Healthcare Utilization Patterns Among Children With a History of Child Protective Services Investigations.

PURPOSE: Examine whether children with a prior child protective services (CPS) investigation had different healthcare utilization compared to children without a history of CPS investigations. METHODS: The Children's Health Assessment and Planning Survey assessed 6,492 primary caregivers of children ages 0-17 years residing in North Texas in 2015. Caregivers reported prior CPS investigations and child healthcare utilization (emergency department [ED] use, unmet medication needs, and unmet medical care needs). PRINCIPLE FINDINGS: A total of 408 (5%) caregivers reported their child had a CPS investigation. Children with CPS investigations had greater odds of visiting the ED (OR = 1.9; 95% CI: 1.4, 2.5) and not receiving necessary medical care (OR = 1.9; 95% CI: 1.4, 2.8) compared to children without a CPS investigation. CONCLUSIONS: Prior CPS investigation was associated with disparities in receipt of necessary medical care and ED utilization for children.

A Qualitative Exploration of Less Acculturated Mexican Mothers' Safety Perceptions of Herbs, Medicines, and Cleaners in the Home.

Childhood poisoning is a leading public health concern in our society. The death rate from unintentional poisonings among children has increased by 80% from 2000 to 2009. Immigrant children are also at-risk. A qualitative study, consisting of a pile sort, was conducted among immigrant Mexican mothers to determine their safety perceptions of commonly used medicines, herbs, and cleaners. Participants (N = 35) were selected for semi-structured interviews from a pediatric primary care clinic in the Dallas/Fort Worth Metroplex. Some mothers over-estimated their children's ability to discern the dangers of substances, relied heavily on sensory skills of children, and perceived a medicine as safe after successful use in the past. Other mothers were more cognizant of allergic reactions, ingestion, and the need to store substances carefully. Brief interventions that incorporate culturally-appropriate safety messages are needed to assist Mexican mothers in creating a safe home environment.

Unintentional ingestion of cleaners and other substances in an immigrant Mexican population: a qualitative study.

Paediatric poisoning is a salient issue worldwide and also affects the USA. In past years, ingestion of household cleaners was the second leading cause of unintentional poisonings in children. All children are at risk for ingestions, although immigrant children may be at greater risk. The purpose of this study was to document child ingestion experiences from toxic household substances via semistructured interviews with immigrant Mexican mothers. Participants were recruited from a paediatric primary care practice in Dallas/Fort Worth, Texas (N=35). Eighteen of 35 respondents (51%) reported that their child, nephew/niece or a friend's child had accidentally ingested a cleaning solution, gasoline or herbal remedy. Of those ingestions, 12 were reportedly from an alternative container, such as a juice box or soda bottle. Improper storage was the primary reason for ingestion. Culturally appropriate home visits and interventions are needed to better prevent ingestion in young children.

From stem cell niche environments to engineering of corneal epithelium tissue.

Studies on stem cells (SC) show that SC functions are determined by the extracellular microenvironment, known as the "niche", and by intrinsic genetic programs in the SCs; both are involved in regulating the delicate balance of self-renewal and differentiation. We have identified an animal model of limbal SC (LSC) deficiency and transplantation of SC-containing limbal tissue to treat the LSC deficiency, which could not only replace LSCs by providing new healthy corneal epithelial cells but also restore the lost niche of the limbal stromal layer, causing the regression of vessels and rearrangement of the corneal stromal lamellae. The purpose of the ex-vivo expansion technique is to develop a method that will enable culture of a small number of SCs which could than be expanded in a defined cultured system while preserving the original characteristics and properties of the SCs. In addition, SC characteristics will continue to be maintained when the cultured cells are transplanted back into the host. Bromodeoxyuridine-retaining, ΔNp63, ABCG2, p120, and N-cadherin immunoreactive studies of LSC cultured on an amniotic membrane have been performed. Pathological studies have been conducted for cases with preexisting central corneal stromal opacity treated by transplantation of LSCs followed by penetrating keratoplasty. The results indicate that the amniotic membrane can provide the niche environment for cultured LSCs and maintain the limbal-like environment for the transplanted area of cornea.

Acculturation in Hispanics and childhood poisoning: are medicines and household cleaners stored properly?

