Everted third eyelid cartilage in a cat: a case report and literature review

An 8-year-old neutered female British Blue cat was presented with a presumed diagnosis of a prolapsed nictitans gland and associated ocular irritation and epiphora. However, during surgery, the apparent nictitans gland protrusion was determined to be an everted cartilage of the nictitating membrane. The scrolled portion of the cartilage was removed through an incision through the conjunctiva on the bulbar aspect of the third eyelid, as previously described in the dog. This operation resolved the ocular irritation occurring, and the third eyelid returned to its anatomically correct position.     

Diseases of the nictitating membrane of the dog

The clinical signs and treatment of the following conditions of the nictitating membrane are described–prominence of the nictitating membrane due to various causes, injuries and foreign bodies, conjunctivitis, plasma cell infiltration, disorders of the nictitans gland, neoplasia, and deformity of the cartilage. The surgical removal of the third eyelid is also discussed.     

Normal anatomical and histochemical characteristics of the lacrimal glands in the American bison and cattle

Dorsal lacrimal glands, superior glands of the third eyelid and Harderian glands (deep gland of the third eyelid) from 19 bison and 18 cattle free of apparent ocular disease were examined to compare the normal anatomical properties of these glands. All glands were characterized and measured (length and width). The gross anatomy of the dorsal lacrimal glands was similar, with the exception of a bipartite gland in cattle. The bison's superior gland of the third eyelid and Harderian gland was longer as compared with cattle. A subset of the bison and cattle samples (five bison and five cattle) was sectioned for histological and histochemical analysis. The histology of the dorsal lacrimal and superior gland of the third eyelid revealed tubuloalveolar cells with basophilic vacuolated cytoplasm in bison and eosinophilic granular cytoplasm in cattle. The Harderian glands consisted of a tubuloalveolar anterior part combined with large lumens acini lined with cuboidal epithelium in the posterior part; the posterior part of the bison Harderian gland was more predominant than in cattle samples. Mucosubstance histochemistry revealed acidic and neutral glycoproteins with similar staining patterns in all glands of both species.     

Mastocytoma in the third eyelid of a dog

An 8-year-old Alsatian showed lachrymation and protrusion of a third eyelid. A hard mass was removed from the eyelid with the palpebral surface of the membrane intact. Histologically, a mastocytoma was diagnosed. Six months later the membrana nictitans appeared normal.
Zusammenfassung. Ein achtjähriger Schäferhund zeigte Tränenfluss und Abstehen Vorwölben eines dritten Augenlids. Aus dem Lid wurde eine harte Masse entfernt, wobei palpebrale Oberfläche der Membrane intakt blieb. Histologisch wurde ein Mastocytom diagnostiziert. Sechs Monate später erschien die membrana nictitans normal.
Résumé. Un berger allemand de 8 ans présentait de la lacrymation avec protrusion de la membrane nictitante. On a enlevé une masse dure de la paupière sans toucher la membrane. L'examen histologique permit le diagnostic de mastocytome. Six mois après l'opération la membrane nictitante avait un aspect normal.     

Perilimbal pocket technique for surgical repositioning of prolapsed nictitans gland in dogs

The objective of this prospective study was to investigate the success rate, practicality and complications of a new perilimbal pocket technique for the replacement of prolapsed nictitans gland in 30 dogs (44 eyes). A first incision was made in the bulbar conjunctiva, 2-3 mm from and parallel to the infero-nasal limbus, a second incision on the bulbar aspect of the nictitating membrane (NM), 2-3 mm parallel to the free edge. The gland was returned to its normal position by suturing the subconjunctival tissues of the NM to the episcleral tissues, using four to six interrupted horizontal mattress sutures. The English bulldog, Neapolitan mastiff, great dane and American cocker spaniel were commonly presented. Nictitans gland prolapse occurred prior to one year of age in 83.3 per cent of dogs, and unilaterally in 15 patients. The procedure was easy to perform, and had a 90.9 per cent success rate, with minimal complications. The median duration of follow-up, conducted by ophthalmic examination or telephone contact with the owners, was 21.5 months. Tear production and ocular health were not affected in 17 eyes with at least six?months follow-up. There was a statistically significant increase between preoperative and?postoperative Schirmer tear test-1 measurements.     

