No abstract

Purpose: To compare the clinical and molecular diagnoses of Herpes Simplex Keratitis (HSK). Materials and Methods: Conjunctival swabs (after fluorescein and anaesthetic wash out) and detailed questionnaire data were obtained from 146 participants. Corneal rims and conjunctival epithelial cells were infected with Herpes Simplex Virus (HSV) type 1 or HSV2 and supernatant collected. HSV1; HSV2; Varicella Zoster Virus (VZV) and Adenovirus (ADV) DNA was assessed using two real time Polymerase Chain Reaction (PCR) methods. Results: Of the 146 participants recruited, 54 were clinically diagnosed with typical epithelial lesions and 38 with atypical epithelial lesions, 17 with old inactive HSK and 37 healthy volunteers. HSV1 DNA was detected in 28 (30%) of the 92 participants with clinically suspect HSK. Patients who presented with typical epithelial lesions had a higher positive rate (46%) than those who presented with atypical type lesions (8%), when using primers against the Glycoprotein (Gp) G region of the virus. When the same samples were retested with primers against the GpB region, the positive rate for the typical and atypical cases increased to 52% and 11% respectively. Antiviral use at the time of sampling reduced the rate of PCR positivity by 20% (p < 0.05). ADV DNA was detected in 6% of the typical cases and 8% of the atypical cases. All control participants with no history of HSK were negative for HSV1 DNA. Sample quantity was confirmed by testing for housekeeping control genes, beta-actin and beta-2 macrog-* Corresponding author. V. E. McGilligan et al. 66lobulin. PCR results from in vitro control investigations of HSV1 and 2 infected corneal rims and conjunctival epithelial cells were 100% positive for infected and 100% negative for uninfected samples when assessed using both PCR methods. Conclusions: Clinical diagnosis of typical HSK is not always confirmed by PCR. Concomitant use of an antiviral reduces levels of PCR positivity. Given this and the findings that other ocular surface pathogens may mimic HSK pathology, and that choice of gene amplification region can also affect accurate detection of HSV1 by PCR, we propose the use of a multiplex assay. This would perform PCR using primers spanning a number of different regions within one gene and would also target a number of different viral genes to ensure potentially different HSV1 viral strains or other viruses do not affect the test and lead to disagreements between the clinical and molecular diagnosis of HSK. From these findings, this paper proposes a clinical supportive algorithmic guide to manage such disagreements.

Purpose To assess the tolerability and outcomes of laser treatment for retinopathy of prematurity (ROP) under sub-tenon anaesthetic with oral or rectal sedation using a reliable, multidimensional, and internationally accepted tool for assessment of neonatal pain. Methods Sixty-two babies have had ROP laser treatment in our neonatal unit in the 7-year interval between 1 March 2005 and 28 February 2012; 44% (27 of the 62) were performed using sub-tenon anaesthesia. Pain scores were routinely assessed using the Neonatal Pain Agitation and Sedation Scale (N-PASS) every 10 min during laser treatment. The outcome and requirement for re-treatment in this group was compared with that in the intravenous sedation group. Results Pain scores were available in 19 of the 27 babies treated under sub-tenon anaesthesia. The mean pain score during treatment was 2.7 (SD±1.7, range 0.5-6.2). There was no statistically significant correlation between the mean pain score and duration of treatment (Spearman correlation coefficient (q) = 0.31; P = 0.09), number of laser burns (r = 0.32; P = 0.09), or post-menstrual age of the baby at the time of treatment (r = 0.38; P = 0.052). Treatments performed under sub-tenon anaesthesia were as successful as those performed under intravenous sedation. The mean pain scores during laser treatment under sub-tenon anaesthesia in our study were lower than those previously reported during ROP screening or heel-stick procedure. ConclusionOur study demonstrated that sub-tenon anaesthesia with oral or rectal sedation provides sufficient pain control for laser treatment for ROP without the need or risks of intravenous sedation and intubation.

Further refinement of currently available ophthalmological tools is required to aid in vivo visualization of herpes simplex keratitis using fluorescein isothiocynate-labeled antibodies.

No abstract