Conjunctival staining with lissamine green as a predictor of tear film deficiency in dogs

Abstract

ObjectiveTo evaluate a grading scheme for conjunctival staining patterns with lissamine green ocular dye in the diagnosis of tear film deficiencies in dogs.ProceduresClient‐owned and research colony dogs were enrolled in a prospective study between February and October 2018 in which slit‐lamp biomicroscopy, Schirmer tear test (STT), tear film breakup time (TFBUT), conjunctival lissamine green staining (LGS), and intraocular pressure (IOP) measurement were performed in both eyes of all dogs. Lissamine green staining of the temporal bulbar conjunctiva was graded from 0‐3, with a higher grade corresponding to an increased stain intensity.ResultsFifty‐four dogs (107 eyes), comprising 31 males and 23 females with a mean age of 5.0 ± 3.9 years (range 0.5‐14.3), were enrolled in the study. STT was <15 mm/min in 21 eyes and ≥15 mm/min in 86 eyes. Lissamine green staining grade for eyes with a STT of <15 mm/min (2.0 ± 0.9) was significantly higher than for eyes with a STT ≥15 mm/min (0.2 ± 0.7) (P < .001). TFBUT for eyes with a STT <15 mm/min (6.5 ± 4.4 seconds) was significantly shorter than for eyes with a STT ≥ 15 mm/min (16.1 ± 3.6 seconds) (P < .001). As LGS grade increased, both STT (P < .001) and TFBUT (P < .001) significantly decreased.ConclusionsA higher LGS grade was significantly associated with a lower STT and more rapid TFBUT in dogs. Lissamine green ocular dye can be considered as an adjunctive diagnostic test when evaluating tear film deficiency in dogs.

Assessment of tear film osmolarity using the IPen®Vet osmometer in Pug and Shih‐Tzu dogs with and without keratoconjunctivitis sicca

“…20 In veterinary medicine, a combination of tests, such as the STT, tear film break up time, use of dyes such as rose bengal and lissamine green, and the tear ferning test must be used together for complete evaluation of the ocular surface. 8,9,22,23 However, data on tear film osmolarity is limited. Increased TFO triggers corneal epithelial cell damage and ocular surface inflammation.…”

The pandemic of ocular surface disease in brachycephalic dogs: The brachycephalic ocular syndrome

“…Importantly, even when corneal ulceration is not present, the corneoconjunctival epithelial barrier is often disrupted in brachycephalic dogs with KCS, as demonstrated by the presence of fluorescein punctate staining on the cornea, 75 and lissamine green uptake on the lateral bulbar conjunctiva 76 …”

A review of diagnostic tests for qualitative and quantitative tear film deficiency in dogs

“…Lissamine green is an organic acid that stains devitalized corneal and conjunctival epithelial cells. 116,117 Visualization of the dye is easy on the conjunctiva but more challenging on the cornea (owing to the dark iris background) and can be improved using a white light source with a red filter (567-634 nm). 116 In dogs, severity of bulbar conjunctival LGS (grade 0-3) showed significant negative correlation with STT and TFBUT.…”

“…116 In dogs, severity of bulbar conjunctival LGS (grade 0-3) showed significant negative correlation with STT and TFBUT. 117 Thus, the authors concluded that lissamine green could be considered as an adjunctive diagnostic test when evaluating tear film deficiencies in dogs. 117…”

“…Visualization of the dye is easy on the conjunctiva but more challenging on the cornea (owing to the dark iris background) and can be improved using a white light source with a red filter (567–634 nm) 116 . In dogs, severity of bulbar conjunctival LGS (grade 0–3) showed significant negative correlation with STT and TFBUT 117 . Thus, the authors concluded that lissamine green could be considered as an adjunctive diagnostic test when evaluating tear film deficiencies in dogs 117 …”