A comparison between topical and retrobulbar anesthesia in 27-gauge vitrectomy for vitreous floaters: a randomized controlled trial.

BACKGROUND: To compare the safety and efficacy of topical anesthesia versus retrobulbar anesthesia in 27-gauge pars plana vitrectomy (PPV) for vitreous floaters. METHODS: 30 patients with vitreous floaters were randomized into Group T (topical anesthesia, proparacaine eye drop) and Group R (retrobulbar anesthesia), and underwent 27-gauge PPV. A 5-point visual analogue pain scale (VAPS) was used to assess patients' pain experience of anesthesia and surgery procedure (during surgery, 2 h and 1 day after surgery). RESULTS: The VAPS of anesthesia procedure was 1.27 ± 0.59 for patients in Group R, while it was all 0 for patients in Group T (p < 0.001). There was no significant difference for VAPS during surgery (Group T: 1.13 ± 0.74, Group R: 0.67 ± 0.62, p = 0.67), 2 h (Group T: 0.80 ± 1.01, Group R: 0.67 ± 0.62, p = 0.67) and 1 day (Group T: 0.20 ± 0.41, Group R: 0.27 ± 0.46, p = 0.68) after surgery between these two groups. Only one patient (6.7%) in Group T required additional topical anesthesia during the surgery. Most of the patients reported the pain experience came from initial trocar insertion in both groups. None of the patients required post operative analgesia in both groups. No intraoperative or postoperative complications were noted in both groups. CONCLUSION: This study suggested that topical anesthesia is a safe and effective anesthetic approach for patients with floaters who underwent 27-gauge PPV. TRIAL REGISTRATION: ClinicalTrials.gov NCT03049163 . Registered 8 February 2017.

Decompression-induced ocular tear film bubbles reflect the process of denitrogenation.

PURPOSE: To confirm that the tear film bubbles observed after decompression from hyperbaric exposure are due to denitrogenation and to assess the time course of denitrogenation based on the number of ocular tear film bubbles. METHODS: The study comprised two parts. In the first, subjects (n = 8) were compressed to a pressure of 2.0 ATA (atmospheres absolute; depth of 10 meters of sea water [msw]) for 60 minutes in a hyperbaric chamber on two separate occasions. On one occasion they breathed air, whereas on the second occasion they inspired pure oxygen. Before and within 30 minutes after each dive, the subjects' tear film was examined with a slit lamp microscope and the average number of bubbles recorded. Ultrasound reflectivity of the lens-vitreous humor compartments was also examined. In the second part of the study, subjects (n = 8) participated in two simulated dives in the hyperbaric chamber: 4.0 ATA (30 msw) for 15 minutes and 2.5 ATA (15 msw) for 180 minutes. The former was a no-stop decompression dive, whereas the latter required a 43-minute decompression stop at 3 msw. Ocular tear film examinations were conducted before the dive, as well as 30 minutes and 1 day, 2 days, and 3 days after the dives. RESULTS: The number of tear film bubbles increased significantly (P < 0.05) after the air dives to 2.0 ATA for 60 minutes, whereas there was no significant postdecompression increase in tear film when oxygen was inspired by the subjects during the dive. Posterior lens-vitreous humor reflectivity increased significantly after decompression from 2 ATA, when air was the breathing mixture, whereas no change in reflectivity was observed when oxygen was inspired during the dive. In the second part of the study, there was a significant elevation in tear film bubbles for 2 days after the two dives (P < 0.05). There was no significant difference in the number of ocular tear film bubbles between the two dives. CONCLUSIONS: After a hyperbaric air exposure, tear film bubbles reflect the process of denitrogenation, which may persist for up to 2 days after the decompression.

Application of transpupillary thermotherapy in a patient with asteroid hyalosis and premacular hemorrhage.

A 70-year-old woman with long-term poor vision was found to have unilateral massive premacular hemorrhage and asteroid hyalosis. Transpupillary thermotherapy (TTT) was applied sequentially to the vitreous in four separate spots, covering the area of the asteroid hyalosis and hemorrhage. Outcome measures included visual acuity, biomicroscopic appearance, ultrasonography, and fluorescein angiography. Significant resolution of the hemorrhage was observed 3 months after TTT, with visual acuity improvement from counting fingers at 25 cm to 20/60. There were no complications noted during the procedure or during follow-up. The long-term safety measures and visual prognosis following TTT for resolution of the vitreous impurities remain to be evaluated, but the procedure may be effective for treating premacular hemorrhage and asteroid hyalosis.

Echographic examination with new generation contrast agent of choroidal malignant melanomas.

PURPOSE: To determine the efficacy of echography with new generation contrast agents in visualizing vascularization of choroidal malignant melanomas. METHODS: An echographic contrast medium consisting of phospholipidic microbubbles filled with sulphur hexafluoride (Sonovue) was used to visualize microcirculation in 25 cases of choroidal lesions already diagnosed with standardized echography (21 choroidal malignant melanomas, four disciform lesions). RESULTS: In untreated malignant melanomas contrast agent echography revealed the presence of a dense microcirculation inside the mass. In one case vitreal seeding of the contrast agent was detectable before enucleation and histological examination revealed the presence of tumoral cells. In 12 cases treated with transpupillary thermotherapy, contrast agent echographic evaluation showed heavy regression of microcirculation after 1 week, confirmed in one case by histology, and a reduction of 70-80% in dimensions after 6 months (which appeared to have stabilized at subsequent examinations). In four cases treated with proton beam brachytherapy 2 years prior to our examination, contrast agent echography showed the absence of a microvascular network and the presence of large vessels and blood lakes. In four cases of disciform lesion, deep and superficial retina-associated vascularization was observed, with a weak spread of contrast agent inside the lesion. CONCLUSION: Live representation with good resolution of choroidal malignant melanoma microcirculation was obtained.

Ocular bubble formation as a method of assessing decompression stress.

Tear film bubble formation and ultrasound reflectivity of the lens-vitreous humor compartments were monitored following simulated dives in a hyperbaric chamber. the sensitivity of these methods in determining decompression stress was compared with the results of precordial Doppler ultrasound. In addition, the utility of these diagnostic techniques in testing decompression dive profiles was evaluated. Eleven divers completed two series of chamber dives according to the decompression schedule of the Professional Association of Diving Instructors. The first dive series comprised dives to 70 feet of seawater (fsw) for 15, 29, and 40 min. The second series comprised maximum duration no-stop decompression dives to 40 fsw for 140 min, 70 fsw for 40 min, 90 fsw for 25 min, and 120 fsw for 13 min. Before and immediately after each dive, the following measurements were obtained from each subject: eye surface tear film bubble counts with a slit-lamp microscope, lens and vitreous humor reflectivity using A- and B-mode ophthalmic ultrasonic scan, and precordial Doppler ultrasonic detection of venous gas bubbles. Tear film bubble assessment and ocular scanning ultrasound were observed to be more sensitive in detecting decompression stress than the conventional Doppler ultrasonic surveillance of the precordial region. In contrast to precordial Doppler ultrasonic surveillance, which failed to detect any significant changes in circulating bubbles, tear film bubble formation displayed a dose-response relationship with increasing duration of the 70-fsw dives. Reflectivity changes of the lens-vitreous humor interface were not significant until the no-stop decompression limit was reached. In addition, for each of the no-stop decompression limit dives, increases in the average tear film bubble formation and lens-vitreous humor interface reflectivity were similar. Ocular bubble observations may provide a practical and objective ocular bubble index for analyzing existing decompression schedules and predicting individual susceptibility to decompression sickness.