OBJECTIVE:To compare the effects of indirect pupillary light reflex (PLR) stimulation using differently colored lights on corneal specular microscopy performance in dogs and to determine the influence of pupil diameter. ANIMALS STUDIED:20 client-owned dogs (38 eyes) with healthy corneas. PROCEDURES:In this prospective study, one eye underwent specular microscopy while the contralateral eye was exposed to white, red, or blue light in a randomized order. The duration of the technique was measured from tracking onset to imaging completion. A 30-s time limit was imposed to prioritize animal welfare, and trials not completed within this duration were recorded as unsuccessful. Pupil diameter was measured immediately before imaging completion or at 30 s in unsuccessful trials. RESULTS:Blue light was associated with the highest success rate within 30 s (97.4%), followed by white (93.4%) and red (88.2%) lights. Linear mixed-model analysis showed that blue light was also associated with the shortest procedural duration and greatest degree of miosis, whereas red light was associated with longer procedural durations and weaker pupillary constriction. After adjusting for light condition, pupil diameter was not independently associated with procedural duration. Because pupil diameter and light condition were closely related, their respective contributions to imaging efficiency could not be fully distinguished. CONCLUSIONS:Indirect PLR stimulation with blue light enhanced the efficiency of corneal specular microscopy in conscious dogs. The relative contributions of miosis and other wavelength-dependent physiological or optical effects remain uncertain.

Objective To compare unsedated noncontact specular microscopy imaging techniques for the canine corneal endothelium and identify the most effective technique.Animals Studied Nineteen eyes of 10 systemically healthy, staff-owned dogs with clinically normal corneas were studied.Procedure Six imaging groups were divided according to the different techniques used in all eyes: central focusing, with (CP) or without (CN) induction of an indirect pupillary light reflex (PLR); peripheral focusing with (PP) or without (PN) an indirect PLR; PP with application of a contact lens (CL); and gaze fixation with a treat (GF). The success rates, imaging times, and endothelial cell indices were compared.Results Success rates differed significantly among the techniques, with PP and CL achieving significantly higher success rates than CN. When only successful images were analyzed, the mean imaging time showed no statistically significant differences between the groups. In the sensitivity analysis, PP required significantly shorter imaging times than CN and PN. The Endothelial cell indices (cell count, endothelial density, and hexagonality) did not differ significantly among the techniques.Conclusions Peripheral focusing combined with the induction of an indirect PLR (PP) achieved significantly higher success rates and shorter imaging times than other techniques, suggesting that this technique provides the most reliable and efficient approach for evaluating the canine corneal endothelium with noncontact specular microscopy under unsedated conditions.

OBJECTIVE:To visualize corneal endothelial cells in enucleated porcine eyes using slit-lamp imaging with a mobile smartphone (SLiM), determine optimal illumination conditions, and explore agreement between SLiM and vital dye stained imaging. ANIMALS STUDIED:Twelve enucleated porcine eyes. PROCEDURES:Corneal endothelium imaging conditions of the SLiM were varied by adjusting the angle between the illumination unit and microscope unit (AIM), slit-width (SW), and light intensity (LI). Subsequently, the corneal endothelium was stained with a vital dye as a reference. SLiM image quality was graded to identify optimal conditions. Endothelial cell density (ECD), percentage of hexagonal cells (HEX), and the coefficient of variation in cell area (CV) were compared between SLiM and stained images. RESULTS:The cumulative link mixed model showed that AIM, SW, and LI significantly influenced the image quality. Image quality grades were significantly higher with 60° AIM than with 40° or 80° AIM (p < 0.001) and lower with 7 mm SW than with 3 or 5 mm (p < 0.001). High and medium LI produced higher grades than full LI (p < 0.05), whereas Low LI significantly reduced image quality (p < 0.001). SW and LI had a statistically significant interaction effect on image quality grades. Best-performing conditions were 60° AIM, 3 mm SW, and high LI. ECD, HEX, and CV values obtained from SLiM and vital dye stained images were comparable in three selected eyes. CONCLUSIONS:SLiM was feasible for imaging porcine corneal endothelial cells, with optimal image quality achieved under specific illumination conditions.

