In Vivo Measurement of the Human Vitreous Chamber Volume Using Computed Tomography Imaging of 100 Eyes

Azhdam, Ariel M.; Goldberg, Robert A.; Ugradar, Shoaib

doi:10.1167/tvst.9.1.2

Cited by 44 publications

(24 citation statements)

References 15 publications

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“…Nearly all subjects exhibited some degree of globe flattening (Table 1). However, the degree of globe flattening was relatively small when compared to the average reported vitreous chamber volume of 4650 and 4969 mm 3 in women and men, respectively [17], with an average volume displacement of 9.88 mm 3 (95% CI 4.56-15.19 mm 3 , p < 0.001) measured at R + 1 (Table 1 and black line in Fig. 2A).…”

Section: Resultsmentioning

confidence: 85%

Automated MRI-based quantification of posterior ocular globe flattening and recovery after long-duration spaceflight

Sater

Sass

Rohr

et al. 2021

Eye

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Background/Objectives Spaceflight associated neuro-ocular syndrome (SANS), a health risk related to long-duration spaceflight, is hypothesized to result from a headward fluid shift that occurs with the loss of hydrostatic pressure gradients in weightlessness. Shifts in the vascular and cerebrospinal fluid compartments alter the mechanical forces at the posterior eye and lead to flattening of the posterior ocular globe. The goal of the present study was to develop a method to quantify globe flattening observed by magnetic resonance imaging after spaceflight. Subjects/Methods Volumetric displacement of the posterior globe was quantified in 10 astronauts at 5 time points after spaceflight missions of ~6 months. Results Mean globe volumetric displacement was 9.88 mm3 (95% CI 4.56–15.19 mm3, p < 0.001) on the first day of assessment after the mission (R[return]+ 1 day); 9.00 mm3 (95% CI 3.73–14.27 mm3, p = 0.001) at R + 30 days; 6.53 mm3 (95% CI 1.24–11.83 mm3, p < 0.05) at R + 90 days; 4.45 mm3 (95% CI −0.96 to 9.86 mm3, p = 0.12) at R + 180 days; and 7.21 mm3 (95% CI 1.82–12.60 mm3, p < 0.01) at R + 360 days. Conclusions There was a consistent inward displacement of the globe at the optic nerve, which had only partially resolved 1 year after landing. More pronounced globe flattening has been observed in previous studies of astronauts; however, those observations lacked quantitative measures and were subjective in nature. The novel automated method described here allows for detailed quantification of structural changes in the posterior globe that may lead to an improved understanding of SANS.

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Section: Resultsmentioning

confidence: 85%

Automated MRI-based quantification of posterior ocular globe flattening and recovery after long-duration spaceflight

Sater

Sass

Rohr

et al. 2021

Eye

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“…First, only a small part of the vitreous is sampled by the current scanning method. The theoretical area sampled is 5.9 mm by 1.5 mm, which represents only a small volume of the entire vitreous (estimated total volume 4.6–4.9 mm3) 13 and most of the anterior vitreous is unaccounted for. The distribution of VH along the axial length of the eye is not well understood, other than in certain uveitic entities (such as toxoplasmosis), which present with patches of VH directly overlying areas of focal chorioretinitis.…”

Section: Discussionmentioning

confidence: 99%

OCT Assisted Quantification of Vitreous Inflammation in Uveitis

Liu

Kale

Ometto

et al. 2022

Trans. Vis. Sci. Tech.

