Canine central corneal thickness measurements via Pentacam‐HR<sup>®</sup>, optical coherence tomography (Optovue iVue<sup>®</sup>), and high‐resolution ultrasound biomicroscopy

Self Cite

Objective To describe and compare normative anterior segment parameters between canine age groups using the Pentacam® HR Scheimpflug camera (Pentacam). Animals Studied Thirty‐six sedated dogs (60 eyes) of varying ages and breeds were imaged with the Pentacam; only nondiseased anterior segments were included. Procedures Dogs were divided into three age groups: Group 1 (1‐5 years), Group 2 (6‐10 years), and Group 3 (11‐15 years). Values assessed included central corneal thickness (CCT), anterior and posterior corneal elevation (ACE/PCE), anterior and posterior corneal curvature metrics, corneal volume (CV), anterior and posterior corneal astigmatism (AA/PA), anterior chamber depth (ACD), anterior chamber volume (ACV), and anterior chamber angle (ACA). Tukey‐adjusted pairwise comparisons were performed. Results Overall CCT (mean ± SD) was 631.07 ± 59.91 µm. Central corneal thickness was 608.60 ± 48.63 µm for Group 1, 648.57 ± 51.06 µm for Group 2, and 635.37 ± 73.71 µm for Group 3. Anterior corneal elevation (ACE) measured 9.08 ± 0.58 mm, PCE measured 8.04 ± 0.50 mm, and CV was 58.13 ± 5.39 mm3. Astigmatism values were 1.34 ± 0.94 D for AA and 0.46 ± 0.44 D for PA. Anterior chamber values were 3.76 ± 0.56 mm for ACD, 383.68 ± 66.24 mm3 for ACV, and 23.62 ± 29.33˚ for ACA. Significant differences were found between Groups 1 and 2 for CV (55.08 ± 4.08 mm3 and 60.32 ± 4.19 mm3, respectively), (P = 0.02). Conclusions Corneal volume significantly increased between Group 1 and Group 2. Central corneal thickness increased from Group 1 to Group 3, but was not significant with the current sample size. There were no other differences between age groups.

Section: Discussioncontrasting

confidence: 63%

Section: Discussioncontrasting

confidence: 46%

mentioning

confidence: 99%

See 1 more Smart Citation

Anterior segment parameters in normal dogs using the Pentacam^®HR Scheimpflug system

Wolfel

Pederson

Cleymaet

et al. 2019

Self Cite

“…However, the small sample size remains a limitation, and further studies are needed to determine whether the differences in the CCT between species are related to factors such as genetic and environmental factors. The SD‐OCT unit used in this study calculated the CCT not as the thickness of a specific point, but as the mean thickness of a specific area 3,25 . If the corneal thickness was thin below a certain standard, the machine did not automatically recognize the thickness.…”

Section: Discussionmentioning

confidence: 99%

Optical coherence tomography of the Tokay gecko (Gekko gecko) eye

Kang

Kwon

et al. 2020

Objective To provide images of the anterior and posterior structures of the gecko eye using spectral domain optical coherence tomography (SD‐OCT). Animals and procedures Eight ophthalmologically normal Tokay geckos (Gekko gecko) were used. The nose‐cloaca distance and body weight were measured for each gecko. Tomographic images were obtained using SD‐OCT without the use of anesthetic or mydriatic agents. The central corneal thickness (CCT), the anterior chamber depth (ACD), and the length of the conus papillaris (CP) were manually measured using OCT images. The thickness of the retinal nerve fiber layer (RNFL) around the CP and the retinal thickness in all four quadrants (superior, nasal, inferior, and temporal areas) were automatically measured using the OCT software program. Results The mean values of the nose‐cloaca distance and body weight were 13.8 ± 0.9 cm and 41.3 ± 9.0 g, respectively. The mean values of CCT, ACD, and CP length were 177.6 ± 20.9 µm, 1205.0 ± 79.9 µm, and 1546.4 ± 208.8 µm, respectively. The mean value of RNFL thickness was 52.0 ± 8.2 µm, and the superior region was the thickest. The mean value of total retinal thickness was 202.5 ± 9.4 µm, and the temporal region was the thickest. Conclusions Tomographic images of the anterior and posterior segments of the living gecko eye could be obtained using the OCT unit. Multiple retinal layers and anatomical features of the CP were identified.

“…It evaluates both the anterior and posterior corneal surfaces and provides a variety of outputs, including total corneal refractive power (TCRP) and true net power (TNP) maps . The Pentacam has been used in veterinary medicine to establish normal anterior segment values in rabbits, cats, and dogs, but has yet to be used in a hypothesis‐driven clinical study.…”

Section: Introductionmentioning

confidence: 99%

Surgically induced astigmatism in canines following sutured dorsonasal vs dorsotemporal clear corneal incisions

Pederson

Cleymaet

Hess

et al. 2019

Self Cite

Objectives: To investigate use of the Pentacam® HR for evaluation of surgically induced corneal astigmatism (SIA) in canines undergoing bilateral phacoemulsification and determine differences between dorsonasal and dorsotemporal clear corneal incisions. Animals: Client-owned canines undergoing bilateral phacoemulsification. Procedures: Patients received anterior segment imaging pre-operatively, immediately post-operatively, and 2-4 months post-operatively (follow-up). Total corneal refractive power was used to determine SIA. Surgically induced astigmatism was compared between right and left eyes, representing dorsotemporal and dorsonasal incisions, respectively. Repeated measures analyses were used between time points and paired t test compared SIA between eyes. Results: Complete imaging series were obtained for seven patients. Follow-up imaging occurred at a median of 112 days (range 60-132 days) post-operatively. For repeated measures analyses, significant differences were found between pre-and immediate post-operative values (P < 0.01), and between immediate post-operative and follow-up values (P < 0.01). There was no significant difference between preoperative and follow-up values. Surgically induced astigmatism was significantly different between right and left eyes, with values of 2.01 ± 1.24 D and 3.05 ± 1.58 D at 3 mm radius (P < 0.05), and 2.04 ± 1.18 D and 3.06 ± 1.27 D at 4 mm radius (P < 0.05) for dorsotemporal and dorsonasal incisions, respectively. Conclusions: Preliminary investigation revealed improvement of corneal SIA 2-4 months post-operatively, but development of significantly more SIA in dorsonasal vs dorsotemporal incisions. This prompts consideration of patient or microscope rotation to create a more dorsotemporal incision when possible. K E Y W O R D S canine, clear corneal incision, cornea, Pentacam, phacoemulsification, surgically induced astigmatism 800 | PEDERSON Et al.