This study determined the choroidal thickness of senior (SN, n = 24) and middle-aged (MA, n = 17) healthy, mixed-breed mesocephalic dogs, both males (M) and females (F), using spectral domain optical coherence tomography (SD-OCT). The dogs were divided into two groups for examination: MA dogs (4–7 years old; 6 M, 11 F) and SN dogs (8–13 years old; 12 M, 12 F). Choroidal thickness of the dogs was investigated using SD-OCT radial and linear scans. The software of the device allowed determination of the exact measurement location on the choroid. Measurements of the choroid were taken manually using the SD-OCT calliper function at distances of 5,000–6,000 μm (dorsal and ventral) and 4,000–7,000 μm (nasal and temporal) from the optic disc. Mean (µm ± SD) (MA, SN) dorsal (188 ± 28, 184 ± 33), ventral (116 ± 23, 111 ± 16), temporal (152 ± 31, 151 ± 26), and nasal (135 ± 27, 132 ± 18) choroidal thicknesses demonstrated significant differences (P < 0.02–0.001) between all areas within each group. The choroid was thickest in the dorsal region and thinnest in the ventral region. There were no significant differences based on age. Mean (µm ± SD) (M, F) dorsal (181 ± 32, 190 ± 30), ventral (117 ± 16, 11 ± 21), temporal (150 ± 26, 153 ± 30), and nasal (128 ± 20, 138 ± 23) choroidal thicknesses demonstrated significant differences (P < 0.05) between dorsal and nasal regions. The choroidal thickness in dogs depends on the area assessed independently of their age and sex.

Background: Noninvasive diagnostic techniques allow for morphological and morphometric in vivo evaluation of the skin. Optical coherence tomography (OCT) is a method that allows visualization of dermal structures up to several 100 μm with a resolution of 3-7.5 μm. Objectives:The aim of the study was the morphological and morphometric assessment of rats' skin using SD-OCT.Animals: Fifteen male Wistar rats, aged 3 and 8 months, weighing 350-450 g. Materials and Methods:The skin of the plantar metatarsal area of the right pelvic limb was assessed. The measurements were performed using Spectral Domain Optical Coherence Tomography (SD-OCT) scans and histological images.Results: Spectral Domain Optical Coherence Tomography could determine the boundary between the epidermis and the dermis. Apart from the stratum corneum (SC), it did not allow for the differentiation of the individual epidermal layers. In the SD-OCT and in the histological examination, the mean thicknesses of the layers (μm ± SD) were (respectively):

The purpose of the study was to evaluate the occurrence and range of refractive errors in dogs of different ages. A total of 99 clinically healthy, mixed-breed mesocephalic dogs were included in the study and divided into three different age groups according to the current human/pet analogy chart: 40 adults (23 males, 17 females, 1-8 years old, 3-70 kg), 21 seniors (14 males, 7 females, 6-11 years old, 7-42 kg), and 38 geriatrics (22 males, 16 females, 8-13 years old, 5-45 kg). All the dogs underwent an ophthalmic examination, including Schirmer tear test, tonometry, biomicroscopy, and ophthalmoscopy. Neither eye drops nor pharmacological sedatives were administered before the autorefractometry. The refractive states were assessed bilaterally using a hand-held Retinomax 3 (Righton) autorefractor. The results underwent statistical analysis using Statistica v12 software (ANOVA and t-test). A P-value < 0.05 was considered as significant. Emmetropia, defined as a refractive state > −0.5 D and < +0.5 D, was found in 36% of the adult, 43% of the senior, and 38% of the geriatric patients. Anisometropia was found in 1% of the adult, 9.5% of the senior and 5.5% of the geriatric dogs when the refractive power of the two eyes differed ≥ 1.0 myopia ≤ −0.5 D and hyperopia ≥ +0.5 D were found in 23% and 41% of the adult eye globes as well as 24% and 33% in the senior dogs and 15% and 47% in the geriatric dogs, respectively. The maximal values of the myopia in the adult and geriatric dogs were −2.5 D and −2.75 D, respectively. The maximal values of the hyperopia in the adult and geriatric dogs were 1.75 D and 2.5 D, respectively. No statistically significant correlation was found between the groups. Ametropia is a common refractive state for dogs of different ages. The most frequent refractive state in ametropic mixed-bed dogs in all age groups is hyperopia.

The choroid, a multifunctional tissue, has been the focus of research interest for many scientists. Its morphology and morphometry facilitate an understanding of pathological processes within both the choroid and retina. This study aimed to determine the choroidal layer thicknesses in healthy, mixed-breed mesocephalic dogs, both male (M) and female (F), using spectral domain optical coherence tomography (SD-OCT) with radial, cross-sectional, and linear scans. The dogs were divided into two groups based on age: middle-aged (MA) and senior (SN). Thicknesses of choroidal layers, namely RPE–Bruch’s membrane–choriocapillaris complex (RPE-BmCc) with tapetum lucidum in the tapetal fundus, the medium-sized vessel layer (MSVL), and the large vessel layer with lamina suprachoroidea (LVLS), as well as whole choroidal thickness (WCT), were measured manually using the caliper function integrated into the OCT software. Measurement was performed dorsally and ventrally at a distance of 5000–6000 μm temporally and nasally at a distance of 4000–7000 μm to the optic disc on enhanced depth scans. The measurements were conducted temporally and nasally in both the tapetal (temporal tapetal: TempT, nasal tapetal: NasT) and nontapetal (temporal nontapetal: TempNT, nasal nontapetal: NasNT) fundus. The ratio of the MSVL thickness to the LVLS thickness for each region was calculated. In all examined dogs, the RPE-BmCc in the dorsal (D) region and MSVL in the Tt region were significantly thicker than those in the other regions. The MSVL was thinner in the ventral (V) region than in the D, TempT, TempNT and NasT regions. The MSVL was significantly thinner in the NasNT region than in the D region. LVLS thickness and WCT were significantly greater in the D and TempT regions than those in the other regions and significantly lesser in the V region than those in the other regions. The MSVL-to-LVLS thickness ratio did not differ between the age groups. Our results reveal that the choroidal thickness profile does not depend on age. Our findings can be used to document the emergence and development of various choroidal diseases in dogs in the future.

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