Dual demise following laser surgery for twin-twin transfusion syndrome: Analysis of 52 cases at a single fetal surgery center.

OBJECTIVE: To evaluate all individual cases of dual twin demise following laser surgery for twin-twin transfusion syndrome (TTTS). METHOD: This is an analysis of all monochorionic diamniotic twin gestations with TTTS complicated by dual demise following laser surgery from 2006 to 2019. Cases were reviewed by (1) a fetal surgeon researcher and (2) a panel of independent experienced maternal-fetal medicine specialists to code an etiology of demise for the donor and recipient, and to assess for possible preventability. RESULTS: Of 753 twins that underwent laser surgery for TTTS, 52 (6.9%) had postoperative dual demise. In this subgroup, gestational age at surgery was 19.5 (16.1-24.9) weeks, and 36 (69.2%) patients were Quintero stage III and IV. The most common etiology was the spectrum of disorders leading to preterm delivery, which included cervical insufficiency, preterm premature rupture of membranes, and preterm labor (44.2% and 48.1%, donor and recipient, respectively). Some degree of preventability was estimated for 23.1% of dual demises. CONCLUSIONS: The most common cause of dual demise post laser surgery for TTTS was preterm birth, reinforcing the need for studies regarding the etiology and prevention of post-fetoscopy prematurity. Nearly one-quarter of dual demise cases were deemed potentially preventable.

Re-evaluation of the predictive value of Quintero staging of twin-twin transfusion syndrome for fetal death after fetoscopic laser photocoagulation.

OBJECTIVE: To elucidate the significance of sonographic indices, including Doppler waveforms, that constitute the Quintero classification for predicting death of the recipient or donor after fetoscopic laser photocoagulation (FLP) for twin-twin transfusion syndrome (TTTS). METHODS: Prospectively collected data of twins who underwent FLP for TTTS were reviewed. Among the abnormal indices of ultrasound performed just before FLP, factors that were significantly associated with fetal and neonatal deaths in the log-rank test, including fetal demise of co-twins and preterm birth before 28 weeks of gestation, were introduced into the Cox proportional-hazards model to calculate risk ratio (RR). RESULTS: We included 235 cases with a prevalence of recipient and donor deaths of 7% and 14%, respectively. In the proportional-hazards model, absent or reversed umbilical artery end-diastolic velocity (UA AREDV) of recipients (n = 7) was independently associated with recipient death (RR = 6.97). In recipients without UA AREDV, reversed ductus venosus (DV) a-wave of recipients (RR = 3.55) was independently associated with recipient death. In donors, UA AREDV with a visible bladder (stage III atypical donor) was independently associated with donor death (RR = 4.24). CONCLUSION: Some individual components of the Quintero stage are associated with death of either recipient or donor twins following FLP.

Outcomes of laparoscopy-assisted fetoscopic laser photocoagulation for twin-twin transfusion syndrome: An established alternative for inaccessible anterior placenta.

OBJECTIVE: To evaluate laparoscopy-assisted fetoscopic laser photocoagulation (FLPC) of placental anastomoses in the treatment of twin-to-twin-transfusion syndrome (TTTS). STUDY DESIGN: We performed a retrospective cohort study analyzing pregnancies complicated by TTTS who underwent FLPC in a single university-affiliated tertiary medical-center. Outcomes were compared between patients who received laparoscopy-assisted FLPC (study group) and patients who underwent the conventional FLPC technique (control group). Baseline characteristics, sonographic findings, procedure details, and neonatal outcomes were compared between groups. RESULTS: The cohort included 278 women with 31 in the study group and 247 in the control group. Sonographic parameters, including fetal biometry and TTTS stage, were comparable between study groups. Gestational age at delivery did not differ between the groups (29.22 ± 4.55 weeks in the study group vs. 30.62 ± 4.3 weeks in the control group, p = 0.09). There were no differences in neonatal survival rates at birth and at 30 days between both groups. A subanalysis comparing the laparoscopy-assisted group to only those patients with anterior placenta in the control group, showed a lower rate of incomplete Solomonization in the laparoscopy-assisted study group (3.4% vs. 33%, p = 0.01). CONCLUSION: Laparoscopy-assisted FLPC is a reasonable and safe option that may be offered in cases of FLPC where an anterior placenta restricts adequate surgical access.

