Objective To report the results of a global survey on cataract practice patterns related to preoperative, intraoperative and postoperative care, surgical setting and personnel allocation. Methods and analysis An online 28 questions survey was sent to 240 ophthalmologists asking to describe prevailing trends in their institutions across 38 countries and 5 continents. Questions inquired country, institution, surgical volume and setting, anaesthesia, preoperative and intraoperative examination and postsurgical care. Statistical analysis used crosstabs lambda statistics for non-parametric nominal variables. P value less than 0.05 was considered statistically significant. Results 209/240 (87%) ophthalmologists responded: 38% representing public hospitals, 36% private practices and 26% academic sites; overall surgical volume was between 241 700 and 410 500 cataracts per year. There was a significant correlation between type of institution and surgical volume. Complete results available in online (https://freeonlinesurveys.com/r/W6BcLLxy). Conclusion Cataract surgery related patterns of perioperative care showed significant difference among respondents, regardless to type of institution, surgical volume and country. Many evidence-based procedures are unevenly practiced around the world and some widespread and expensive habits lack solid scientific evidence while consuming enormous amount of resources both monetary and human. There is a need to reach consensus and share evidence-based practice patterns.
3 September 2020 in Neurology Neuroimmunology & Neuroinflammation
To review prevalence, long-term progression, and prognosis of vitreoretinal interface modifications in pathologic myopia with posterior staphyloma and investigate foveal sensitivity and fixation stability. Retrospective single-institution series of 214 eyes (116 patients) with pathologic myopia, axial length >30 mm, and posterior staphyloma. Exclusion criteria included follow-up less than five years, incomplete records, and/or less than three optical coherence tomography or microperimetry. Patients were divided into 5 groups according to optical coherence tomography: 1) epiretinal membrane without schisis (ERM); 2) macular retinal schisis (Schisis); 3) partial thickness macular hole (PTMH); 4) full-thickness macular hole (FTMH); and 5) posterior retinal detachment (PRD) with or without macular hole. Disease progression was defined as a visual acuity decrease of two or more lines associated to objective worsening of the optical coherence tomography and/or microperimetry. Vitreoretinal abnormalities at baseline were present in 116 of 204 patients (56.8%) and 214 of 408 eyes (52.4%); 98 of 116 patients (84.4%) showed bilateral involvement. Baseline visual acuity and foveal sensitivity varied significantly with ERM performing better and PRD worse than others; PTMH and FTMH did not differ. During the 66 months of average follow-up, 33 of 214 eyes (15.4%) required surgery and 13 of 33 eyes (39.3%) needed reintervention. Surgery rate significantly differed among groups: 2% for ERM, 20% to 25% for Schisis, PTMH, and FTMH, and up to 50% for PRD. Progression rate of Schisis and FTMH was the same, regardless of symptoms, while macula-off PRD always required surgery. Decrease of fixation stability and foveal sensitivity correlated to need for surgery, while baseline foveal sensitivity and fixation did not. Vitreoretinal interface pathology in pathologic myopia with posterior staphyloma encompasses a spectrum of conditions whose baseline functionality, prognosis, rate, and amount of progression vary significantly. Customized treatment for each different condition should be considered.
1 June 2011 in Investigative Ophthalmology & Visual Science
To test the hypothesis that blunt trauma shockwave propagation may cause macular and peripheral retinal lesions, regardless of the presence of vitreous. The study was prompted by the observation of macular hole after an inadvertent BB shot in a previously vitrectomized eye. The computational model was generated from generic eye geometry. Numeric simulations were performed with explicit finite element code. Simple constitutive modeling for soft tissues was used, and model parameters were calibrated on available experimental data by means of a reverse-engineering approach. Pressure, strain, and strain rates were calculated in vitreous- and aqueous-filled eyes. The paired t-test was used for statistical analysis with a 0.05 significance level. Pressure at the retinal surface ranged between -1 and +1.8 MPa at the macula. Vitreous-filled eyes showed significantly lower pressures at the macula during the compression phase (P < 0.0001) and at the vitreous base during the rebound phase (P = 0.04). Multiaxial strain reached 20% and 25% at the macula and vitreous base, whereas the strain rate reached 40,000 and 50,000 seconds(-1), respectively. Both strain and strain rates at the macula, vitreous base, and equator reached lower values in the vitreous- compared with the aqueous-filled eyes (P < 0.001). Calculated pressures, strain, and strain rate levels were several orders of magnitude higher than the retina tensile strength and load-carrying capability reported in the literature. Vitreous traction may not be responsible for blunt trauma-associated retinal lesions and can actually damp shockwaves significantly. Negative pressures associated with multiaxial strain and high strain rates can tear and detach the retina. Differential retinal elasticity may explain the higher tendency toward tearing the macula and vitreous base.