Bilateral ocular toxoplasmosis in a returning traveller: age and route of infection as potential risk factors.

We report the case of a 69-year-old man, who presented in the UK with a short history of deteriorating vision and clinical features of bilateral atypical retinochoroiditis, after travelling to South America. Vitreous samples demonstrated Toxoplasma gondii DNA by PCR. Serology tests demonstrated recent acquired Toxoplasma gondii infection with IgM antibodies. He responded well to treatment with trimethoprim-sulfamethoxazole, azithromycin and oral steroids.This case is a reminder of the global importance of Toxoplasma related eye disease, and its uncommon bilateral severe presentation in a returning traveller, where the risk factors were age and the route of infection likely to be a virulent parasite oocyst from vegetables or water rather than undercooked meat or direct contact with cats.

Use of a corneal impression membrane and PCR for the detection of herpes simplex virus type-1.

Purpose. To investigate the use of a corneal impression membrane (CIM) for the detection of herpes simplex virus type 1 (HSV-1) in suspected herpes simplex keratitis (HSK).Methodology. In the laboratory study, swabs and CIMs made from polytetrafluoroethylene were spiked with different concentrations of HSV-1. DNA was extracted and real-time PCR undertaken using two sets of primers. In the clinical study, consecutive patients presenting with suspected HSK were included. For each patient, samples were collected from corneal lesions with a swab and a CIM in random order. Clinical details were collected using a standardized clinical form and patients were categorized into probable, presumed and possible HSK.Results. There was no difference in the performance of both primer sets for all HSV-1 dilutions (P=0.83) using a CIM or between a CIM and a swab (P=0.18). In total, 110 patients were included. Overall, 73 patients (66.4 %) had probable, 20 patients (18.2 %) presumed and 17 patients (15.5 %) possible HSV-1 keratitis. The HSV-1 detection rate was significantly higher using a CIM (40/110, 36.4 %) than a swab (28/110, 25.5 %) (P=0.004). In the probable HSV keratitis group, the detection rate using a CIM was 43.8 % compared to 27.4 % for a swab (P=0.004). The cycle threshold values obtained for the conjunctival swabs were higher than those obtained for the CIMs (P<0.001).Conclusions. In suspected HSK, a CIM is a useful alternative to a swab and more likely to detect the presence of HSV-1.

Polydimethyl Siloxane as an Internal Tamponade for Vitreoretinal Surgery.

PURPOSE: To report the efficacy and safety of polydimethyl siloxane (Siluron Xtra®) as an internal tamponade. DESIGN: Audit and adverse event screening of procedures (March 2014-2015). METHODS: Patients who had undergone vitreoretinal procedures with Siluron Xtra® tamponade were retrospectively analysed with respect to anatomical outcome, visual outcomes, and perioperative complications, in particular intraocular pressure. INCLUSION CRITERIA: all patients who had undergone Siluron Xtra® tamponade. EXCLUSION CRITERIA: No cases were excluded; however, there were no paediatric or pregnant patients within this cohort. All vitreoretinal cases were included, including retinal detachments, but also trauma, endophthalmitis, and intraocular foreign bodies. RESULTS: Twenty-eight patients had polydimethyl siloxane as an intraocular tamponade; 24 retinal detachments (83% complicated by proliferative vitreoretinopathy ≥grade C), 12 had previous failed surgery, and 4 had procedures for intraocular lymphoma, endophthalmitis, or trauma. Follow-up was 14-20 months, and mean duration of tamponade was 6.8 months (3-12 months). Anatomical success was 79% after polydimethyl siloxane injection, 58% 3 months following removal (14/24), 5 remain with long-term tamponade, and 5 with redetachment under tamponade required further intervention. Five required topical anti-glaucomatous agents, and 1 following trauma required glaucoma surgery. Cataract developed in 3/6 phakic patients, and visible emulsification occurred in a single patient. CONCLUSION: Polydimethyl siloxane seems to be an acceptable alternative tamponade agent for the management of complex retinal detachments with comparable anatomical success and comparable rates of raised intraocular pressure to other low-viscosity silicone oil agents, but more importantly, with a lower rate of emulsified oil-related complications, which is important particularly for cases requiring long-term tamponade.

Preparation of ultrathin grafts for Descemet-stripping endothelial keratoplasty with a single microkeratome pass.

We present a technique to achieve ultrathin Descemet-stripping automated endothelial keratoplasty (DSAEK). Using a simple method of controlling artificial anterior chamber pressure and drying the corneal surface, it was possible to thin the donor cornea at a rate of 11 µm a minute. When the donor cornea was between 500 µm and 510 µm, a single pass was made using a 350 µm microkeratome head followed by a peripheral dissection. The resulting mean graft thickness was 83.2 µm ± 14.9 (SD) (range 50 to 98 µm) with a mean peripheral graft edge thickness of 106.8 ± 10.9 µm (range 90 to 120 µm). There were no surgical complications, and all grafts remained attached. This is a reliable method for preparing ultrathin donor corneal lenticules for DSAEK in the operating room or eye bank without using multiple microkeratome heads or risking double passes.