Tissue distribution of dexamethasone in canine ocular compartments following topical application of dexamethasone-21-isonicotinate and oxytetracycline HCl

Objective  To study the dexamethasone (DXM) concentration at different time points in various compartments of the canine eye following topical application of DXM-21-isonicotinate and oxytetracycline hydrochloride
Animals studied  Thirty dogs to be euthanized for reasons not related to this study were selected and their ocular health status evaluated. Selected animals were treated with DXM-oxytetracycline ointment and euthanized after 6, 11 or 16 h.
Procedure  The concentration of DXM was determined in the following compartments of the eye: third eyelid, cornea, aqueous humor, iris, lens, vitreous body and choroid/retina. The DXM concentration in the eye was measured by radioimmunoassay. The applied amount of DXM was 0.04 mg in 0.2 mL ointment. Dogs were treated once with Corti Biciron^® eye ointment (DXM-21-isonicotinate and oxytetracycline hydrochloride, S & K Pharma, Perl, Germany) and were euthanized 6, 11 and 16 h after treatment.
Results  At 6 h following topical application the mean DXM concentration was highest in the anterior structures of the eye (third eyelid: 18 ng/g, cornea: 36 ng/g). The concentration in the posterior structures was below detection level. A decreased DXM concentration in the anterior structures was measured 11 and 16 h after treatment.
Conclusion  It could be demonstrated that therapeutically relevant concentrations of DXM after a single topical administration are only achieved in anterior structures of the eye. A dosing interval of 6–11 h is recommended to achieve therapeutic drug concentration in those structures. The posterior structures of the eye are not reached by topical administration.     

A preliminary study of changes in tear film proteins in the feline eye following nictitating membrane removal

Objective To investigate the influence of nictitating membrane (third eyelid) removal on selected proteins in feline tears. Animal studied Domestic short‐haired cats (7–17 months; 2.6–5.2 kg) were used. Procedures Eye‐flush tears were collected periodically for up to 18 weeks from both eyes of animals with nictitating membranes removed, but nictitating gland left intact, (n = 4) or with nictitating membranes intact (n = 4). Tear comparisons were based on total protein content (TPC) using micro bicinchoninic acid assay, immunoglobulin A (IgA), and matrix‐metalloproteinase (MMP)‐9 measurements using sandwich enzyme‐linked immunosorbent assay (ELISA) and tear gelatinase activity using gelatin zymography. Expression of MMP‐2 and ‐9 in nictitating membranes removed at baseline (week 0) and eyes collected at 18 weeks were also investigated in histological sections using immunoperoxidase for visualization. Results Nictitating membrane removal did not significantly change TPC and MMP‐9 in tears within the first 4 weeks. MMP‐9 was not detected by ELISA in tears from eyes without nictitating membranes from week 5 onwards. IgA (%IgA of TPC) data varied between animals. Gelatin zymography showed increased MMP‐2 and ‐9 activity in tears from eyes without nictitating membranes at week 1 and a decrease following week 2 post‐surgery. MMP‐2 and ‐9 were immunolocalised to conjunctival goblet cells of removed nictitating membranes and to the conjunctival epithelium, respectively. After 18 weeks, the distribution of MMPs in tissue was comparable between eyes with and without nictitating membranes. Conclusions Based on this preliminary study, nictitating membrane removal appeared to cause long‐term changes in expression of tear proteins, including reduced MMP‐9 expression.     

Dacryops of the lacrimal gland in a dog

A case of congenital lacrimal cyst or dacryops of the lacrimal gland in an 8‐month‐old Neapolitan Mastiff dog is reported. The dog presented with a swelling dorsolateral to the left globe, which had been present since birth. In addition, hyperplasia and prolapse of the superficial gland of the left nictitating membrane, and bilateral macropalpebral fissure and ‘diamond eye’ conformation were apparent. On manual eversion of the upper eyelid, a subconjunctival mass was visible that was translucent and pink and affected the upper conjunctival fornix. B‐mode ultrasonography revealed the presence of an echolucent thin‐walled cystic structure measuring 15 by 12 mm and containing an echodense border and a distended tubular fluid‐filled structure that extended posteriorly. A viscous and transparent fluid was aspirated from the lesion. Surgery was performed to excise the lesion, reposition the nictitans gland, and correct the morphology of the palpebral fissure. Histopathology confirmed the mass to be a cyst and distended duct of the lacrimal gland. Although tear secretion was compromised, resection of the cyst was curative.     

Adenocarcinoma of the gland of the third eyelid in seven dogs

Adenocarcinoma of the gland of the third eyelid developed as a smooth, pink nodule on the bulbar aspect of the third eyelid of seven 10- to 16-year-old dogs. Tumors recurred in 4 dogs. One dog, which initially had the most infiltrative-appearing tumor among those studied, was euthanatized 7 months after the first excision, because of extensive local recurrence and suspected metastasis. Tumors did not recur after removal of the entire third eyelid as the initial or follow-up procedure. We recommend removal of the entire third eyelid to prevent local recurrence of the tumor.     

