Fine sediment and particulate organic matter: A review and case study on ridge-to-reef transport, transformations, fates, and impacts on marine ecosystems.

Studies documenting the effects of land-derived suspended particulate matter (SPM, i.e., particulate organic matter and mineral sediment) on marine ecosystems are typically disconnected from terrestrial studies that determine their origin, transport and fate. This study reviews sources, transport, transformations, fate and effects of SPM along the 'ridge-to-reef' continuum. We show that some of the SPM can be transported over long distances and transformed into large and easily resuspendible organic-rich sediment flocs. These flocs may lead to prolonged reductions in water clarity, impacting upon coral reef, seagrass and fish communities. Using the Great Barrier Reef (NE Australia) as a case study, we identify the latest research tools to determine thresholds of SPM exposure, allowing for an improved appreciation of marine risk. These tools are used to determine ecologically-relevant end-of-basin load targets and reliable marine water quality guidelines, thereby enabling enhanced prioritisation and management of SPM export from ridge-to-reef.

Development of a time-stepping sediment budget model for assessing land use impacts in large river basins.

The use of river basin modelling to guide mitigation of non-point source pollution of wetlands, estuaries and coastal waters has become widespread. To assess and simulate the impacts of alternate land use or climate scenarios on river washload requires modelling techniques that represent sediment sources and transport at the time scales of system response. Building on the mean-annual SedNet model, we propose a new D-SedNet model which constructs daily budgets of fine sediment sources, transport and deposition for each link in a river network. Erosion rates (hillslope, gully and streambank erosion) and fine sediment sinks (floodplains and reservoirs) are disaggregated from mean annual rates based on daily rainfall and runoff. The model is evaluated in the Burdekin basin in tropical Australia, where policy targets have been set for reducing sediment and nutrient loads to the Great Barrier Reef (GBR) lagoon from grazing and cropping land. D-SedNet predicted annual loads with similar performance to that of a sediment rating curve calibrated to monitored suspended sediment concentrations. Relative to a 22-year reference load time series at the basin outlet derived from a dynamic general additive model based on monitoring data, D-SedNet had a median absolute error of 68% compared with 112% for the rating curve. RMS error was slightly higher for D-SedNet than for the rating curve due to large relative errors on small loads in several drought years. This accuracy is similar to existing agricultural system models used in arable or humid environments. Predicted river loads were sensitive to ground vegetation cover. We conclude that the river network sediment budget model provides some capacity for predicting load time-series independent of monitoring data in ungauged basins, and for evaluating the impact of land management on river sediment load time-series, which is challenging across large regions in data-poor environments.

Reducing dissolved inorganic nitrogen in surface runoff water from sugarcane production systems.

Nitrogen (N) lost from farms, especially as the highly bioavailable dissolved inorganic form, may be damaging Australia's Great Barrier Reef (GBR). As sugarcane is the dominant cropping system in GBR catchments, its N management practises are coming under increasing scrutiny. This study measured dissolved inorganic N lost in surface runoff water and sugarcane productivity over 3 years. The experiment compared the conventional fertiliser N application rate to sugarcane (average 180kg N/ha/year) and a rate based on replacing N exported in the previous crop (average 94kg N/ha/year). Dissolved inorganic N losses in surface water were 72%, 48% and 66% lower in the three monitored years in the reduced N fertiliser treatment. There was no significant difference in sugarcane yield between the two fertiliser N treatments, nor any treatment difference in soil mineral N - both of these results are indicators of the sustainability of the lower fertiliser N applications.

The effect of orbital decompression surgery on lid retraction in thyroid eye disease.

PURPOSE: To determine the effect of orbital decompression surgery on lid retraction as a function of proptosis reduction in the setting of thyroid eye disease. METHODS: Retrospective interventional case series of all consecutive medial and lateral orbital decompressions performed by the authors for thyroid eye disease from 1999 to 2008. Primary outcome measures included postoperative proptosis and lid retraction. RESULTS: One hundred sixty-five eyes of 89 patients were included. The average amount of proptosis reduction at final follow up (average 30 months) was 4.6 mm. The average improvement in upper lid retraction was 0.9 mm, and the average improvement in lower lid retraction was 0.8 mm. There was a statistically significant correlation (0.12, p = 0.005) between the amount of proptosis reduction and lower lid elevation. No such correlation (-0.010, p = 0.90) was seen for upper lid position. In cases where inferior rectus recession was performed subsequent to decompression surgery (n = 20), the effect of proptosis reduction on lower lid position was negated (correlation -0.01, p = 0.980). CONCLUSION: A statistically significant correlation exists between the amount of proptosis reduction from orbital decompression surgery and improvement in lower lid retraction. No such correlation exists between proptosis reduction and upper lid retraction. Inferior rectus recession negates the positive effect of orbital decompression on lower lid position.

