Vitrectomy for idiopathic macular hole.

BACKGROUND: A macular hole is an anatomic opening in the retina that develops at the fovea. Macular holes can be seen in highly myopic eyes or following ocular trauma, but the great majority are idiopathic. Pars plana vitrectomy was introduced to treat full-thickness macular holes, which if left untreated have a poor prognosis since spontaneous closure and visual recovery are rare.Vitrectomy is a surgical technique involving the removal of the vitreous body that fills the eye. The surgeon inserts thin cannulas into the eyes through scleral incisions to relieve traction exerted by the vitreous or epiretinal membranes to the central retina and to induce glial tissue to bridge and close the hole. OBJECTIVES: The primary objective of this review was to examine the effects of vitrectomy for idiopathic macular hole on visual acuity. A secondary objective was to investigate anatomic effects on hole closure and other dimensions of visual function, as well as to report on adverse effects recorded in included studies. SEARCH METHODS: We searched the Cochrane Eyes and Vision Group Trials Register (4 March 2015), the Cochrane Central Register of Controlled Trials (CENTRAL; 2015, Issue 2), Ovid MEDLINE, Ovid MEDLINE In-Process and Other Non-Indexed Citations, Ovid MEDLINE Daily, Ovid OLDMEDLINE (January 1946 to March 2015), EMBASE (January 1980 to March 2015), Latin American and Caribbean Health Sciences Literature Database (LILACS) (January 1982 to March 2015), the Web of Science Conference Proceedings Citation Index-Science (CPCI-S) (January 1980 to March 2015), the ISRCTN registry (www.isrctn.com/editAdvancedSearch), ClinicalTrials.gov (www.clinicaltrials.gov) and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en). We did not use any date or language restrictions in the electronic searches for trials. We last searched the electronic databases on 4 March 2015. SELECTION CRITERIA: We included randomised controlled trials comparing vitrectomy (with or without internal limiting membrane peeling) to no treatment (that is observation) for macular holes. DATA COLLECTION AND ANALYSIS: We used standard methodological procedures expected by Cochrane. Two review authors independently extracted the data. We estimated best corrected visual acuity and macular hole closure at 6 to 12 months of follow-up. MAIN RESULTS: Three studies provided data on the comparison between vitrectomy and observation in eyes with macular hole and visual acuity less than 20/50. Two studies, conducted in the USA and published in 1996 and 1997, used a similar protocol and included participants with stage II macular hole (42 eyes randomised, 36 analysed, number of participants not reported) or participants with stage III/IV hole (129 eyes of 120 participants, 115 eyes in analyses). The third study, conducted in the UK and published in 2004, included 185 eyes of 174 participants with full-thickness macular hole (41 eyes with stage II holes and 74 eyes with stage III/IV holes in analyses). Studies were of good quality for randomisation and allocation concealment, whereas visual acuity measurement was unmasked.At 6 to 12 months, visual acuity was improved by about 1.5 Snellen lines (-0.16 logMAR, 95% confidence intervals -0.23 to -0.09 logMAR, 270 eyes, moderate-quality evidence). The chances of macular hole closure at 6 to 12 months were greatly increased using vitrectomy, yielding an odds ratio of 31.4 (95% confidence intervals 14.9 to 66.3, 265 eyes, high-quality evidence; raw sum data: 76% vitrectomy, 11% observation). Vitrectomy was beneficial both in smaller (stage II) and in larger (stage III/IV) macular holes.The largest study reported that cataract surgery was needed in about half of cases at two years after operation and that retinal detachment occurred in about 5% of operated eyes. AUTHORS' CONCLUSIONS: Vitrectomy is effective in improving visual acuity, resulting in a moderate visual gain, and in achieving hole closure in people with macular hole. However, these results may not apply to modern surgery due to technological improvements in vitrectomy techniques.

Prph2 mutations as a cause of electronegative ERG.