Inferomedial placement of a single-entry subpalpebral lavage tube for treatment of equine eye disease

The objective of this study was to describe method of placement, and frequency and severity of complications associated with a subpalpebral lavage system placed in the medial aspect of the equine inferior eyelid. The inferomedial subpalpebral lavage (ISPL) tube is positioned deep in the medial aspect of the inferior conjunctival fornix so that the footplate lies flat between the lower eyelid and the anterior surface of the nictitans. Retrospective data from the placement of 92 ISPL systems placed in 86 horses during a 31-month period were examined. Tube placement was performed using sedation and regional anesthesia only in 59% of horses. The median duration of tube placement was 19 days (range: 1-61 days). Seventy-one horses were treated for up to 55 days following discharge from hospital with an ISPL tube in place. No complications were reported with 59% of ISPL systems. Non-ocular complications were found in 38% of ISPL systems and included tube displacement from the conjunctival fornix (18%), suture loss requiring resuturing of the system to the horse's head (14%), and damage necessitating replacement of the injection port (6%). Ocular complications were recorded in 3% of horses and were limited to inferior eyelid swelling. Vision was retained in 88% of horses. The ISPL system is easily and safely placed, and well tolerated for extended periods. It appears to be associated with infrequent and minor complications when compared with placement of subpalpebral lavage tubes in the superior eyelid.     

Malignant melanoma of the third eyelid in a horse

An 8‐year‐old grey Quarter Horse gelding was referred for evaluation of a rapidly growing mass associated with the third eyelid of the left eye. A pigmented mass of approximately 2 cm in diameter was palpated and visualised associated with the conjunctival lining of the nictitans. It was not possible to palpate normal nictitans deep to the base of the mass. A full dermatological examination revealed no other melanomas in common sites. Based on the size and rapid growth of the mass, surgical excision and one application of local chemotherapy was performed under general anaesthesia. Histopathology confirmed the diagnosis of malignant melanoma and the presence of clean surgical margins. There was no recurrence at 5 weeks post surgery. To our knowledge, this is the first report of a primary malignant melanoma of the third eyelid in a horse.     

Evaluation of lysozyme and lactoferrin in lacrimal and other ocular glands of bison and cattle and in tears of bison

OBJECTIVE: To evaluate lactoferrin and lysozyme content in various ocular glands of bison and cattle and in tears of bison. SAMPLE POPULATION: Tissues of ocular glands obtained from 15 bison and 15 cattle and tears collected from 38 bison. PROCEDURE: Immunohistochemical analysis was used to detect lysozyme and lactoferrin in formalin-fixed, paraffin-embedded sections of the ocular glands. Protein gel electrophoresis was used to analyze ocular glands and pooled bison tears by use of a tris-glycine gel and SDS-PAGE. Western blotting was used to detect lactoferrin and lysozyme. RESULTS: Immunohistochemical staining for lactoferrin was evident in the lacrimal gland and gland of the third eyelid in cattle and bison and the deep gland of the third eyelid (Harder's gland) in cattle. Equivocal staining for lactoferrin was seen for the Harder's gland in bison. An 80-kd band (lactoferrin) was detected via electrophoresis and western blots in the lacrimal gland and gland of the third eyelid in cattle and bison, Harder's glands of cattle, and bison tears. An inconsistent band was seen in Harder's glands of bison. Lysozyme was not detected in the lacrimal gland of cattle or bison with the use of immunohistochemical analysis or western blots. Western blots of bison tears did not reveal lysozyme. CONCLUSIONS AND CLINICAL RELEVANCE: Distribution of lactoferrin and a lack of lysozyme are similar in the lacrimal gland of cattle and bison. Differences in other tear components may be responsible for variability in the susceptibility to infectious corneal diseases that exists between bison and cattle.     

Effect of removal of lacrimal and third eyelid glands on Schirmer tear test results in cats

Schirmer tear tests I and II values for 10 healthy cats were 16.2 +/- 3.8 mm/min and 13.2 +/- 3.4 mm/min, respectively. Surgical removal of the lacrimal gland or the third eyelid gland from the left eye resulted in decreased Schirmer tear test-I values. Clinical signs of keratoconjunctivitis sicca were not seen until the lacrimal and third eyelid glands were removed, at which time the Schirmer tear test-I value was close to 0 mm/min. Conjunctival glands (accessory lacrimal glands of Krause and Wolfring) appeared to contribute little to tear production in these cats.     

