Coronofrontal rhytidectomy: A new approach for the treatment of severe pseudoptosis and superior entropion in dogs.

PURPOSE: To describe the use of coronofrontal rhytidectomy (CFR) for the treatment of severe pseudoptosis and superior entropion in dogs, and to provide guidelines for the selection of surgical technique depending on presentation. METHODS: A review of medical records of dogs that underwent rhytidectomy from 2002 to 2023 was carried out, including signalment, clinical signs, type of rhytidectomy, concurrent surgical techniques, re-interventions, post-operative complications, follow-up time, and outcome. RESULTS: Twenty dogs with a median age of 5.1 years were included in this study. English Cocker Spaniel was the most common breed (8 dogs:40%) and males were overrepresented (13 dogs: 65%). Besides pseudoptosis and visual impairment (100%), the other most common clinical signs were entropion and/or ectropion (19 dogs: 95%), conjunctivitis (17 dogs: 85%), euryblepharon (12 dogs: 60%) and non-ulcerative keratitis (10 dogs: 50%). CFR was performed in 12 dogs (60%), frontal rhytidectomy in 5 (25%), coronal in 2 (10%), and modified shared in 1 (5%). Concurrent surgical techniques were performed in 17 dogs (85%), being lateral canthoplasty (13 dogs; 65%), and Celsus-Hotz (10 dogs; 50%) the most common. The median follow-up time was 115 days with no complications and good outcomes reported in all dogs. At last re-recheck, complete correction of the eyelid positioning was obtained in 92% (11/12) and 87.5% (7/8) of the cases that underwent CFR and other rhytidectomy techniques, respectively. CONCLUSION: CFR is an effective surgical treatment for severe pseudoptosis and superior entropion in dogs. The provided guidelines will assist in the selection of the most appropriate eyelid lifting technique.

Follicular conjunctivitis in dogs: A retrospective study (2007-2022).

OBJECTIVE: To evaluate the incidence, clinical features, treatment, and outcome of canine follicular conjunctivitis (CFC). PROCEDURE: Medical records of dogs diagnosed with CFC were reviewed. Data recorded included signalment, duration of clinical signs and treatment details prior to presentation, concurrent ocular/systemic diseases, ocular clinical signs, cytology, treatment, follow-up, and outcome. Blepharospasm, signs of self-trauma, hyperemia, chemosis, ocular discharge, and follicle location and severity (0.5-4) were retrospectively evaluated. Based on severity, treatment consisted of topical 0.1% diclofenac or 0.1% dexamethasone sodium eyedrops. Dogs were classified into young (YD < 18 months) and adult (AD ≥ 18 months). RESULTS: One hundred and fifty-three dogs (276 eyes) were included in the study: 83YD (54%) and 70AD (46%). Males and bilateral disease were over-represented in both groups. Severity was associated with young age (p = .032) and bilaterality (p = .025), and not with dermatological diseases (p > .05). No differences in follicular location were observed except for more frequent involvement of the nictitating membrane (MN) in YD (p = .02). Response to treatment was faster in AD (p = .001), with complete resolution in 80.6% of the eyes (100/124) at 1 month. YD treated with diclofenac showed faster resolution than those treated with 0.1% dexamethasone (p = .009). CONCLUSIONS: Although CFC is a bilateral ocular disease occurring at any age, the clinical presentation is influenced by age. Follicular conjunctivitis in adult dogs is less sever, less commonly affects the NM, and responds more quickly to topical treatment. One month of topical diclofenac may be adequate for mild cases, and 1 month of topical 0.1% dexamethasone is recommended as initial therapy for moderate to severely affected cases.

Safety and efficacy of unilateral topical application of rocuronium bromide in healthy scops owls (Otus scops).