Objective:To describe a nonsurgical treatment for superficial corneal epithelial inclusion cysts (CEICs) in dogs and to characterize their clinical and diagnostic features using ultrasound biomicroscopy (UBM) and optical coherence tomography (OCT). Animals:4 client-owned dogs with superficial CEICs. Clinical Presentation:Complete ophthalmic examinations and diagnostic imaging using UBM and/or OCT were performed on smooth, fluctuant, painless masses protruding from vascularized corneas. For superficial CEICs, needle lancing was performed under topical anesthesia. Results:All dogs had been previously managed for keratoconjunctivitis sicca. Ultrasound biomicroscopy or OCT revealed superficial intrastromal cystic lesions surrounded by hyperechoic or hyper-reflective stroma, consistent with CEICs. All cysts were located within vascularized corneal stroma, with sufficient posterior stromal thickness and intact Descemet membrane beneath the cysts. Among 6 initially identified cysts, 1 ruptured spontaneously following trauma and was no longer detectable at reexamination. One cyst was excised by superficial keratectomy, and histopathologic examination confirmed CEIC; this cyst subsequently recurred. The remaining 4 cysts were intentionally treated by needle lancing using a 26-gauge needle under topical anesthesia. Cytologic examination of the drained material revealed predominantly extracellular matrix and epithelial cells without evidence of infection, supporting the diagnosis of CEIC. Topical anti-inflammatory agents and antibiotics were prescribed after lancing. None of the lanced cysts recurred during a follow-up period of 17 to 62 months. Clinical Relevance:Needle lancing may represent a safe, simple, and effective treatment option for superficial vascularized CEICs in dogs. Advanced diagnostic imaging, such as UBM/OCT, may aid in determining cyst depth and guiding treatment selection.

OBJECTIVE:To evaluate the accuracy of the TONOVET Plus (TVP) and TONOVET Pro (TVPR) in measuring intraocular pressure (IOP) in ex vivo cynomolgus monkey eyes compared to manometry, and to determine the accuracy of Canine and Lapine calibration modes: ANIMALS STUDIED: Five enucleated eyes from three cynomolgus monkeys. PROCEDURES:The anterior chambers were cannulated to regulate IOP manometrically from 5 to 80 mmHg. Agreement between tonometric and manometric readings was analyzed using a linear mixed-effects model (LMM), Lin's concordance correlation coefficient (CCC), and repeated-measures Bland-Altman analysis. Data points at the 80 mmHg manometric setting were excluded to prevent artificial distortion from the devices' maximum display limits. RESULTS:Strong linear relationships were observed between manometric and tonometric IOPs for all modes. However, the Lapine mode demonstrated proportional overestimation with steeper regression slopes compared to the Canine mode. The Canine mode showed excellent agreement (CCC: 0.967 for TVP, 0.971 for TVPR) with minimal mean bias. In contrast, the Lapine mode exhibited significant positive bias and wider limits of agreement, particularly at higher pressures. CONCLUSIONS:Both TVP and TVPR provided accurate and reliable IOP measurements in cynomolgus monkeys when using the Canine calibration mode. Despite the central corneal thickness of cynomolgus monkeys being closer to that of rabbits, the Lapine mode resulted in significant overestimation and is not recommended. Among the tested settings, the Canine mode provided highly accurate IOP measurements with minimal bias, whereas the Lapine mode significantly overestimated IOP.

There is a clinical challenge in decision-making regarding prophylactic glaucoma treatment based solely on intraocular pressure (IOP) trends for long-term cataract management or before phacoemulsification surgery in canines. This study aimed to compare IOP and ultrasound biomicroscopy (UBM) parameters with cataract maturity in small dog breeds. We conducted a retrospective review of medical records pertaining to ophthalmic examinations and UBM assessments of small breed dogs diagnosed with cataracts at the Veterinary Medical Teaching Hospital of Seoul National University from January 2020 to August 2024. UBM images obtained under topical anesthesia were analyzed to quantify various parameters. Subsequently, the 47 eyes examined were classified into four groups according to cataract maturity. The ciliary cleft area (CCA), ciliary cleft length (CCL) and width (CCW), and iridocorneal angle (ICA) were measured. The measured values were compared to determine their degree of correlation with cataract maturity. Statistical analyses of patient demographics were also performed. Both CCA (P=0.0024) and CCL (P=0.0004) decreased significantly with increasing cataract maturity. However, IOP, CCW, and ICA were not significantly associated with cataract maturity. Age and sex did not have significant effects on any dependent variable. Among the UBM parameters, CCA and CCL demonstrated a significant correlation with cataract maturity, indicating structural alterations in the ICA might develop in association with cataracts, independent of direct IOP effects. These findings underscore the importance of considering prophylactic glaucoma management in patients with advanced cataracts to mitigate potential complications.

