Comparison of Lens Thickness Measurements Using the Anterior Segment Optical Coherence Tomography and A-scan Ultrasonography

Purpose: To assess age-related changes in the rhesus macaque eye and evaluate them to corresponding human age-related eye disease. Methods: Data from eye exams and imaging tests including intraocular pressure (IOP), lens thickness, axial length, and retinal optical coherence tomography (OCT) images were evaluated from 142 individuals and statistically analyzed for age-related changes. Quantitative autofluorescence (qAF) was measured as was the presence of macular lesions as related to age. Results: Ages of the 142 rhesus macaques ranged from 0.7 to 29 years (mean=16.4 years, stdev=7.5 years). Anterior segment measurements such as IOP, lens thickness, and axial length were acquired. Advanced retinal imaging in the form of optical coherence tomography and qAF were obtained. Quantitative assessments were made and variations by age groups were analyzed to compare with established age-related changes in human eyes. Quantitative analysis of data revealed age-related increase in intraocular pressure, ocular biometry (lens thickness and axial length), and presence of macular lesions. Age-related changes in thicknesses of retinal layers on OCT were observed and quantified. Age was correlated with increased qAF. Conclusions: The rhesus macaque has age-related ocular changes similar to humans. IOP increases with age while retinal ganglion cell layer thickness decreases. Macular lesions develop in some aged animals. Our findings support the concept that rhesus macaques may be useful for the study of important age-related diseases such as glaucoma, macular diseases, and cone disorders, and for development of therapies for these diseases.

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Comparison of Central Corneal Thickness Measurements by Visante Anterior Segment Optical Coherence Tomography With Ultrasound Pachymetry

American Journal of Ophthalmology ◽

10.1016/j.ajo.2007.01.050 ◽

2007 ◽

Vol 143 (6) ◽

pp. 1047-1049 ◽

Cited By ~ 73

Author(s):

Paul S. Zhao ◽

Tien Yin Wong ◽

Wan-Ling Wong ◽

Seang-Mei Saw ◽

Tin Aung

Keyword(s):

Optical Coherence Tomography ◽

Central Corneal Thickness ◽

Corneal Thickness ◽

Anterior Segment ◽

Optical Coherence ◽

Ultrasound Pachymetry ◽

Thickness Measurements

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Anterior segment optical coherence tomography and ultrasound biomicroscopy for measuring thickness of corneal and bulbar conjunctival tumours

British Journal of Ophthalmology ◽

10.1136/bjophthalmol-2018-312337 ◽

2021 ◽

pp. bjophthalmol-2018-312337

Author(s):

Noémie Lauwers ◽

Katleen Janssens ◽

Michelle Mertens ◽

Danny Mathysen ◽

Martin Lammens ◽

...

Keyword(s):

Optical Coherence Tomography ◽

Gold Standard ◽

Imaging Techniques ◽

Anterior Segment ◽

Ultrasound Biomicroscopy ◽

Thickness Measurement ◽

Histopathological Analysis ◽

Optical Coherence ◽

Tumour Thickness ◽

Thickness Measurements

Background/ObjectiveAnterior segment optical coherence tomography (AS-OCT) and ultrasound biomicroscopy (UBM) are two non-invasive imaging techniques used for the measurement of tumour thickness in corneal and bulbar conjunctival tumours. Histopathology (HP), however, remains the gold standard for the measurement of tumour thickness. The aim of this study was to determine whether AS-OCT and UBM are as accurate as HP for measuring tumour thickness.MethodsForty-two corneal and bulbar conjunctival tumours were imaged using AS-OCT and UBM. Images were assessed and tumour thickness was measured. Eleven patients subsequently underwent surgical excision. All specimens were measured during histopathological analysis. The correlation of the thickness measurement on HP to AS-OCT and UBM was then statistically analysed. In cases where the tumour was not excised, thickness measurement comparisons between AS-OCT and UBM were analysed.ResultsAS-OCT and UBM measurements of tumour thickness were found to be significantly positively correlated (p=<0.001), as were UBM and HP thickness measurements (p=0.031). HP and AS-OCT measurements, however, only showed a mild but non-significant positive correlation.ConclusionBoth AS-OCT and UBM are useful techniques to image and measure the thickness of corneal and conjunctival bulbar tumours. While AS-OCT provides better details than UBM, it was more limited in visualising the posterior boundary of the tumour, particularly in malignant tumours. While thickness measurements of both methodologies were correlated, neither should yet be considered as replacements to the gold standard of HP.

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Optical Coherence Tomography Reveals New Insights into the Accommodation Mechanism

Journal of Ophthalmology ◽

10.1155/2015/510459 ◽

2015 ◽

Vol 2015 ◽

pp. 1-5 ◽

Cited By ~ 5

Author(s):

Mahmoud Mohamed Farouk ◽

Takeshi Naito ◽

Kayo Shinomiya ◽

Hiroshi Eguchi ◽

Khulood Mohammed Sayed ◽

...

Keyword(s):

Optical Coherence Tomography ◽

Outcome Measures ◽

Anterior Segment ◽

Case Series ◽

Optical Coherence ◽

Anterior Pole ◽

Forward Movement ◽

Anterior Segment Oct ◽

Lens Thickness ◽

Significant Difference

Purpose. To evaluate the movement of the anterior and posterior lens poles during naturally stimulated accommodation in children using anterior segment optical coherence tomography (OCT).Methods. This is a prospective, observational, noncomparative case series including 18 eyes of nine children. Analysis of the anterior segment in the accommodated and unaccommodated state (with cycloplegia) was done using anterior segment OCT. The main outcome measures were the position of the anterior and posterior lens poles (in relation to the cornea) and lens thickness (LT).Results. A Statistically significant forward movement of the anterior lens pole and backward movement of the posterior lens pole with an increase in LT were found during accommodation (P<0.001). There was no significant difference between the degree of movement of the anterior lens pole and the posterior lens pole during accommodation (P=0.944).Conclusions. Anterior segment OCT provides a rapid noncontact method for studying accommodation in children. The backward movement of the posterior lens pole during accommodation nearly equals the forward movement of its anterior pole. These data minimize the theoretical hydraulic effect of the vitreous during accommodation, adding more support to the capsular theory of Helmholtz.

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