- Veterinary Professionals
- Referring a case
- Referred Case Registration Form
- Cat Friendly Clinic – Gold Level
- Pet Blood Donor Sessions
CPD at Willows
- External CPD by Willows Clinicians
- Willows Scientific Publications
- Internships at Willows
- Nursing at Willows
- Veterinary Professionals Newsletters
- Veterinary Professionals
This site is optimised for modern web browsers, and does not fully support your browser version, we suggest the use of one of the following browsers: Chrome, Firefox, Microsoft Edge, some sections of the website may not work correctly such as web forms
Willows Scientific Papers for the following veterinary specialists:
Rodrigo Pinheiro de Lacerda
Hamzianpour N., Pinheiro de Lacerda R., Rhodes M. Recurrent Corneal Ulceration in a Young Dog Due to an Ectopic Cilium in an Unusual Location. Vet Record Case Reports Open – Accepted for publication
Lacerda RP, Peña Gimenez MT, Laguna F, Costa D, Ríos J, Leiva M. (2016) Corneal grafting for the treatment of full-thickness corneal defects in dogs: a review of 50 cases. Vet Ophthalmology. doi: 10.1111/vop.12392. [Epub ahead of print]
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.
Coyo, N., Peña, M. T., Costa, D., Ríos, J., Lacerda, R. and Leiva, M. (2015) Effects of age and breed on corneal thickness, density, and morphology of corneal endothelial cells in enucleated sheep eyes. Veterinary Ophthalmology. doi: 10.1111/vop.12308
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/mm2 ) and CT (μm) were calculated in the central cornea and four peripheral quadrants by means of specular microscopy. Mean cell area (MCA (μm2 )), 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.
Laguna F, Leiva M, Costa D, Lacerda RP, Peña Gimenez T. (2014) Corneal grafting for the treatment of feline corneal sequestrum: a retrospective study of 18 eyes (13 cats). Vet Ophthalmol. doi: 10.1111/vop.12228. [Epub ahead of print]
To determine the clinical outcome of corneal grafting for the treatment of feline corneal sequestrum (FCS).
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.
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%).
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.
Lacerda RP, Obón E, Peña MT, Costa D, Ríos J, Leiva M. (2014) A comparative study of corneal sensitivity in birds of prey. Vet Ophthalmol. 17(3):190-4. doi: 10.1111/vop.12068. Epub 2013 Jun 11.
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.
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.
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).
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.
S. Mazzucchelli, M. D. Vaillant, F. Wéverberg, H. Arnold-Tavernier, N. Honegger, G. Payen, M. Vanore, L. Liscoet, O. Thomas, B. Clerc, and S. Chahory (2012) Retrospective study of 155 cases of prolapse of the nictitating membrane gland in dogs. Veterinary Record 170, 443
G. Payen, R. L. Hänninen, S. Mazzucchelli, O. P. Forman, C. S. Mellersh, M. Savoldelli and S. Chahory (2011) Primary lens instability in ten related cats: clinical and genetic considerations. Journal of Small Animal Practice 52, 402–410
Braus B.K., Rhodes M, Featherstone H.J., Renwick P.W., Heinrich C.L. (2011) Cataracts are not associated with retinal detachment in the Bichon Frise in the UK - a retrospective study of preoperative findings and outcomes in 40 eyes. Veterinary Ophthalmology (in press)
The aim of this study was to evaluate whether the Bichon Frise Objective population in the UK is at the same risk of developing retinal detachment in association with cataract formation and following phacoemulsification as described in reports from the USA. The medical records of Bichon Frises which were presented for Procedures cataract assessment and of those which were treated with phacoemulsification at Forty Willows Referral Service between 1997 and 2009 were reviewed. Results eyes (26 dogs) with unilateral or bilateral cataracts were included in the study. There was no evidence of retinal detachment associated with the cataracts at initial presentation. Phacoemulsification was performed on 34 eyes (20 dogs). Clinically evident lens-induced uveitis was treated preoperatively in 17/34 eyes. Artificial lens implantation was carried out in 30/34 eyes; automated anterior vitrectomy was performed in 7/34 eyes. The months). At the last months (range 1.5-73 mean follow-up time was 16.6 re-examination, 31/34 eyes (91.2%) were visual. Three eyes (8.8%) were blind - two (in the same dog) because of presumptive bilateral optic nerve disease and one because of uveitis and secondary glaucoma. There was no evidence of retinal detachment following phacoemulsification in any This study suggests that the Bichon Frise population of the 34 eyes. Conclusion in the UK does not appear to have a predisposition for retinal detachment in association with cataract formation or following cataract surgery. Prophylactic random transscleral laser retinopexy or transscleral cryopexy cannot therefore be routinely recommended for Bichon Frises with cataracts in the UK.
