The Nitrogen Balancing Act: Tracking the Environmental Performance of Food Production.

Farmers, food supply-chain entities, and policymakers need a simple but robust indicator to demonstrate progress toward reducing nitrogen pollution associated with food production. We show that nitrogen balance-the difference between nitrogen inputs and nitrogen outputs in an agricultural production system-is a robust measure of nitrogen losses that is simple to calculate, easily understood, and based on readily available farm data. Nitrogen balance provides farmers with a means of demonstrating to an increasingly concerned public that they are succeeding in reducing nitrogen losses while also improving the overall sustainability of their farming operation. Likewise, supply-chain companies and policymakers can use nitrogen balance to track progress toward sustainability goals. We describe the value of nitrogen balance in translating environmental targets into actionable goals for farmers and illustrate the potential roles of science, policy, and agricultural support networks in helping farmers achieve them.

Dynamic Model Improves Agronomic and Environmental Outcomes for Maize Nitrogen Management over Static Approach.

Large temporal and spatial variability in soil nitrogen (N) availability leads many farmers across the United States to over-apply N fertilizers in maize ( L.) production environments, often resulting in large environmental N losses. Static Stanford-type N recommendation tools are typically promoted in the United States, but new dynamic model-based decision tools allow for highly adaptive N recommendations that account for specific production environments and conditions. This study compares the Corn N Calculator (CNC), a static N recommendation tool for New York, to Adapt-N, a dynamic simulation tool that combines soil, crop, and management information with real-time weather data to estimate optimum N application rates for maize. The efficiency of the two tools in predicting the Economically Optimum N Rate (EONR) is compared using field data from 14 multiple N-rate trials conducted in New York during the years 2011 through 2015. The CNC tool was used with both realistic grower-estimated potential yields and those extracted from the CNC default database, which were found to be unrealistically low when compared with field data. By accounting for weather and site-specific conditions, the Adapt-N tool was found to increase the farmer profits and significantly improve the prediction of the EONR (RMSE = 34 kg ha). Furthermore, using a dynamic instead of a static approach led to reduced N application rates, which in turn resulted in substantially lower simulated environmental N losses. This study shows that better N management through a dynamic decision tool such as Adapt-N can help reduce environmental impacts while sustaining farm economic viability.

Association between Cataract and Keratinocytic Skin Cancers or Melanoma: Speculating on the Common Role of Sun and Ultraviolet Radiation Exposures.

PURPOSE: Cataract and sun-related skin conditions are proxies to lifetime UV exposure. We examined the association between them using real-world data from an unselected Israeli population. METHODS: Computerized data was obtained from an Israeli health maintenance organization regarding cases of sun-related skin pathologies and cataract diagnosed between 2006 and 2011 in 686,260 members aged 40 or above. RESULTS: Sun-related skin disorders were found in 9.3% of the study population, more commonly among the elderly, and those who reside in areas of higher socioeconomic status. Cataract was diagnosed in 13.1% of the study population, with highest prevalence (47%) among squamous cell carcinoma patients, who were the oldest group. Multivariable analysis adjusting for age, sex, residential district, birth region, smoking, and chronic comorbidities showed no statistically significant association between melanoma and cataract (OR = 1.06; 95% CI: 0.91-1.22). Basal cell carcinoma, squamous cell carcinomas, and actinic keratosis were associated with increased likelihood of prevalent cataract with adjusted odds ratios (95% CI) of 1.14 (1.08-1.20), 1.11 (1.01-1.19), and 1.16 (1.13-1.19), respectively. When stratified by gender, the association between actinic keratosis and cataract was stronger in women than in men, particularly in patients under 65 years. CONCLUSIONS: The association between the prevalence of skin cancers and the prevalence of cataract enhances the conclusion that cataract is related to UVR exposure.

Drainage and Nitrate Leaching from Artificially Drained Maize Fields Simulated by the Precision Nitrogen Management Model.

