Nerve growth factor in dogs: Assessment of two immunoassays and selected ocular parameters following a nicergoline challenge per os

Role of nicergoline in corneal wound healing in diabetic rats

Background

To investigate the effect of nicergoline on the rate of complete corneal ulcer reepithelialization (CCUR) in diabetic rats with diabetic keratopathy.

Methods

Forty-eight streptozotocin-induced diabetic rats were randomly divided into two groups. The experimental group (n = 24) received nicergoline (10 mg.kg^− 1.day^− 1), while the control group (n = 24) received a placebo. A corneal epithelial defect was induced using a corneal diamond burr, and defect area was compared at time points of 0, 12, 24, 48 and 72 h after the injury using image analysis software. The probability of CCUR within 72 h was assessed using the Kaplan–Meier survival analysis log-rank test.

Results

When compared, 4 of the 24 rats (17%) in the placebo group and 12 of the 24 rats (50%) in the nicergoline group were found to have CCUR within 72 h (log-rank = 0.027). Cox regression analysis found no effect of the covariates blood glucose (P = 0.601) or weight (P = 0.322) on the corneal reepithelialization (survival) curve.

Conclusions

Nicergoline increased wound healing rates relative to placebo and may therefore be investigated as a treatment option in diabetic keratopathy.

Aqueous tear assessment in dogs: Impact of cephalic conformation, inter-test correlations, and test-retest repeatability

OBJECTIVE

To characterize diagnostic findings, test-retest repeatability, and correlations among lacrimal tests in dogs of diverse cephalic conformations.

ANIMAL STUDIED

Fifty healthy dogs (25 brachycephalic, 25 nonbrachycephalic).

PROCEDURES

A series of diagnostics were performed in each dog, allowing for a 10-minute interval between tests and repeating each test 24 hours later under similar conditions: corneal tactile sensation (CTS), strip meniscometry test (SMT), phenol red thread test (PRTT), endodontic absorbent paper point tear test (EAPPTT), Schirmer tear test-1 without (STT-1) or with nasolacrimal stimulation (NL-STT1), and Schirmer tear test-2 (STT-2).

RESULTS

Mean ± SD test values were lower in brachycephalic vs. nonbrachycephalic dogs (except for SMT; 7.4 ± 2.0 mm/5 seconds vs 7.3 ± 2.4 mm/5 seconds), with statistically significant differences noted for CTS (1.8 ± 0.5 cm vs 3.4 ± 0.8 cm), PRTT (37.2 ± 4.0 mm/15 seconds vs 41.1 ± 5.5 mm/15 seconds), STT-1 (20.1 ± 3.4 mm/min vs 23.3 ± 5.7 mm/min), STT-2 (13.0 ± 3.4 mm/min vs 16.9 ± 3.9 mm/min), and NL-STT1 (23.2 ± 3.6 mm/min vs 27.1 ± 5.4 mm/min), and nonsignificant differences for EAPPTT (16.6 ± 2.7 mm/15 seconds vs 17.5 ± 2.9 mm/15 seconds). Nasolacrimal stimulation increased STT-1 values by 18% on average. Correlations among tests were generally weak to moderate (r < .70) except for a strong correlation between STT-1 and NL-STT1 (r = .83, P < .001). Test reliability was good although test-retest repeatability was generally poor to moderate, as depicted by low intraclass correlation coefficients (ICC ≤ 0.75) and wide 95% limits of agreement, except for CTS (ICC = 0.91).

CONCLUSIONS

Corneal sensitivity and aqueous tear secretion are lower in brachycephalic dogs. A comprehensive assessment of the ocular surface requires the combination of several diagnostic tests. The nasolacrimal reflex may provide a useful diagnostic and therapeutic tool in dogs.