Rhodes M., Heinrich C., Featherstone H., Braus B., Manning S., Cripps P.J., Renwick P. (2011) Parotid duct transposition in dogs: a retrospective review of 92 eyes from 1999 to 2009. Veterinary Ophthalmology (in press)
The aim of this study was to perform a retrospective review of Objective parotid duct transposition (PDT) in the dog to determine the rate and nature of complications, the success and failure rates Medical records of 56 dogs (92 and to evaluate owner satisfaction. Methods eyes) that underwent PDT and subsequent follow-up by a veterinary ophthalmologist were reviewed. Forty owners (40 dogs/66 eyes) were contacted by telephone and 37 owners (37 dogs/60 eyes) also completed a visual analog scale questionnaire. Statistical evaluation included Wilcoxon Signed Rank tests, one-way analysis of variance and Kaplan-Meier survival The mean follow-up was analysis with Wilcoxon and Log-rank tests. Results months). The surgical success rate was 92% (85/92 months (range 1-109 38.7 eyes). Total failures (8%, 7/92 eyes) were because of severe saliva intolerance 5 eyes) and = (n PDT 2 eyes). The = failure (n complication rate was 50% (46/92 eyes) of which 61% (28/46 eyes) were managed medically and 39% (18/46 eyes) required further surgery. Ninety percent (36/40) of owners indicated that they would proceed with surgery again. Statistically significant improvements in owner perception of ocular comfort, number of daily topical treatments, ocular wetness, and postoperative vision were identified. This study shows that Conclusions PDT is a successful procedure based on clinical findings and in terms of owner perception. It has also demonstrated that PDT improves ocular comfort and vision in medically refractive cases of keratoconjunctivitis sicca, and that a low level of on-going management is required in 33% of cases.
Featherstone HF, Renwick PR, Heinrich C, Manning SM (2009): Efficacy of lamellar resection, cryotherapy and adjunctive grafting for the treatment of canine limbal melanoma. Veterinary Ophthalmology 12, 65-72
Renwick P. & Petersen-Jones S. (2009) Orbital and ocular pain. In: Small Animal Ophthalmology 4th Edn. Eds. Peiffer R & Petersen-Jones S. WB Saunders, London
Renwick P. (2007) Eyelid surgery in dogs. In Practice 29, 256-271
Renwick P. (2002) Glaucoma. In: Manual of Small Animal Ophthalmology. Eds. Petersen-Jones S. & Crispin S. BSAVA Publications, Gloucester
Renwick P. & Petersen-Jones S. (2001) Orbital and ocular pain. In: Small Animal Ophthalmology 3rd Edn. Eds. Peiffer R & Petersen-Jones S. W B Saunders, London
Renwick P. (1998) Ocular surface disease. In: Canine Medicine and Therapeutics 4th Edn. Ed. Gorman N. Blackwell Science, Oxford
Renwick P. (1996) Diagnosis and management of corneal disorders in dogs. In Practice 18, 315-328
Renwick P. & Petersen-Jones S. (1996) Orbital and ocular pain. In: Small Animal Ophthalmology 2nd Edn. Eds. Peiffer R & Petersen-Jones S. W B Saunders, London
Renwick P. (1995) Diagnosis and management of glaucoma. In Practice 17, 10-21
Renwick P. (1993) Glaucoma. In: Manual of Small Animal Ophthalmology. Eds. Petersen-Jones S. & Crispin S. BSAVA Publications, Cheltenham