Reproductive Outcomes following Laser Surgery for Twin-Twin Transfusion Syndrome.

BACKGROUND: There are limited studies describing future reproductive outcomes in women who have had selective fetoscopic laser photocoagulation (SFLP) for twin-twin transfusion syndrome (TTTS). OBJECTIVE: Our study aims to compare reproductive outcomes following monochorionic multiple gestational pregnancies complicated by TTTS requiring SFLP to those not requiring SFLP. METHODS: This is a retrospective cohort study that analyzed records of patients who were evaluated at the Cincinnati Fetal Center (2007-2014) for monochorionic multiple gestations. A questionnaire regarding reproductive, obstetric, gynecologic, and psychological outcomes following the index pregnancy was administered to consented participants by electronic distribution. The data was compared between pregnancies with prior SFLP versus no prior SFLP. RESULTS: There was a higher response rate in the SFLP group (219/474, 46.2%) versus the referent group (62/187, 33.2%). The median interval between the index pregnancy and survey completion was 74 months and 46 months in the SFLP and referent groups, respectively. Approximately 38 and 37% of the women in the SFLP and referent groups attempted conception after the index pregnancy with a >90% pregnancy success rate in both groups. Use of assisted reproductive technology was highly prevalent in both the index and subsequent pregnancies, with no significant difference between the groups. Over 60% of the women in each group did not attempt future pregnancy. Of those, approximately 1 in 3 cited the outcome of the index pregnancy as the primary reason for not pursuing future conception. There were no significant differences in selected maternal-fetal complications and new-onset gynecologic problems. More than 1 in 4 women in both groups were diagnosed with a mental health disorder following the index pregnancy. CONCLUSION: SFLP does not appear to be associated with adverse reproductive, obstetric, or gynecologic outcomes. The data may help facilitate evidence-based counseling for this patient population.

Conditional copula models for right-censored clustered event time data.

This article proposes a modeling strategy to infer the impact of a covariate on the dependence structure of right-censored clustered event time data. The joint survival function of the event times is modeled using a conditional copula whose parameter depends on a cluster-level covariate in a functional way. We use a local likelihood approach to estimate the form of the copula parameter and outline a generalized likelihood ratio-type test strategy to formally test its constancy. A bootstrap procedure is employed to obtain an approximate $p$-value for the test. The performance of the proposed estimation and testing methods is evaluated in simulations under different rates of right-censoring and for various parametric copula families, considering both parametrically and nonparametrically estimated margins. We apply the methods to data from the Diabetic Retinopathy Study to assess the impact of age at diabetes onset on the time to loss of visual acuity.

Percutaneous plasma laser disc coagulation and navigable ablation decompression in the treatment of cervical disc herniation: a single center experience

Background/aim: We aimed to compare the effectivity of percutaneous disc coagulation therapy (PDCT) and navigable ablation decompression treatment (L-DISQ) in patients who were diagnosed with cervical disc herniation. Materials and methods: Visual analog scale (VAS) and Neck Pain Index (NPI) scores were recorded initially and at the 1st, 3rd, 6th, and 12th months after the procedures. Patient Satisfaction Scale (PSS) scores were recorded 12 months after the procedures Results: Mean VAS scores were 7.55 and 3.1 points in the PDCT group and 7.6 and 3.00 points in the L-DISQ group; mean NPI scores were 34.2 and 20.75 points in the PDCT group and and 34.1 and 20.4 points in the L-DISQ group initially and at the 12th month. When compared between months, there was a significant decrease in time-dependent VAS and NPI scores in both PDCT and L-DISQ groups (P = 0.001). Some complications included esophageal, vascular, and neural injuries; hoarseness; Horner syndrome; infections; dural puncture; and muscle spasm. The only difference between groups was the rate of cervical spasm within 1 month after the procedure: 75% in the PDCT group and 15% in the L-DISQ group. Conclusion: The diameter of the canal of the cervical vertebrae is narrower than of the lumbar and thoracic regions; therefore, the smaller part of the disc may be sufficient to create clinical signs. The response to decompression therapies is faster in the case of cervical percutaneous procedures that are performed correctly. Proper patient selection and practitioner's experience are important in the treatment success

Perinatal outcomes of single fetal survivor after fetal intervention for complicated monochorionic twins.

