Sara J. Haug

The Decline of Pneumococcal Resistance after Cessation of Mass Antibiotic Distributions for Trachoma

After 6 biannual mass distributions of oral azithromycin for trachoma in Ethiopian communities, 76.8% (95% confidence interval [CI], 66.3%-85.1%) of nasopharyngeal Streptococcus pneumoniae isolates from children aged 1-5 years were resistant to macrolides. Twelve and 24 months after the last azithromycin treatment, resistance decreased to 30.6% (95% CI, 18.8%-40.4%; P <.001 ) and 20.8% (95% CI, 12.7%-30.7%; P < .001), respectively. Macrolide resistance decreases after antibiotic pressure is removed.

Activity of antibiotics against Fusarium and Aspergillus

Background/aims: To study the susceptibility of Fusarium and Aspergillus isolated from keratitis to amoxicillin, cefazolin, chloramphenicol, moxifloxacin, tobramycin and benzalkonium chloride (BAK). Methods: 10 isolates of Fusarium and 10 isolates of Aspergillus from cases of fungal keratitis at Aravind Eye Hospital in South India were tested using microbroth dilution for susceptibility to amoxicillin, cefazolin, chloramphenicol, moxifloxacin, tobramycin and BAK. The minimum inhibitory concentration (MIC) median and 90th percentile were determined. Results: BAK had the lowest MIC for both Fusarium and Aspergillus. Chloramphenicol had activity against both Fusarium and Aspergillus, while moxifloxacin and tobramycin had activity against Fusarium but not Aspergillus. Conclusions: The susceptibility of Fusarium to tobramycin, moxifloxacin, chloramphenicol and BAK and of Aspergillus to chloramphenicol and BAK may explain anecdotal reports of fungal ulcers that improved with antibiotic treatment alone. While some of the MICs of antibiotics and BAK are lower than the typically prescribed concentrations, they are not in the range of antifungal agents such as voriconazole, natamycin and amphotericin B. Antibiotics may, however, have a modest effect on Fusarium and Aspergillus when used as initial treatment prior to identification of the pathological organism.

The fitness cost of antibiotic resistance in Streptococcus pneumoniae: insight from the field.

Background Laboratory studies have suggested that antibiotic resistance may result in decreased fitness in the bacteria that harbor it. Observational studies have supported this, but due to ethical and practical considerations, it is rare to have experimental control over antibiotic prescription rates. Methods and Findings We analyze data from a 54-month longitudinal trial that monitored pneumococcal drug resistance during and after biannual mass distribution of azithromycin for the elimination of the blinding eye disease, trachoma. Prescription of azithromycin and antibiotics that can create cross-resistance to it is rare in this part of the world. As a result, we were able to follow trends in resistance with minimal influence from unmeasured antibiotic use. Using these data, we fit a probabilistic disease transmission model that included two resistant strains, corresponding to the two dominant modes of resistance to macrolide antibiotics. We estimated the relative fitness of these two strains to be 0.86 (95% CI 0.80 to 0.90), and 0.88 (95% CI 0.82 to 0.93), relative to antibiotic-sensitive strains. We then used these estimates to predict that, within 5 years of the last antibiotic treatment, there would be a 95% chance of elimination of macrolide resistance by intra-species competition alone. Conclusions Although it is quite possible that the fitness cost of macrolide resistance is sufficient to ensure its eventual elimination in the absence of antibiotic selection, this process takes time, and prevention is likely the best policy in the fight against resistance.

Spectral domain optical coherence tomography findings in eyes with acute ischaemic retinal whitening

Acute retinal ischaemia presents in various forms depending on the type and location of the associated vascular occlusion. Cotton wool spots have been considered one manifestation of ischaemia and represent swelling in the nerve fibre layer. However, clinical retinal whitening also occurs in areas not affected by cotton wool spots, and has distinguishing spectral domain optical coherence tomography (SD-OCT) features. We present SD-OCT findings of hyper-reflectivity and thickening in four eyes with representative retinal arterial or retinal venous occlusions, specifically branch retinal artery occlusion, central retinal vein occlusion, Purtscher-like retinopathy and ophthalmic artery occlusion. The spectrum of retinal ischaemia from various causes was found to manifest in inner nuclear layer hyper-reflectivity and thickening on SD-OCT. En Face OCT imaging further characterises the topographical distribution of ischaemia, and reveals patterns which provide insight into the pathological processes involved.