Tooth resorption (TR) is a clinically significant dental condition in dogs; however, its classification and prevalence, particularly in small breeds, remain understudied despite its impact on quality of life. This retrospective study aimed to assess and classify the types of TR in small-breed dogs and investigate associations between TR and factors such as sex, skull type, body weight, number of missing teeth, TR type, breed, and age. Dental radiographs of 248 dogs weighing less than 15 kg, examined over a three-year period, were included in this study. Statistical analyses were performed to investigate the associations between the examined variables and TR. The most common type of resorption was external replacement resorption (ERR), followed by external inflammatory resorption (EIR). Significant associations were found among age, number of missing teeth, and total TR (p < 0.01). In addition, the prevalence of ERR and EIR increased with age (p < 0.01). The rate of TR was significantly higher in premolars than in incisors, canines, and molars (p < 0.001). Maltese dogs showed a significantly higher prevalence of TR (p < 0.05), particularly ERR (p < 0.05), than other breeds. The TR rate increased significantly in dogs aged 9-11 years, 12-15 years, and over 15 years. Given the high prevalence of TR in older small-breed dogs, particularly in premolars and breeds such as Maltese, clinicians should exercise caution during tooth extraction. Thorough radiographic evaluation is recommended to accurately assess the extent of resorption, especially in older dogs and predisposed breeds.

ABSTRACT Objective To evaluate the accuracy of recalibrated TONOVET Plus (rTVP) and the newly released TONOVET Pro (TVPR) in measuring intraocular pressure (IOP) in ex vivo canine eyes compared to manometer and the established TONOVET (TV). Procedure Sixteen enucleated canine eyes were cannulated to establish manometric IOPs ranging from 5 to 80 mmHg. IOP measurements were obtained using TV, rTVP, and TVPR. Results All tonometers showed a strong correlation with the manometer ( R 2 > 0.98). Measurements from rTVP and TVPR exhibited almost perfect agreement with the manometer (CCC = 0.9974 for both), whereas TV demonstrated lower agreement (CCC = 0.9874) associated with greater systematic bias. Specifically, TV showed a lower proportional bias (95% confidence interval [CI] of the slope = 0.987–1.006) but a larger systematic bias (intercept = −3.33 mmHg) compared to rTVP and TVPR (95% CI of the slope = 1.045–1.066 and 1.045–1.063; intercept = −2.532 and −2.633 mmHg, respectively). In accuracy analyses by range, rTVP and TVPR showed no significant difference from the manometer in the 30–70 mmHg and 35–80 mmHg IOP ranges, respectively. Conclusions Among the ICare rebound tonometers, rTVP and TVPR provided the most accurate IOP measurements in the ex vivo analysis and demonstrated particularly strong agreement in the high IOP range, suggesting their suitability for IOP measurement in glaucomatous patients.

This study aimed to design and evaluate a novel trans-bleb device (TBD) for draining aqueous humor trapped within fibrotic blebs following Ahmed glaucoma valve (AGV) implantation in dogs. Two clinically normal, purpose-bred Beagles underwent AGV implantation surgery in one eye. When a bleb was formed with increased intraocular pressure (IOP), the TBD was inserted through a fenestration created in the bleb. IOP measurements, slit-lamp biomicroscopic and ultrasound biomicroscopic (UBM) evaluations were performed during follow-up. Results showed that IOP in the eyes undergoing AGV surgery was significantly lower than in the contralateral normal eye (P < .001). After 3 weeks, the IOP increased, and the UBM examination confirmed the presence of a bleb wall and an underlying cavity. After TBD application surgery, a significant decrease in IOP was observed (P < .001). Histological findings indicated that the TBD effectively penetrated the fibrotic membrane surrounding the AGV, with observed mild inflammatory cell infiltration, neovascularization, and myofibroblast differentiation, suggesting filtering bleb formation. The TBD may offer a novel approach to address bleb fibrosis-related failure following glaucoma surgery, restoring aqueous humor flow, and thus reducing IOP. Further research is needed to validate its effectiveness, optimize its design, and assess long-term outcomes.

