Anti-Inflammatory Effect of Melatonin for Cataract Surgery in Dogs

SANDE PH; ROSENSTEIN RE; SAENZ, DANIEL

Fort Lauderdale, USA

Congreso; The Association for Research in Vision and Ophthalmology; 2010

The Association for Research in Vision and Ophthalmology

Anti-Inflammatory Effect of Melatonin for Cataract Surgery in Dogs P. Sande, R. E. Rosenstein and D. A. Saenz Human Biochemistry/Sch of Med, University of Buenos Aires, Buenos Aires, Argentina Commercial Relationships: P. Sande, None; R.E. Rosenstein, None; D.A. Saenz, None. Support: None. Abstract Purpose:Cataract is a major cause of blindness in dogs. The more frequent etiologies for cataract in dogs are from a diabetic and hereditary origin. While the treatment is cataract removal, the therapeutic success depends largely on post-surgical inflammation. The commonly used compounds (corticosteroids or non-steroidal anti-inflammatory drugs,) are effective but exhibit significant side effects. We have demonstrated that melatonin is a potent ocular anti-inflammatory without adverse effects in the hamster. The aim of this study was to analyze the anti-inflammatory effect of melatonin for cataract surgery in dogs. Methods:With the consent of the owners, dogs were divided into 4 groups, submitted to different treatments, starting 3 days before surgery, as follows: group A: dogs with hereditary cataract treated with dexamethasone (1 drop/6 h), group B: dogs with hereditary cataract treated with melatonin (3 mg/12 h), group C: diabetic dogs with carprofen (1 mg/kg /12 h) + diclofenac (1 drop/6 h), and group D: diabetic dogs with melatonin (3 mg/12 h). All groups were treated with tobramicin (1 drop/8 h) and atropine (1 drop/12 h). The surgery was performed by phacoemulsification. During a period of 120 days after surgery, dogs were evaluated periodically using a slit lamp, direct and indirect ophthalmoscopy, and tonometry. At 2, 7, and 20 days post-surgery, clinical severity of the inflammatory signs was assessed by a clinical score, considering blepharospasm, Tyndall effect, miosis, episcleral veins, alterations in the cornea and intraocular pressure (IOP)) and at 120 days post-surgery, the presence of sequelae (corneal edema, synechiae, and posterior capsule opacification) was analyzed. Statistical analysis was performed using Mann-Whitney and Tukey’s tests. Results:In non-diabetic animals, results obtained with melatonin did not differ from those obtained with dexamethasone at 2 and 7 days post-surgery, while at 20 days post-surgery, the inflammation was lower in the group treated with melatonin (p <0.05). In the group of diabetic animals, post-surgical inflammation was lower in the group treated with melatonin than in the carprofen-treated eyes at all the examined time-points (p <0.01). The percentage of eyes showing sequelae was: 33%, 11%, 44%, 11%, for groups A, B, C and D, respectively. The IOP did not differ among groups. Conclusions:These results support the use of melatonin as an anti-inflammatory treatment for cataract surgery in dogs. Keywords: inflammation • cataract • drug toxicity/drug effects © 2010, The Association for Research in Vision and Ophthalmology, Inc., all rights reserved. Permission to republish any abstract or part of an abstract in any form must be obtained in writing from the ARVO Office prior to publication.