Environmental nitrogen (N) losses (e.g., nitrate leaching, denitrification, and ammonia volatilization) frequently occur in maize ( L.) agroecosystems. Decision support systems, designed to optimize the application of N fertilizer in these systems, have been developed using physically based models such as the Precision Nitrogen Management (PNM) model of soil and crop processes, which is an integral component of Adapt-N, a decision support tool providing N fertilizer recommendations for maize production. Such models can also be used to estimate N losses associated with particular management practices and over a range of current climates and future climate projections. The objectives of this study were to update the PNM model to include an option for simulating soil-water processes in artificially drained soils, and to calibrate the revised PNM model and test it against multiyear field studies in New York and Minnesota with different soils and management practices. Minimal calibration was required for the model. Denitrification rate constants were calibrated by minimizing the error between simulated and observed nitrate leaching for each study site. The normalized root mean squared error of cumulative daily drainage for the validation sets ranged from 10 to 23%. For cumulative daily nitrate leaching, the normalized root mean squared error ranged from 11 to 28% for the validation sets. The minimal calibration required and relatively simple data inputs make the PNM model a broadly applicable tool for simulating water and N flows in maize systems.

Long-term outcomes of triamcinolone acetonide-assisted anterior vitrectomy during complicated cataract surgery with vitreous loss.

PURPOSE: To report the long-term outcomes of triamcinolone acetonide-assisted anterior vitrectomy during complicated cataract surgery with vitreous loss. SETTING: Tel Aviv Medical Center, Tel Aviv, Israel. DESIGN: Case series. METHODS: Consecutive patients who had triamcinolone acetonide-assisted anterior vitrectomy for complicated cataract surgery with vitreous loss between January 2010 and January 2012 were studied. The main outcome measures were the results of the ocular examination and spectral-domain optical coherence tomography of the macula at the last follow-up visit 12 months or more postoperatively. The ocular examination included corrected distance visual acuity (CDVA), intraocular pressure (IOP), and anterior segment and fundus biomicroscopy. RESULTS: The study included 15 patients (15 eyes) with a mean age of 71 years (range 50 to 92 years). The mean follow-up was 21 months (range 12 to 29 months). At the last follow-up, the mean CDVA was statistically significantly better than preoperatively (0.24 logMAR ± 0.31 [SD] versus 0.89 ± 0.81 logMAR) (P=.0033); all patients had improved CDVA over the preoperative values. Except for 1 patient with a macular scar, all the patients had a CDVA between 20/40 and 20/20. At last follow-up, 1 patient required 2 IOP-lowering medications that had been used preoperatively as well. The mean IOP was 15.3 ± 2.4 mm Hg. There were no cases of residual vitreous strands in the anterior chamber, inflammatory reactions, triamcinolone acetonide crystals, retinal breaks, retinal detachment, or pseudophakic cystoid macular edema. CONCLUSION: Triamcinolone acetonide-assisted anterior vitrectomy during complicated cataract surgery with vitreous loss was safe and effective.

Secondary membrane formation after cataract surgery with primary intraocular lens implantation in children.

To evaluate the risk factors for secondary membrane (SM) formation after congenital cataract surgery with intraocular lens (IOL) implantation. A retrospective non-interventional comparative study. Thirty-nine patients (63 eyes) aged 1-135 months. The study included patients who underwent cataract extraction and primary IOL implantation between 1994 and 2001 at the University Hospital. The postoperative follow-up was 6-24 months. Thirty-three eyes received a poly(methyl methacrylate) (PMMA) IOL without square edges, 29 eyes received a hydrophobic acrylic IOL with truncated square edges (AcrySof), and there was no data for IOL type in one eye. Thirty-nine eyes had primary posterior capsulotomy (PPC) and anterior vitrectomy (AV) and in 24 eyes the posterior capsule was left intact. Cox proportional hazard regression analysis was performed to identify significant risk factors for SM formation, and Wilcoxon test to evaluate the difference in time from surgery to SM formation. SM developed in 24 eyes (38 %)--58 % of eyes with an intact posterior capsule and 26 % of eyes having PPC and AV, 42 % of eyes with a PMMA IOL, and 34 % of eyes with an AcrySof lens. In multivariate Cox regression analysis intraoperative PPC and AV (P = 0.02) and AcrySof lens implantation (P = 0.097) were associated with decreased postoperative incidence of SM formation. Median time until SM development was 2.9 months with PMMA IOLs (range 1-17 months) and 6 months with AcrySof lenses (range 1-21.8 months) (P = 0.037). Posterior capsule management as well as IOL design and material influence the incidence and the timing of SM formation after primary IOL implantation in children.