OBJECTIVE: To evaluate the safety and efficacy of unilateral topical application of rocuronium bromide in scops owls. ANIMALS STUDIED: Ten healthy adult scops owls. PROCEDURES: Birds weighting between 82-111 g were enrolled. Complete physical and ophthalmic examinations were performed. Each animal received a single dose of 0.15 mg of rocuronium bromide (30 µL) in a randomly selected eye. Static pupillometric evaluations were performed before and after drug instillation at 0, 30, 60, 90, and 120 minutes, in a room with fixed light intensity. Physical and ophthalmic examinations were carried out to evaluate possible adverse effects. RESULTS: Median pupil (95% CI) size at t0 was 7.10 mm (5.51-7.41) for placebo eyes and 7.22 mm (6.93-7.48) for treated eyes, showing no statistical differences (P > .05). When compared to the placebo eye, significant mydriasis was achieved at t30 [8.18 mm (7.22-9.00)] (P = .014) and lasting until t90 [7.35 mm (6.20-9.52)] (P = .004). Maximal mydriasis was obtained at t60 [8.63 mm (7.72-9.81)] (P = .001). During this period, the treated eye no longer responded to direct light stimulation. Complete mydriasis was observed in 5/10 birds (mean weight 97.4 g). Pupil size at t90 and t120 did not differ from baseline (P > .05) in treated eyes. No adverse effects were seen during the study period. CONCLUSION: Single-dose topical rocuronium bromide (0.15 mg) is a safe and effective medium duration mydriatic agent in scops owls. Further studies are needed to evaluate bilateral topical application and standardize the mydriatic protocol.

Effects of topical 1% cyclopentolate hydrochloride on quantitative pupillometry measurements, tear production and intraocular pressure in healthy horses.

OBJECTIVE: To evaluate the effect of topical cyclopentolate hydrochloride (CH) on quantitative pupillometric readings (PR), tear production (TP), and intraocular pressure (IOP) in healthy horses. ANIMALS STUDIED: Fourteen client-owned horses. PROCEDURES: In a two-phase design study, each animal received 1% CH ophthalmic solution in the left eye [treated] and 0.9% NaCl in the right eye [control] (0.2 mL each). In the first phase (n = 7), TP, IOP, and PR assessment was performed by Schirmer tear test I, rebound tonometry and static pupillometry, at 1, 8, 24, 48, 72, 96, 120, 148, 172, and 196-hours post-instillation. In the second phase (n = 7), plateau mydriasis was evaluated by assessing PR hourly for 8 hours post-instillation. For PR assessment, pupil area (PA), vertical diameter (VPD), and horizontal diameter (HPD) were recorded. All pupillometries were obtained in a room with fixed light intensity (45-60 lux). Statistical analysis was performed by generalized estimating equations method for the effect on parameters over time. RESULTS: After topical CH, significant differences in pupil dilation were seen from 1 to 172 hours for VPD and from 8 to 24 hours for PA, without significant differences on HPD over time. In the second phase, plateau PA and VPD were reached at 3 hours, while plateau HPD at 2 hours. No significant effects were detected on TP and IOP in both eyes at any time, nor on PR of the nontreated eyes. CONCLUSIONS: Topical 1% cyclopentolate hydrochloride could be considered an effective and safe option when a mydriatic/cycloplegic drug is needed in horses.

Corneoconjunctival transposition for the treatment of deep stromal to full-thickness corneal defects in dogs: A multicentric retrospective study of 100 cases (2012-2018).

OBJECTIVE: To describe and evaluate the use of corneoconjunctival transposition (CTT) as a surgical treatment for canine deep stromal ulcers, descemetoceles, and full-thickness corneal defects and to determine its efficacy in preserving corneal graft transparency and vision. ANIMALS STUDIED: One hundred client-owned dogs with deep stromal ulcers, descemetoceles, or full-thickness corneal defects. METHODS: Medical records of canine patients that underwent CCT, from 2012 to 2018, were reviewed. Only, patients with preoperative positive consensual pupillary light and dazzle reflexes were included. RESULTS: There were 59 males and 41 females, from 0.3 to 17 years. Brachycephalic breeds were overrepresented (65%). All patients were unilaterally affected, with 16 deep stromal ulcers, 33 descemetoceles, and 51 corneal perforations, of a median (range) size of 4 (2-8) mm. The central cornea was affected in the majority of cases (57%), and euryblepharon and keratoconjunctivitis sicca were the most common concurrent ocular diseases (42% and 40%, respectively). The graft was most frequently harvested from dorsal (67%), and 9/0 absorbable suture material was used. Intraoperative and postoperative complications were seen in 7 and 21 cases, respectively. Mean follow-up time was 107.8 days. Vision was preserved in 96% patients, with 62% showing faint to mild opacification. Among the statistically analyzed variables, euryblepharon and pigmentary keratitis were found to be significantly associated with greater corneal graft opacification (P = .040 and P = .028, respectively). CONCLUSIONS: Corneoconjunctival transposition is an effective surgical treatment for deep stromal, descemetocele, and full-thickness corneal defects in dogs, achieving a highly satisfactory degree of corneal graft transparency and preserving vision.

Ophthalmologic findings associated with Rhodococcus equi bronchopneumonia in foals.

