Impact of Valsalva maneuver on central choroid, central macula, and disk fiber layer thickness among high myopic and hyperopic patients

Impact of the Valsalva manoeuvre on the choroid: A systematic review with meta-analyses

A variety of daily activities can intentionally or unintentionally cause the Valsalva manoeuvre, which induces a physiological response of elevated peripheral venous pressure. Studies have speculated that it may ultimately affect the choroidal anatomy. This is particularly important from a clinical point-of-view since patients occasionally hold their breath while undergoing macular optical coherence tomography (OCT). In this study, we systematically reviewed the literature to understand the impact of the Valsalva manoeuvre on the choroid and conducted meta-analyses on the changes induced in the subfoveal choroidal thickness (SFCT) and the choroidal vascularity index (CVI). We searched 12 literature databases for studies in healthy participants undergoing Valsalva manoeuvre with choroidal OCT scans before and during the manoeuvre. Seven studies with a total of 444 eyes of 279 individuals were eligible for the review. The Valsalva manoeuvre led to a statistically significant but numerically small increase in the SFCT of 6.5 μm (95% CI: 1.6-11.4 μm; p = 0.01) and a statistically significant increase in the CVI of 1.48 (95% CI: 1.23-1.73; p = 0.0002). Thus, the Valsalva manoeuvre has a measurable impact on the choroid, and we recommend careful observation of how the patient sits and behaves behind the OCT scanner while scanning in order to allow accurate measurements of the choroid for diagnosis and monitoring.

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.

Impact of Valsalva Manuever on Choroidal Vascularity Index, Central Choroid and Central Macula

BACKGROUND

Evaluation of the effects of the Valsalva maneuver on choroidal vascularity index, central choroid and the central macula.

METHODS

Eighty-four eyes of 42 healthy volunteers were evaluated in this prospective study. The central macular layer was assesed using the retinal map mode of the spectral domain OCT (Optovue RTVue XR, Optovue Inc., Fremont, CA), OCT images taken in the Enhanced Deep Imaging mode were transferred to the Image J program and the choroidal vascularity index and subfoveal choroidal thickness measurements were calculated.

RESULTS

The mean age of volunteers was 35.4±7.2 years. Choroidal vascularity index, subfoveal choroidal thickness, central macular thickness and intraocular pressure measurements in the resting position were 67.99±2.1%, 337.73±12.8 µm, 232.04± 8.4 µm, 14.04±2.5 mmHg respectively, during Valsalva maneuver were 69.44±2.1%, 351.15±12.2 µm, 238.84±8.1 µm, 19.4±5.4 mmHg respectively. There was a statistically significant increase during valsalva maneuver.

CONCLUSION

The valsalva maneuver may cause temporary changes in choroidal vascularity index, subfoveal choroidal thickness, central macular thickness and intraocular pressure. These measurements may be misinterpreted in situations where patients breath-hold inadvertantly causing the Valsalva maneuver.

Choroidal vascularity index changes during the Valsalva manoeuvre in healthy volunteers

PURPOSE

To evaluate the effects of the Valsalva manoeuvre (VM) on the choroidal vascularity index (CVI) in healthy volunteers.

METHODS

This prospective, cross-sectional study included 60 eyes of 30 healthy volunteers. Enhanced depth imaging-optical coherence tomography scans of both eyes involving the fovea were taken, and a 1500 μm subfoveal choroidal area was selected for image binarization with open-access Fiji software. The binarized image was segmented into the stromal area (SA) and luminal area (LA), and CVI was calculated as the ratio (%) of LA to the total choroidal area (TCA). CVI, subfoveal choroidal thickness (SFCT), IOP, systolic and diastolic blood pressure were evaluated at rest and during the VM.

RESULTS

During the VM, a mean ± standard deviation increase in LA (0.02 ± 0.05 mm² , p < 0.001) and CVI (1.72 ± 2.83%, p < 0.001) was observed, whereas SA (-0.02 ± 0.05 mm² , p < 0.001) decreased. There was no significant change in TCA (0.00 ± 0.03 mm² , p = 0.55) or SFCT (1.05 ± 10.92 μm, p = 0.46). There was a moderate positive correlation between the spherical equivalent refractive error (SE) and SFCT both at rest and during VM (r₅₈  = 0.49, p < 0.0005 and r₅₈  = 0.49, p < 0.0005, respectively). However, there was no significant correlation between SE and CVI either at rest or during VM (p = 0.11 and 0.06, respectively). In a multiple linear regression analysis, CVI was only associated with SFCT; however, SFCT was also associated with SE, both at rest and during VM (p < 0.001).