Intermediate term follow-up after a single-piece-acrylic intraocular lens implantation in the ciliary sulcus- a cross-sectional study.

BACKGROUND: Implantation of a single-piece-acrylic intraocular lens (SPA-IOL) in the ciliary sulcus during phacoemulsification complicated with posterior capsule tear (PCT) may be associated with severe complications. The purpose of this study was to report the efficacy and safety of sulcus implantation of a SPA-IOL, designed for both in-the-bag and sulcus positioning. METHODS: A prospective cross-sectional study including 12 patients, who underwent phacoemulsification with PCT and sulcus implantation of SPA-IOL designed for both in-the-bag and sulcus positioning (Seelens AF, Hanita, Israel) between January 2009 and March 2012 (follow-up 12-37 months). Preoperatively corrected distance visual acuity (CDVA), subjective refraction and intraocular pressure (IOP) were recorded. Postoperative evaluation included anamnesis for IOL edge symptoms and transient visual obscurations (TVO) along with CDVA, subjective refraction IOP, anterior segment biomicroscopy, gonioscopy, assessment of IOL centration, fundus biomicroscopy and spectral-domain optical coherence tomography of the macula. RESULTS: Preoperatively, mean CDVA was 0.84 ± 0.60 LogMAR (Counting Finger-20/33) improving to 0.18 ± 0.13 LogMAR (20/40-20/20) at last examination (p = 0.004), as all the patients gained better CDVA. Mean preoperative spherical equivalent was -0.2 ± 2.5 Diopter (D) (-4.0D to +5.4D) reaching -1.9 ± 0.9 (-4.0D to -0.6D) at last examination (p = 0.12). Mean preoperative refractive astigmatism magnitude was 1.0 ± 0.6D (0.3D to 2.3D) changing to 1.1 ± 1.0D (0.0D to 3.0D) at last examination (p = 0.88). Mean preoperative IOP was 14.7 ± 3.2 mmHg (11-23 mmHg) without medications reaching 15.9 ± 3.3 mmHg (10-21 mmHg) at last follow up (p = 0.21). Postoperatively one patient required two medications for IOP control in his study and contralateral eyes. None of the patients had symptoms of IOL edge or TVO. There were no intraocular hemorrhages, inflammatory reactions, or pigment dispersion and the IOLs were well centered in all cases. Central foveal thickness was 280 ± 33 µm (193-310 µm). CONCLUSIONS: Appropriately designed SPA-IOL may be implanted in the ciliary sulcus during phacoemulsification with PCT rather than switching to another backup IOL demanding wound enlargement.

The relationship between patient age and astigmatism magnitude after congenital cataract surgery.