Marcus Gunn jaw-winking synkinesis: clinical features and management.

OBJECTIVE: To evaluate the clinical features including eyelid excursion and management of Marcus Gunn jaw-winking synkinesis (MGJWS). DESIGN: Observational case series. PARTICIPANTS: Forty-eight consecutive patients with MGJWS. METHODS: Clinical features and management of 48 patients with MGJWS were reviewed retrospectively. Upper eyelid excursion was measured and graded. Complications of surgical intervention were evaluated. MAIN OUTCOME MEASURES: Resolution of MGJWS and symmetry of upper eyelids in primary position. RESULTS: Excursion of the ptotic eyelid with jaw movement in MGJWS was graded as mild (<2 mm) in 16% of patients, moderate (2-4 mm) in 76% of patients, and severe (> or = 5 mm) in 8% of patients. Thirty patients with moderate or severe MGJWS underwent disabling of the involved levator muscle and bilateral or unilateral frontalis suspension and had more than 6 months of follow-up. After a mean follow-up of 62 months, MGJWS resolved in 29 (97%) patients and improved from 6 mm to 2 mm in 1 (3%) patient. Relative upper eyelid height was within 1 mm in 87% of patients in primary position and within 1 mm in 80% of patients in downgaze. Twenty-six patients had bilateral frontalis suspension with disabling of unilateral levator muscle on the involved side. Relative upper eyelid height was within 1 mm in 88% of patients in the primary position and within 1 mm in 88% of patients in downgaze. Four non-amblyopic patients had unilateral frontalis suspension with levator muscle disabling. Relative upper eyelid height was symmetrical in 75% of the patients in primary position and in 25% of patients in downgaze. Complications included eyelash ptosis in 10% of the patients, loss of eyelid crease in 10%, and entropion in 3%. CONCLUSIONS: Most of the patients with MGJWS exhibited moderate eyelid excursion. Disabling of the involved levator muscle and bilateral frontalis suspension and, in selected cases, disabling of the involved levator muscle and unilateral frontalis suspension were effective in the treatment of MGJWS. Eyelash ptosis and loss of eyelid crease were the most common complications, each occurring in 10% of the patients. FINANCIAL DISCLOSURE(S): The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Outcomes in silicone rod frontalis suspension surgery for high-risk noncongenital blepharoptosis.

PURPOSE: To evaluate the outcomes of silicone rod frontalis suspension for complicated cases of ptosis with poor levator function. METHODS: A retrospective interventional case series of consecutive patients undergoing silicone rod frontalis suspension by 2 surgeons over 20 years generated records of 51 eyelids (33 patients) with ptosis secondary to cranial nerve III palsy, myasthenia gravis, chronic progressive external ophthalmoplegia, or oculopharyngeal dystrophy. Outcome measures included postoperative change in eyelid height, lagophthalmos, and corneal fluorescein staining; need for reoperation; patient and physician satisfaction; grading of postoperative photographs; and interobserver agreement. RESULTS: Forty-five percent of patients had preoperative corneal staining. Surgery resulted in a significant increase in eyelid height (+2.8 mm; p < 0.0001), lagophthalmos (+0.4 mm, p < 0.0001), and corneal staining grade (+0.3 units; p = 0.02). Most patients achieved a subjectively acceptable result. Patient and physician agreement with outcome assessment was good (kappa = 0.65, p < 0.0001). Twenty eyelids (39%) required revision of the silicone sling, most often for adjustment of eyelid height. Survival analysis differed by diagnosis (p = 0.0154) and was most favorable for patients with myasthenia gravis. Interobserver agreement on postoperative photographs was marginal. CONCLUSIONS: Silicone rod frontalis suspension surgery increases the eyelid height in complicated blepharoptosis patients with minimal eyelid excursion. Patients and physicians concur closely regarding satisfaction; masked assessment of photographic outcome parameters by observers yields marginal agreement. Because most patients undergoing this procedure have a narrow window for appropriate postoperative eyelid height, a relatively high proportion of patients required revision. Silicone rod frontalis suspension surgery is chosen in these challenging cases for the ease of adjustment.