OBJECTIVE: To describe ocular findings associated with Rhodococcus equi bronchopneumonia in foals, and to determine whether severity of the ocular lesions is related with outcome. ANIMALS STUDIED: Foals diagnosed with R equi infection at the VTH-UAB from January 2002 to December 2017. PROCEDURE: Rhodococcus equi infection was diagnosed by means of clinical signs, radiographic/ultrasonographic findings, and/or positive culture. In all the foals, a complete ophthalmic examination by a boarded ophthalmologist was performed and ocular signs were recorded and graded (0-4). RESULTS: Thirty-nine foals were included in the study, from which 12 showed signs of bilateral anterior uveitis (30.8%). Among these, three foals were classified as mildly uveitis-affected (MUA:7.7%) and nine as severely uveitis-affected (SUA:23.1%). Five SUA foals showed green aqueous flare (5/9;55.5%). Despite the systemic treatment, 9/39 sick foals died (23.1%), the fatality rate being different between groups: SUA (4/9;44.4%), MUA (0/3; 0%) and nonuveitis-affected foals (5/27;18.5%). Among SUA foals, only one with green aqueous flare died (1/5;20%). CONCLUSION: Bilateral anterior uveitis is highly prevalent in foals with R equi pneumonia (30.8%). The severity of anterior uveitis might be considered a nonsurvival prognostic factor and, until proven otherwise, green aqueous flare could be taken as a strongly suggestive ocular sign of the disease. Findings of this study remark the clinical relevance of performing a complete ophthalmic examination in sick foals, in order to help in the diagnosis and prognosis of uveal diseases, as well as to guaranteeing visual soundness.

Cryopreservation (-20°C) of equine corneoscleral tissue: Microbiological, histological, and ultrastructural study.

OBJECTIVE: To evaluate microbiological, histological, and ultrastructural characteristics of short-term cryopreserved (STC) equine corneoscleral tissue (<1 year), and to compare it with long-term cryopreserved (LTC) tissue (>7 years). ANIMALS STUDIED: Thirty-four healthy equine globes. PROCEDURE: After a decontamination protocol, globes were enucleated and stored at -20°C in broad-spectrum antibiotics. Corneoscleral tissue was evaluated at different storage periods: 1 month-1 year (20 eyes) and 7-9 years (12 eyes). Two eyes were used as controls. Microbiologic study included direct (blood, McConkey, and Sabouraud agars) and enrichment (brain-heart infusion broth) cultures. Cryopreservation artifacts were evaluated by hematoxylin-eosin. Corneoscleral collagen organization and number of normal and dead keratocytes were established by transmission electron microscopy. RESULTS: All microbiologic direct cultures were negative. Enrichment cultures were positive in 12.5% of corneal and 59.4% of scleral tissues (pcornea  = 0.136; psclera  = 1.000). Cryopreservation artifacts were most commonly observed in LTC tissues (P = 0.002). Normal keratocytes were predominant in STC corneas (STC 60% and LTC 0%) and apoptotic ones in LTC (STC 40% and LTC 90%), whereas necrotic keratocytes were only seen in LTC (LTC 10%) (P = 0.001). No structural differences were detected in collagen organization between STC and LTC (pcornea  = 1.000; psclera  = 0.703). CONCLUSIONS: Cryopreservation of equine corneoscleral tissue did not yield direct bacterial contamination. Apoptosis is the main cause of death of cryopreserved equine keratocytes. Based on the lack of significant structural differences between STC and LTC samples, these cryopreserved tissues could potentially be used for tectonic support for at least 9 years without structural or microbiological impediment.

Endothelial cell density and characterization of corneal endothelial cells in the Tawny Owl (Strix aluco) using specular microscopy.