PURPOSE: To evaluate the magnitude of refractive astigmatism after congenital cataract surgery and to define its correlation with patient age. METHODS: The authors retrospectively reviewed the charts of all pediatric patients who underwent congenital cataract extraction with intraocular lens (IOL) implantation through a 3.0-mm clear corneal incision from 1998 to 2003, and had no suture removal for 5 months afterward. Thirty-four children were included, aged 2 months to 15 years. Refractive astigmatism was assessed manually 1 week, 3 months, and 5 months after surgery by an experienced optometrist. The paired t test was used to compare the magnitude of postoperative astigmatism at different postoperative periods. Spearman correlation was used to determine the correlation between patient age and the postoperative refractive astigmatism. RESULTS: Mean refractive astigmatism in all patients was 1.8+/-1.5 diopters (D) at 1 week postoperatively. It significantly decreased to 1.0+/-0.7 D at 3 months postoperatively (p=0.001), and to 0.8+/-0.7 D at 5 months postoperatively (p=0.03). The change in astigmatism was significantly greater during the first 3 postoperative months than during the following 2 months (p=0.04). Patient age was significantly correlated with 1 week postoperative astigmatism (Spearman coefficient, r = -0.46; p=0.006) and with 3 months postoperative astigmatism (Spearman coefficient, r =-0.37; p=0.03). CONCLUSIONS: Congenital cataract surgery using a small, clear corneal incision for IOL implantation caused high early postoperative astigmatism, which spontaneously regressed thereafter. Younger patients had higher early postoperative astigmatism.

Intraocular pressure elevation within the first 24 hours after cataract surgery in patients with glaucoma or exfoliation syndrome.

OBJECTIVE: To investigate whether eyes with glaucoma or exfoliation syndrome without glaucoma are prone to exhibit intraocular pressure (IOP) elevation shortly after cataract surgery and, if so, whether timolol maleate 0.5% reduces these spikes. DESIGN: Prospective randomized double-masked clinical trial. PARTICIPANTS: One hundred twenty-two patients with normal eyes, medically well-controlled glaucoma, or exfoliation syndrome who underwent uneventful phacoemulsification cataract extraction. METHODS: Patients were randomly assigned to an immediately postoperative drop of either timolol maleate 0.5% or no treatment. Intraocular pressure was measured preoperatively and 4, 8, and 24 hours and 1 week later. MAIN OUTCOME MEASURES: Intraocular pressure measurements. RESULTS: The changes in postoperative IOP over time differed significantly between glaucoma, exfoliation syndrome, and normal (P = 0.005). Intraocular pressure was significantly lower in the normal group (n = 25) than in both the glaucoma (n = 18) and exfoliation syndrome (n = 19) groups (P<0.001). With 1 drop of prophylactic timolol maleate 0.5% at completion of surgery, the normal group (n = 25) again had IOP significantly lower than those of the glaucoma (n = 15) and exfoliation syndrome (n = 20) groups (P<0.001). Treatment with timolol maleate 0.5% significantly changed postoperative IOP over time in the glaucomatous eyes (P = 0.003), but it made no difference in the exfoliation syndrome (P = 0.4) or normal (P = 0.5) eyes. Intraocular pressure > 25 mmHg did not occur among normal eyes. Intraocular pressure > 25 mmHg and > 30 mmHg occurred in 10 (55%) and 5 (28%) glaucoma patients, respectively, and 5 (27%) and 2 (11%) exfoliation syndrome patients, respectively. Timolol maleate 0.5% eliminated IOP spikes > 30 mmHg and reduced the frequency of IOP > 25 mmHg in both groups to 14% in the glaucoma group and 5% in the exfoliation syndrome group. Most IOP elevation occurred at 4 hours postoperatively. The mean IOP was <20 mmHg in all groups 1 day postoperatively. CONCLUSIONS: Medically well-controlled glaucoma patients and patients with exfoliation syndrome may experience IOP elevation shortly after cataract surgery. Instillation of timolol maleate 0.5% at the end of the procedure in this series eliminated IOP > 30 mmHg, but IOP elevation below that level can still occur.

A feasibility study of an Internet-based telemedicine system for consultation in an ophthalmic emergency room.

