the angiogenic potential of these samples in vitro.

Material and Methods

Vitreous samples from patients with PDR (n = 13) and ED (n = 5) were quantified for various cytokines using a cytokine biochip array and sandwich ELISA. An additional group of patients (n = 5) with macular hole (MH) was also studied for comparison. To determine the angiogenic potential of these vitreous samples, they were analyzed for their ability to induce tubulogenesis in human microvascular endothelial cells. Further, the effect of anti-VEGF (Ranibizumab) and anti-IL-6 antibodies were studied on vitreous-mediated vascular tube formation.

Results

Elevated levels of IL-6, IL-8, MCP-1 and VEGF were observed in vitreous of both PDR and ED when compared to MH. PDR and ED vitreous induced greater levels of endothelial cell tube formation compared to controls without vitreous (P<0.05). When VEGF in vitreous was neutralized by clinically-relevant concentrations of Ranibizumab, tube length was reduced significantly in 5 of 6 PDR and 3 of 5 ED samples. Moreover, when treated with IL-6 neutralizing antibody, apparent reduction (71.4%) was observed in PDR vitreous samples.

Conclusions

We have demonstrated that vitreous specimens from PDR and ED patients share common elevations of pro-inflammatory and pro-angiogenic cytokines. This suggests that common cytokine profiles link these two conditions.     

High Dynamic Range Processing for Magnetic Resonance Imaging

Purpose

To minimize feature loss in T₁- and T₂-weighted MRI by merging multiple MR images acquired at different T_R and T_E to generate an image with increased dynamic range.

Materials and Methods

High Dynamic Range (HDR) processing techniques from the field of photography were applied to a series of acquired MR images. Specifically, a method to parameterize the algorithm for MRI data was developed and tested. T₁- and T₂-weighted images of a number of contrast agent phantoms and a live mouse were acquired with varying T_R and T_E parameters. The images were computationally merged to produce HDR-MR images. All acquisitions were performed on a 7.05 T Bruker PharmaScan with a multi-echo spin echo pulse sequence.

Results

HDR-MRI delineated bright and dark features that were either saturated or indistinguishable from background in standard T₁- and T₂-weighted MRI. The increased dynamic range preserved intensity gradation over a larger range of T₁ and T₂ in phantoms and revealed more anatomical features in vivo.

Conclusions

We have developed and tested a method to apply HDR processing to MR images. The increased dynamic range of HDR-MR images as compared to standard T₁- and T₂-weighted images minimizes feature loss caused by magnetization recovery or low SNR.     

Rapid Diagnostic Algorithms as a Screening Tool for Tuberculosis: An Assessor Blinded Cross-Sectional Study

Background

A major obstacle to effectively treat and control tuberculosis is the absence of an accurate, rapid, and low-cost diagnostic tool. A new approach for the screening of patients for tuberculosis is the use of rapid diagnostic classification algorithms.

Methods

We tested a previously published diagnostic algorithm based on four biomarkers as a screening tool for tuberculosis in a Central European patient population using an assessor-blinded cross-sectional study design. In addition, we developed an improved diagnostic classification algorithm based on a study population at a tertiary hospital in Vienna, Austria, by supervised computational statistics.

Results

The diagnostic accuracy of the previously published diagnostic algorithm for our patient population consisting of 206 patients was 54% (CI: 47%–61%). An improved model was constructed using inflammation parameters and clinical information. A diagnostic accuracy of 86% (CI: 80%–90%) was demonstrated by 10-fold cross validation. An alternative model relying solely on clinical parameters exhibited a diagnostic accuracy of 85% (CI: 79%–89%).

Conclusion

Here we show that a rapid diagnostic algorithm based on clinical parameters is only slightly improved by inclusion of inflammation markers in our cohort. Our results also emphasize the need for validation of new diagnostic algorithms in different settings and patient populations.     

A Bayesian Meta-Analysis on Prevalence of Hepatitis B Virus Infection among Chinese Volunteer Blood Donors

Background

Although transfusion-transmitted infection of hepatitis B virus (HBV) threatens the blood safety of China, the nationwide circumstance of HBV infection among blood donors is still unclear.

Objectives

To comprehensively estimate the prevalence of HBsAg positive and HBV occult infection (OBI) among Chinese volunteer blood donors through bayesian meta-analysis.