OBJECTIVE: To determine endothelial cell density (ECD) and morphology and morphometry of corneal endothelial cells in the tawny owl (Strix aluco), as well as to report the effects of aging on these parameters. ANIMAL STUDY AND PROCEDURES: Twenty tawny owls were included in the study and classified into 2 groups according to their age: fledglings (<1 year old) and adults (>1 year old). Central corneal endothelium was studied by means of noncontact specular microscopy (Specular Microscope SP-2000P; Topcon, Tokyo, Japan), and results for ECD (cells/mm2 ), mean cell area ((MCA (µm2 )), polymegathism (CV), and pleomorphism (% hexagonal cells) were obtained. Results are described by median, interquartile range (25th, 75th percentiles), and absolute range for ECD, MCA, pleomorphism, and polymegathism. In addition, inferential analyses by Mann-Whitney U test were also performed. A two-tailed Type I error of 5% was established. RESULTS: Results in fledglings were as follows: ECD = 2864 cells/mm2 , MCA = 348 µm2 , % hexagonal cells = 72.75%, and CV = 21. Results in adults were as follows: ECD = 2602 cells/mm2 , MCA = 384 µm2 , % hexagonal cells = 78.83%, and CV = 16. No significant differences in ECD and MCA were seen between the groups (P > .05), although there were significant differences in % hexagonal cells and CV (P < .05). CONCLUSIONS: Tawny owls present a uniform endothelium in cell size and shape, although ECD and MCA differ greatly from other bird species. Differences in ECD and MCA could not be found between fledglings and adults probably because of the youth of adult specimens, although there were differences in pleomorphism and polymegathism.

A multicenter retrospective study on cryopreserved amniotic membrane transplantation for the treatment of complicated corneal ulcers in the dog.

OBJECTIVE: To describe the surgical technique and outcome of amniotic membrane transplantation (AMT) for treatment of complicated corneal ulcers in dogs. ANIMALS STUDIED: One hundred and eleven dogs. PROCEDURE: Medical records (2010-2017) were reviewed to identify canine patients that underwent AMT for the treatment of complicated corneal ulcers. Quantitative and ordinal variables were analyzed using Mann-Whitney U test and Fisher's Exact test. RESULTS: Brachycephalic breeds were overrepresented (74/111; 66.6%). Three dogs were bilaterally affected. Fifty-one had melting ulcers (51/114; 44.7%), 33 stromal ulcers (33/63; 52.4%), 17 descemetoceles (17/63; 27%), and 13 perforations (13/63;20.6%). Mean defect size was 6.2 mm (2-18 mm). Human (32/114; 28.1%) or bovine (82/114; 71.9%) (AmnioVet(R)) cryopreserved amniotic membranes were used. Monolayer (31/114; 27.2%), bilayer (44/114; 38.6%) or multilayer technique (39/114; 34.2%) was performed, being anchored to the limbus (52/114; 45.6%), to the defect (48/114; 42.1%) or both (14/114; 12.3%). Mean epithelial healing and follow-up times were 25.6 days (15-45) and 98.7 days (21-400), respectively. Most common postsurgical complications included pigmentation (10/114; 8.8%) and graft failure (5/114; 4.4%). Depth and size of corneal lesions, human amniotic membrane (AM) and concurrent ocular diseases were associated with more complications (P < 0.05). Good cosmetic and visual outcomes were achieved in 99.1% (113/114) and 97.4% (111/114) of cases, respectively. Zero to low graft opacity was seen in 23.9% of the eyes (27/113), mild to moderate in 64.6% (73/113) and complete in 11.5% (13/113). CONCLUSIONS: Cryopreserved AMT is an effective surgical technique for the treatment of complicated corneal ulcers in the dog, with highly satisfactory visual and cosmetic outcomes.

A dose-escalation ex vivo study on the effects of intracameral benzalkonium chloride in rabbits.

BACKGROUND: Rabbits are currently not a good model for studying diseases of the corneal endothelium because their corneal endothelial cells (CECs) maintain a high proliferative capacity throughout almost all their life. Addressing this particular feature might allow the use of this species for such a purpose. The aim of this study was to evaluate the corneal endothelial injury after intracameral benzalkonium chloride (BAC) injection into rabbit eyes ex vivo, and to establish the most suitable starting dose for an in vivo study aimed at developing an animal model of corneal endothelial disease. RESULTS: Forty rabbit eyes obtained postmortem by transconjunctival enucleation were divided into 8 groups according to the injected compound: Control (no injection), BSS, and increasing BAC concentrations (0.005%, 0.01%, 0.025%, 0.05%, 0.1% and 0.2%). At 0, 6, 24 and 48 h, ophthalmologic examination of the anterior segment, pachymetry and specular microscopy were performed, and corneas were finally vital-stained and observed under the light microscope to assess the CECs morphology and mortality rate. When compared to BSS, CECs density started to decrease significantly at 0.025% BAC concentration, while mean cell area, corneal edema and corneal thickness began to increase significantly at 0.05%, 0.005% and 0.1% BAC concentrations, respectively. Concentrations of 0.05% BAC and above caused significant increases in CECs pleomorphism (decreased hexagonality) and mortality, compared to control and BSS. CONCLUSIONS: Ex vivo intracameral BAC injection induces corneal endothelial toxicity in rabbits. However, confirmatory in vivo studies are required to develop the desired model, with 0.05% BAC being a suggested starting point.