Nondiagnostic conjunctival map biopsies for sebaceous carcinoma.

OBJECTIVE: To compare the prevalence of nondiagnostic conjunctival map biopsies in patients with extensive pagetoid sebaceous carcinoma (defined as involvement of 3 or 4 quadrants of the ocular surface) and in patients without extensive pagetoid tumor (defined as involvement of 1 or 2 quadrants of the ocular surface). METHODS: Retrospective medical record and pathologic specimen review of 20 patients treated for sebaceous carcinoma at a tertiary care center. Biopsies with artifactual loss of or damage to the epithelium were categorized as nondiagnostic. RESULTS: One hundred forty-four map biopsies were reviewed, an average of 7.2 (standard deviation [SD], 4.4) biopsies per patient. Sixteen patients had extensive pagetoid tumor, 4 did not. Fifteen percent of biopsies were nondiagnostic. The frequency of nondiagnostic biopsies in patients with and without extensive pagetoid tumor was 37% and 10%, respectively. The odds ratio of nondiagnostic biopsy in the setting of extensive pagetoid tumor was 5.9 (95% confidence interval, 2.3-15.6; P = .004). Six of the sixteen patients (38%) without extensive pagetoid tumor had at least 1 nondiagnostic biopsy, with an average of 1.8 (SD, 1.6) nondiagnostic biopsies per patient (22% of biopsies). Two of the 4 patients (50%) with extensive pagetoid tumor had at least 1 nondiagnostic biopsy, with an average of 5.5 (SD, 3.5) nondiagnostic biopsies per patient (57% of biopsies). CONCLUSIONS: Nondiagnostic, de-epithelialized conjunctival map biopsies are more common in patients with extensive pagetoid tumor than in those with limited or no pagetoid tumor. Artifactual epithelial loss may result from disruption of epithelial adhesion to the basement membrane by infiltrating tumor cells.

Palpebral spring in the management of lagophthalmos and exposure keratopathy secondary to facial nerve palsy.

PURPOSE: To evaluate the use of a palpebral spring, a dynamic facial reanimation technique, in the management of lagophthalmos and exposure keratopathy secondary to facial nerve palsy. METHODS: A palpebral spring was placed in 29 eyelids of 28 patients with symptomatic facial nerve palsy. Preoperative and postoperative symptoms, upper eyelid margin to midpupil distance, lagophthalmos, and exposure keratopathy were evaluated. RESULTS: At an average of 83 months follow-up, preoperative symptoms improved or resolved in 26 (90%) eyes. The upper eyelid margin to midpupil distance decreased and lagophthalmos and exposure keratopathy significantly improved after palpebral spring placement (p < 0.001). After modification of the technique by suturing the spring to the anterior tarsal surface, rather than encasing the tip in a silicone tube and letting it ride freely, tension of the spring required adjustment in 4 eyes (27%). Dislocation of the spring from the tarsus without exposure through the skin was observed in 1 eyelid (7%). The spring was replaced because of loss of function secondary to metal fatigue in 5 eyelids (33%) after an average of 43 months. Exposure of the spring through the skin was observed in 2 eyelids (14%) and required spring removal from 1 eyelid and replacement of the spring in the other. CONCLUSION: A palpebral spring is an effective treatment for lagophthalmos and exposure keratopathy in patients with facial nerve palsy who do not receive adequate relief from the static procedures of lower eyelid tightening and upper eyelid lowering. This technique significantly improved symptoms and signs in these patients while allowing some of the blink reflex.

Primary cutaneous anaplastic large cell lymphoma of the medial canthus and orbit.