OBJECTIVE: To compare perinatal outcomes between acute single fetal demise following fetoscopic laser photocoagulation to planned selective reduction (SR) in complicated monochorionic twin pregnancies. METHODS: This was a secondary analysis of prospectively collected data in complicated monochorionic twin pregnancies from 2 fetal centers from 2011 to 2016. Group 1 included women undergoing fetoscopic laser photocoagulation for twin-twin transfusion syndrome (TTTS) who experienced a single fetal demise within 24 hours of the procedure. Group 2 consisted of women undergoing planned selective reduction (SR) with TTTS, and Group 3 SR for indications other than TTTS. RESULTS: Survival of the remaining co-twin at birth was highest in Group 1 (n = 77 patients; 95%) compared with that in Group 2 (n = 15; 80%) and Group 3 (n = 32; 78%; P = .047). The preterm premature rupture of membrane rate was higher in Group 1 (47%) compared with that in Group 2 (33%) and Group 3 (7%; P < .001). Group 1 had a lower gestational age at delivery and shorter procedure-to-delivery interval compared with the other 2 groups (P < .01). CONCLUSION: When single fetal demise occurs following fetoscopic laser photocoagulation, the surviving co-twin is more likely to survive to delivery but has higher PPROM rates and a shorter latency period compared with planned selective reduction for TTTS or other indications.

Factors associated to early intrauterine fetal demise after laser for TTTS by preoperative fetal heart and Doppler ultrasound.

OBJECTIVE: To determine the prognostic value of fetal Doppler and echocardiographic parameters for intrauterine fetal demise (IUFD) within 24 hours and within 1 week after laser coagulation in monochorionic pregnancies complicated by twin-twin transfusion syndrome. METHOD: This retrospective study correlated the preoperative hemodynamic and echocardiography parameters to the outcome in fetuses with twin-twin transfusion syndrome undergoing laser therapy. RESULTS: One hundred and twelve laser coagulations were performed between February 2006 and June 2015. The total (single and double) IUFD rate was 27.7%. Further, 59% of IUFD occurred within 24 hours and 74.4% occurred within 1 week after laser. The following were associated to IUFD within 24 hours: the middle cerebral arterial pulsatility index in the donor, abnormal umbilical artery (UA) end diastolic flow, increased middle cerebral artery peak systolic velocity, and right ventricular myocardial performance index (RV-MPI) z-score in the recipient. For IUFD within 1 week were the pulsatility index in the donor UA and the recipient abnormalities in UA, ductus venosus, middle cerebral artery-peak systolic velocity, and RV-MPI z-score. CONCLUSION: Following laser was early IUFD that was associated with Doppler findings suggesting donor cerebroplacental redistribution, and recipient overload cardiomyopathy, such as abnormal ductus venosus and UA Dopplers as well as an increase of RV-MPI.

Monotherapy laser photocoagulation for diabetic macular oedema.