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Purpose Vitreous haze (VH) is a key marker of inflammation in uveitis but limited by its subjectivity. Optical coherence tomography (OCT) has potential as an objective, noninvasive method for quantifying VH. We test the hypotheses that OCT can reliably quantify VH and the measurement is associated with slit-lamp based grading of VH. Methods In this prospective study, participants underwent three repeated OCT macular scans to evaluate the within-eye reliability of the OCT vitreous intensity (VI). Association between OCT VI and clinical findings (including VH grade, phakic status, visual acuity [VA], anterior chamber cells, and macular thickness) were assessed. Results One hundred nineteen participants were included (41 healthy participants, 32 patients with uveitis without VH, and 46 patients with uveitis with VH). Within-eye test reliability of OCT VI was high in healthy eyes and in all grades of VH (intraclass correlation coefficient [ICC] > 0.79). Average OCT VI was significantly different between healthy eyes and uveitic eyes without and uveitic eyes with VH, and was associated with increasing clinical VH grade ( P < 0.05). OCT VI was significantly associated with VA, whereas clinical VH grading was not. Cataract was also associated with higher OCT VI ( P = 0.03). Conclusions OCT VI is a fast, noninvasive, objective, and automated method for measuring vitreous inflammation. It is associated with clinician grading of vitreous inflammation and VA, however, it can be affected by media opacities. Translational Relevance OCT imaging for quantifying vitreous inflammation shows high within-eye repeatability and is associated with clinical grading of vitreous haze. OCT measurements are also associated with visual acuity but may be affected by structures anterior to the acquisition window, such as lens opacity and other anterior segment changes.

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“…Furthermore, the resolution is greater than that of traditional CT scanning. Azhdam et al [ 18 ] reported a study about the measurement of the vitreous volume using Computed Tomography Imaging. The mean vitreous volume in their study was 4649.97 mm 3 , larger than emmetropic group (4248.66 ± 358.12 mm 3 ) but small than pathological myopic group (8482.32 ± 677.44 mm 3 ) in our study.…”

Section: Discussionmentioning

confidence: 99%

Quantitative analysis with volume rendering of pathological myopic eyes by high-resolution three-dimensional magnetic resonance imaging

Zhou

Chen

et al. 2020

Medicine

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Discovering a relationship between axial length and vitreous volume would be helpful since the axial length is easier to measure than magnetic resonance imaging (MRI) parameters. This study aimed to analyze the topography of human eyes with pathological myopia through volume rendering images by high-resolution 3D-MRI and to establish a model to estimate the vitreous volume. This was a retrospective, non-randomized, controlled study of patients evaluated at Tongren Hospital from July 7, 2007 to December 12, 2018. The controls were emmetropic volunteers. All participants underwent ophthalmic examinations. Axial length was measured with an IOL Master. High-resolution 3D MRI and volume rendering was utilized for all the eyes. Logistic regression was used to establish a model to predict the vitreous volume. A total of 280 emmetropic eyes and 290 eyes with pathological myopia were included. Males represented 60.7% and 65.5% of the individuals. The mean axial lengths of those two groups were 23.1 ± 0.8 mm (95%CI: 22.7–23.4 mm) and 28.3 ± 2.2 mm (95%CI: 27.5–29.2 mm), respectively ( P < .001). The regression model in the pathological myopic group for calculating the vitreous volume according to the axial length was: Vitreous volume = 546.27 × axial length − 6977.12. The regression model in the emmetropic group for calculating the vitreous volume according to the axial length was: Vitreous volume = 458.35 × axial length − 6331.14 ( R 2 = 0.360, P = .001). Elongation of the axial length is involved in eyeball enlargement in pathological myopic eyes. Measurement of the axial length could be recommended for the estimation of the vitreous volume during vitrectomy if vitreous cavity filling is needed.

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In Vivo Measurement of the Human Vitreous Chamber Volume Using Computed Tomography Imaging of 100 Eyes

Cited by 44 publications

References 15 publications

Automated MRI-based quantification of posterior ocular globe flattening and recovery after long-duration spaceflight

Automated MRI-based quantification of posterior ocular globe flattening and recovery after long-duration spaceflight

OCT Assisted Quantification of Vitreous Inflammation in Uveitis

Quantitative analysis with volume rendering of pathological myopic eyes by high-resolution three-dimensional magnetic resonance imaging

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