OBJECTIVE:To investigate responses to surgical interventions in concentrations of transforming growth factor-β2 (TGF-β2) and total protein (TP) in the aqueous humor (AH) of primary angle-closure glaucoma (PACG) eyes, with and without Ahmed glaucoma valve surgery in dogs. ANIMAL STUDIED:Nineteen eyes diagnosed with PACG from client-owned dogs and nine non-glaucomatous eyes from both client-owned dogs and research Beagles. PROCEDURES:AH samples were collected and analyzed for TP and TGF-β2 via bicinchoninic acid assay and an enzyme-linked immunosorbent assay. The samples included AH from pre-surgical eyes that had aqueous paracentesis for intraocular pressure (IOP) management (pre-surgical group; n = 6) and from post-surgical eyes when tissue plasminogen activator was injected (post-surgery group; n = 7); fluid aspirated from blebs during surgical revision (bleb group; n = 6), and normal control AH samples from both client-owned dogs undergoing ocular surgery for non-glaucomatous conditions and research Beagles (control group; n = 9). RESULTS:TP and TGF-β2 concentrations were significantly higher in all PACG groups compared to normal AH (p < 0.01). Bleb fluid exhibited the highest TP and TGF-β2 concentrations among glaucomatous groups. Post-surgical AH had significantly lower TGF-β2 concentrations than both pre-surgical and bleb fluid (p = 0.0168, p = 0.0023, respectively). No significant correlation was found between IOP and either TP or TGF-β2 in any group (p > 0.05). CONCLUSIONS:Elevated TGF-β2 in PACG could contribute to disease progression and post-surgical fibrosis. These findings support future studies to examine the potential of TGF-β2 modulation as a therapeutic approach to improving long-term surgical outcomes following Ahmed glaucoma valve surgery in canine PACG.

OBJECTIVE:To investigate ocular factors that influence the development of corneal calcareous degeneration (CCD) in dogs. ANIMALS AND PROCEDURES:The medical records of 96 eyes of dogs with CCD and 288 eyes without CCD were retrospectively reviewed. Dogs with evidence of causative systemic illness associated with CCD were excluded from the study. Logistic regression analysis was used to identify the ocular factors associated with the development of CCD. To identify the effect of phosphate-containing eyedrops on CCD, the application periods of phosphate-containing antiglaucoma eyedrops were compared between the glaucomatous eyes in the CCD and non-CCD groups. RESULTS:Increased age, brachycephalic breed, keratoconjunctivitis sicca, advanced cataract, history of phacoemulsification, and topical corticosteroid application were significantly associated with CCD development. Glaucoma was significantly overrepresented in the non-CCD group, and the application period of phosphate-containing antiglaucoma eyedrops was significantly longer in eyes with CCD than in those without CCD. CONCLUSIONS:Ophthalmic diseases requiring long-term management of ocular inflammation and long-term application of phosphate-containing eyedrops may contribute to the development of CCD. Glaucoma is overrepresented in dogs without CCD, which is thought to be due to the differences in predisposed age and breeds between dogs with glaucoma and CCD.