Cryopreservation (-20 °C) of canine corneoscleral tissue: histological, microbiological, and ultrastructural study.

OBJECTIVE: To evaluate microbiological, histological, and ultrastructural characteristics of short-term cryopreserved (STC) canine corneoscleral tissue (<1 year) and to compare it with long-term cryopreserved (LTC) tissue (>6 years). ANIMALS STUDIED: Thirty-six healthy canine globes. PROCEDURE: After a decontamination protocol, globes were enucleated and stored at -20 °C. Corneoscleral tissue was evaluated at different periods: <1 year (20 eyes) and >6 years (12 eyes). Four eyes were used as controls. Microbiologic study included direct (blood, McConkey and Sabouraud agars) and enrichment (brain-heart infusion broth) cultures. Cryopreservation artifacts were evaluated by hematoxylin-eosin. Corneoscleral collagen organization and number of normal and dead keratocytes were established by transmission electron microscopy (TEM). Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) was also used for keratocyte characterization. RESULTS: Corneal microbial growth was observed in 25% of the direct STC cultures, and in 47.4% and 16.7% of the enriched STC and LTC cultures, respectively. Scleral STC direct cultures were 30% positive, while enrichment cultures were positive in 66.7% and 16.7% of the STC and LTC, respectively (P = 0.011). Cryopreservation artifacts were higher in LTC tissues (P < 0.001). Apoptotic keratocytes were predominant by TEM and TUNEL, in both STC and LTC. Minimal structural differences were detected in collagen organization between STC and LTC. CONCLUSIONS: Cryopreservation of canine corneoscleral tissue seems to reduce bacterial contamination over time. Apoptosis is the main way of death of cryopreserved canine keratocytes. Based on the lack of significant structural differences between STC and LTC samples, these cryopreserved tissues could potentially be used for tectonic support for at least 8 years without structural or microbiological impediment.

Modified brow suspension technique for the treatment of pseudoptosis due to redundant frontal skin in the dog: a retrospective study of 25 cases.

PURPOSE: To describe the outcome of modified brow suspension technique for the treatment of upper eyelid pseudoptosis in canine patients with redundant frontal skin folds. METHODS: Medical records from 1999 to 2015 were retrospectively reviewed. Only dogs that underwent modified brow suspension for treating bilateral pseudoptosis were included in the study. Recorded data included breed, age, gender, main ophthalmic complaint, ocular findings, suture material used for brow suspension, number of slings placed, postoperative treatment, complications, follow-up time, and outcome. RESULTS: Twenty-five adult dogs of different gender and breed fulfilled the inclusion criteria, with the Shar-Pei being overrepresented (19/25;76%). The main complaint at first presentation was mucopurulent discharge (10/25;40%) and blepharospasm (10/25;40%). Concurrent corneal disease was diagnosed in 47 eyes (47/50;94%). Monofilament polyamide was the most frequently used suture material (46/50;92%). Number of slings placed varied, with one in two eyes (4%), two in 28 eyes (56%), three in 17 eyes (34%), and four in three eyes (6%). Complications were seen in three eyes (6%): suture rupture (one eye; 2%) and skin abscess (two eyes; 4%). Mean follow-up time was 17.6 months (1-84 months), with no cases of fold dermatitis or dermatologic disease observed within this period. Good esthetic and functional outcomes were obtained in 47 eyes at first intervention (97%) and in all patients after re-intervention. CONCLUSIONS: The modified brow suspension technique described offers a surgical alternative for dogs with pseudoptosis secondary to redundant frontal skin folds that potentially reduces anesthetic time and facial changes.

Corneal grafting for the treatment of full-thickness corneal defects in dogs: a review of 50 cases.