A 59-year-old man sought evaluation for a rapidly enlarging, nontender, ulcerated right medial canthal lesion unresponsive to antibiotics. Biopsy revealed CD30+ anaplastic large cell lymphoma. CT demonstrated contiguous spread in the orbit. Systemic evaluation for lymphoma was negative, and he underwent local radiotherapy. The lesion regressed completely, and he has remained disease free for 7 months. CD30+ anaplastic large cell lymphoma of the periocular skin and orbit are usually distinct, exceedingly rare entities; no reported cases had simultaneous involvement of both tissues. The authors present the first reported case, to their knowledge, of simultaneous skin and orbital involvement by anaplastic large cell lymphoma.

Fibrous dysplasia-like tumor of the lacrimal sac.

A 75-year-old woman developed epiphora and a slowly enlarging right medial canthal mass for 1 year. CT revealed a mass with ground-glass radiodensity and hazy borders in the lacrimal sac. At external dacryocystorhinostomy, a tan, gritty, spherical mass was easily removed from the sac lumen. Histopathologic characteristics were typical of fibrous dysplasia. The postoperative course was uneventful.

Management of periocular cutaneous melanoma with a staged excision technique and permanent sections the square procedure.

OBJECTIVE: To evaluate the outcome of the square procedure, a multidisciplinary, staged excision technique using standard formalin-fixed, vertically oriented sections for periocular cutaneous melanoma. DESIGN: Observational, retrospective, case series. PARTICIPANTS: Forty patients with periocular cutaneous melanoma treated with the square procedure. METHODS: Demographic features, tumor data, and recurrence rate were reviewed retrospectively for 40 patients with periocular cutaneous melanoma treated with the square procedure. MAIN OUTCOME MEASURE: Local recurrence rate. RESULTS: Of 40 patients, 26 (65%) had lentigo maligna melanoma in situ (MIS), 12 (30%) had lentigo maligna melanoma, and 2 (5%) had superficial spreading melanoma. Tumor-free margins were reached within a mean margin of 13 mm for patients with MIS and of 16 mm for patients with invasive melanoma. There was no statistical difference for the margin width in patients with MIS and invasive melanoma. The lesion size and margin width were significantly correlated. Recurrence was observed in 1 (2.5%) patient at 8 months after the square procedure, and a Kaplan-Meier survival curve estimated a local recurrence rate of 2.5% at 8 years. CONCLUSIONS: The square procedure is an effective procedure for management of periocular lentigo maligna melanoma in situ and lentigo maligna melanoma with a low local recurrence rate of 2.5% at 8 years. FINANCIAL DISCLOSURE(S): The authors have no proprietary or commercial interest in any materials discussed in this article.

Radioiodine therapy and Graves' ophthalmopathy.

UNLABELLED: Appearances of and increases in Graves' ophthalmopathy (GO) have been reported after treatment of patients with hyperthyroidism with radioiodine. We sought to determine the rates of appearance or increase in manifestations of GO in American patients treated with radioiodine for hyperthyroidism. METHODS: The study population, which consisted of 76 patients (range, 10.6-72 y), included 61 women and individuals of diverse ethnicity. The patients were followed for 1 y after radioiodine treatment. The clinical activity score (CAS) included 10 items of ophthalmic change that were evaluated at 2 and 6 mo and at 1 y; appearance of a new item scored 1 point. We evaluated interactions of 6 covariates-prolonged hyperthyroidism, prolonged hypothyroidism, smoking, treatment with an antithyroid drug (ATD), and serum levels of thyroid-stimulating immunoglobulin (TSI) and of high free T3 (FT3)--with the numbers of patients with 2 or more CAS points and with exophthalmometer readings increased by at least 2 mm. In addition, patients completed a scored quality-of-life (QOL) questionnaire at baseline and at 1 y to assess eye symptoms. RESULTS: The mean CAS points for all patients at 2 mo was 0.63 and was not significantly different at 1 y. In 9 of 10 CAS items, there were few patients affected at 1 y and for the most part there were fewer patients affected than at baseline. However, exophthalmometer readings increased in 39% of patients by a mean of 2.6 mm. Individual patients frequently exhibited increases and decreases in item manifestations. Exophthalmometer readings decreased by 2 mm or less in 13%. Of the covariates, only hyperthyroidism prolonged by at least 2.5 mo was significantly associated with 2 or more CAS points at 1 y; no covariate was significantly associated with the development of increased exophthalmometer readings. Eye symptoms recorded in the QOL were insignificantly improved over the year; symptoms did not correlate with CAS points or with exophthalmometer readings. CONCLUSION: After radioiodine treatment, no substantial change was seen in manifestations of CAS items except for a modest increase in exophthalmometer readings in 39% of patients. Manifestations of CAS items frequently appeared and disappeared. Prolonged hyperthyroidism is best avoided. Ocular symptoms were insignificantly fewer at 1 y after radioiodine therapy. The observed changes do not warrant prophylactic treatment of patients with steroids.