Investigations on the conjunctival goblet cells and the characteristics of the glands associated with the eye in chinchillas (Chinchilla Laniger)

Objective To investigate the density and distribution of conjunctival goblet cells (GC) and study the anatomy and microscopic characteristics of glands associated with the eye in chinchillas (Chinchilla Laniger). Procedure 12 chinchillas were included in the study. Conjunctiva (divided into four regions), eyelids, and glands were embedded in paraffin wax, sectioned, stained, and analyzed. Results Highest GC densities were found in the palpebral region of the nasal and temporal conjunctiva of both eyelids (GC index: 25.1-18.2%), and lowest densities, in the bulbar and marginal region of the nasal and temporal conjunctiva of both eyelids (GC index: 1.5-0.0%). Meibomian glands extend along the entire length of both eyelids, and the whole glandular complex broadens toward the temporal canthus. This is macroscopically visible through the conjunctiva. The openings of the Meibomian glands are macroscopically not discernible. The light pink, smooth, and crescent-shaped lacrimal gland lies next to the aforementioned broadened part of the Meibomian glands in the temporal canthus. The whitish, 0.9-cm-long, smooth Harderian gland is firmly attached to the posterior part of the globe and extends nasally from the optic nerve to the equator. Furthermore, chinchillas possess two lacrimal puncta, situated on the inner conjunctival surface of both eyelids near the medial canthus. A pigmented lacrimal canaliculus originates from each punctum. The vestigial nictitating membrane is supported by a hyaline cartilage and is pigmented at its free margin. Conclusions Chinchillas possess a Harderian gland, a lacrimal gland, and Meibomian glands. The GC density in the nasal and temporal palpebral conjunctiva is higher than in guinea pigs.     

Morphology of the third eyelid and superficial gland of the third eyelid on pig fetuses

The morphological and histological examinations of the third eyelid and superficial gland of the third eyelid were conducted in pig fetuses coming from the 20th, 24th, 27th, 30th, 35th, 50th, 63rd, 94th and 112th day of gestation. The morphological examinations were carried out by applying the method of macroscopic preparation with a forehead magnifying glass and binocular (magnification 1.5-5.0x). In order to make anatomical elements more visible, 60-80% absolute alcohol and 0.5-4% acetic acid solution were used for the examinations. On the 20th, 24th, 27th and 30th day of gestation, the whole fetuses were collected for the histological examinations. The whole eyeball with developing accessory organs was collected from the pig fetuses on the 35th day of gestation. On the 50th, 63rd, 94th and 112th day of gestation, only the superficial gland with the third eyelid was collected. Staining with haematoxylin-eosin (H-E) and Azan method was performed. On the 20th, 24th, 27th and 30th day of gestation, the primordia of the glandular epithelium were not found in the examined material. The process of the third eyelid and superficial gland formation starts on the 35th day of gestation. On the 50th and 63rd day of gestation, the gland surrounding the cartilage of the third eyelid is composed of the high amount of loose connective tissue and gland cells which give rise to excretory segments. On the 94th day of gestation, the gland lobes become visible, the efferent ducts form. On the 112th day, the cartilage of the third eyelid assumes the appearance of the mature hyaline cartilage. The excretory segments are composed of simple cuboid epithelium with a large, round nucleus arranged less or more peripherally. Their number increases 2- or even 3-fold at the end of gestation.     

IgA and secretory component (SC) in the third eyelid of domestic animals: a comparative study

Objective The third eyelid of domestic animals is important for the production and distribution of tears, in removing ocular debris and in protection of the globe, and has significant immunologic functions. Although it is known that tears contain antibodies of the immunoglobulin A (IgA) isotype which are produced mainly by plasma cells of the lacrimal gland, very little is known about the antibody repertoires in the third eyelid of domestic animals. To assess whether IgA is derived from local synthesis, we analyzed the location of IgA‐producing cells and the cellular distribution of secretory component (SC) in the third eyelid of domestic animals in a comparative study. Animal studied A total of 83 third eyelids of dogs, cats, pigs, cows, sheep, goats and horses were investigated in the course of this study. Procedures Third eyelids were obtained immediately after death, cut length‐wise, fixed overnight and processed for immunohistochemical detection of IgA and SC by the ABC technique. Results The results show that IgA‐producing plasma cells are densely populated in subepithelial spaces of the surface epithelium as well as in the nictitating gland in a species‐specific manner. In contrast, the SC could be demonstrated exclusively in glandular acinar and ductal epithelial cells and in different cell types of the surface epithelium, preferentially located on the bulbar side of the nictitating membrane. Conclusion It is suggested that most of the SC is locally produced by resident plasma cells and subsequently transferred through the surface epithelium and glandular duct cells by transcytosis. This indicates that the third eyelid is an important member of the secretory immune system in domestic animals.     

