RESUMEN
PURPOSE: The objectives of this study were to determine the prevalence of microbial contamination of multi-user preserved ophthalmic drops (POD) in Ophthalmology Outpatient Clinic (OOC), to compare the rate of contamination between the dropper tip and the residual contents in the bottle, and to identify the contaminating organisms. METHODS: This was an observational cross-sectional study using a convenience sampling method conducted in the OOC of Universiti Kebangsaan Malaysia Medical Center, Malaysia. The samples of POD bottles were divided into groups obtained after 14 days (T14) and after 30 days (T30) of use. The contamination rate at the dropper tip and in the residual contents was determined and the contaminating organisms were identified. RESULTS: A total of 140 of 149 extended-use POD bottles were included. The prevalence of contamination was 30%. There was a statistically significant difference in the rate of contamination between samples T14 and T30 (19% and 11%, respectively; p=0.046). Proparacaine and tropicamide showed higher contamination rates in the T14 samples (p=0.027 and p=0.497, respectively) than in the T30 samples. The site of contamination was higher at the dropper tip than in the residual contents (p>0.05). Coagulase-negative Staphylococcus species were the most frequently identified contaminants (89%). CONCLUSION: The dropper tip was more contaminated than the residual contents, and coagulase-negative Staphylococcus species, which are common commensal flora of the ocular conjunctiva and skin, were the most frequently identified organisms.
RESUMEN
SIGNIFICANCE: Ocular tilt reaction (OTR) is an abnormal eye-head postural reaction that consists of skew deviation, head tilt, and bilateral ocular torsion. Understanding of the pathway of the vestibulo-ocular reflex (VOR) is essential because this will help to localize the pathology. PURPOSE: The aim of this study was to report a case of OTR with contralateral internuclear ophthalmoplegia (INO) and fifth and seventh cranial nerve palsies. CASE REPORT: A 51-year-old gentleman with underlying diabetes mellitus presented with sudden onset of diplopia for 3 days. On examination, his visual acuity was 20/30 bilaterally without a relative afferent pupillary defect. He had a right OTR consisting of a right head tilt, a skew deviation with a left eye hypertropia, and bilateral ocular torsion (right excyclotorsion and left incyclotorsion) with nystagmus. He also had a left adduction deficit and right abduction nystagmus consistent with a left INO. Ocular examination revealed evidence of proliferative diabetic retinopathy bilaterally. Two days after the initial presentation, the patient developed left seventh and fifth cranial nerve palsies. MRI showed left pontine infarction and multiple chronic lacunar infarctions. There was an incidental finding of a vascular loop compression on cisternal portions of the left trigeminal, facial, and vestibulocochlear nerves. Antiplatelet treatment was started on top of a better diabetic control. The diplopia was gradually resolved with improved clinical signs. In this case, the left pontine infarction had likely affected the terminal decussated part of the vestibulocochlear nerve from the right VOR pathway, medial longitudinal fasciculus, and cranial nerve nuclei in the left pons. CONCLUSIONS: The OTR can be ipsilateral to the lesion if the lesion is before the decussation of the VOR pathway in the pons, or it can be contralateral to the lesion if the lesion is after the decussation. In case of an OTR that is associated with contralateral INO and other contralateral cranial nerves palsy, a pathology in the pons that is contralateral to the OTR should be considered. Neuroimaging study can hence be targeted to identify the possible cause.