BACKGROUND: Diabetic macular oedema (DMO) is a complication of diabetic retinopathy and one of the most common causes of visual impairment in people with diabetes. Clinically significant macular oedema (CSMO) is the most severe form of DMO. Intravitreal antiangiogenic therapy is now the standard treatment for DMO involving the centre of the macula, but laser photocoagulation is still used in milder or non-central DMO. OBJECTIVES: To access the efficacy and safety of laser photocoagulation as monotherapy in the treatment of diabetic macular oedema. SEARCH METHODS: We searched CENTRAL, which contains the Cochrane Eyes and Vision Trials Register; MEDLINE; Embase; LILACS; the ISRCTN registry; ClinicalTrials.gov and the WHO ICTRP. The date of the search was 24 July 2018. SELECTION CRITERIA: We included randomised controlled trials (RCTs) comparing any type of focal/grid macular laser photocoagulation versus another type or technique of laser treatment and no intervention. We did not compare laser versus other interventions as these are covered by other Cochrane Reviews. DATA COLLECTION AND ANALYSIS: We used standard methodological procedures expected by Cochrane. Our primary outcomes were gain or loss of 3 lines (0.3 logMAR or 15 ETDRS letters) of best-corrected visual acuity (BCVA) at one year of follow-up (plus or minus six months) after treatment initiation. Secondary outcomes included final or mean change in BCVA, resolution of macular oedema, central retinal thickness, quality of life and adverse events, all at one year. We graded the certainty of the evidence for each outcome using the GRADE approach. MAIN RESULTS: We identified 24 studies (4422 eyes). The trials were conducted in Europe (nine studies), USA (seven), Asia (four) and, Africa (one), Latin America (one), Europe-Asian (one) and Oceania (one). The methodological quality of the studies was difficult to assess as they were poorly reported, so the predominant classification of bias was unclear.At one year, people with DMO receiving laser were less likely to lose BCVA compared with no intervention (risk ratio (RR) 0.42, 95% confidence interval (CI) 0.20 to 0.90; 3703 eyes; 4 studies; I2 = 71%; moderate-certainty evidence). There were also favourable effects observed at two and three years. One study (350 eyes) reported on partial or complete resolution of clinically significant DMO and found moderate-certainty evidence of a benefit at three years with photocoagulation (RR 1.55, 95% CI 1.30 to 1.86). Data on visual improvement, final BCVA, central macular thickness and quality of life were not available. One study related minor adverse effects on the central visual field and another reported one case of iatrogenic premacular fibrosis.Nine studies compared subthreshold versus standard macular photocoagulation (517 eyes). Subthreshold treatment was achieved with different methods of photocoagulation: non-visible conventional (two studies), micropulse (four) or nanopulse (one).Only one small study (29 eyes) reported on improvement or worsening of BCVA and estimates were very imprecise (improvement: RR 0.31, 95% CI 0.01 to 7.09; worsening: RR 0.93, 95% CI 0.15 to 5.76; very low-certainty evidence). All studies reported on continuous BCVA at one year; there was low-certainty evidence of no important difference between subthreshold and standard photocoagulation (mean difference (MD) in logMAR BCVA -0.02, 95% CI -0.07 to 0.03; 385 eyes; 7 studies; I2 = 42%), and were possibly different for different techniques (P = 0.07 and I2 = 61.5% for subgroup heterogeneity), with better results achieved with micropulse photocoagulation (MD -0.08 logMAR, 95% CI -0.16 to 0.0) as compared to the results achieved with nanopulse (MD 0.0 logMAR, 95% CI -0.06 to 0.06) and non-visible conventional (MD 0.04 logMAR, 95% CI -0.03 to 0.11), all of them compared to the standard lasers. One study reported partial to complete resolution of macular oedema at one year. There was low-certainty evidence of some benefit with standard photocoagulation, but estimates of effect were imprecise (RR 0.47, 95% CI 0.21 to 1.03; 29 eyes; 1 study). Studies also reported on the change in central macular thickness at one year and found moderate-certainty evidence of no important difference between subthreshold and standard photocoagulation (MD -9.1 µm, 95% CI -26.2 to 8.0; 385 eyes; 7 studies; I2 = 0%). There were no important adverse effects recorded in the studies.Nine studies compared argon laser versus another type of laser (997 eyes). There was moderate-certainty evidence of a small reduction or no difference between the interventions, with respect to improvement (RR 0.87, 95% CI 0.62 to 1.22; 773 eyes; 6 studies) and worsening of BCVA (RR 0.83, 95% CI 0.57 to 1.21; 773 eyes; 6 studies). Three studies reported few cases of subretinal fibrosis and neovascularization with argon laser and one study found subretinal fibrosis in the krypton group.One study (323 eyes) compared the modified ETDRS (mETDRS) grid technique with the mild macular grid (MMG), which uses mild, widely spaced burns throughout the macula. There was low-certainty evidence of an increased chance of visual improvement with MMG, but the estimate was imprecisely measured and the CIs include an increased risk or decreased risk of visual improvement at one year (RR 1.43, 95% CI 0.56 to 3.65; visual worsening: RR 1.40, 95% CI 0.64 to 3.05; change of logMAR visual acuity: MD -0.04 logMAR, 95% CI -0.01 to 0.09). There was a more significant reduction of central macular thickness with the mETDRS compared to the MMG technique (MD -34.0 µm, -59.8 to -8.3) in the MMG group. The study did not record important adverse effects. AUTHORS' CONCLUSIONS: Laser photocoagulation reduces the chances of visual loss and increases those of partial to complete resolution of DMO compared to no intervention at one to three years. Subthreshold photocoagulation, particularly the micropulse technique, may be as effective as standard photocoagulation and RCTs are ongoing to assess whether this minimally invasive technique is preferable to treat milder or non-central cases of DMO.