OBJECTIVE: To describe corneal grafting for the treatment of full-thickness corneal defects in dogs and to determine its effectiveness in preserving vision. METHODS: A review of the medical records of dogs that underwent corneal grafting following corneal perforations (≥3 mm) at the VTH-UAB from 2002 to 2012 was carried out. RESULTS: Fifty dogs of different breed, age and gender were included. Brachycephalic breeds were overrepresented (37/50;74%). All cases were unilateral, with euryblepharon being the most common concurrent ocular abnormality (20/50;40%). Full-thickness penetrating keratoplasties (FTPK) were performed in 21/50 eyes (42%) and lamellar keratoplasties (LK) in 29/50 eyes (58%). Frozen grafts (FroG) were used in 43/50 eyes (86%) and fresh homologous grafts (FreHoG) in 7/50 (14%). Of the former group, 26 were homologous (FroHoG:60%) and 17 heterologous (FroHeG:40%). A combination of topical medication (antibiotics, corticosteroids, cycloplegics, and 0.2% cyclosporine A) and systemic mycophenolate mofetil was administered. Median follow-up time was 200 days. Postsurgical complications included wound dehiscence (6/50;12%) and glaucoma (4/50;8%). Clinical signs of graft rejection were diagnosed as follows: FroHoG (13/26;50%), FroHeG (11/17;65%), FreHoG (4/7;57%), FTPK (12/21;57%), and LK (16/29;55%). Medical treatment successfully controlled graft rejection in 11/28 eyes (39%). Good anatomical outcome was achieved in 86% (43/50), of which 95% (41/43) were visual at last examination, with moderate opacification to complete transparency of the graft present in 48.2%. CONCLUSIONS: Corneal grafting is an effective surgical treatment for full-thickness corneal defects in dogs. If graft rejection is present, additional medical or surgical therapy may be necessary, achieving a highly satisfactory visual outcome.

Effects of age and breed on corneal thickness, density, and morphology of corneal endothelial cells in enucleated sheep eyes.

OBJECTIVE: The purpose of the study was to determine corneal thickness (CT), endothelial cell density (ECD), morphology, and morphometry in ovine eyes, and to report the effects of age and breed on these parameters. ANIMALS STUDIED AND PROCEDURES: Forty-eight healthy ovine eyes were classified into six groups (eight eyes per group) according to animals' age (lambs and adults) and breed (Manchega, Ripollesa, and Rasa Aragonesa). Endothelial cell density (cells/mm(2) ) and CT (µm) were calculated in the central cornea and four peripheral quadrants by means of specular microscopy. Mean cell area (MCA (µm(2) )), pleomorphism (% hexagonal cells), and polymegethism (CV) were evaluated in the central cornea. Statistics consisted of an ANOVA model and a LSD test for the post hoc analysis. RESULTS: Results in lambs were as follows: ECD = 3532 ± 259, CT = 699 ± 56, MCA = 283 ± 22, % hexagonal cells = 75.64 ± 3.09, and CV = 18 ± 8.4; and in adults: ECD = 2204 ± 261, CT = 804 ± 87, MCA = 473 ± 53, % hexagonal cells = 69.9 ± 3.42, and CV = 18.1 ± 5.2. There were differences (P < 0.001) in all parameters studied between both groups except for the CV (P = 0.962). Regarding the breed, Rasa Aragonesa presented a higher CT (P = 0.001) and CV (P = 0.04) compared to other breeds. Mean values of all groups together showed that central and dorsal areas of the cornea were the thickest, whereas temporal quadrant was the thinnest (P < 0.001). CONCLUSIONS: This study demonstrates that age and breed influence corneal and endothelial parameters in sheep.

Cryopreservation (-20 °C) of feline corneoscleral tissue: histologic, microbiologic, and ultrastructural study.

OBJECTIVE: To evaluate microbiological, histologic, and ultrastructural characteristics of short-term cryopreserved (STC) feline corneoscleral tissue (<1 year) and to compare it with long-term cryopreserved (LTC) tissue (>7 years). ANIMALS STUDIED: Twenty healthy feline globes were obtained from 2003 to 2013. PROCEDURE: After a decontamination protocol, globes were enucleated and stored at -20 °C in broad-spectrum antibiotics. Corneoscleral tissue was evaluated at different storage periods: <1 year (10 eyes) and >7 years (8 eyes). Two eyes were used as controls. Microbiologic study included direct (blood, McConkey, and Sabouraud agars) and enrichment (brain-heart infusion broth) cultures. Cryopreservation artifacts were evaluated by hematoxylin-eosin. Corneoscleral collagen organization and number of normal and dead keratocytes were established by transmission electron microscopy. RESULTS: Although microbiologic cultures were positive only in STC [direct (20.8%); enrichment (37.5%)], significant differences between periods were only found in enrichment cultures (P = 0.006). Cryopreservation artifacts were most commonly observed in LTC tissues (P < 0.001). Normal keratocytes were predominant in STC corneas (STC 58.3%, LTC 12.5%) and apoptotic ones in LTC (STC 41.7%, LTC 75%), whereas necrotic keratocytes were only seen in LTC (LTC 12.5%) (P = 0.046). No structural differences were detected in collagen organization between STC and LTC (Pcornea = 0.147; Psclera = 0.362). CONCLUSIONS: Cryopreservation of feline corneoscleral tissue seems to reduce bacterial contamination over time. Apoptosis is the main cause of death of cryopreserved feline keratocytes. Based on the lack of significant structural differences between STC and LTC samples, these cryopreserved tissues could potentially be used for tectonic support for at least 10 years without structural or microbiological impediment.