We examined the feasibility of a low-bandwidth, Internet-based tele-ophthalmology system for consultation in an ophthalmic emergency room. Forty-nine patients (98 eyes) with complicated cases were seen during night shifts in the ophthalmic emergency room. Ocular images were taken using a slit-lamp connected to a video camera, processed and transmitted to a senior physician by email. A telephone was used for real-time audio communication. Each case was re-examined by the same senior physician the following day. The time needed to capture and to process the images was 5 min (SD 2). Each case was given a feasibility score (0-100%), which was defined as the contribution made by the transmitted images in presenting clinical details which could not have been described verbally. High feasibility scores (mean scores ranging from 85 to 90) were found for the following images: ocular surface, anterior chamber, anterior chamber angle, pupils, lens, optic nerve and macula. In contrast, images of vitreous and peripheral retina received low feasibility scores (mean score 65). There was 100% agreement between the diagnosis made during consultation and the on-site examination made by the senior ophthalmologist later on. Ninety-eight percent of the patients stated that they would prefer being examined under the telemedicine system on their next emergency room visit, rather than the traditional resident on-site examination.

Valsalva retinopathy associated with vigorous dancing in a discotheque.

Valsalva retinopathy develops in response to a Valsalva maneuver. Decreased visual acuity may be caused by preretinal hemorrhage, which is related to the fovea, or by vitreous hemorrhage. The hemorrhage usually clears spontaneously. A case of Valsalva maculopathy in a young, healthy boy caused by physical exertion while dancing at a club is described. Reduced visual acuity and premacular hemorrhage spontaneously resolved during the 5-month postoperative period.

Suture-related complications after congenital cataract surgery: Vicryl versus Mersilene sutures.

PURPOSE: To evaluate 10-0 polyester sutures (Mersilene) and 10-0 absorbable polyglactin sutures (Vicryl) for small-incision congenital cataract surgery. SETTING: Goldschleger Eye Institute, Sheba Medical Center, Tel-Aviv University, Tel-Aviv, Israel. METHODS: A retrospective review comprised 51 patients (70 eyes) who had small-incision congenital cataract extraction and intraocular lens implantation between 1999 and 2005. Surgery was done using Mersilene sutures or Vicryl sutures. Retinoscopy and a careful examination for suture-related complications were done 1 week after surgery and then every month for 6 months. The sutures were removed in cases of local tissue reaction but not for high postoperative astigmatism. The t test was used to evaluate postoperative astigmatism and the Fisher exact test, to evaluate the difference in the incidence of suture-related complications. RESULTS: The patients' age ranged from 2 months to 15 years. Ten cases (18%) of corneal vascularization occurred in the Mersilene group during the 6-month follow-up period. This necessitated suture removal, after which 1 incident of endophthalmitis occurred. In contrast, no suture-related complications were noted in the Vicryl group during that time. The difference in the incidence of complications between the 2 groups approached statistical significance (P = .07). Mean astigmatism 1 week postoperatively was 2.3 diopters (D) +/- 2.1 (SD) in the Mersilene group, which was significantly higher than in the Vicryl group (mean 1.4 +/- 1.1 D) (P = .038). However, the mean astigmatism decreased to less than 1.0 D in both groups during the 6-month follow-up period. CONCLUSION: Vicryl sutures are recommended for small-incision congenital cataract surgery.

Vector analysis of high early postoperative astigmatism after congenital cataract surgery.