Persistent fetal intraocular vasculature in the European ferret (Mustela putorius): clinical and histological aspects

Objective To describe the clinical and histological appearance of persistent fetal intraocular vasculature in a colony of ferrets.
Design Prospective study.
Animals studied Eighty-six European ferrets ( Mustela putorius ).
Procedure Both eyes of 76 genetically related progeny and 10 breeding, adult, colony-raised ferrets were studied using a slit lamp biomicroscope and an indirect ophthalmoscope. Ferret progeny were examined after eyelid opening at 5–6 weeks of age, and at 12 months of age. After euthanasia, globes were enucleated and examined histologically.
Results Persistent fetal intraocular vasculature was evident in 21 progeny ferrets at 5–6 weeks of age and in three mature progenitor ferrets. Clinical appearance of diminutive vasculature was characterized by focal remnants of the posterior tunica vasculosa lentis, muscae volitantes, and an occluded hyaloid artery extending from the optic papilla and terminating in the anterior vitreous body. Extensive persistent vasculature was characterized by a perfused hyaloid artery, vasa hyaloidea propria and posterior tunica vasculosa lentis, posterior cortical and capsular cataract, and proliferation of fibrovascular tissue along the posterior lens capsule. Fetal vasculature persisted in 7 of 21 progeny ferrets at one year of age and in three progenitor ferrets. Results of histologic examination showed persistence of the hyaloid vasculature, proliferation of retrolental fibrovascular tissue with osseous metaplasia, posterior capsular and cortical cataract, and occasional retinal detachment.
Conclusions Persistent fetal intraocular vasculature in ferrets appears similar clinically and histologically to persistent fetal intraocular vasculature reported in humans and dogs. The ferret may be a suitable animal model for vasculogenic mechanisms of persistent fetal intraocular vasculature and for evaluating vasoinhibitory growth factors and angiostatic test compounds.     

Porphyrins are not present in feline ocular tissues or corneal sequestra

Objective To determine if feline lacrimal glands, glands of the third eyelid, corneas, and corneal sequestra contain porphyrins, which could be responsible for the brown/amber discoloration of corneal sequestra and tears in affected cats. Procedures Samples of grossly normal cornea, lacrimal gland, gland of the third eyelid, and sequestra obtained via keratectomy were collected. Porphyrin concentrations of the homogenate were determined by spectrofluorometry with protoporphyrin IX and coproporphyrin III dihydrochloride used as standards. A hamster harderian gland was used as a positive control. Results Normal tissues were harvested from one eye each of 14 nonclient owned, adult, mixed‐breed, short‐hair cats euthanized for reasons not associated with this study. Eighteen sequestra were acquired from cats undergoing unilateral lamellar keratectomies. Breeds of the affected cats included eight Himalayan, five domestic shorthair, and one each of four other breeds. Only the positive control and standards contained levels of porphyrins above background. All feline samples examined were histologically normal with no evidence of porphyrins. Conclusions Porphyrins are absent in normal feline lacrimal glands, corneas, and corneal sequestra. Porphyrins do not appear to be the cause of the brown/amber color of feline corneal sequestra.     

犬第三眼睑增生切除法与包埋法治疗效果的比较

犬第三眼睑增生是由于腺体肥大等原因与瞬膜一起从眼内向外翻转而发生炎症的一种眼病,多采用切除法与包埋法进行治疗。为研究犬第三眼睑增生切除法与包埋法的利弊,本试验将20只双眼患第三眼睑增生且不患其他疾病的犬分为切除组和包埋组,进行手术并跟踪观察比较治疗效果。结果显示,切除法具有手术简便、恢复时间短等优势,但患犬治愈后会有干眼病等后遗症发生,对犬的健康有极大危害;而包埋法虽然手术复杂,恢复时间较长,但只要能熟练的操作也能达到治愈效果,且对患犬不会产生其他不良影响。结果表明,虽然2种手法各有利弊,但切除法的弊大于利,后遗症会带给犬更多的不便;而包埋法的利大于弊,只要能熟练掌握手术方法,做好术后的护理,就可以克服弊端。建议在今后的临床中应尽量的建议前来就诊的畜主使用包埋法对第三眼睑增生进行治疗。