The treatment and risk factors of retinopathy of prematurity in neonatal intensive care units.

BACKGROUND: Retinopathy of prematurity (ROP) is a vascular proliferative disorder of the developing retina and a significant cause of childhood blindness around the world. The incidence of ROP is affected by many factors, and the incidence rate varies from country to country. The purpose of this study is to report the incidence and risk factors of ROP in neonatal intensive care unit (NICU) of Guangzhou First People's Hospital in China. METHODS: A retrospective review was performed on 436 premature infants who were consecutive ROP screened in the NICU of Guangzhou First People's Hospital from March 2013 to October 2017. The single-factor analysis and the logistic multivariate regression analysis were used to detect risk factors of ROP. RESULTS: Total 436 premature infants were consecutive ROP screened, 138 (31.65%) were found ROP, and 61(13.99%) were treated. The single-factor analysis revealed that the incidence of ROP was associated with multiple births, gestational age, birth weight, mechanical ventilation, intravascular hemolysis, the number of operations and blood culture results. The logistic multivariate regression analysis revealed that gestational age; birth weight, mechanical ventilation, minimum SaO2 and daily weight gain were independent risk factors for ROP onset. Forty-nine patients underwent retinal laser photocoagulation with recurrence 20 patients. Twelve patients underwent anti-VEGF drug (Ranibizumab) via intraocular injection with 5 patients of recurrence. CONCLUSIONS: The incidence of ROP in NICU of Guangzhou China will match those in middle-income countries, but higher than high-income countries. Anti-VEGF drugs could be preferred as a good treatment method for zone 1 ROP and aggressive posterior ROP.

Fetoscopic laser photocoagulation for amniotic fluid discordance bordering on twin-twin transfusion syndrome: Feasibility, perinatal and long-term outcomes.

AIM: This study investigated the feasibility and safety of fetoscopic laser photocoagulation (FLP) for amniotic fluid discordance (AFD) bordering on twin-twin transfusion syndrome (TTTS) with an absent or reverse end-diastolic velocity (AREDV) in the umbilical artery (UA), and evaluated the perinatal and long-term outcomes. METHODS: A prospective intervention study was performed between 20 + 0 and 25 + 6 weeks of gestation (UMIN000004165). AFD bordering on TTTS was defined as maximum vertical pocket (MVP) of amniotic fluid in one twin's sac ≤3 cm and amniotic fluid MVP in the other twin's sac ≥7 cm excluding TTTS. Neurodevelopmental outcome was evaluated at 6 months and at 3 years of age. RESULTS: Eleven women were treated without complications between September 2010 and July 2011. In all cases amnioinfusion was required, with a median surgical time of 70 min. There were nine cases of selective intrauterine growth restriction in which the growth discordant rate was >25%. The survival rates of the donor and recipient twins were 27.3% (3/11) and 100% (11/11), respectively. None of the surviving donor twins and two of the 11 recipient twins had hemiplegia at 6 months of age. One additional recipient twin had developmental delay at 3 years of age. CONCLUSIONS: Fetoscopic laser photocoagulation for AFD bordering on TTTS with AREDV in the UA was feasible without complications but frequently resulted in donor twin death and a high survival rate of the recipient twin, albeit with neurodevelopmental abnormalities in some cases. FLP does not seem to be a promising treatment option for AFD bordering on TTTS.

[Economic aspects of diabetic macular edema treatment at regional level in Russian Federation]. / Ékonomicheskie aspekty lecheniia diabeticheskogo makuliarnogo oteka na regional'nom urovne v Rossiiskoi Federatsii.