Comparison of Pu and (137)Cs as tracers of soil and sediment transport in a terrestrial environment.

Following atmospheric nuclear weapons testing in the 1950s and 1960s significant quantities of (137)Cs and (239+240)Pu were deposited worldwide. In recent decades, (137)Cs has been commonly used as a tracer of soil erosion and sedimentation, particularly in the Northern Hemisphere where atomic deposition was three times as great as in the Southern Hemisphere. The relatively short 30-year half-life of this isotope means that its sensitivity as a tracer is rapidly decreasing. In contrast, with half-lives of 24,110 and 6561 years, the sensitivity of the two plutonium isotopes remains essentially the same as when it was deposited. Here we use the technique of Accelerator Mass Spectrometry to demonstrate the potential of anthropogenic Pu as an alternative to (137)Cs as a tracer of soil transport in Australia. We measure an average (137)Cs/(239+240)Pu activity ratio of 27.3+/-1.5 and an average (240)Pu/(239)Pu atom ratio of 0.149+/-0.003, both slightly lower than the global average.

Malignant fibrous histiocytoma of the lateral conjunctiva and anterior orbit.

A 25-year-old woman presented for evaluation of a rapidly enlarging mass of the left bulbar conjunctiva. Debulking biopsy was performed, which led to the diagnosis of myxoid malignant fibrous histiocytoma. The patient underwent left orbital exenteration with clear margins. Histopathology showed involvement of the conjunctiva substantia propria, superior conjunctival fornix, and episclera, as well as extension from the lateral rectus muscle sheath. Immunohistochemical staining was strongly positive for CD68, alpha1-antitrypsin, CD34, and vimentin.

Errors of single-mirror or prism Hertel exophthalmometers and recommendations for minimizing the errors.

PURPOSE: Analysis is performed of the geometry of a Hertel exophthalmometer to determine the intrinsic error of reading that results from using the instrument in the manner that the manufacturer intended. Recommendations for improvement of the design and/or use of the instrument are made based on the findings. METHODS: A schematic drawing of the manufacturer-recommended use of an exophthalmometer is created. The geometry is analyzed to reveal the sources of error in the exophthalmometer reading and an equation for the magnitude of the error is derived. RESULTS: The exophthalmometer reading error is directly proportional to the difference between the reading obtained and the reading at the no-parallax-alignment position used to make the reading (commonly 18 mm), with the reading being low when the reading is greater than the no-parallax-alignment position and high when the reading is less. The error is increased by the observer's eye being closer to the reflecting surface and by widening the base or separation of the 2 reflecting surfaces of the instrument. The exophthalmometer reading may be 1.7 mm less than actual when it reads as 35 mm, which is 17 mm from the no-parallax-alignment position. CONCLUSIONS: To minimize error in exophthalmometer readings, the reading should be as close to the no-parallax-alignment-position as possible. Exophthalmometers should therefore be modified to have multiple sets of no-parallax-alignment lines, each pair of a different color. The instrument should be used with the narrowest feasible base and the examiner should be consistently positioned as far from the reflecting surface of the instrument as possible.

Complications of pegged and non-pegged hydroxyapatite orbital implants.