CONCLUSION

Valsalva manoeuvre increases CVI by choroidal vascular dilation as demonstrated by an increase in LA and a decrease in SA. Researchers should be careful about unintentional VM during examinations.

Evaluation of choroidal thickness in children with acute asthma attack by optical coherence tomography

OBJECTIVE

To evaluate the change in central choroidal thickness in children with asthma attack before and after treatment with β₂ agonists.

MATERIALS AND METHODS

About 100 eyes of 50 patients (5-17 years old) with visual acuity of 20/20 who had no retinal, choroidal, and systemic comorbidity were examined by enhanced depth optical coherence tomography (EDI-OCT) before and after asthma attack treatment. Sixty eyes of 30 healthy children of similar age and gender were evaluated as the control group. The central choroidal thickness, peak expiratory flow (PEF), forced expiratory volume 1(FEV₁), oxygen saturation, and heart rate were evaluated.

RESULTS

The mean age of the patients was 9.2 ± 3.1 years, and the mean saturation values of patients was 97.2 ± 1.3 before treatment, and it increased to 98.3 ± 0.9 after treatment with a statistically significant difference. The mean FEV₁ values were 80.8 ± 15.2 before, and 92.7 ± 12.9 after the treatment and PEF values were 75.9 ± 18.6 before and 89.3 ± 18.9 after treatment. This differences were statistically significant (p < 0.001). The average choroidal thickness before the treatment were 310.4 ± 34.2 μm and decreased to 302.7 ± 34.4 μm after the treatment, this decrease was statistically significant (p < 0.001). The mean choroidal thickness of the control group was 303.0 ± 7.3 μm and compared to the pre-treatment and post-treatment values, it was more similar to the post-treatment values, although there was no statistically difference.

CONCLUSION

In our study, it was shown that choroidal thickness was significantly reduced in children with asthma who received attack treatment with β₂ agonists, and it was similar to the control group after the treatment.

Vascular Aspects in Glaucoma: From Pathogenesis to Therapeutic Approaches

Glaucomatous optic neuropathies have been regarded as diseases caused by high intraocular pressure for a long time, despite the concept of vascular glaucoma dating back to von Graefe in 1854. Since then, a tremendous amount of knowledge about the ocular vasculature has been gained; cohort studies have established new vascular risk factors for glaucoma as well as identifying protective measures acting on blood vessels. The knowledge about the physiology and pathophysiology of the choroidal, retinal, as well as ciliary and episcleral circulation has also advanced. Only recently have novel drugs based on that knowledge been approved for clinical use, with more to follow. This review provides an overview of the current vascular concepts in glaucoma, ranging from novel pathogenesis insights to promising therapeutic approaches, covering the supply of the optic nerve head as well as the aqueous humor production and drainage system.

Tuina for children with myopia: A protocol for a systematic review

BACKGROUND

The study aims to evaluate the effectiveness and safety of Tuina for children with myopia.

METHODS

The following electronic databases will be searched from establishment to July 2019: Cochrane Library, MEDLINE, EMBASE, Web of Science, Springer, World Health Organization International Clinical Trials Registry Platform (ICTRP), China National Knowledge Infrastructure (CNKI), Wan-fang database, Chinese Scientific Journal Database (VIP), Chinese Biomedical Literature Databases (CBM), and other databases. All published randomized controlled trials (RCTs) about this topic will be included. Two independent researchers will operate article retrieval, duplication removing, screening, quality evaluation, and data analyses by Review Manager (V.5.3.5). Meta-analyses, subgroup analysis, and/or descriptive analysis will be performed based on the included data conditions.

RESULTS

High-quality synthesis and/or descriptive analysis of current evidence will be provided from improvement of distant vision, improvement of myopic diopter, and side effects.

CONCLUSION

This study will provide the evidence of whether Tuina is an effective and safe intervention for children with myopia.

PROSPERO REGISTRATION NUMBER

CRD42019142283.