An assessment of economic burden of Diabetic Macular Edema (DME) in Russian Federation was conducted on the example of four pilot regions including Samara Region, Republic of Bashkortostan, Chuvash Republic and Yaroslavl Region. The assessment involved a newly developed interactive pharmacoeconomic model that uses data from questionnaire surveys of leading DME experts residing in the regions. In the course of the study, direct and indirect costs associated with DME were calculated. The highest direct costs of DME treatment were seen in the Republic of Bashkortostan - 302 482 RUB/year per patient. Direct cost of treating a single DME patient in the Samara Region was 34 271 RUB/year, in the Yaroslavl Region - 32 308 RUB/year and in the Chuvash Republic - 12 243 RUB/year. Indirect costs per DME patient in the Samara Region amounted to 67 530 RUB/year, in the Yaroslavl Region - 75 177 RUB/year, in the Republic of Bashkortostan - 102 884 RUB/year and in the Chuvash Republic - 81 082 RUB/year. Total annual costs per DME patient in the Samara Region was 101 801 RUB/year, in the Yaroslavl Region - 107 485 RUB/year, in the Republic of Bashkortostan - 405 366 RUB/year and in the Chuvash Republic - 93 325 RUB/year.

Neonatal Risk Factors for Treatment-Demanding Retinopathy of Prematurity: A Danish National Study.

PURPOSE: One goal of the study was to identify "new" statistically independent risk factors for treatment-demanding retinopathy of prematurity (ROP). Another goal was to evaluate whether any new risk factors could explain the increase in the incidence of treatment-demanding ROP over time in Denmark. DESIGN: A retrospective, register-based cohort study. PARTICIPANTS: The study included premature infants (n = 6490) born in Denmark from 1997 to 2008. METHODS: The study sample and the 31 candidate risk factors were identified in 3 national registers. Data were linked through a unique civil registration number. Each of the 31 candidate risk factors were evaluated in univariate analyses, while adjusted for known risk factors (i.e., gestational age [GA] at delivery, small for gestational age [SGA], multiple births, and male sex). Significant outcomes were analyzed thereafter in a backward selection multiple logistic regression model. MAIN OUTCOME MEASURES: Treatment-demanding ROP and its associations to candidate risk factors. RESULTS: Mechanical ventilation (odds ratio [OR], 2.84; 95% confidence interval [CI], 1.99-4.08; P < 0.01) and blood transfusion (OR, 1.97; 95% CI, 1.20-3.14; P = 0.01) were the only new statistically independent risk factors, in addition to GA at delivery, SGA, multiple births, and male sex. Modification in these prognostic factors for ROP did not cause an increase in treatment-demanding ROP. CONCLUSIONS: In a large study population, blood transfusion and mechanical ventilation were the only new statistically independent risk factors to predict the development of treatment-demanding ROP. Modification in the neonatal treatment with mechanical ventilation or blood transfusion did not cause the observed increase in the incidence of preterm infants with treatment-demanding ROP during a recent birth period (2003-2008).

The Relationship between Medicare Payment and Service Volume for Retina Procedures from 2005 through 2009.

PURPOSE: To calculate the relationship between Medicare payment and service volume for the 3 highest-volume retina procedures: intravitreal injection (Current Procedural Terminology [CPT] code 67028), laser treatment for retinal edema (CPT code 67210), and laser treatment for proliferative retinopathy (CPT code 67228). DESIGN: Retrospective, longitudinal database study. PARTICIPANTS: One hundred percent dataset of all retina procedures performed on Medicare Part B beneficiaries within the United States from 2005 through 2009. METHODS: Fixed-effects regression model using Medicare Part B carrier data for all 50 states and the District of Columbia, controlling for time-invariant carrier-specific characteristics, national trends in service volume, Medicare beneficiary population, number of ophthalmologists, and income per capita. MAIN OUTCOME MEASURES: Medicare payment-service volume elasticities, defined as the percent change in service volume per 1% change in Medicare payment, for intravitreal injection, laser treatment for retinal edema, and laser treatment for proliferative retinopathy. RESULTS: For all 3 retina procedures, the regression coefficients representing the Medicare payment-service volume elasticity were nonsignificant: intravitreal injection elasticity, -0.75 (95% confidence interval [CI], -1.62 to 0.13; P = 0.09); laser treatment for retinal edema elasticity, 0.14 (95% CI, -0.38 to 0.65; P = 0.59); and laser treatment for proliferative retinopathy elasticity, 0.05 (95% CI, -0.26 to 0.35; P = 0.77). CONCLUSIONS: This study found no evidence suggesting that there is an association between Medicare payment and service volume for the 3 highest-volume retina procedures from 2005 through 2009.

