Veterinary ophthalmology最新文献

Objective: Cataract surgery remains the sole method to resolve blindness secondary to cataract formation. One complication includes fibrin web formation post-operatively. This study aimed to investigate the presence of endotoxin within materials used during cataract surgery as a possible cause of fibrin web phenomenon.

Methods: Preservative-free epinephrine, heparin, viscoelastic devices, and intraocular lenses were collected for evaluation. Various manufacturers and manufacturing lot numbers were used when available. Viscosity of viscoelastics was reduced by incubating samples with human recombinant hyaluronidase. Intraocular product (IOL) packaging fluid was collected and stored for testing. The IOLs were then washed with a sterile balanced salt solution, incubated at 37°C for 48 h, and then fluid was collected for testing to mimic intraocular placement. Samples were tested using a commercially available rFC kit. Fluorescence was measured at time zero and after 1 h using a fluorescence microplate reader. The change in fluorescence was corrected for blank fluorescence and plotted to a standard curve.

Results: Endotoxin levels were below the limit of detection (0.05 EU/mL) in all samples. Incubation of IOLs at intraocular temperature did not increase extraction of endotoxin.

Conclusion: Endotoxin was not identified in any tested sample, including those used in cases of fibrin web formation post-phacoemulsification. As fibrin webs are often observed episodically, it is possible that endotoxin levels may vary between batches, or that endotoxin is not related to fibrin formation.

Objective: To investigate the prevalence and surgical outcome of lens capsule disruption (LCD) in dogs undergoing cataract removal.

Animals studied: Medical records of 924 eyes undergoing phacoemulsification were analyzed retrospectively.

Procedures: Routine cataract surgeries with or without LCD were included. Any LCD other than routine anterior capsulorhexis was defined as LCD and classified according to location and etiology. Odds ratios (OR) were calculated for maintaining vision, implantation of an artificial intraocular lens (IOL), and enucleation.

Results: In total, 520 eyes were included. A LCD occurred in 145 eyes (27.8%; 145/520) and affected the posterior (85.5%; 124/145), anterior (6.2%; 9/145), and equatorial lens capsule (4.8%; 7/145) and at multiple locations (3.4%; 5/145). The etiology of the LCD was spontaneous preoperative in 41 eyes (28.3%; 41/145), accidental intraoperative in 57 eyes (39.3%; 57/145), and planned in 47 eyes (32.4%; 47/145). Disruption did not increase the odds of enucleation (OR = 1.48, 95% confidence interval [CI] 0.56-3.67; p = .36). The presence of LCD significantly increased the risk of losing vision 1 year post-operatively (OR = 8.17, 95% CI 1.41-84.93; p = .007) associated with retinal detachment. However, this was not present at 2 years follow-up or in PCCC cases at any time point. An IOL was implanted in 108 eyes (108/145; 75.2%) with LCD and in 45/47 (95.7%) eyes with a PCCC.

Conclusion: Increased surgeon awareness of possible intraoperative, accidental LCDs is important, as LCDs were relatively common and associated with increased odds for vision loss after 1 year in the present study. A prospective study investigating the causes of intraoperative, accidental LCD is warranted.

Purpose: To describe the clinical features surgical technique, early and long-term outcome with or without surgery, and histopathological findings of melanocytic anterior uveal lesions in young dogs.

Methods: Medical records of dogs at a guide dog facility removed from training due to a pigmented iris lesion were reviewed from 2014 to 2021. Selected dogs had surgical iridectomies performed.

Results: Iridal melanocytic lesions were characterized as well-delineated, pigmented, and flat (nevus) or raised (mass) lesions of the iris. Forty dogs (18 Labrador retrievers, 18 German shepherd dogs, 1 Golden retriever, 3 Labrador/Golden mixes) ranging from 0.5 to 3.1 years of age were affected unilaterally (n = 35) or bilaterally (n = 5). Sector iridectomy was performed in 13 dogs with prominent and well-isolated mass lesion and enucleation was carried out in 2 dogs with extensive lesions, while all other cases were monitored without surgical intervention. Postoperative complications included dyscoria (13/13), focal posterior synechia (9/13) and focal nonprogressive cataract (8/13). All eyes remained visual and comfortable up to 6.2 years post-iridectomy with no clinically identifiable local recurrence. Histopathology was consistent with uveal melanocytoma in all samples obtained surgically. All cases that did not undergo surgery remained free of complications up to 4.5 year post diagnosis.