PURPOSE: The purpose of this study is twofold: to assess the incidence and implications of complications unique to placing a freestanding polycarbonate peg in patients with hydroxyapatite implants and to compare the incidence of complications in these patients with the incidence in patients with non-pegged hydroxyapatite implants. METHODS: This is a retrospective clinical case series of 103 patients who underwent hydroxyapatite implant insertion at our institution. The incidence of postoperative complications in patients who underwent freestanding polycarbonate pegging procedures (n = 21) and those who had not (n = 82) were compared. RESULTS: One postoperative complication - infection - occurred in a significantly higher percentage of patients in the pegged group (42.9%, 9/21) compared with the non-pegged group (19.5%, 16/82), (p = 0.037). Fifteen of the 21 patients (71.4%) in the pegged group experienced complications unique to freestanding polycarbonate pegging. Overall, 95.2% (20/21) of patients in the pegged group experienced a complication compared with 58.5% (48/82) of patients in the non-pegged group, (p = 0.001). In addition, there was an average of 3.1 (66/21) complications per patient in the pegged group compared with an average of 1.9 (106/82) complications per patient in the non-pegged group (p = 0.010). CONCLUSIONS: Patients who received a freestanding polycarbonate pegged implant had a high risk of experiencing complications unique to pegging, and therefore a significantly higher rate of complications overall when compared with patients whose implant was not pegged. In addition, patients who received a pegged implant had a higher incidence of infection. However, most patients retained their pegs despite complications.

Avulsion of the optic nerve with luxation of the eye after motor vehicle accident.

A 27-year-old man suffered simultaneous avulsion of the optic nerve and luxation of an intact globe in a motor vehicle accident. CT was not diagnostic of the nerve avulsion. The injury was addressed by emergent replacement of the globe within the orbit. The patient obtained psychological benefit by retaining the eye initially, but required subsequent enucleation for prolonged ocular inflammation. Initial repositioning of intact, luxated globes offers potential cosmetic and psychological benefits. If necessary, enucleation can be performed later.

Graded full-thickness anterior blepharotomy for correction of upper eyelid retraction not associated with thyroid eye disease.

PURPOSE: To evaluate the efficacy of graded full-thickness anterior blepharotomy for upper eyelid retraction of various causes not associated with Graves eye disease. METHODS: Twenty-one eyelids of 18 patients with upper eyelid retraction not caused by Graves eye disease were treated with graded full-thickness anterior blepharotomy. Preoperative and postoperative symptoms, midpupil to upper eyelid distance, lagophthalmos, and superficial punctuate keratopathy were evaluated. RESULTS: Upper eyelid retraction was due to facial nerve palsy in 4 patients (22%), overcorrected ptosis in 5 patients (28%), and cicatrix after trauma in 6 patients (33%). One patient each (6% each) had retraction from graft-versus-host disease, after blepharoplasty, and after orbicularis oculi myectomy for blepharospasm. At a mean of 10 months follow-up, presenting symptoms resolved or improved in 17 patients (94%) and remained unchanged in 1 patient (6%). Midpupil to upper eyelid distance, lagophthalmos, and superficial punctuate keratopathy all improved significantly (all p < 0.001). No surgical complications occurred. CONCLUSIONS: Graded full-thickness anterior blepharotomy is a safe, effective, and rapid technique for patients with symptomatic upper eyelid retraction due to etiologies other than Graves eye disease. This technique improves symptoms and signs of ocular exposure while addressing relative upper eyelid height symmetry and contour.

Müllerectomy for upper eyelid retraction and lagophthalmos due to facial nerve palsy.

BACKGROUND: Facial nerve palsy often results in symptoms of ocular irritation due to inadequate eyelid closure. Weakened protractor function results in relative upper eyelid retraction and contributes to lagophthalmos. OBJECTIVE: To evaluate the role of müllerectomy in the comprehensive surgical treatment of ocular exposure due to facial nerve palsy. METHODS: Thirty-four patients with chronic facial nerve palsy underwent unilateral transconjunctival removal of Müller muscle and were followed up for an average of 20 months postoperatively. Other procedures were performed to treat lower eyelid retraction, as required. Preoperative and postoperative ocular exposure symptoms, upper eyelid position, lagophthalmos, and keratopathy were compared. RESULTS: Of the 59 preoperative symptoms, 15 (25%) resolved and 39 (66%) improved. Upper eyelid position was lowered by an average of 1.35 mm (P<.001). Lagophthalmos (P = .002) and corneal exposure (P<.001) were significantly improved. Three patients required levator aponeurosis repair, 2 for preexisting dehiscence and 1 for inadvertent aponeurosis transection. CONCLUSION: Müllerectomy is a rapid, safe, and reproducible surgical method for lowering the upper eyelid and reducing ocular exposure symptoms and signs due to chronic facial nerve palsy.