To determine intra- and interobserver reliability of a fluorescein stain–based tear film breakup time (TFBUT) test as performed in a clinical environment with and without administration of a topical anesthetic.
21 privately owned dogs.
A randomized study design was used. Two independent observers that commonly perform the TFBUT test in clinical practice read the same description of TFBUT. Observers performed TFBUT testing for each dog before and after topical administration of 0.5% proparacaine solution in 4 testing periods with a 1-hour interval between periods. Intraclass correlation coefficient (ICC) analysis was used to assess inter- and intraobserver test reliability. Linear mixed models were used to assess the main effects of testing period, observer, eye, and presence of ophthalmic disorders and their interactions on TFBUT.
Mean TFBUT measurements performed by observer 1 and observer 2 were 5.9 seconds and 8.6 seconds, respectively, when adjusted for other effects in the model. Intraobserver ICC was poor for one observer and moderate for the other. Interobserver ICC was poor without use of topical anesthetic and slightly lower when anesthetic was used. Observer and testing period were each significantly associated with TFBUT; the measurements decreased and were more variable after multiple applications of fluorescein stain and proparacaine.
CONCLUSIONS AND CLINICAL RELEVANCE
Results suggested tear film stability is negatively affected by topical administration of 0.5% proparacaine solution and repeated applications of fluorescein stain. The TFBUT test as performed in this study had poor to moderate reliability.
Objective—To evaluate the in vitro antifungal properties of silver sulfadiazine (SSD) and natamycin against filamentous fungi isolated from eyes of horses with keratomycosis.
Sample Population—Filamentous fungal isolates obtained from eyes of keratomycosis-affected horses.
Procedures—Fungal culture of ocular samples yielded 6 Fusarium spp; 7 Aspergillus spp; and 1 isolate each of Curvularia, Scopulariopsis, Penicillium, and Chrysosporium. For each fungal isolate, minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) of SSD and natamycin were determined.
Results—For all 17 fungal isolates, SSD MIC distribution ranged from ≤ 1 to > 64 μg/mL; MIC50 and MIC90 (MICs at which 50% and 90% of organisms were inhibited) were 4 and 32 μg/mL, respectively. The SSD MFC distribution for all isolates was ≤ 1 to > 64 μg/mL; MFC50 and MFC90 (MFCs at which 50% and 90% of organisms were killed) were 8 and > 64 μg/mL, respectively. For all fungal isolates, natamycin MIC distribution ranged from 256 to > 1,000 μg/mL; MIC50 and MIC90 were 512 and > 1,000 μg/mL, respectively. The natamycin MFC distribution for all isolates ranged from 512 to > 1,000 μg/mL; MFC50 and MFC90 were each > 1,000 μg/mL.
Conclusions and Clinical Relevance—These in vitro data suggest that SSD is fungicidal against the fungal isolates that were obtained from eyes of horses with keratomycosis and that natamycin is fungicidal against some of the isolates at the drug concentrations evaluated. Silver sulfadiazine may be a therapeutic option for equine keratomycosis.