Conclusion: Melanocytic anterior uveal lesions may be overrepresented in certain lineages of breeds and be present at a young age. While none of the eyes developed complications when monitored without surgery, early surgical excision of the mass by sector iridectomy yields noteworthy functional outcome and retention of a comfortable globe.

Objective: To evaluate the success and failure rate of photoactivated chromophore for keratitis-corneal cross-linking (PACK-CXL) therapy in a single population of dogs and cats. To identify the usefulness of the PACK-CXL based on ulcer depth and establish a cutoff at which this procedure could be recommended. To analyze the influence of the different variables in corneal healing time and to report the presence of secondary endothelial damage and cataract formation.

Materials and methods: Medical records of dogs and cats with presumptive infectious keratitis which underwent accelerated epithelium-off PACK-CXL between 2016 and 2023 were reviewed and analyzed.

Results: Records for 369 animals were included, and the overall success rate for healing was 97% (range 4-74 days and no rescue procedure). The second success (re-epithelialization <30 days and no rescue procedure) rate was 86%, and a total of 40 eyes needed more than 1 month for the corneal repair. Corneal ulcers were classified in three categories based on the depth: 0%-33% (46%), 34%-66% (37.4%), and 67%-100% (16.5%). The cutoff at which PACK-CXL had a higher probability of failure was with ulcer depth >66.5%. Animals who suffered from keratomalacia and hypopyon at presentation, or were treated with topical serum or gentamicin after PACK-CXL showed an increase in epithelial healing time (EHT). Increasing age, brachycephalic conformation, keratomalacia alone, and deeper ulcers were identified as risk factors for the treatment outcome. Secondary endothelial injury or cataract formation was not noted in this study.

Conclusions: Accelerated PACK-CXL is a non-invasive, adjunctive treatment to medical therapy, which can be used in presumed infectious keratitis with a high probability of success. However, it is important to take in consideration the patient age, skull conformation, presence of keratomalacia, and the ulcer depth.

Purpose: To describe a novel treatment for dissolving calcareous corneal degeneration (CCD)-associated mineral in 17 dogs with 13.8% ethylenediaminetetraacetic acid (EDTA) solution.

Methods: Cases seen between 2021 and 2023 were reviewed. Seventeen dogs with CCD associated with corneal ulcerations were treated with a mineral dissolution procedure using 13.8% EDTA solution. A diamond burr keratotomy (DBK) was subsequently performed in some cases when residual mineralization remained present.

Results: Of the 19 eyes (17 dogs) included in the study, 10 eyes (8 dogs) required a DBK procedure. One eye (one dog) required a repeat procedure 26 weeks following the initial procedure and two eyes (one dog) required a repeat procedure 24 and 37 weeks following initial treatment in the left and right eye, respectively. Mean follow-up time to last recheck for eyes not requiring a second chelation procedure was 20.4 weeks (range, 10-47 weeks). At the last follow-up examination for all 17 dogs, the CCD resolved in 26.3%, improved in 57.9%, and recurred in 15.8% of eyes. Complications occurred in two eyes (two dogs) and included an infected stromal ulcer at 2-week recheck and the creation of a 40% depth stromal defect immediately following debridement. Both complications were successfully addressed with medical management.

Conclusions: The utilization of 13.8% EDTA solution appears to be an effective and safe means of treating lesions associated with CCD.

Objectives: To describe the traction suture fixation technique for severely displaced lenses (≥180°) using a capsular tension ring (CTR) fragment during cataract surgery in dogs, and to retrospectively investigate its clinical outcomes.

Animals studied: Eight dogs (nine eyes).

Procedures: The medical records of dogs with severe lens displacement (≥180°) due to cataracts that underwent traction suture fixation during cataract surgery using a CTR fragment at the Grand Animal Hospital (Hyogo, Japan) between November 2019 and September 2022 were retrospectively reviewed. The retrieved data included the signalment, type of CTR, and postoperative outcomes.

Results: A single CTR fragment was used to fix the capsular bag to the sclera in six eyes, and two CTR fragments were used at two sites in three eyes. The lengths of the CTR fragments used were 1 one-fifth fragment, 3 one-fourth fragments, and 8 one-third fragments. Postoperative complications included uveitis (nine eyes), glaucoma (one eye), posterior iris adhesion (one eye), corneal ulcer (one eye), and intracorneal stromal hemorrhage (one eye). Vision was maintained in all dogs during the follow-up period (2 months to 2 years and 8 months) without recurrent capsular bag displacement.

Conclusions: This technique can correct and stabilize capsular bag displacement relatively easily through a small incision during cataract surgery in dogs with severe lens displacement. Intraocular lens implantation was also possible.