A Quantitative Analysis of the Relationship between Medicare Payment and Service Volume for Glaucoma Procedures from 2005 through 2009.

PURPOSE: To calculate the association between Medicare payment and service volume for 6 commonly performed glaucoma procedures. DESIGN: Retrospective, longitudinal database study. SUBJECTS: A 100% dataset of all glaucoma procedures performed on Medicare Part B beneficiaries within the United States from 2005 to 2009. METHODS: Fixed-effects regression model using Medicare Part B carrier data for all 50 states and the District of Columbia, controlling for time-invariant carrier-specific characteristics, national trends in glaucoma service volume, Medicare beneficiary population, number of ophthalmologists, and income per capita. MAIN OUTCOME MEASURES: Payment-volume elasticities, defined as the percent change in service volume per 1% change in Medicare payment, for laser trabeculoplasty (Current Procedural Terminology [CPT] code 65855), trabeculectomy without previous surgery (CPT code 66170), trabeculectomy with previous surgery (CPT code 66172), aqueous shunt to reservoir (CPT code 66180), laser iridotomy (CPT code 66761), and scleral reinforcement with graft (CPT code 67255). RESULTS: The payment-volume elasticity was nonsignificant for 4 of 6 procedures studied: laser trabeculoplasty (elasticity, -0.27; 95% confidence interval [CI], -1.31 to 0.77; P = 0.61), trabeculectomy without previous surgery (elasticity, -0.42; 95% CI, -0.85 to 0.01; P = 0.053), trabeculectomy with previous surgery (elasticity, -0.28; 95% CI, -0.83 to 0.28; P = 0.32), and aqueous shunt to reservoir (elasticity, -0.47; 95% CI, -3.32 to 2.37; P = 0.74). Two procedures yielded significant associations between Medicare payment and service volume. For laser iridotomy, the payment-volume elasticity was -1.06 (95% CI, -1.39 to -0.72; P < 0.001): for every 1% decrease in CPT code 66761 payment, laser iridotomy service volume increased by 1.06%. For scleral reinforcement with graft, the payment-volume elasticity was -2.92 (95% CI, -5.72 to -0.12; P = 0.041): for every 1% decrease in CPT code 67255 payment, scleral reinforcement with graft service volume increased by 2.92%. CONCLUSIONS: This study calculated the association between Medicare payment and service volume for 6 commonly performed glaucoma procedures and found varying magnitudes of payment-volume elasticities, suggesting that the volume response to changes in Medicare payments, if present, is not uniform across all Medicare procedures.

Use of Various Glaucoma Surgeries and Procedures in Medicare Beneficiaries from 1994 to 2012.

PURPOSE: Determine how procedural treatments for glaucoma have changed between 1994-2012. DESIGN: Retrospective, observational analysis. PARTICIPANTS: Medicare Part B beneficiaries. METHODS: We analyzed Medicare fee-for-service paid claims data between 1994-2012 to determine the number of surgical/laser procedures performed for glaucoma in the Medicare population each year. MAIN OUTCOME MEASURES: Number of glaucoma-related procedures performed. RESULTS: Trabeculectomies in eyes without previous scarring decreased 52% from 54 224 in 1994 to 25 758 in 2003, and a further 52% to 12 279 in 2012. Trabeculectomies in eyes with scarring ranged from 9054 to 13 604 between 1994-2003, but then decreased 48% from 11 018 to 5728 between 2003-2012. Mini-shunts done via an external approach (including ExPRESS [Alcon Inc, Fort Worth, TX]) increased 116% from 2718 in 2009 to 5870 in 2012. The number of aqueous shunts to the extraocular reservoir increased 231% from 2356 in 1994 to 7788 in 2003, and a further 54% to 12 021 in 2012. Total cyclophotocoagulation procedures increased 253% from 2582 in 1994 to 9106 in 2003, and a further 54% to 13 996 in 2012. Transscleral cyclophotocoagulations decreased 45% from 5978 to 3268 between 2005-2012; over the same period, the number of endoscopic cyclophotocoagulations (ECPs) increased 99% from 5383 to 10 728. From 2001 to 2005, the number of trabeculoplasties more than doubled from 75 647 in 2001 to 176 476 in 2005, but since 2005 the number of trabeculoplasties decreased 19% to 142 682 in 2012. The number of laser iridotomies was fairly consistent between 1994-2012, increasing 9% over this period and ranging from 63 773 to 85 426. Canaloplasties increased 1407% from 161 in 2007 to 2426 in 2012. Between 1994-2012, despite a 9% increase in beneficiaries, the total number of glaucoma procedures and the number of glaucoma procedures other than laser procedures decreased 16% and 31%, respectively. CONCLUSIONS: Despite the increase in beneficiaries, the number of glaucoma procedures performed decreased. Glaucoma procedures demonstrating a significant increase in use include canaloplasty, mini-shunts (external approach), aqueous shunt to extraocular reservoir, and ECP. Trabeculectomy use continued its long-term downward trend. The continued movement away from trabeculectomy and toward alternative intraocular pressure-lowering procedures highlights the need for well-designed clinical trials comparing these procedures.

