Pies: Here’s looking at you

Evidence: 77 • authority: 72

An eyelid ( EYE-lid) is a thin fold of skin that covers and protects the eye. The levator palpebrae superioris muscle retracts the eyelid, exposing the cornea to the outside, giving vision. This can be either voluntarily or involuntarily. "Palpebral" (and "blepharal") means relating to the eyelids. Its key function is to regularly spread the tears and other secretions on the eye surface to keep it moist, since the cornea must be continuously moist. They keep the eyes from drying out when asleep. Moreover, the blink reflex protects the eye from foreign bodies. A set of specialized hairs known as lashes grow from the upper and lower eyelid margins to further protect the eye from dust and debr…

Evidence: 57 • authority: 72

Cherry eye is a disorder of the nictitating membrane (NM), also called the third eyelid, present in the eyes of dogs and cats. Cherry eye is most often seen in young dogs under the age of two. Common misnomers include adenitis, hyperplasia, adenoma of the gland of the third eyelid; however, cherry eye is not caused by hyperplasia, neoplasia, or primary inflammation. In many species, the third eyelid plays an essential role in vision by supplying oxygen and nutrients to the eye via tear production. Normally, the gland can turn inside-out without detachment. Cherry eye results from a defect in the retinaculum which is responsible for anchoring the gland to the periorbita. This defect causes t…

Evidence: 51 • authority: 88

Histological Diversity of Eyelids and the Nictitating Membrane in Six Woodpecker Species (Picidae). Woodpeckers (Picidae) are exposed to repeated mechanical loading and particulate material during climbing, drilling, pecking, and foraging on tree trunks, but the microscopic organization of their eyelids and nictitating membrane remains poorly known. This study asked whether European woodpeckers share a common histological pattern of ocular adnexa and whether selected structural features may be interpreted in the context of ocular surface protection. The upper eyelid, lower eyelid, and nictitating membrane were examined in 40 birds representing six European woodpecker species using routine h…

Evidence: 44 • authority: 92

Bilateral Eyelid Agenesis With Multiple Congenital Ocular Anomalies in an Australian Labradoodle Puppy: Case Report and Surgical Management.. A 15-week-old Australian Labradoodle puppy was presented to The University of Queensland Small Animal Hospital for bilateral eyelid agenesis/coloboma and associated ocular complications. Enucleation of the left globe and repair of the right eyelid via a lip-to-lid transmucosal flap was performed. Given the subsequent development of prolapse of the gland of the nictitating membrane and a lack of vision of the right eye, enucleation of the right globe was then performed 2 months following the initial procedure. Both globes and a skin wedge from the righ…

Evidence: 44 • authority: 92

Surgical and Conservative Management of Periorbital Tumors in Four Dogs.. Four client-owned dogs with histopathologically confirmed periorbital tumors were included in this retrospective case series: one spayed female, one intact male, and two neutered males. The dogs ranged in age from 6 to 8 years. The most common clinical signs were slowly progressive exophthalmos (4/4 dogs), epiphora (3/4 dogs), and prolapse of the nictitating membrane gland (2/4 dogs). Periorbital disease was initially suspected based on the clinical examination. Computed tomography (CT) was subsequently used to characterize the presence, location, and extent of the lesion and for surgical planning, whereas histopathol…

Evidence: 44 • authority: 72

The musculus retractor bulbi (Latin for "the muscle that retracts the eyeball") is an extraocular muscle found in the orbit of most mammals and some other vertebrates, but is notably absent in humans and other primates. Its primary function is to retract the eyeball deeper into the orbit, usually as part of an eye-protection reflex. This action also often aids in the movement of the nictitating membrane (third eyelid) across the cornea for additional protection. The retractor bulbi muscle is a muscle posterior to the eyeball. It generally originates from the orbital apex near the optic canal, often attaching to the periorbita. The base encloses a core of fat and the optic nerve. It surround…

Evidence: 44 • authority: 92

Bilateral Blepharoplasty and Shortening of the Third Eyelid Cartilage as Treatment for Chronic Corneal Ulceration in a Giant Rabbit-A Case Report.. This case report describes the clinical presentation and successful surgical management of a combined dorsal entropion-ectropion macroblepharon with an elongated and folded nictitating membrane in a 2-year-old male giant rabbit. The rabbit initially presented with bilateral chronic, recurrent corneal erosions secondary to abnormal eyelid and third eyelid conformation. Surgical correction was performed via wedge excision of the upper eyelid and shortening of the third eyelid cartilage. Following the procedure, the corneal erosions resolved comple…

Evidence: 44 • authority: 92

Idiopathic Granulomatous Inflammation of the Periocular Structures in Four Dogs: Clinical, Histopathological, and Imaging Findings and Therapeutic Outcome.. Purpose To describe cases of canine idiopathic periocular granulomatous inflammation. Material and methods Clinical records were reviewed. Animal studied At the time of presentation, the four patients (German Shepherd dog, mixed breed, Magyar Vizsla, Hovawart) were 1.5-5 (mean 3.75) years old. All dogs were female; two were spayed. Lesions were unilateral in 3/4 cases. Dogs presented with ulcerated (1) or non-ulcerated (3) mass lesions affecting the periocular skin (3/4), medial canthal area (2/4), or third eyelid (1/4). Results Incisio…

Evidence: 38 • authority: 80

Nictitating Membrane Removal: A Surgical Procedure to Remove Nictitating Membrane from Rabbit Eye

Evidence: 38 • authority: 80

The Conjunctiva and Nictitating Membrane of the Eyelids in Some Reptilian Species: A SEM Overview

Evidence: 38 • authority: 88

Marsupialization of a cyst of the nictitating membrane in three dogs. Abstract Background Development of cysts has been reported as a potential complication after surgical repositioning of nictitating membrane gland protrusion using the conjunctival pocket technique. To the authors' knowledge, no treatment for these cysts has ever been published. Objectives This short case series describes a surgical technique of marsupialization as a treatment option for these cysts and proposes a pathogenesis for cyst formation. Cases description Three dogs were each referred for a unilateral subconjunctival mass‐like lesion involving the bulbar side of the nictitating membrane. Complete ophthalmologic ex…

Evidence: 38 • authority: 92

Lateral Tarsorrhaphy and Fixation on the Orbital Ligament to Correct Macroblepharon in Dogs: 77 Palpebral Fissures.. Purpose To describe a surgical method for correcting lower lid entropion, lateral canthal entropion, and macroblepharon. Methods Lid margins were incised at a 45° angle, and lateral lid margins and a rhomboid shaped piece of skin were resected based on the degree of macroblepharon. Subcutaneous tissue was sutured with absorbable sutures and anchored to the orbital ligament with a non-absorbable suture to maintain lateral canthal position. A new lateral canthus was formed using a "figure of eight" technique with absorbable sutures, and the skin was closed with simple interrupt…