En Face Spectral Domain Optical Coherence Tomography Analysis Of Lamellar Macular Holes

Purpose: To analyze the anatomical characteristics of lamellar macular holes using cross-sectional and en face spectral domain optical coherence tomography. Methods: Forty-two lamellar macular holes were retrospectively identified for analysis. The location, cross-sectional length, and area of lamellar holes were measured using B-scans and en face imaging. The presence of photoreceptor inner segment/outer segment disruption and the presence or absence of epiretinal membrane formation were recorded. Results: Forty-two lamellar macular holes were identified. Intraretinal splitting occurred within the outer plexiform layer in 97.6% of eyes. The area of intraretinal splitting in lamellar holes did not correlate with visual acuity. Eyes with inner segment/outer segment disruption had significantly worse mean logMAR visual acuity (0.363 ± 0.169; Snellen = 20/46) than in eyes without inner segment/outer segment disruption (0.203 ± 0.124; Snellen = 20/32) (analysis of variance, P = 0.004). Epiretinal membrane was present in 34 of 42 eyes (81.0%). Conclusion: En face imaging allowed for consistent detection and quantification of intraretinal splitting within the outer plexiform layer in patients with lamellar macular holes, supporting the notion that an area of anatomical weakness exists within Henles fiber layer, presumably at the synaptic connection of these fibers within the outer plexiform layer. However, the en face area of intraretinal splitting did not correlate with visual acuity, disruption of the inner segment/outer segment junction was associated with significantly worse visual acuity in patients with lamellar macular holes.

Acute retinal necrosis secondary to multidrug-resistant herpes simplex virus 2 in an immunocompetent adolescent

PURPOSE To report the clinical course of a patient with acute retinal necrosis resulting from a multidrug-resistant strain of herpes simplex virus 2. METHODS Observational case report. RESULTS A 17-year-old man with no identifiable immune deficiency presented with pain and decreased vision in his left eye. He had dense anterior and posterior segment inflammation with retinal whitening suggestive of acute retinal necrosis, which progressed despite treatment with intravenous acyclovir, methylprednisolone, and ganciclovir. A transition to intravitreal and intravenous foscarnet led to clinical improvement. Genetic analysis revealed the etiology to be a multidrug-resistant strain of herpes simplex virus 2. CONCLUSION Antiviral resistance is an uncommon finding among viruses causing acute retinal necrosis in immunocompetent patients. Patients with these infections may be adequately treated with prompt recognition and a change in therapy to alternative antiviral agents such as foscarnet.

A National Survey of Practice Patterns: Temporal Artery Biopsy

OBJECTIVE To assess current clinical practice patterns for temporal artery biopsy (TAB) among clinicians in establishing the diagnosis of giant cell arteritis. DESIGN A survey was sent via e-mail using the Survey Monkey website (www.surveymonkey.com; accessed January 24, 2013). The survey initially was sent in July 2010 and continued through October 2010. PARTICIPANTS The survey was sent via e-mail to the members and affiliates of the American Society of Ophthalmic Plastic and Reconstructive Surgery, the North American Neuro-Ophthalmology Society, and the American College of Rheumatology. METHODS Data from the survey were collected via Survey Monkey and data analysis was performed using the Fisher exact test and Wilcoxon rank-sum test. MAIN OUTCOME MEASURES Response to the survey questions on primary unilateral versus bilateral biopsy, performing second-side biopsy if first side results were negative, and the duration for which biopsy findings are reliable after initiating immunosuppressive therapy. RESULTS The self-described primary subspecialty of the 1074 respondents was as follows: oculoplastic surgery (n = 127), neuro-ophthalmology (n = 119), rheumatology (n = 799), and other (n = 28). Overall, 66% of respondents advocated initial unilateral TAB, 18% advocated bilateral biopsy in all cases, and 16% recommended either unilateral or bilateral TAB depending on the degree of clinical suspicion. Rheumatologists were 4.5 times more likely to advocate initial bilateral biopsy than neuro-ophthalmologists or oculoplastic surgeons (P<0.0001, Fisher exact test). Most respondents believed that biopsy results were accurate for more than 14 days. These results were not affected by stratification of years in practice by the Kruskal-Wallis rank-sum test. CONCLUSIONS Temporal artery biopsy practices vary greatly among treating physicians. This lack of consensus underscores the need for a systematic assessment of varying practice patterns. FINANCIAL DISCLOSURE(S) The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Chandelier-Assisted External Subretinal Fluid Drainage in Primary Scleral Buckling for Treatment of Rhegmatogenous Retinal Detachment.

