ARE INTRAVITREAL INJECTIONS WITH ULTRATHIN 33-G NEEDLES LESS PAINFUL THAN THE COMMONLY USED 30-G NEEDLES?

PURPOSE: This study investigated whether pain from intravitreal injections (IVIs) can be reduced by injecting with a 33-G needle instead of the commonly used 30-G needle. Additionally, several pain-related psychological factors were explored as predictors of outcome. METHODS: This randomized crossover trial included 36 patients who received injections with both needles in randomized order. After the injection, patients rated IVI pain on a 0 to 10 scale. Before injection, distress and pain expectations were assessed. Afterward, patients rated the IVI procedure and anticipated consequences. In addition, we assessed the force necessary to penetrate the sclera for both needles in porcine eyes. RESULTS: The 33-G needle did not result in lower IVI pain (2.8 vs. 3.1, P = 0.758) but tended to cause less vitreal reflux (0 vs. 5 times, P = 0.054). Factors related to more pain were distress, expecting IVI pain and discomfort, dissatisfaction with the preparation procedure, anticipating negative consequences, and female gender. Patients regarded povidone-iodine disinfection as particularly unpleasant. Exploration of the needles' mechanical properties showed that 33-G needles penetrate the sclera more easily. CONCLUSION: The thinner 33-G needle does not reduce IVI pain but may limit scleral damage. Future efforts could be aimed at optimizing patient information, reducing distress, and the use of better tolerable disinfectants.

The rising incidence of Acanthamoeba keratitis: A 7-year nationwide survey and clinical assessment of risk factors and functional outcomes.

PURPOSE: To evaluate the incidence of Acanthamoeba keratitis in the Netherlands between 2009 and 2015 and to analyse predicting factors for treatment outcome. METHODS: Patient characteristics, diagnostic methods, diagnostic delay, therapy prior to and after diagnosis, and visual outcome were obtained from medical files of all patients diagnosed with Acanthamoeba keratitis in the Netherlands between 2009 and 2015. A logistic regression analysis on treatment failure, defined as a best corrected visual acuity of less than 20/40 Snellen decimals (i.e. >0.3 logMAR or an approximate loss of three lines of visual acuity) and/or the need for keratoplasty, was performed to determine predicting factors. RESULTS: Two hundred and twenty-four eyes of 224 patients were included. Ninety-five percent of the patients were contact lens wearers, of whom 74% wore soft contact lenses. The number of cases increased from 16 in 2009 to 49 in 2015. This resulted in an estimated incidence of 1 in 21,000 for soft contact lens wearers in 2015. Eighty-seven eyes (39%) met the criteria for treatment failure. In a multivariable regression analysis, higher age at presentation, a higher severity stage and corticosteroid use before diagnosis were positively correlated with treatment failure. Early referral to a cornea specialist was associated with better clinical outcomes. CONCLUSIONS: Although Acanthamoeba keratitis is still a relatively uncommon disease, the incidence in soft contact lens wearers has increased to reach 1 in 21,000 in 2015. Treatment failure occurred in 39% of cases, with age, higher severity stage, corticosteroid use before diagnosis and indirect referral to a cornea specialist as important risks factors.