Ultrasonography and Optical Low-Coherence Interferometry Compared in the Chicken Eye

Penha, Alexandra Marchã; Burkhardt, Eva; Schaeffel, Frank; Feldkaemper, Marita

doi:10.1097/opx.0b013e318257a255

Cited by 16 publications

(11 citation statements)

References 8 publications

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“…49, 50 In the chick eye, Penha, et al, report high correlation for anterior chamber depth, vitreous chamber depth, and axial length, with only a 0.5 mm difference in axial length between A-scan ultrasound and optical low-coherence tomography. 59 Here, we measured enucleated globes and isolated lenses against a ruler under a dissecting microscope, and found the measurements were similar to those from the LenStar. However, enucleated tissue may be subject to deformation.…”

Section: Discussionmentioning

confidence: 56%

In Vivo Imaging of the Retina, Choroid, and Optic Nerve Head in Guinea Pigs

Jnawali

Beach

Ostrin

2018

Current Eye Research

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Purpose Guinea pigs are increasingly being used as a model of myopia, and may also represent a novel model of glaucoma. Here, optical coherence tomography (OCT) imaging was performed in guinea pigs. In vivo measurements of retinal, choroidal and optic nerve head parameters were compared with histology, and repeatability and interocular variations were assessed. Methods OCT imaging and histology were performed on adult guinea pigs (n = 9). Using a custom program in Matlab, total retina, ganglion cell/nerve fiber layer (GC/NFL), outer retina and choroid thicknesses were determined. Additionally, Bruch’s membrane opening (BMO) area and diameter, and minimum rim width were calculated. Intraobserver, interocular and intersession coefficients of variation (CV) and intraclass correlation coefficients (ICC) were assessed. Results Retina, GC/NFL, outer retina and choroid thicknesses from in vivo OCT imaging were 147.7 ± 5.8 μm, 59.2 ± 4.5 μm, 72.4 ± 2.4 μm, and 64.8 ± 11.6 μm, respectively. Interocular CV ranged from 1.8 to 11% (paired t-test, p = 0.16 to 0.81), and intersession CV ranged from 1.1 to 5.6% (p = 0.12 to 0.82), with the choroid showing the greatest variability. BMO area was 0.192 ± 0.023 mm2, and diameter was 493.79 ± 31.89, with intersession CV of 3.3% and 1.7%, respectively. Hyper reflective retinal layers in OCT correlated with plexiform and RPE layers in histology. Conclusion In vivo OCT imaging and quantification of guinea pig retina and optic nerve head parameters were repeatable and similar between eyes of the same animal. In vivo visibility of retinal cell layers correlated well with histological images.

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Section: Discussionmentioning

confidence: 56%

In Vivo Imaging of the Retina, Choroid, and Optic Nerve Head in Guinea Pigs

Jnawali

Beach

Ostrin

2018

Current Eye Research

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“…Few studies have investigated ocular dimensions in chicken, although one study evaluated the size of the various ocular structures in two-week-old chickens, without breed distinction and using A-mode and Optical Low-Coherence Interferometry [17]. The ultrasonographic appearance of the eyes of chickens in our study is the same as that described for other avian species [12,13].…”

Section: Species Tear Production Methods Used Referencesmentioning

confidence: 75%

“…Although the anatomy of the chicken eye has been well described [27,28], few articles report the normal values of some ocular parameters such as tear production, intraocular pressure, and ultrasound biometric measurements [1,3,7,17,29]. In addition, to the best of our knowledge, no data on conjunctival flora have been reported in this species.…”

Section: Introductionmentioning

confidence: 99%

Tear Production, Intraocular Pressure, Ultrasound Biometric Features and Conjunctival Flora Identification in Clinically Normal Eyes of Two Italian Breeds of Chicken (Gallus gallus domesticus)