Effect of topical 1% cyclopentolate hydrochloride on tear production, pupil size, and intraocular pressure in healthy Beagles.

OBJECTIVE: The objective of the study was to evaluate the effect of topical 1% cyclopentolate hydrochloride (CH) on tear production (TP), pupil size (PS), and intraocular pressure (IOP) in dogs. ANIMAL STUDIED: Fifteen healthy beagle dogs from the UAB research-teaching colony. PROCEDURE: Dogs without ocular diseases were included. Each animal received one drop of 1% CH ophthalmic solution in a randomly selected eye. TP, PS, and IOP were evaluated by means of STT-1, static pupillometry, and rebound tonometry, respectively. Evaluations were performed before drug instillation and at 0.5, 1, 2, 4, 8, 12, 24, 30, 36, 48, 54, 60, 72, 84, and 96 h postinstillation. Examinations took place in a room with fixed light intensity (40-55 lux). Statistical analysis was performed by means of generalized estimating equations for the effect on STT-1, pupil size, and IOP over time. RESULTS: After unilateral application of 1% CH, significant pupillary dilation started at 30 min, reached its maximum at 12 h, and returned to pre-instillation size after 72 h. No significant effects were found on TP or IOP, at any time. No effects were observed in the untreated eye on any of the parameters evaluated. CONCLUSION: Cyclopentolate hydrochloride could be considered a therapeutic alternative when use of a cycloplegic drug is needed and effects on tear production and IOP are unwanted.

Corneal grafting for the treatment of feline corneal sequestrum: a retrospective study of 18 eyes (13 cats).

OBJECTIVE: To determine the clinical outcome of corneal grafting for the treatment of feline corneal sequestrum (FCS). ANIMAL STUDIED: Domestic cats. PROCEDURES: A review of the medical records of cats that underwent keratoplasty as a treatment of FCS at the VTH-UAB, from 2002 to 2012, was carried out. RESULTS: Thirteen cats (18 eyes) of different breed, age, and gender were included. Persian cats were overrepresented (12/13;92%). There were nine males and four females, of a mean age of 3.4 years (0.7-7.1). Ipsilateral chronic corneal ulceration was reported as the most common concurrent ocular disease (6/18;33%). Keratoplasty was performed bilaterally in 5 cats (5/13;38%) and unilaterally in 8 (8/13;62%). Lamellar keratoplasty was performed in 17 eyes (17/18;95%) and full-thickness keratoplasty in 1 (1/18;5%). Mean graft size was 8.3 mm (4-11.5). Fresh homologous graft was performed in 2 eyes (2/18;11%) and frozen graft in 16 (16/18;89%). Of the latter group, homologous graft was performed in 6 eyes (6/16;37.5%) and heterologous in 10 (10/16;62.5%). In all the cats, postoperative treatment included topical antibiotics, corticosteroids, cycloplegics, and 0.2% cyclosporine A. Median follow-up time was 18.2 months, and main postoperative complications were diffuse mild epithelial pigment formation (2/18;11%), graft malacia (1/18;5%), and sequestrum recurrence (1/18;5%). Mean epithelial healing time was 19.2 days. Good visual outcome was achieved in all the eyes (100%), the majority of them having faint or mild corneal opacity (15/18;83%). CONCLUSIONS: Keratoplasty is an effective surgical treatment for FCS. The donor tissue provides excellent tectonic support to the affected corneas, with good visual and cosmetic outcome.

A comparative study of corneal sensitivity in birds of prey.

