Comparison of parasitic mite retrieval methods in a population of community cats.

Objectives This study compared methods of mite retrieval from community cats in the Ohio River Valley region of the USA and determined incidence of parasitic mites in this region. Methods In total, 493 community cats were humanely trapped and anesthetized for a trap-neuter-return program. Cats received a dermatologic examination, ear swabs, superficial skin scraping, flea combing, acetate tape preparation and feces collection. All samples were examined microscopically. Large volumes of hair and scale from flea combing were dissolved in 10% potassium hydroxide and centrifuged with Sheather's solution. Fecal samples were mixed with Sheather's solution, filtered and centrifuged. Results Ear swabs were significantly ( P <0.05) better than other methods for finding chigger mites and Otodectes cynotis, and skin scraping was significantly better than ear swabs for finding Cheyletiella species. Only cats with O cynotis had clinical lesions. Mites remained identifiable for 6 months at room temperature. Mite incidence rates were as follows: Notoedres cati (1/493 cats), 0.002 (95% confidence interval [CI] 0-0.006); Lynxacarus radovskyi (2/493 cats), 0.004 (95% CI 0-0.01); Demodex gatoi (5/493 cats), 0.01 (95% CI 0.001-0.019); chigger mites (10/493 cats), 0.02 (95% CI 0.008-0.033); Cheyletiella species (12/493 cats), 0.024 (95% CI 0.011-0.038); and O cynotis (124/493 cats), 0.252 (95% CI 0.213-0.29). Conclusions and relevance Ear swabs are recommended when O cynotis or chigger mites are suspected. Skin scraping is more likely to yield positive results than ear swabs, but was not significantly better than acetate tape preparations, flea combing or fecal flotation for finding Cheyletiella species. Mites can remain identifiable for prolonged periods at room temperature. With the exception of O cynotis, the incidence of feline parasitic mites in the Ohio River Valley region of the USA is low; however, D gatoi and L radovskyi were present in the area and should be considered in cats with dermatologic disease attributable to them. In this population of community cats, asymptomatic carriage of mites was common.

Automated Perimetry and Visual Dysfunction in Blast-Related Traumatic Brain Injury.

PURPOSE: To evaluate feasibility and results of automated perimetry in veterans with combat blast neurotrauma. DESIGN: Prospective, longitudinal, observational case series. PARTICIPANTS: Sixty-one patients in a Veterans Affairs Polytrauma Center diagnosed with traumatic brain injury (TBI) from combat blast exposure. METHODS: Study participants underwent automated perimetry at baseline (median interval, 2 months after injury) (Humphrey Field Analyzer, Carl Zeiss Meditec, Dublin, CA, Swedish Interactive Threshold Algorithm 30-2 Standard or Fast), and 36 of them were followed up (median interval, 10 months after baseline). Presence of significant mean deviation and pattern standard deviation was determined for testing with reliability indices ≤20% for fixation loss, 15% for false-positives, and 33% for false-negatives. Test-retest stability of global visual field indices was assessed for tests with these cutoffs or with elevated fixation loss. Associations between global visual field defects and predictors were examined. MAIN OUTCOME MEASURES: Global visual field indices (mean deviation and pattern standard deviation). RESULTS: Among 61 study participants (109 study eyes) with baseline testing, a field that met reliability cutoffs was obtained for 48 participants (79%) and 78 eyes (72%). Fixation loss was found in 29% of eyes in initial testing. Nine study participants (15%) demonstrated hemianopia or quadrantanopia, and an additional 36% had an abnormal global visual field index. Global indices were relatively stable at follow-up testing for tests meeting fixation-loss cutoffs and tests that did not. Visual scotomas due to post-chiasmal lesions were associated with moderate to severe TBI or penetrating head injury, but other visual field deficits were prevalent across the range of mild to severe TBI. Ocular injury to the retina or choroid, poorer visual acuity, and pupillary defect were associated with visual field defects. Participants with depressed visual field sensitivity reported lower visual quality of life. CONCLUSIONS: Reliable automated perimetry can be accomplished in most patients with TBI from combat blast exposure and reveals high rates of visual field deficits, indicating that blast forces may significantly affect the eye and visual pathways.

Closed-globe injuries of the ocular surface associated with combat blast exposure.

PURPOSE: To describe closed-globe conjunctival and corneal injuries and endothelial cell abnormalities associated with blast exposure and their relationships to other closed-globe injuries and blast-event characteristics. DESIGN: Observational cross-sectional study. PARTICIPANTS: Veterans with a history of blast-related traumatic brain injury (TBI). METHODS: History and ocular examination, including slit-lamp biomicroscopy, gonioscopy, specular microscopy. MAIN OUTCOME MEASURES: Type and location of blast injuries to the conjunctiva and cornea. RESULTS: Ocular surface injuries were present in 25% (16 of 65) of blast-exposed veterans with TBI. Injuries included partial-thickness anterior stromal corneal scars (15 eyes), Descemet membrane ruptures (6 eyes), and conjunctival or corneal foreign bodies (7 eyes). Based on normative information from an age-matched comparison group, endothelial cell abnormalities were identified in 37% of participants. Eyes with ocular surface injury were more likely to have lower endothelial cell density, higher coefficient of variation of cell area, and lower percentage of hexagonal cells compared with eyes without injury. Presence of ocular surface injury or endothelial cell abnormalities was associated with elevated rates of other anterior and posterior segment injuries, as well as impairment of visual acuity. We found no relationship between ballistic eyewear use or severity level of TBI and presence of ocular surface injuries from blast. CONCLUSIONS: Independent of TBI severity or use of protective eyewear, ocular surface injuries and endothelial cell abnormalities were found in significant numbers of veterans with blast-related brain injury. Descemet membrane ruptures from blast exposure were described. Ocular surface trauma was associated with other ocular injuries throughout the globe. Potential mechanisms for the types and locations of ocular injuries seen were discussed. Any corneal or conjunctival injury in a blast survivor should prompt a thorough ocular trauma examination, including gonioscopy and specular microscopy, with appropriate follow-up for associated injuries. Longitudinal studies are required to determine long-term visual outcomes after blast exposure.

