Ocular morphologic traits in the American Cocker Spaniel may confer primary angle closure glaucoma susceptibility

Abstract

Acute primary angle closure glaucoma is a potentially blinding ophthalmic emergency requiring prompt treatment to lower the elevated intraocular pressure in humans and dogs. The PACG in most of canine breeds is epidemiologically similar to humans with older and female patients overrepresented with the condition. The American Cocker Spaniel (ACS) is among the most common breeds observed with PACG development in dogs. This study initially sought to identify genetic risk factors to explain the high prevalence of PACG in ACSs by using a case–control breed-matched genome-wide association study. However, the GWAS failed to identify candidate loci associated with PACG in this breed. This study then assessed intrinsic ocular morphologic traits that may relate to PACG susceptibility in this breed. Normal ACSs without glaucoma have a crowded anterior ocular segment and narrow iridocorneal angle and ciliary cleft, which is consistent with anatomical risk factors identified in humans. The ACSs showed unique features consisting of posterior bowing of iris and longer iridolenticular contact, which mirrors reverse pupillary block and pigment dispersion syndrome in humans. The ACS could hold potential to serve as an animal model of naturally occurring PACG in humans.

Factors Influencing the Incidence and Onset of Primary Angle‐Closure Glaucoma in the Unaffected Eye of Dogs

“…Breed distributions in our study were similar to previous reports, with Cocker Spaniels, Basset Hounds, and Shih Tzus being the most common [6,7,29,32]. Previous studies have demonstrated a female sex predilection for PACG, either within the overall study population or within certain dog breeds [6][7][8][9]33]. Our study supports this, with 69.2% of our population being female.…”

Factors Influencing the Incidence and Onset of Primary Angle‐Closure Glaucoma in the Unaffected Eye of Dogs

“…Breed distributions in our study were similar to previous reports, with Cocker Spaniels, Basset Hounds, and Shih Tzus being the most common [6,7,29,32]. Previous studies have demonstrated a female sex predilection for PACG, either within the overall study population or within certain dog breeds [6][7][8][9]33]. Our study supports this, with 69.2% of our population being female.…”

Comparative Analysis of Iridocorneal Angle in Cats and Dogs Using Ultrasound Biomicroscopy: Implications for Glaucoma Prevalence

“…In this study, dogs exhibited smaller CC parameters compared to cats. It is known that the CC has a signi cant effect on aqueous humor out ow in canine eyes, and a closed CC increases the likelihood of PACG by 20 times (17,18,27). Therefore, we concluded that the smaller CC in dogs compared to cats might explain the relatively higher incidence of PACG in dogs.…”

Pluripotent Stem Cell-Derived Corneal Endothelial Cells Form a Functional Corneal Endothelium in Canines

“…It is worth noting that the cell count is much higher compared to 0.75 × 10 6 and 1.0 × 10 6 cryopreserved hESC-derived CECs previously injected in the anterior chamber of rabbits and monkeys, respectively, 7 after scraping 8 mm of central CE in the two preclinical models. Since the anterior chamber depth (4.17 ± 0.43 mm) and the axial globe length (21.48 ± 1.02 mm) of the beagle canine is much larger compared to the anterior chamber depth (2.11 ± 0.27 mm) and the axial globe length (16.64 ± 0.66 mm) of rabbits and anterior chamber depth (2.77 ± 0.23 mm) and the axial globe length (15.71 ± 1.02 mm) of monkeys, 9 – 11 an increased count of CECs was injected into the anterior chamber in canines to form a functional CE.…”

Factors Influencing the Incidence and Onset of Primary Angle‐Closure Glaucoma in the Unaffected Eye of Dogs

“…Breed distributions in our study were similar to previous reports, with Cocker Spaniels, Basset Hounds, and Shih Tzus being the most common [6,7,29,32]. Previous studies have demonstrated a female sex predilection for PACG, either within the overall study population or within certain dog breeds [6][7][8][9]33]. Our study supports this, with 69.2% of our population being female.…”

Comparative Analysis of Iridocorneal Angle in Cats and Dogs Using Ultrasound Biomicroscopy: Implications for Glaucoma Prevalence

“…In this study, dogs exhibited smaller CC parameters compared to cats. It is known that the CC has a signi cant effect on aqueous humor out ow in canine eyes, and a closed CC increases the likelihood of PACG by 20 times (17,18,27). Therefore, we concluded that the smaller CC in dogs compared to cats might explain the relatively higher incidence of PACG in dogs.…”

Pluripotent Stem Cell-Derived Corneal Endothelial Cells Form a Functional Corneal Endothelium in Canines

“…It is worth noting that the cell count is much higher compared to 0.75 × 10 6 and 1.0 × 10 6 cryopreserved hESC-derived CECs previously injected in the anterior chamber of rabbits and monkeys, respectively, 7 after scraping 8 mm of central CE in the two preclinical models. Since the anterior chamber depth (4.17 ± 0.43 mm) and the axial globe length (21.48 ± 1.02 mm) of the beagle canine is much larger compared to the anterior chamber depth (2.11 ± 0.27 mm) and the axial globe length (16.64 ± 0.66 mm) of rabbits and anterior chamber depth (2.77 ± 0.23 mm) and the axial globe length (15.71 ± 1.02 mm) of monkeys, 9 – 11 an increased count of CECs was injected into the anterior chamber in canines to form a functional CE.…”

Factors Influencing the Incidence and Onset of Primary Angle‐Closure Glaucoma in the Unaffected Eye of Dogs

“…Breed distributions in our study were similar to previous reports, with Cocker Spaniels, Basset Hounds, and Shih Tzus being the most common [6,7,29,32]. Previous studies have demonstrated a female sex predilection for PACG, either within the overall study population or within certain dog breeds [6][7][8][9]33]. Our study supports this, with 69.2% of our population being female.…”

Comparative Analysis of Iridocorneal Angle in Cats and Dogs Using Ultrasound Biomicroscopy: Implications for Glaucoma Prevalence

“…In this study, dogs exhibited smaller CC parameters compared to cats. It is known that the CC has a signi cant effect on aqueous humor out ow in canine eyes, and a closed CC increases the likelihood of PACG by 20 times (17,18,27). Therefore, we concluded that the smaller CC in dogs compared to cats might explain the relatively higher incidence of PACG in dogs.…”

Pluripotent Stem Cell-Derived Corneal Endothelial Cells Form a Functional Corneal Endothelium in Canines

“…It is worth noting that the cell count is much higher compared to 0.75 × 10 6 and 1.0 × 10 6 cryopreserved hESC-derived CECs previously injected in the anterior chamber of rabbits and monkeys, respectively, 7 after scraping 8 mm of central CE in the two preclinical models. Since the anterior chamber depth (4.17 ± 0.43 mm) and the axial globe length (21.48 ± 1.02 mm) of the beagle canine is much larger compared to the anterior chamber depth (2.11 ± 0.27 mm) and the axial globe length (16.64 ± 0.66 mm) of rabbits and anterior chamber depth (2.77 ± 0.23 mm) and the axial globe length (15.71 ± 1.02 mm) of monkeys, 9 – 11 an increased count of CECs was injected into the anterior chamber in canines to form a functional CE.…”