ABSTRACT
OBJECTIVE: To evaluate differences in pain, photophobia, retinal and optic nerve function in test eyes given intracameral lidocaine compared with control eyes given intracameral saline after phacoemulsification under topical anesthesia. DESIGN: Prospective paired-eye intervention study with random treatment allocation. PARTICIPANTS: Thirty eyes of 15 patients underwent cataract surgery in both eyes under topical anesthesia. INTERVENTION: The first eye of each patient was randomly assigned to either 0.5 ml preservative-free 2% intracameral lidocaine or 0.5 ml of intracameral sterile saline. Within 5 months, the second eye automatically received intracameral saline if the first eye received intracameral lidocaine or vice versa. MAIN OUTCOME MEASURES: The duration of surgery was recorded. Immediately after surgery, each patient was asked to evaluate the degree of pain and photophobia experienced during surgery using a nominal scale. In addition, in five patients, electroretinography (ERG) and visual evoked response (VER) were performed within 1 week before surgery, immediately after surgery, and 1 day after surgery. Amplitudes and latencies were calculated. RESULTS: There was no difference in the duration of surgery comparing test eyes given intracameral lidocaine with control eyes given sterile saline (P = 0.81). There was no significant difference in the level of pain reported when comparing test eyes given intracameral lidocaine with control eyes (P = 1.00). None of the patients reported any significant difference in photophobia between their two eyes (P = 1.00). When comparing ERG measurements, test eyes given intracameral lidocaine did not show any significant decrease in ERG amplitudes or prolonged latencies compared with control eyes. When comparing VER measurements, test eyes given intracameral lidocaine did not show any increase in P1 latencies compared with control eyes (P = 0.31). When evaluating all postoperative ERG results 1 day after surgery, there was a suggestion of improved cone function. CONCLUSIONS: Although intracameral lidocaine does not depress retinal or optic nerve function, the addition of intracameral lidocaine to topical anesthesia during phacoemulsification does not significantly reduce intraoperative pain or photophobia.
Subject(s)
Anesthetics, Local/administration & dosage , Lidocaine/administration & dosage , Optic Nerve/physiopathology , Pain/physiopathology , Phacoemulsification , Photophobia/physiopathology , Retina/physiopathology , Adult , Aged , Aged, 80 and over , Electroretinography , Evoked Potentials, Visual , Female , Humans , Male , Middle Aged , Pain/prevention & control , Pain Measurement , Photophobia/prevention & control , Prospective Studies , Time Factors , Visual AcuityABSTRACT
Isolates of Gaeumannomyces graminis var. tritici, the causal agent of take-all of wheat, varied in sensitivity in vitro to the antibiotics phenazine-1-carboxylic acid (PCA) and 2,4-diacetylphloroglucinol (Phl) produced by fluorescent Pseudomonas spp. shown previously to have potential for biological control of this pathogen. None of the four isolates of G. graminis var. avenae examined were sensitive to either of the antibiotics in vitro at the concentrations tested. The single isolate of G. graminis var. graminis tested was insensitive to PCA at 1.0 (mu)g/ml. Pseudomonas fluorescens 2-79 and Pseudomonas chlororaphis 30-84, both of which produce PCA, effectively suppressed take-all caused by each of two PCA-sensitive isolates of G. graminis var. tritici. PCA-producing strains exhibited a reduced ability or complete inability to suppress take-all caused by two of three isolates of G. graminis var. tritici that were insensitive to PCA at 1.0 (mu)g/ml. P. fluorescens Q2-87, which produces Phl, suppressed take-all caused by three Phl-sensitive isolates but failed to provide significant suppression of take-all caused by two isolates of G. graminis var. tritici that were insensitive to Phl at 3.0 (mu)g/ml. These findings affirm the role of the antibiotics PCA and Phl in the biocontrol activity of these fluorescent Pseudomonas spp. and support earlier evidence that mechanisms in addition to PCA are responsible for suppression of take-all by strain 2-79. The results show further that isolates of G. graminis var. tritici insensitive to PCA and Phl are present in the pathogen population and provide additional justification for the use of mixtures of Pseudomonas spp. that employ different mechanisms of pathogen suppression to manage this disease.