Visual quality of life in veterans with blast-induced traumatic brain injury.

IMPORTANCE: Traumatic brain injury (TBI) is an important cause of morbidity worldwide, with increasing awareness of the role of blast exposure in military and civilian casualties. Visual problems have been reported in TBI and may affect functioning and quality of life. OBJECTIVE: To evaluate the 25-item National Eye Institute Visual Functioning Questionnaire and Neuro-Ophthalmic Supplement for utility in assessing the effect of blast exposure on perceived visual functioning among veterans with TBI. DESIGN, SETTING, AND PARTICIPANTS: Observational cohort study from a tertiary care Veterans Health Administration hospital. Reported visual quality of life was compared with existing norms, and relationships between perceived visual quality and ocular injury, diplopia, visual performance, and blast exposure characteristics were examined. Participants included inpatients with blast-induced TBI who underwent baseline examination between December 7, 2006, and January 11, 2012, at a multiple-trauma rehabilitation center and who had at least 1 intact eye and were able to undergo psychometric testing and ocular examination. Among 64 sequentially eligible patients, 60 completed visual quality testing, 1 declined study participation, and 3 were evaluated prior to inclusion of visual quality testing in the protocol. Thirty-nine patients returned for outpatient follow-up, with a median test-retest interval of 11 months. EXPOSURE: Combat blast exposure with documented TBI. MAIN OUTCOMES AND MEASURES: Composite and subscale scores on the 25-item National Eye Institute Visual Functioning Questionnaire and Neuro-Ophthalmic Supplement. RESULTS: Both tests had high test-retest reliability. Blast-exposed veterans reported significantly poorer visual quality compared with healthy samples and some patient samples with known eye disease. Scores tended to be worse for participants with identified visual performance deficits (poorer visual acuity or spatial contrast sensitivity, visual field depression or defects). Scores were not related to the extent of ocular injury or to blast exposure characteristics such as use of protective eyewear or TBI severity level. CONCLUSIONS AND RELEVANCE: Individuals with blast-induced TBI reliably completed both tests and reported significant decrements in their subjective visual experiences. Measures of subjective visual quality may be useful to identify patients needing additional visual or neurologic evaluation and to monitor the effect of visual rehabilitation on patients with blast-related visual disabilities.

Visual performance and the ocular surface in traumatic brain injury.

The pathophysiology of neurotrauma is reviewed and an original study investigating the prevalence of dry eye disease in a sample of veterans with traumatic brain injury (TBI) is presented. Fifty-three veterans with TBI were evaluated by history of injury, past ocular history, and medication use. Ocular Disease Surface Index (OSDI), ocular examination, cranial nerve evaluation, tear osmolarity, tear film break-up time (TFBUT), ocular surface staining and tear production testing were performed. A matched comparison group underwent similar testing. TBI causes were blast (44) or non-blast (9). TBI subjects scored significantly worse on the OSDI (P<.001), and ocular surface staining by Oxford scale (P<.001) than non-TBI subjects. Scores for tear film breakup (P=.6), basal tear production less than 3 mm (P=.13), and tear osmolarity greater than 314 mOsm/L (P=.15) were all higher in TBI subjects; significantly more TBI subjects had at least one abnormal dry eye measure than comparisons (P<.001). The OSDI related to presence of dry eye symptoms (P<.01). These effects were present in both blast and non-blast TBI. Seventy percent of TBI subjects were taking at least one medication in the following classes: antidepressant, atypical antipsychotic, anticonvulsant, or h1-antihistamine. There was no association between any medication class and the OSDI or dry eye measures. Reduced corneal sensation in 21 TBI subjects was not associated with OSDI, tear production, or TFBUT, but did correlate with reduced tear osmolarity (P=.05). History of refractive surgery, previous contact lens wear, facial nerve weakness, or meibomian gland dysfunction was not associated with DED. In summary, we found a higher prevalence of DED in subjects with TBI, both subjectively and objectively. This effect is unrelated to medication use, and it may persist for months to years. We recommend that patients with TBI from any cause be evaluated for DED using a battery of standard testing methods described in a protocol presented in this article. Further research into the pathophysiology and outcomes of DED in neurotrauma is needed.

Primary open-angle glaucoma.

Primary open-angle glaucoma (POAG), by far the most common form of glaucoma, currently afflicts more than 2 million Americans, more than half of whom probably don't know they have it. Asymptomatic in the early stages, it gradually and progressively reduces the visual field and leads to blindness if untreated. Elevated intraocular pressure is believed to play a role, yet some people with normal pressure develop POAG. There is no single diagnostic test; screening and diagnosis involve periodic comprehensive eye evaluations. Treatment is aimed at delaying onset, slowing progression, and preserving vision.