Prevalence and outcomes of laser treatment of aggressive posterior retinopathy of prematurity.

BACKGROUND: To describe outcomes in a cohort of extremely premature infants treated for aggressive posterior retinopathy of prematurity by diode laser panretinal photocoagulation. DESIGN: Retrospective study. PARTICIPANTS: Fifteen eyes in eight infants. METHODS: A review was carried out on infants between 23 and 25.6 weeks gestational age admitted to The Royal Brisbane and Women's Hospital neonatal intensive care unit between 1992 and 2009. MAIN OUTCOME MEASURES: Success of treatment, visual and refractive outcomes. RESULTS: Five hundred fifty-four infants were admitted to neonatal intensive care unit, 373 survived till screening, and 304 had retinopathy of prematurity. Sixty-six infants required treatment, and eight of these had aggressive posterior retinopathy of prematurity (2.5% of all infants with retinopathy of prematurity). Mean gestational age was 24.2 weeks, mean birthweight was 634 g, and treatment occurred at mean 34.1 weeks post-menstrual age. The mean total number of burns per eye was 2967. Five of 15 treated eyes required retreatment. Two patients subsequently died of unrelated causes. Regression occurred in 9 of 11 remaining eyes; one eye progressed to stage 4b and another to stage 5 retinopathy of prematurity. Vitrectomy was performed in two eyes. Five eyes had 6/12 vision, one had 3/60, and three had no perception of light. Of the remaining two eyes, one had good fixation and the other had poor fixation. CONCLUSIONS: Despite good structural outcomes, visual outcomes for conventional laser treatment of aggressive posterior retinopathy of prematurity are poor.

Management of Stage I twin-to-twin transfusion syndrome: an international survey.

OBJECTIVE: To determine practice patterns for evaluation and treatment of Stage I twin-to-twin transfusion syndrome (TTTS) among international physicians. METHODS: An e-mail cross-sectional survey of members from the IFMSS, NAFTNet and SMFM societies and participants at a Eurofoetus-sponsored TTTS meeting was undertaken between May 2008 and November 2008. Questionnaires consisted of physician demographics and their recommendations for managing Stage I TTTS. Alternative therapies to expectant management were assessed based on the following special circumstances of the patient: residence more than 200 miles from the center, severe symptoms, or a cervical length of

Modeling of laser coagulation of tissue with MRI temperature monitoring.

Light energy from a laser source that is delivered into body tissue via a fiber-optic probe with minimal invasiveness has been used to ablate solid tumors. This thermal coagulation process can be guided and monitored accurately by continuous magnetic resonance imaging (MRI) since the laser energy delivery system does not interfere with MRI. This report deals with mathematical modeling and analysis of laser coagulation of tissue. This model is intended for "real-time" analysis of magnetic resonance images obtained during the coagulation process to guide clinical treatment. A mathematical model is developed to simulate the thermal response of tissue to a laser light heating source. For fast simulation, an approximate solution of the thermal model is used to predict the dynamics of temperature distribution and tissue damage induced by a laser energy line source. The validity of these simulations is tested by comparison with MRI-based temperature data acquired from in vivo experiments in rabbits. The model-simulated temperature distribution and predicted lesion dynamics correspond closely with MRI-based data. These results demonstrate the potential for using this combination of fast modeling and MRI technologies during laser heating of tissue for online prediction of tumor lesion size during laser heating.