Nardi

Leoni

Monticelli

et al. 2021

Animals

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Given the abundance of chickens in Italy, it is important for veterinarians to know the normal state of chickens’ eyes in order to identify any ophthalmic pathological changes. The aim of this study was to determine the normal values of select ocular parameters and to evaluate conjunctival microflora in two Italian chicken breeds. Sixty-six healthy chickens underwent a complete ophthalmic examination, which included a phenol red thread test (PRTT) for the evaluation of tear production and the assessment of intraocular pressure by rebound tonometry. B-mode ultrasound biometric measurements and conjunctival microflora identification were also performed in twenty-seven chickens. Mean PRTT was 23.77 ± 2.99 mm/15 s in the Livorno breed and 19.95 ± 2.81 mm/15 s in the Siciliana breed. Mean intraocular pressure was 14.3 ± 1.17 mmHg in the Livorno breed and 14.06 ± 1.15 mmHg in the Siciliana breed. Reference ranges for morphometric parameters were reported in the two breeds. Twenty-three chickens (85.18%) were bacteriologically positive. Chlamydia spp. antigen was detected in 14.81% of chickens. No positive cultures were obtained for fungi. Normal reference range values for selected ophthalmic parameters were obtained in clinically healthy chickens, which could facilitate accurate diagnosis and better management of ophthalmic diseases in these animals.

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“…This system uses optical low-coherence optical interferometry, and has been found to typically give similar dimensions as other techniques such as ultrasonography, but with greater repeatability (Penha, Burkhardt et al 2012). The LenStar provides and stores waveforms with peaks that correspond to the front and back of the cornea, front and back of the lens, front and back of the retina, and the front and back of the choroid (Ward, Siegwart et al 2016).…”

Section: Methodsmentioning

confidence: 99%

Long-wavelength (red) light produces hyperopia in juvenile and adolescent tree shrews

2017

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In infant tree shrews, exposure to narrow-band long-wavelength (red) light, that stimulates long-wavelength sensitive cones almost exclusively, slows axial elongation and produces hyperopia. We asked if red light produces hyperopia in juvenile and adolescent animals, ages when plus lenses are ineffective. Animals were raised in fluorescent colony lighting (100–300 lux) until they began 13 days of red-light treatment at 11 (n=5, “infant”), 35 (n=5, “juvenile”) or 95 (n=5, “adolescent”) days of visual experience (DVE). LEDs provided 527–749 lux on the cage floor. To control for the higher red illuminance, a fluorescent control group (n=5) of juvenile (35 DVE) animals was exposed to ~ 975 lux. Refractions were measured daily; ocular component dimensions at the start and end of treatment and end of recovery in colony lighting. These groups were compared with normals (n=7). In red light, the refractive state of both juvenile and adolescent animals became significantly (P<0.05) hyperopic: juvenile 3.9±1.0 diopters (D, mean±SEM) vs. normal 0.8±0.1 D; adolescent 1.6±0.2 D vs. normal 0.4±0.1 D. The fluorescent control group refractions (0.6±0.3 D) were normal. In red-treated juveniles the vitreous chamber was significantly smaller than normal (P<0.05): juvenile 2.67±0.03 mm vs. normal 2.75±0.02 mm. The choroid was also significantly thicker: juvenile 77±4 μm vs. normal 57±3 μm (P<0.05). Although plus lenses do not restrain eye growth in juvenile tree shrews, the red light-induced slowed growth and hyperopia in juvenile and adolescent tree shrews demonstrates that the emmetropization mechanism is still capable of restraining eye growth at these ages.

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Ultrasonography and Optical Low-Coherence Interferometry Compared in the Chicken Eye

Cited by 16 publications

References 8 publications

In Vivo Imaging of the Retina, Choroid, and Optic Nerve Head in Guinea Pigs

In Vivo Imaging of the Retina, Choroid, and Optic Nerve Head in Guinea Pigs

Tear Production, Intraocular Pressure, Ultrasound Biometric Features and Conjunctival Flora Identification in Clinically Normal Eyes of Two Italian Breeds of Chicken (Gallus gallus domesticus)

Long-wavelength (red) light produces hyperopia in juvenile and adolescent tree shrews

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