BACKGROUND: Corneal astigmatism is a well-documented finding after cataract surgery. Postoperative astigmatism is of greater importance in children than in adults, because of its adverse effect on vision development and the risk of amblyopia. The purpose of this study was to evaluate refractive outcomes in eyes- which had high early postoperative astigmatism after congenital cataract surgery. METHODS: We retrospectively reviewed the charts of 74 children (112 eyes), who underwent congenital cataract extraction with intraocular lens implantation, using limbal incision, scleral tunnel, or clear corneal incision. Thirty-two eyes of 28 children, aged 2 months to 11 years, had astigmatism of 3.0 diopters (D) or more when assessed 1 week after surgery. Changes in cylinder vector, spherical equivalent (SEQ) and defocus equivalent (DEQ) between 1 week and 5 months postoperatively were calculated for each group. RESULTS: Mean SEQ and DEQ were 0.7+/-3.5 D and 5.1+/-2.8 D, respectively, at 1 week postoperatively- and -0.2+/-3.4 D and 3.1+/-2.3 D, respectively, at 5 months postoperatively in the three groups. DEQ levels showed a significant reduction during the 5-month follow-up period (P<0.001). The mean astigmatism vector was 2.9+/-3.3 D x 93 degrees in all the three groups 1 week postoperatively- and 0.2+/-1.1 D x 153 degrees at 5 months after surgery. A significant change during 5-month follow-up in cylinder vector (P<0.02) and SEQ (P=0.01) was found after operations using scleral tunnel technique. CONCLUSION: Children- who underwent congenital cataract surgery by different surgical techniques showed a significant spontaneous reduction in DEQ values. A significant change in cylinder vector and SEQ was found after operations using scleral tunnel technique.

Changes in astigmatism after congenital cataract surgery and intraocular lens implantation: a comparative study.

OBJECTIVE: To evaluate the postoperative changes in astigmatism in the pseudophakic eyes of children who underwent 1 of 3 different types of surgical incisions for congenital cataract extraction with intraocular lens implantation, and in whom astigmatism of at least 3 diopters (D) was recorded 1 week after the operation. METHODS: We retrospectively reviewed the medical records of all the children in our department who had undergone surgery for nontraumatic cataract between 1992 and 2001. Cataract surgery with intraocular lens implantation was performed using 1 of 3 types of surgical incisions: a limbal incision, a scleral tunnel, or a clear corneal incision allowing the use of a foldable intraocular lens. In 28 children (32 eyes) aged 2 months to 11 years (mean +/- SD, 4.7 +/- 3.4 years), astigmatism of 3 D or more was found when assessed 1 week after surgery. The refraction was measured and recorded again 3 months and 5 months after surgery. The paired t test was used to compare the outcome variables. MAIN OUTCOME MEASURES: Refractive error 1 week, 3 months, and 5 months after surgery. RESULTS: Mean +/- SD astigmatism 1 week postoperatively was 5.8 +/- 2.2 D, 5.1 +/- 2.1 D, and 4.0 +/- 1.3 D in groups 1, 2, and 3, respectively. Thereafter, the astigmatic component of the refractive error underwent a spontaneous decline, reaching mean +/- SD values of 0.9 +/- 1.0 D, 1.6 +/- 1.6 D, and 1.0 +/- 0.8 D, respectively, in the 3 groups 5 months after the operation. The difference between the mean values at 1 week and at 5 months in each group was statistically significant (P <.001 in group 1; P =.01 in group 2; and P<.001 in group 3). CONCLUSION: Children who underwent extraction of congenital cataract and intraocular lens implantation by different surgical techniques showed a significant spontaneous reduction in astigmatism postoperatively.

Changes in astigmatism after congenital cataract surgery and foldable intraocular lens implantation.

PURPOSE: To evaluate the changes in astigmatism after cataract extraction and implantation of a foldable intraocular lens (IOL) in children. Only eyes with astigmatism of 3.0 D or more were included in the study. METHODS: The charts of children who had undergone surgery for nontraumatic cataract using a foldable IOL were retrospectively reviewed. In 13 eyes with astigmatism of 3.0 D or more, the refraction was tested and recorded at 1 week, 3 months, and 5 months postoperatively. A paired t test was used to compare the variables. RESULTS: Mean astigmatism 1 week postoperatively was 4.7 +/- 1.9 D (range, 3.0-10.0 D). Thereafter, the astigmatic component of the refractive error underwent a spontaneous steady decline, reaching a mean value of 0.9 +/- 0.9 D (range, 0-2.25 D) 5 months after surgery. The difference between the mean values at 1 week and 5 months was statistically significant (P < .0001). CONCLUSION: Children who underwent congenital cataract surgery and IOL implantation showed a significant spontaneous reduction in astigmatism postoperatively.