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Purpose The study aimed to construct a new retinal tack design with high retention forces to prevent spontaneous disentanglement in cases of complicated retinal surgery. Methods Six new forms for the peak of a retinal tack were developed using computer-aided design (CAD); then a prototype was produced for each model. Finally, standardised design testing was conducted using human (ex vivo) sclera by logging 15 consecutive measurements for each model. Results Seven different models underwent pull-out testing (six new models and the original tack model), but two tack models (Model 4, Model 5) failed to penetrate the human tissue. The highest pull-out forces (median) were measured for Model 3, followed by Model 6, Model 2 and Model 1. The original Heimann tack (Model H) was found to have the lowest retention forces. Conclusion The different tack designs altered the penetration and holding forces. The retention forces of the proposed peak design led to a significant increase in the retention forces that were more than twice as high as those in the original Heimann Model.

Background Prevalence and spectrum of hypertensive retinopathy in the population reflects the status of hypertension control and the associated risks for cardiovascular events. We investigated the prevalence and clinical spectrum of hypertensive retinopathy among patients attending hypertension clinic at a tertiary hospital in Malawi. Methods This was a cross-sectional study of systematically selected patients attending hypertension clinic at Queen Elizabeth Central Hospital. Patient interviews using a structured questionnaire and review of patients’ medical records (health passports) were done to obtain the following information: demographics, duration since the diagnosis of hypertension, history of stroke and blood pressure measurements. The presence and severity of hypertensive retinopathy was determined by dilated fundoscopy through slit lamp biomicroscopy. Results We recruited 104 patients. Women outnumbered men by 3:1. Women tended to be younger compared to men (mean ages 54 and 61 years respectively). Of the surveyed patients, 80% had sub-optimal blood pressure control and 75% had evidence of hypertensive retinopathy. History of stroke was associated with hypertensive retinopathy. Conclusions Hypertensive retinopathy is very common in patients attending the hypertension clinic at Queen Elizabeth Central Hospital in Blantyre, Malawi. This may be a reflection of sub-optimal blood pressure control in this patient population. There is a need to identify the actual reasons, rectify them and intensify intervention in control of hypertension in this patient population.

A 3-year-old girl presented to the Eye Hospital, Blantyre, Malawi, with multiple ulcerating lesions on her face and in her eyes. Her skin was freckled, with hypopigmented and hyperpigmented areas (poikilodermia) typical of xeroderma pigmentosa. The tumors on the conjunctiva of the right eye and the lower eyelid of the left eye appeared to be squamous cell carcinomas. Chemotherapy with intravenous 5-flourouracil (1000 mg/m) for 5 days and cisplatin (50 mg/m) for 2 days for 3 cycles every 3 weeks was well tolerated. Good response occurred after 1 cycle and after 2 more courses the tumors had resolved.

Stevens-Johnson syndrome (SJS) is a severe form of erythema multiforme that primarily affects skin and mucous membranes. In Malawi, manifestations of SJS may become more common in human immunodeficiency virus–infected patients receiving nevirapine-based antiretroviral therapy (ART) because the CD4 cell threshold for starting ART has increased from 250 to 350 cells/μL. We describe a patient with severe ocular complications from SJS that developed soon after initiation of nevirapine-based ART and cotrimoxazole preventive treatment, which led to blindness. We draw attention to preventive measures that can potentially reduce permanent ocular damage from SJS.

Background: Controversy still surrounds the intravenous (IV) treatment of endophthalmitis. The purpose of this study was to compare IV and intraocular (IO) treatment in experimental Staphylococcus aureus endophthalmitis: intravitreal injection of vancomycin and amikacin (VA/AN) in comparison with IV imipenem (IPM) and a combination of IV and IO (IV+IO) therapy. Methods: The right eyes of 27 rabbits were injected with 25,000 S. aureus. After 24 h, animals were either treated with IO VA/AN (n=5; 1.0 mg/0.4 mg in 0.1 ml saline), or IV IPM (n=9; 37 mg/kg body weight 3× daily), or IV+IO therapy (n=7), or served as untreated controls (n=6). Clinical appearance was evaluated daily and vitreous aspirates were obtained for bacterial culture 24 h and 6 days after therapy, when the eyes were enucleated for histopathologic examination. Results: Eyes in the IO or IO+IV treatment group had a significantly better appearance clinically and histologically than did eyes in the IV or untreated control group. Eyes in the IO+IV group had a similar appearance to the IO-treated eyes. All aspirates from the IO and IO+IV groups were culture-negative 24 hours after therapy, whereas only five of nine in the IV-treated group were culture-negative. Aspirates from all treatment groups were culture-negative by day 6 after the initiation of therapy. Untreated control eyes were culture-positive at all times. Conclusion: IO therapy with VA/AN proved more effective in treating experimental S. aureus endophthalmitis than did IV therapy with IPM alone. IV+IO treatment was not superior to IO treatment alone.

Background: To compare the efficacy of intravenous (IV) imipenem (IPM) and a combination of IV ceftazidime (CAZ) and amikacin (AN) in the treatment of Staphylococcus aureus endophthalmitis in a rabbit model. Methods: Right eyes of 60 albino rabbits were injected with 1000 colony-forming units of S. aureus intravitreally. After 24 h, treatment with either IV IPM (37.5 mg/kg) every 8 h (n=18) or IV CAZ (50 mg/kg) and AN (10 mg/kg) every 8 hours (n=18) was begun and continued until the animals were killed at the indicated timepoints; 24 control animals received no treatment. The concentration of bacteria in the vitreous from six animals per group was determined microbiologically on days 2, 3, and 5 after infection, and histologic examination was performed on all eyes. Results: The number of eyes with positive cultures on day 5 was lower in the group that received IV IPM (2/6) compared with the IV CAZ/AN group (4/6) and the control group (6/6). For the culture-positive eyes, the bacterial concentrations were significantly lower for the IV IPM group compared with the IV CAZ/AN group on days 2 and 5 (P

Objective To study whether the clinical outcome of Staphylococcus epidermidis -induced endophthalmitis in rabbits is related to the antibiotic resistance pattern of the infecting strain. Design Experimental animal study. Participants The right eyes of 36 New Zealand white albino rabbits were inoculated with strains of S. epidermidis that displayed various patterns of antibiotic resistance. Methods There were 12 rabbits in each of three study groups: fully antibiotic susceptible (FS), partially antibiotic resistant (PR), and multiresistant (MR). Five days after inoculation, the eyes were enucleated and prepared for histologic studies. Main outcome measures Comparisons among the three groups were made based on electroretinographic (ERG) findings, histologic evaluation by a masked observer, and clinical examination. Results Electroretinographic findings on all rabbits were made by an unmasked observer. At 30 hours after inoculation, the ERG was diminished to 65% of normal for group FS, compared with a flat ERG waveform for groups PR ( P P Conclusions In a rabbit model of S. epidermidis -induced endophthalmitis, antibiotic-susceptible strains caused less inflammation and destruction of the infected retina than did antibiotic-resistant strains.