OBJECTIVE To evaluate whether the administration of 2% dorzolamide ophthalmic solution in dogs undergoing ophthalmic surgery is associated with perianesthetic metabolic acidosis. ANIMALS 60 dogs, with or without dorzolamide administration, underwent arterial blood gas analysis immediately after anesthesia for ophthalmic surgery between 2019 and 2022; a total of 60 surgeries were evaluated. METHODS This was a retrospective cross-sectional study. Logistic regression analysis was performed to investigate the association between the administration of 2% dorzolamide ophthalmic solution in dogs and the development of metabolic acidosis. Additionally, the influence of various potential risk factors, including age, body weight, sex, use of topical or systemic NSAIDs, and preoperative medications on the occurrence of metabolic acidosis, was evaluated. RESULTS A significant association was found between the use of 2% dorzolamide ophthalmic solution and perianesthetic metabolic acidosis (OR, 6.79; 95% CI, 2.00 to 23.02; P = .002). Furthermore, topical dorzolamide administration was significantly associated with both perianesthetic hypokalemia (OR, 3.52; 95% CI, 1.11 to 11.20; P = .033) and perianesthetic hyperchloremia (OR, 9.25; 95% CI, 1.71 to 50.01; P = .010). CLINICAL RELEVANCE The use of 2% dorzolamide ophthalmic solution is associated with perianesthetic metabolic acidosis, hypokalemia, and hyperchloremia in dogs. It is prudent to be aware of these risks, especially before anesthesia.

OBJECTIVE:To evaluate the prevalence of oral bacteria in the conjunctiva of brachycephalic and nonbrachycephalic dogs.ANIMALS:12 brachycephalic (9.58 ± 3.55 years) and 12 nonbrachycephalic (8.33 ± 4.92 years) dogs without systemic disease, regardless of breed and sex, were included in the study, and half of the dogs in each group had periodontitis.METHODS:This prospective study investigated clinical data including craniofacial ratio, ophthalmic examination results, and periodontal status of the included dogs. Bacterial samples were collected by swabbing the oral mucosa and conjunctival surfaces. The presence and quantity of bacteria were analyzed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, 16S rRNA sequencing analysis, and the 10-fold dilution method. Statistical analyses were performed to assess correlations and factors influencing the presence of oral bacteria in the conjunctiva.RESULTS:The most common bacteria in the conjunctival flora in both groups were Micrococcus luteus, Corynebacterium spp, and Staphylococcus spp. The prevalence of oral bacteria on the conjunctival surface was 33%, with a significantly higher incidence in brachycephalic dogs (P = .027). Oral bacteria detected in the conjunctiva were predominantly Frederiksenia canicola, Neisseria spp, and Moraxella spp. Multiple regression analysis identified age, craniofacial ratio, and gingival index as factors influencing the presence of oral bacteria in the conjunctival flora.CLINICAL RELEVANCE:Oral resident bacteria have often been isolated from severe infectious corneal ulcers. This study provided evidence that brachycephalic dogs may require dental prophylaxis to reduce their oral bacterial load and that the association of oral bacteria in ocular diseases should be considered.

OBJECTIVE:To evaluate the changes in the width of the lower lacrimal canaliculi (LC) upon instillation of artificial tears (AT) at different temperatures and viscosities using spectral-domain optical coherence tomography (SD-OCT). ANIMAL STUDIED:Eight eyes of four client-owned adult dogs. PROCEDURES:Imaging of lower LC was performed under general anesthesia. AT at temperatures of 2°C, 20°C, and 38°C, and a high-viscosity tear gel of 20°C, were topically instilled in 100 μL volumes. SD-OCT tracked LC width changes following each instillation. RESULTS:The average baseline width of the LC was 96.38 ± 30.18 μm. The 2°C AT expanded LC width to 183.50 ± 44.11 μm, returning to baseline in 5.00 ± 1.31 min. The 20°C AT resulted in a width of 155.25 ± 35.79 μm, with a 3.88 ± 1.25 min return. The 38°C AT expanded LC width to 131.75 ± 29.49 μm, with a 2.25 ± 0.89 min return. The high-viscosity tear gel expanded LC width to 208.57 ± 56.31 μm, with remained expanded for 10 or more minutes. In temperature comparisons, the 2°C and 20°C AT significantly expanded the LC width more and had longer return times than the 38°C AT (p < .05). Viscosity comparisons showed higher viscosity eye drops significantly expanded LC width more than lower viscosity eye drops (p < .05). CONCLUSIONS:This study found that lower temperature and higher viscosity of eye drops had tendency to result in a wider expansion of the LC width. Additionally, the return time to baseline for LC width tended to be longer with eye drops of lower temperature and higher viscosity. This finding could be helpful in advancing future research on tear dynamics.