Objective: To determine and compare the fixation strength of conjunctival pedicle flaps to cornea achieved via conventional ophthalmic suture and three different adhesive compounds.

Animals studied: Ex vivo porcine globes.

Procedures: Following a 6 mm wide 500-micron-restricted depth lamellar keratectomy, conjunctival pedicle flaps were secured to the keratectomy site with either 8-0 VICRYL® suture or one of three adhesive products, including Tisseel® bioadhesive, ReSure® synthetic adhesive, or ethyl cyanoacrylate adhesive (n = 10 per surgical group). Adhesive application protocol varied by product based upon adhesive biocompatibility. Corneoconjunctival tissues were then harvested, clamped in a tensile testing device, and loaded at a rate of 1 mm/s under video surveillance until the point of failure. Peak load was determined for each test and used to compare fixation strength between samples.

Results: Forty conjunctival flaps were performed, with 6 omitted from evaluation due to dehiscence prior to tensile testing. Of the 34 flaps analyzed, 10 were secured with suture, 10 with cyanoacrylate, 8 with ReSure®, and 6 with Tisseel®. Flaps secured with suture withstood significantly higher applied tensile force compared with cyanoacrylate (p = .02474), ReSure® (p = .00000), and Tisseel® (p = .00002). Flaps secured with cyanoacrylate withstood significantly greater force than those secured with ReSure® and Tisseel® (p = .01194 and 0.01798, respectively). There was no significant difference in fixation strength between ReSure® and Tisseel® glue (p = .95675).

Conclusions: Conjunctival pedicle flap fixation using 8-0 VICRYL® suture fixation was able to withstand significantly greater maximum tensile force compared to ReSure®, Tisseel®, or cyanoacrylate adhesives. Fixation strength achieved with cyanoacrylate adhesive was significantly greater than that achieved with ReSure® or Tisseel®.

Objectives: To describe patient demographics and treatment protocols in a population of feline patients undergoing photoactivated chromophore for keratitis-corneal cross-linking (PACK-CXL) as an adjunctive treatment for infectious keratitis. Furthermore, to determine the proportion of PACK-CXL treatment success in the population studied, explore risk factors for treatment failure, and provide recommendations for future PACK-CXL clinical studies.

Materials and methods: Records from four veterinary ophthalmology practices were reviewed to identify eligible patients and extract data. Recorded variables included patient-related factors, ocular examination findings, PACK-CXL protocol parameters, and treatment outcome.

Results: Records for 153 cats (154 eyes) were included. Median age in the treatment success group was 8 years (interquartile range (IQR) 4-12), with a median ulcer depth of 30% (IQR 30-40). Median age in the treatment failure group was 10.5 years (IQR 4.75-12) with a median ulcer depth of 45.9% (IQR 30-75). Persian cats were the most represented brachycephalic breed (52 out of 64 cats). Modified PACK-CXL protocols were used, including fast energy delivery (134 eyes), and increased fluence (52 eyes). The overall proportion of success was 88% (95% CI 84-93), which was variable between clinics. Eighty-two of 89 mesocephalic cat eyes (92%), and 54 of 65 brachycephalic cat eyes (83%) were classified as treatment successes.

Conclusions: PACK-CXL appeared to be a useful, adjunctive therapeutic modality for the treatment of infectious keratitis in the feline patient population presented here. Brachycephalic cats, older cats, and those with deeper ulcers may be at increased risk for treatment failure.

Corneal reconstruction is a key part of veterinary ophthalmic practice and numerous reconstructive techniques have been described for use in small animals in the peer-reviewed veterinary literature written in English. Despite the evidence accrued over the last six decades in over 40 clinical articles and numerous other publications on ocular surface health, several key areas require further study. The comparison between studies is difficult due to elements that go beyond common factors, such as the indication for surgery, the reconstructive technique preferred by the surgeon or the availability of reconstructive materials. However, the differences in reporting style adopted by different authors between similar studies and the lack of data found in retrospective studies add to this complexity. The present review is divided into three parts. One covers the use of autologous materials for reconstruction and corneal transplants, as well as corneal clarity. A second part focuses on biomaterials and keratoprosthetics, while the third part focuses on the use of corneal sutures and report of ocular discomfort/pain in the veterinary literature. The review focuses on the main findings of each reconstruction technique. It aims to identify areas where key information about common procedures is missing so that general guidelines may be provided for the planning of patient record keeping and future retrospective or prospective studies, while it also aims to highlight the presence of knowledge gaps that deserve further attention.