PURPOSE: To describe the phenotypic and genotypic features in patients with PRPH2 mutations and negative electroretinograms. METHODS: Retrospective observational case series. Records of patients with a confirmed molecular diagnosis of PRPH2 mutation, and an electronegative electroretinogram (reduced b-wave to a-wave amplitude ratio) under either photopic or scotopic conditions, were identified. Data examined included clinical history and retinal images, electrophysiology, and mutational analysis. RESULTS: Six patients were ascertained. All had presented with clinically evident maculopathy and Snellen visual acuities in the range of 6/6 to 1/60. All had negative electroretinograms in scotopic or photopic electroretinograms or both. Four patients were heterozygous for a previously reported missense mutation c.514C>T, p.R172W; 2 were heterozygous for the frame-shifting mutations c.259_266del8, p.D87fs and c.394delC, p.Q132fs. No other cause of electronegative electroretinogram was identified in any patient. Photopic On- and Off-response recording was useful in identifying On-pathway dysfunction. CONCLUSION: PRPH2 mutation can be associated with negative electroretinograms. This novel finding is not mutation specific and does not relate to the severity of the disease. The data add to the documented phenotypical variability of PRPH2 mutations and represent a further cause of negative electroretinogram.

Effects of large exercise-induced weight loss on insulin sensitivity and metabolic risk factors in young males with obesity.

BACKGROUND: Obesity around the world is increasing at an alarming rate. One of the issues with obesity is whether exercise with large energy expenditure have any effect on obesity risk factors such as insulin resistance and coronary heart diseases. METHODS: Twenty participants (mean age: 19.5±1.09 years) with Body Mass Index (BMI) of >30 kg/m2, and body fat percentage (BF%) of >25% completed an institutionalized regimented training (IRT) for 16 weeks. 12-hour fasting blood samples were collected at least 48 hours after the last exercise session. Glucose and insulin variables were determined through an oral glucose tolerance test. Participants underwent 446 hours of IRT and ate from four standardized meal menus per day with a caloric intake of 3066 kcal. RESULTS: IRT resulted in a significant weight loss of 13.48±1.97 kg. Pre- and Post-Training total cholesterol (4.80±0.92 vs. 4.12±0.82 mmol/L) (P<0.01), low-density lipoprotein cholesterol (3.04±0.83 vs. 2.51±0.74 mmol/L) (P<0.01), triglycerides (1.19±0.57 vs. 0.74±0.30 mmol/L) (P<0.01) and apolipoprotein levels (Apo-A: 133.30±13.10 vs. 120.40±14.54 mg/dL; Apo-B: 88.08±25.72 vs. 70.12±18.21 mg/dL) (P<0.01) were significantly reduced, and glucose tolerance and insulin sensitivity were also improved. CONCLUSIONS: Large exercise-induced weight loss can be achieved through IRT and may be a solution for weight loss for individuals with obesity to reduce obesity related complications.

A normalized rate of perceived exertion at ventilatory breakpoint for different exercise modalities and production of exercise intensity with self-regulation for Singapore children.

BACKGROUND: The purpose of this study was to identify a normalized RPE response at ventilatory breakpoint (Vpt) for male adolescents 13-17 years old, and whether these adolescents could self-regulate at target RPEs of 4 and 6. METHODS: Twenty healthy males participated in the study, with 10 males in each of the cycling and walking/running groups. Participants performed orientation and V̇O2peak trials before performing a perceptual estimation exercise trial to obtain RPE Vpt, and two production trials to assess self-regulation ability. RESULTS: Vpt corresponded to 67.7% V̇O2peak for the cycling group and 70.4% V̇O2peak for the walking/running group. There were no group differences on RPE-Overall Vpt (cycling: 4.6; walking/running: 4.4), RPE-Legs Vpt (cycling: 5.4; walking/running: 4.6), and RPE-Chest Vpt (cycling: 4.0; walking/running: 4.8). A normalized RPE-Overall Vpt response was identified at five. V̇O2 did not differ between the estimation and production trials at targets RPE of 4 (1.59 vs. 1.57 L·min-1) and 6 (1.87 vs. 1.79 L·min-1). Similarly, heart rate (HR) did not differ between estimation and production trials at targets RPE 4 (152.4 vs. 151.1 beats·min-1) and 6 (167.1 vs. 162.4 beats·min-1). Both V̇O2 and HR were significantly higher at RPE 6 compared to RPE 4. Responses were not affected by exercise mode or production sequence. CONCLUSIONS: This study demonstrated that undifferentiated and differentiated RPE Vpt were similar between cycling and walking/running participants. Male adolescents between 13- and 17-year-olds were able to use the OMNI scale to self-regulate exercise intensities that would be useful in field settings.

Formation, modeling and validation of trihalomethanes (THM) in Malaysian drinking water: a case study in the districts of Tampin, Negeri Sembilan and Sabak Bernam, Selangor, Malaysia.