ObjectiveTo describe the hyperproliferation of Elschnig pearl-type posterior capsule opacification and concurrent uveitis in two canine eyes after phacoemulsification, followed by spontaneous resolution of the Elschnig pearls.Animal StudiedA 10-year-old castrated male Spitz (Case 1) and a 4-year-old spayed female Bichon Frise (Case 2).ProcedureElschnig pearls proliferating beyond the anterior capsulotomy site were observed in the right eye 10 months after bilateral diabetic cataract surgery (Case 1) and 7 months after unilateral cataract surgery (Case 2). In both cases, hyperproliferation occurred where the anterior capsule did not overlap with the intraocular lens (IOL), and was accompanied by aqueous flare. In Case 1, the pearls extended from the anterior capsule and adhered to the iris, causing focal posterior synechia. No other possible causes of uveitis were apparent.ResultsInitially, uveitis severity improved after the administration of topical and systemic anti-inflammatory drugs. However, uveitis recurred when the dosage of anti-inflammatory treatment was reduced. The Elschnig pearls underwent morphological changes throughout the follow-up period. In both cases, the pearls beyond the anterior capsulotomy resolved spontaneously after 5 months. Only a few pearls remained between the IOL and posterior capsule, and no recurrence of pearl proliferation was observed at the last follow-up.ConclusionsTo the best of our knowledge, this is the first report of spontaneous Elschnig pearl regression in dogs. Lens-induced uveitis (LIU) may have been caused by anterior chamber hyperproliferative pearls. LIU associated with hyperproliferative pearls may be managed with appropriate anti-inflammatory treatment and monitoring.

OBJECTIVE:To evaluate alterations in epithelial thickness during corneal degeneration, corneal pigmentation, and additional features observed through spectral-domain optical coherence tomography (SD-OCT) in brachycephalic dogs.ANIMALS AND PROCEDURES:The study used 55 eyes from 49 brachycephalic dogs that underwent OCT-containing ophthalmic examinations. The examined eyes were classified into corneal degeneration, corneal pigmentation, and normal groups according to corneal lesions. For each eye, corneal epithelial thickness (CET) in the central cornea and maximum limbal epithelial thickness (maxLET) in 4 quadrants of limbus (superior, inferior, nasal, and temporal) were measured from OCT images. Additional abnormal findings on OCT images, including irregular epithelium, subepithelial hyperreflectivity, and conjunctivochalasis, were also recorded.RESULTS:The corneal degeneration group had significantly thinner nasal and temporal maxLETs than that of the normal group (p < .001). In the central corneal OCT image of the corneal degeneration group, an irregular epithelium was observed in 70.6% and subepithelial hyperreflectivity in 82.4%, both of which were significantly higher than the normal group (p < .001). In a comparative analysis, the nasal, temporal, and inferior maxLETs were significantly thinner in the corneal pigmentation group than those in the normal group (p < .001, p < .001, and p = .01, respectively).CONCLUSIONS:Morphological changes in the limbal epithelium were observed in dogs with corneal degeneration and corneal pigmentation. LET reduction could be associated with their pathogenesis and would be valuable as an additional parameter for corneal diseases.

This report aims to describe a case of tumor-like lymphoplasmacytic conjunctivitis in a 7-year-old spayed-female Pomeranian. On complete ophthalmic examination, a mass with papillary projections was noted on the bulbar surface of the right third eyelid. Debulking of the mass was performed while preserving as much of the third eyelid as possible. On the histopathological examination, the mass was diagnosed as lymphoplasmacytic conjunctivitis with mild epithelial hyperplasia. Although a slight regrowth of the mass was noted 3 weeks after surgery, intralesional injection of triamcinolone acetonide led to its disappearance. There was no further recurrence after 5 months.