Chandelier-Assisted External Subretinal Fluid Drainage in Primary Scleral Buckling for Treatment of Rhegmatogenous Retinal Detachment Scleral buckling has historically been the surgical gold standard for rhegmatogenous retinal detachment repair. There has been a trend toward primary pars plana vitrectomy or pneumatic retinopexy for many retinal detachments. However, there are still cases in which a primary scleral buckle procedure may be the preferred procedure for retinal detachment repair, such as phakic inferior detachments and detachment in younger patients with lattice degeneration in the absence of a posterior vitreous detachment. Scleral buckling involves identifying and treating all the retinal breaks, usually with cryotherapy. After treatment of all retinal breaks, the buckle is positioned and sutured into place. Previous studies suggest that if a retinal break, particularly a break no larger than 1 clock hour, is well mounted on the buckle, the retina will reattach even when not treated with cryoretinopexy. To ensure that the retinal breaks are mounted on the scleral buckle, subretinal fluid can be drained to flatten the retina. Conventionally, a scleral incision is made with a 69 blade, external diathermy applied to the exposed choriocapillaris, and subretinal fluid allowed to egress passively. This is a delicate procedure that can result in choroidal hemorrhage, retinal incarceration, or retinal breaks. An alternative method to scleral cutdown was first reported by Charles in 1985, and described subretinal fluid drainage under direct visualization with indirect ophthalmoscopy using a tuberculin syringe with a 25-gauge three-eighth inch needle obliquely inserted into the subretinal space. A recent case report describes a novel method of visualizing external drainage by using a wide-field noncontact lens system and 25-gauge cannula-based chandelier endoillumination. Our report confirms this technique and presents a case series of seven patients, all with rhegmatogenous retinal detachments that underwent primary scleral buckling with external drainage performed with this modified technique.

Rhegmatogenous Retinal Detachment in Patients with Acute Syphilitic Panuveitis

Abstract Purpose: To describe the clinical characteristics and surgical management of rhegmatogenous retinal detachment (RD) in patients with acute syphilitic panuveitis. Methods: Retrospective case series and comprehensive literature review. Results: Including present and previously reported cases, we identified 11 eyes in 8 patients with acute syphilitic panuveitis that developed a rhegmatogenous RD. Seven of 11 eyes (63.6%) were repaired with a combined scleral buckling, vitrectomy, and endolaser photocoagulation surgery; 1 eye (9.1%) was repaired with scleral buckling only; and 2 eyes (18.2%) with vitrectomy only. Cryotherapy was used to treat a giant retinal tear in 1 eye (9.1%). Four eyes (36.4%) redetached and 3 underwent a second vitrectomy surgery. Conclusions: Although uncommon, rhegmatogenous RD can occur in patients with moderate to severe acute syphilitic panuveitis. We believe scleral buckling, vitrectomy, endolaser photocoagulation, and silicone oil tamponade give the best chance for successful retinal reattachment.

Cytomegalovirus retinitis in dyskeratosis congenita.

PURPOSE The purpose of this study was to report a case of cytomegalovirus retinitis in the setting of dyskeratosis congenita. METHODS Case report and literature review. RESULTS A 23-year-old woman who had peripheral occlusive retinal vasculopathy and neovascularization as a result of pancytopenia caused by bone marrow failure also developed cytomegalovirus retinitis. She had been diagnosed with dyskeratosis congenita, which had caused the bone marrow failure and pancytopenia. CONCLUSION Dyskeratosis congenita is a multisystem disorder that causes bone marrow failure. It can have retinal manifestations in the form of peripheral proliferative retinopathy and retinitis.