A modeling procedure that predicts trihalomethane (THM) formation from field sampling at the treatment plant and along its distribution system using Tampin district, Negeri Sembilan and Sabak Bernam district, Selangor as sources of data were studied and developed. Using Pearson method of correlation, the organic matter measured as TOC showed a positive correlation with formation of THM (r=0.380,P=0.0001 for Tampin and r=0.478,P=0.0001 for Sabak Bernam). Similar positive correlation was also obtained for pH in both districts with Tampin (r=0.362,P=0.0010) and Sabak Bernam (r=0.215,P=0.0010). Chlorine dosage was also found to have low correlation with formation of THM for the two districts with Tampin (r=0.233,P=0.0230) and Sabak Bernam (r=0.505,P=0.0001). Distance from treatment plant was found to have correlation with formation of THM for Tampin district with r=0.353 and P=0.0010. Other parameters such as turbidity, ammonia, temperature and residue chlorine were found to have no correlation with formation of THM. Linear and non-linear models were developed for these two districts. The results obtained were validated using three different sets of field data obtained from own source and district of Seremban (Pantai and Sg. Terip), Negeri Sembilan. Validation results indicated that there was significant difference in the predictive and determined values of THM when two sets of data from districts of Seremban were used with an exception of field data of Sg. Terip for non-linear model developed for district of Tampin. It was found that a non-linear model is slightly better than linear model in terms of percentage prediction errors. The models developed were site specific and the predictive capabilities in the distribution systems vary with different environmental conditions.

Postoperative analgesia and respiratory events in patients with symptoms of obstructive sleep apnoea.

Symptoms of obstructive sleep apnoea are common in patients presenting for surgery and are associated with increased morbidity. Analgesia contributes significantly to postoperative respiratory depression and obstruction, so we compared standard morphine patient-controlled analgesia with an opioid-sparing protocol (tramadol patient-controlled analgesia, parecoxib and rescue-only morphine) in these patients. Sixty-two patients presenting for elective surgery with body mass index > or = 28 and signs or symptoms suggesting obstructive sleep apnoea were randomised to receive either the opioid or opioid-sparing postoperative analgesia protocol, with continuous respiratory monitoring for 12 hours on the first postoperative night. The number of respiratory events (apnoeas and hypopnoeas) and oxygen desaturations were compared. There was no difference between treatment groups in the number of obstructive apnoeas, hypopnoeas or central apnoeas. However, central apnoeas and a rate of respiratory events > 15 per hour were related to postoperative morphine dose (P = 0.005 and P = 0.002). In patients at risk of obstructed breathing, intention to treat with an opioid-sparing analgesia protocol did not decrease the rate of respiratory events, although the rate was still related to the total morphine dose.

Pre- and postoperative sinus penetration of nasal irrigation.

OBJECTIVE/HYPOTHESIS: Endoscopic sinus surgery is an accepted treatment for medically recalcitrant chronic rhinosinusitis. Effective saline douching may improve long-term outcomes of chronic rhinosinusitis but is often impaired by postoperative ostial stenosis. The aim of this study is to determine a critical ostial size at which douching solution reliably enters the sinus cavities. STUDY DESIGN: Prospective study of consecutive patient cohort. METHODS: Seventeen preoperative or well-healed postoperative endoscopic sinus surgery patients were irrigated with 5 mL blue food coloring mixed with 200 mL buffered saline from a squeeze bottle. The degree of sinus penetration, sinus ostial patency, and ostial size were endoscopically determined. RESULTS: Sinuses penetrated by blue dye had a significantly larger minimal ostial dimension (7.31 mm; 95% confidence interval 5.54-9.08) than those that had no blue dye penetration (1.26 mm; 95% confidence interval 0.86-1.66) as determined by Student t test. Chi-square analysis showed that operated sinuses were more likely to be penetrated than nonoperated sinuses (P = .0016) and obstructed sinuses (P = .0325). Logistic regression showed a 95% probability of penetration when the minimum ostial dimension is 3.95 mm or greater. CONCLUSIONS: Unoperated sinuses or cases with gross sinus ostial obstruction will not be reliably penetrated by sinus irrigant. A 3.95-mm ostial diameter seems to be the minimum size to guarantee penetration in paranasal sinuses to maximize the potential for topical sinus treatment.