OBJECTIVE:To evaluate the long-term efficacy, prognostic factors, and complications of intravitreal cidofovir injection in dogs with end-stage glaucoma.ANIMALS:130 client-owned dogs.METHODS:Medical records of dogs that underwent intravitreal cidofovir injections were reviewed. A minimum follow-up period of 6 months was required as the inclusion criterion. Signalment, type of glaucoma, preinjection intraocular pressure (IOP), types of applied glaucoma eye drop, coexisting ocular diseases, outcomes, and complications were recorded. Success was defined as IOP of ≤ 25 mm Hg at the 2-week recheck that remained to the 6-month recheck.RESULTS:The overall success rate of intravitreal cidofovir injection was 91.5% (140/153). The success rate of a single injection was 69.3% (106/153), of a second injection was 59.5% (25/42), of a third injection was 42.9% (6/14), of a fourth injection was 33.3% (2/6), and of a fifth injection was 50.0% (1/2). Intraocular pressures at 6 months after injection were relatively higher when the injection was repeated, fewer types of glaucoma eye drop were applied prior to the injection, and cataract stages were advanced at the time of injection (P < .05). The most common complications were phthisis bulbi (42.5%), cataract progression (30.1%), and intraocular hemorrhage (16.3%). Six eyes were enucleated, and 3 were enucleated due to corneal perforation.CLINICAL RELEVANCE:Intravitreal cidofovir injection had a high long-term success rate in lowering IOP in dogs with end-stage glaucoma.

OBJECTIVE To assess the characteristics of blebs formed after Ahmed glaucoma valve (AGV) surgery in dogs using ultrasound biomicroscopy (UBM) and to analyze their correlation with postoperative intraocular pressure (IOP). ANIMALS 16 eyes (13 dogs) were diagnosed with primary angle -closure glaucoma and were followed up after AGV surgery from June 2021 to September 2023. METHODS In this prospective study, UBM examinations were performed to assess bleb characteristics, including bleb wall thickness and reflectivity. IOP at the time of UBM imaging and the duration from AGV surgery to UBM imaging were recorded. Histological examination of an enucleated eye removed due to uncontrolled IOP leading to blindness was also conducted. RESULTS A significant correlation was observed between IOP and relative reflectivity (Pearson r = 0.60; P = .01), and a negative correlation was observed between bleb wall thickness and relative reflectivity (Pearson r = -0.72; P = .002). No significant correlation was observed between the duration from AGV surgery to UBM imaging and either bleb wall thickness or relative reflectivity, respectively. Histological examination of the enucleated eye revealed collagenrich fibrous encapsulation of the bleb wall, including myofibroblasts that exhibited positive alpha-smooth muscle actin immunostaining. CLINICAL RELEVANCE In dogs that underwent AGV surgery, less dense, thick-walled blebs on UBM tended to maintain IOP within the normal range. However, denser, thinner -walled blebs showed IOP levels above the normal range despite the use of antiglaucoma medications. UBM is a useful tool for evaluating bleb characteristics and their influence on IOP regula - tion after AGV surgery in dogs.

Objective: To evaluate the effects of alfaxalone, medetomidine, and xylazine on intraocular pressure (IOP) in domestic pigeons (Columba livia domestica). Animals Studied: Eight 12-month-old pigeons (16 eyes). Procedures: The pigeons were randomly assigned to three treatment groups (10 mg/kg of alfaxalone, 0.2 mg/kg of medetomidine, or 10 mg/kg of xylazine) with a 7-day washout period. The IOP was measured using a rebound tonometer and calibrated using the formula y = 0.439x + 2.059, where y is the tonometric IOP and x is the actual IOP. Results: All three drugs significantly reduced IOP. Alfaxalone led to the least reduction at 5.2 mm Hg, medetomidine reduced IOP to 12.5 mm Hg, whereas xylazine resulted in the greatest reduction at 15.3 mm Hg. Alfaxalone achieved its maximum IOP reduction in 6 min, whereas medetomidine and xylazine required 95 and 115 min, respectively. Both alpha-2 agonists, medetomidine, and xylazine, showed a prolonged duration of effect and a greater reduction in IOP than those of alfaxalone. All three medications provided adequate sedation without any discernible adverse effects. Conclusions: The findings revealed the varied effects of these drugs on IOP in pigeons, potentially providing valuable insights that could be useful for broader applications in veterinary medicine.