An Evidence-Based Rapid Review of Surgical Techniques for Correction of Prolapsed Nictitans Glands in Dogs

Abstract

Prolapsed nictitans gland (PNG) is an important ocular condition of dogs. Various surgical interventions have been described, but effective technique is currently considered to be a matter of personal clinician preference. The aim of this rapid review was to evaluate existing peer-reviewed evidence of effectiveness for surgical techniques and their subsequent effects on quantitative and clinical lacrimal outcomes for PNG. We performed a structured bibliographic search of CAB Abstracts, PubMed, and Medline using terms relevant to dogs, nictitans gland, and surgery on 13 September 2017. Included studies were assessed for study design, reporting characteristics, surgical techniques, and surgical and lacrimal outcomes. Fifteen of three hundred fifteen identified studies were eligible for inclusion. Seven different replacement techniques were identified, along with gland excision. All studies were observational or descriptive, with the exception of a single crossover trial. Outcomes reporting was heterogeneous and provided limited detail on lacrimal outcomes or on breed propensity for recurrence. Insufficient data precluded comparison of techniques for either surgical failure rates or lacrimal outcomes, although proportional meta-analysis yielded an overall failure rate of 3% (95% CI 1–7%) for the Morgan’s pocket procedure. Improved reporting of veterinary surgical studies will improve evidence appraisal and synthesis, as well as reduce potential sources of bias.

Evaluation of Morgan’s pocket technique in the treatment of nictitans gland prolapse in dogs

“…Breed distribution of dogs in our study is consistent with previous studies with the majority of breeds such as Terrier and Cane corso, which are predisposed to NGP [13,15,17,18]. Medical treatment or conservative local therapies including antibiotic and steroid combination in NGP is not indicated as a solution [2,5,21]. It has been stated in the studies that surgery is the best option in the treatment of NGP [2,5,22].…”

“…Medical treatment or conservative local therapies including antibiotic and steroid combination in NGP is not indicated as a solution [2,5,21]. It has been stated in the studies that surgery is the best option in the treatment of NGP [2,5,22]. Postoperative use of topical corticosteroids is recommended in some studies but also discouraged in some [23,24].…”

“…Removal of the gland may cause tear secretion to be reduced by up to 40% and secondary keratoconjunctivitis sicca (dry eye disease) formation. Therefore, partial or complete removal of the gland should not be preferred [2,15,22,26]. Most of the breeds identified to be predisposed to NGP have also been reported to be predisposed to dry eye disease, but there is no defined relationship between these 2 diseases [27].…”

“…Due to the simplicity of the technique, some researchers have tried the treatment by removing the gland [17,28]. However, surgical repositioning techniques are more successful than gland removal, and fewer complications are seen (2,17,23). In particular, as the breeds with the inherited predisposition to NGP are also predisposed to dry eye disease, this risk cannot be ruled out [22,23,29].…”

“…In particular, as the breeds with the inherited predisposition to NGP are also predisposed to dry eye disease, this risk cannot be ruled out [22,23,29]. In this context, repositioning and fixation of the gland is the most appropriate choice in surgical treatment [2,23,30]. Several surgical techniques have been described for the reposition and fixation of the NGP in dogs [2,14,23].…”