Methods

We performed an electronic search in Pub-Med, Web of Knowledge, Medline, Wanfang Data and CNKI, complemented by a hand search of relevant reference lists. Two authors independently extracted data from the eligible studies. Then two bayesian random-effect meta-analyses were performed, followed by bayesian meta-regressions.

Results

5957412 and 571227 donors were identified in HBsAg group and OBI group, respectively. The pooled prevalence of HBsAg group and OBI group among donors is 1.085% (95% credible interval [CI] 0.859%∼1.398%) and 0.094% (95% CI 0.0578%∼0.1655%). For HBsAg group, subgroup analysis shows the more developed area has a lower prevalence than the less developed area; meta-regression indicates there is a significant decreasing trend in HBsAg positive prevalence with sampling year (beta = −0.1202, 95% −0.2081∼−0.0312).

Conclusion

Blood safety against HBV infection in China is suffering serious threats and the government should take effective measures to improve this situation.     

Prevalence of Hypertension in Rural Areas of China: A Meta-Analysis of Published Studies

Background

Hypertension is one of the leading causes of disease burden across the world. In China, the latest nationwide survey of prevalence of hypertension was ten year ago, and data in rural areas is little known. More information about hypertension prevalence could help to improve overall antihypertensive health care. We aimed to estimate the pooled prevalence of hypertension in rural areas of China.

Methods

Comprehensive electronic searches of PubMed, Web of Knowledge, Chinese Web of Knowledge, Wangfang, Weipu and SinoMed databases were conducted to identify any study in each database published from January 1, 2004 to December 31, 2013, reporting the prevalence of hypertension in Chinese rural areas. Prevalence estimates were stratified by age, area, sex, publication year, and sample size. All statistical calculations were made using the Stata Version 11.0 (College Station, Texas) and Statsdirect Version 2.7.9.

Results

We identified 124 studies with a total population of 3,735,534 in the present meta-analysis. Among people aged 18 years old in Chinese rural areas, the summarized prevalence is 22.81% (19.41%–26.41%). Subgroup analysis shows the following results: for male 24.46% (21.19%–27.89%, for female 22.17% (18.25%–26.35%). For 2004–2006: 18.94% (14.41%–23.94%), for 2007–2009, 21.24% (15.98%–27.01%) for 2010–2013: 26.68%, (20.79%–33.02%). For Northern region 25.76% (22.36%–29.32%), for Southern region 19.30%, (15.48%–24.08%).

Conclusions

The last decade witnessed the growth in prevalence of hypertension in rural areas of China compared with the fourth national investigation, which has climbed the same level as the urban area. Guidelines for screening and treatment of hypertension in rural areas need to be given enough attention.     

Assessment of Choroidal Thickness in Healthy and Glaucomatous Eyes Using Swept Source Optical Coherence Tomography

Purpose

To evaluate choroidal thickness (CT) in healthy and glaucomatous eyes using Swept Source Optical Coherence Tomography (SS-OCT).

Methods

A cross-sectional observational study of 216 eyes of 140 subjects with glaucoma and 106 eyes of 67 healthy subjects enrolled in the Diagnostic Innovations in Glaucoma Study. CT was assessed from wide-field (12×9 mm) SS-OCT scans. The association between CT and potential confounding variables including age, gender, axial length, intraocular pressure, central corneal thickness and ocular perfusion pressure was examined using univariable and multivariable regression analyses.

Results

Overall CT was thinner in glaucomatous eyes with a mean (± standard deviation) of 157.7±48.5 µm in glaucoma compared to 179.9±36.1 µm in healthy eyes (P<0.001). The choroid was thinner in both the peripapillary and macular regions in glaucoma compared to controls. Mean peripapillary CT was 154.1±44.1 µm and 134.0±56.9 µm (P<0.001) and macular CT 199.3±46.1 µm and 176.2±57.5 µm (P<0.001) for healthy and glaucomatous eyes respectively. However, older age (P<0.001) and longer axial length (P<0.001) were also associated with thinner choroid and when differences in age and axial length between glaucomatous and healthy subjects were accounted for, glaucoma was not significantly associated with CT. There was also no association between glaucoma severity and CT.

Conclusions

Glaucoma was not associated with CT measured using SS-OCT; however, older age and longer axial length were associated with thinner choroid so should be considered when interpreting CT measurements.