OBJECTIVE: To determine and compare the corneal sensitivity in healthy wild diurnal and nocturnal birds of prey (BP) indigenous to Catalonia (Spain), and to establish if age is a determining factor in corneal sensitivity in those species. METHODS: Ophthalmic examination was performed in 105 BP. Only birds with no ocular abnormalities were included in the study (n = 81): 21 diurnal BP (Falco tinnunculus: 16 fledglings, 5 adults) and 60 nocturnal BP (20 Athene noctua [9 fledglings, 11 adults], 20 Strix aluco [15 fledglings, 5 adults], and 20 Otus scops [6 fledglings and 14 adults]). Corneal touch threshold (CTT) was determined for each eye in five different corneal regions. Five attempts to cause a blink reflex were made in each region, and when three or more reflexes were positive, the pressure was deemed the CTT. Statistical analysis was performed using a Student's t-test for independent data or an anova model. The results between species and age groups were compared using the Generalized Estimated Equations model. RESULTS: There were no significant differences between any of the corneal regions (P = 0.25), or between the right (CTT = 4.9 ± 1.7 cm) and left (CTT = 4.8 ± 1.7 cm) eye in any of the species (P = 0.692). No difference was found between diurnal and nocturnal species (P = 0.913). Considering all the species, a significant difference was found between the mean CTT of fledglings (5.4 ± 1.2 cm) and adults (4.1 ± 2 cm), P < 0.001. A significant difference was found between fledglings and adults of A. noctua (P < 0.001) and S. aluco (P = 0.002). CONCLUSIONS: There is no significant difference in CTT between the different corneal regions in all the species studied. Corneal sensitivity is similar between diurnal and nocturnal birds of prey. Age is a determining factor in the CTT of A. noctua and S. aluco, with fledglings having a significantly higher CTT.

Surgical treatment of epibulbar melanocytomas by complete excision and homologous corneoscleral grafting in dogs: 11 cases.

OBJECTIVE: The aim of the study was to evaluate the efficacy, outcome, and complications following penetrating sclerokeratoplasty and frozen homologous corneoscleral grafting for the management of extensive canine epibulbar melanocytomas. METHODS: Medical records of canine patients treated at three different veterinary hospitals between 1999 and 2010 were reviewed. Signalment, location and extent of melanocytomas, recurrence rate, and early and late complications were reported. Patients were re-examined postoperatively to provide follow-up information. RESULTS: Patients included one intact male, three castrated males, six intact females, and one spayed female, with a median age of 5 years (range, 3-9). German Shepherds were overrepresented. Tumors extended from 2 to 4 clock hours at the limbus and up to 17 mm from clear cornea to globe equator. One case showed iridocorneal angle invasion; corneal involvement was present in all cases, and lipid keratopathy was present in four cases. In two cases, there was incomplete resection owing to tumor extent. Follow-up time ranged from 3 to 72 months (median, 17 months), with one case of intraocular tumor progression. Early complications included anterior uveitis (11/11), intracameral fibrin (5/11), hyphema (4/11), corneal edema (4/11), exuberant corneal granulation tissue (2/11), focal retinal edema (1/11), dyscoria (1/11), and partial suture dehiscence (1/11). Late complications included corneal fibrosis and/or pigmentation (11/11), faint anterior cortical cataracts (3/11), and lipid keratopathy (1/11). Vision was retained in all cases. CONCLUSIONS: This technique offers a surgically challenging but effective treatment for extensive epibulbar melanocytomas. In this case series, complications were mild and transient, with preservation of ocular anatomy and function.

Benign intraocular teratoid medulloepithelioma causing glaucoma in an 11-year-old Arabian mare.

CASE DESCRIPTION: An 11-year-old Arabian mare was presented for investigation of a visible, pale-colored intraocular mass in the right eye. CLINICAL FINDINGS: An intraocular mass was detected clinically and ultrasonographically as originating from the superior temporal quadrant of the ciliary body and iris and causing secondary glaucoma. The echodense mass was occupying the majority of the vitreous chamber and extended into the anterior chamber. The left eye appeared normal. TREATMENT AND OUTCOME: Enucleation was recommended for therapeutic and diagnostic purposes. No adjuvant treatment was given. Histopathological examination demonstrated a benign intraocular teratoid medulloepithelioma located at the ciliary body. Immunohistochemical studies showed that neoplastic cells were positive for vimentin, S-100 protein, neuron-specific enolase (NSE), and nestin and negative for glial fibrillary acidic protein (GFAP). Electron microscopy revealed abundant cellular matrix and blood vessels surrounding tumor cells, which had indented, round to oval nuclei. There were also apoptotic bodies and cells containing melanosomes of variable shape and size. Eight years later, the horse has had no recurrence and maintains normal vision in the left eye. CLINICAL RELEVANCE: This is the first report of a benign teratoid intraocular medulloepithelioma in an adult horse and the ultrastructural and immunohistochemical characterization of a teratoid medulloepithelioma in this species.