The effect of third eyelid gland removal on the ocular surface of dogs

Abstract

To evaluate the effect of third eyelid removal on the ocular surface of dogs, we operated on five young Beagle dogs and observed changes to tear function using the following tests: phenol red thread test (PRT), Schirmer tear test (STT-1), modified Schirmer tear test (STT-2), pH and tear break-up time (BUT). There was a significant decrease (37%) in STT-2 within 2 weeks after the excision and this declined further to 60% at 1 year. The pH value increased after excision. Presurgical pH was 7.17 +/- 0.20 (mean +/- SD), which increased to 7.55 +/- 0.24 in the 14-60 days following removal, and further increased to 7.77 +/- 0.65 at 1 year. The PRT and STT-1 decreased by 26% within 3-7 months compared to pre-excision values, but by 1 year the values recovered to near normal. The BUT pre-excision value was 24.0 +/- 8.1 s, which shortened to 13.5 +/- 4.5 s after 5 months and continued to decrease further during the study. There were no overt visual signs of KCS during the observational period. However, microinjury of the keratoconjunctival epithelium was observed for all operated eyes when vital staining was used at 1 year post surgery. Surgical excision of the third eyelid in Beagle dogs influenced tear quality level and affected the stability of the tear layer, and at 1 year there was evidence of microinjury to the keratoconjunctival epithelium.

Third eyelid gland protrusion in dogs: an experimental model proposal

“…The lacrimal and third eyelid, or nictitating, glands are responsible for, respectively, the production of 70% and 30%, on average, of the aqueous portion of tears (GELLAT, 1991;SAITO et al, 2001).…”

Adenopexia nictitante como alternativa quirúrgica del ojo cereza en caninos

“…A este respecto, los estu-dios describen técnicas básicas como el anclaje al borde orbitario, el anclaje escleral, el método de sobre o bolsillo y la conjuntivectomía periglandular (11,(15)(16)(17). Anteriormente se realizaba la exéresis de la glándula, pero existe una predisposición a la queratoconjuntivitis seca tiempo después de realizado el procedimiento (7,18).…”

Microalterations in the third eyelid gland of dogs with keratoconjunctivits sicca secondary to distemper

“…The aqueous layer is produced by the main lacrimal gland (70%) and by the third eyelid gland (30%), the oily layer is secreted by the meibomian glands, and the mucous layer is produced by goblet cells of the conjunctiva (Saito et al, 2001). …”

“…Initially, the eyes appear red and inflamed, with excessive mucous or mucopurulent ocular secretion. In more severe cases, the ocular surface loses its brightness and the conjunctiva becomes hyperemic, and in the most severe cases new vessels, pigments and corneal ulcers might be present (Moore, 1999;Saito et al, 2001). …”