BACKGROUND: Unintentional poisonings are a major public health issue in the United States (US). With the increasing number of Hispanics in the US, childhood poisoning is a salient public health issue to address within this population. There is a paucity of research examining the relationship between acculturation in Hispanics and the safe storage of medicines and cleaners. The purpose of the study was to determine if demographic variables, such as acculturation in Hispanics, age, gender and education, were predictive of incorrectly storing medicines and household cleaners. METHODS: We conducted a study among parents/guardians of small children at two pediatric primary care clinics in the Dallas/Fort Worth (DFW) Metropolitan area. We enrolled 201 parents to identify where they stored medicines and household cleaners, and measured acculturation with the Short Acculturation Scale for Hispanics. RESULTS: Of Hispanic participants, 49% were categorized as less acculturated (n = 99) while 21% were more acculturated (n = 42). Less acculturated participants were over 4 times more likely to store medicines incorrectly, and participants with a high school education or less were over 3 times more likely to improperly store cleaners. With each additional child in the household, the risk for improper storage of cleaners increased by 44%. CONCLUSION: The fact that children of less acculturated families are at greater risk for poisoning and have lower levels of education demonstrates the need for readable educational materials on this salient topic. Because social networks are integral in Hispanic culture, especially among new immigrants, poison prevention messages should be disseminated by interpersonal communications.

Changes in corneal basal epithelial phenotypes in an altered basement membrane.

BACKGROUND: To examine the corneal epithelial phenotype in an altered basement membrane. METHODOLOGY/PRINCIPAL FINDINGS: Corneas from 9 patients with symptoms of continuous unstable corneal curvature (CUCC) were harvested by penetrating keratoplasty and subjected to histology examination and immunohistochemical staining with transactivating and N-terminally truncated pP63 transcript (ΔNp63), cytokeratin 3 (Krt3), ATP-binding cassette sub-family G member 2 (ABCG2), connexin 43 (CX43), p38 mitogen-activated protein kinases (p38MAPK), activating protein 2 (TFAP2), and extracellular signal-regulated kinase (Erk1/2) monoclonal antibodies. Positive immunostaining with ABCG2, p38MAPK, and TFAP2 monoclonal antibodies was observed in the basal epithelial cells of CUCC patients, and CX43 and ΔNp63 were detected in the full-thickness epithelial cells of CUCC patients. CONCLUSIONS/SIGNIFICANCE: Our results indicate that alteration of the corneal basement membrane induces a de-differentiation-like phenotype in corneal basal epithelial cells.

Estimation accuracy of surgically induced astigmatism on the cornea when neglecting the posterior corneal surface measurement.

PURPOSE: To evaluate the accuracy of corneal surgically induced astigmatism (SIA) estimation when neglecting the posterior corneal surface measurement. METHODS: Fifty right eyes undergoing phacoemulsification were measured with a rotating Scheimpflug camera (Pentacam; Oculus Inc., Wetzlar, Germany) both before and after surgery. Clear corneal incisions with one suture were used in the phacoemulsification surgery. The keratometric corneal SIA (KSIA) was derived using the anterior corneal surface measurement and the keratometric index (1.3375) while neglecting the posterior corneal surface measurement. The Pentacam-derived total corneal SIA (PSIA) was derived by vergence tracing and polar value analysis [KP(135) and KP(180)] of the measurements on both corneal surfaces. RESULTS: The mean arithmetic estimation errors of the KSIA for the PSIA were 0.16 ± 0.32 (-0.52 to 1.14) D for the KP(135), and -0.02 ± 0.30 (-0.75 to 1.29) D for the KP(180). There was a significant difference between the KP(135) components of the KSIA and PSIA. Bivariate analysis revealed a statistically significant difference between the combined means of the KSIA and PSIA. Overall, 24% had either a KP(135) component of the KSIA that differed by > 0.50 D from that of the PSIA or a KP(180) component of the KSIA that differed by > 0.50 D from that of the PSIA. The blurring strength caused by neglecting the posterior corneal measurement was > 0.50 D in 24% of eyes. CONCLUSION: Neglecting the posterior corneal surface measurement may lead to significant deviation in the corneal SIA estimation after phacoemulsification in a proportion of eyes.

Ex vivo expansion of corneal stem cells on amniotic membrane and their outcome.

OBJECTIVES: To identify the stem-cell property of the ex vivo expansion of limbal stem cells (LSCs) on amniotic membrane (AM) in culture system and after clinical transplantation. METHODS: Four key factors have to be performed in the defined culture system: (1) the label-retaining cells have to be identified; (2) the cells can be serially expanded and passaged in vitro; (3) the expanded cells can be labeled by tissue-specific keratin or markers, and (3) their stem cells cannot be labeled by those keratin or markers. RESULTS: The ex vivo-expanded LSCs on AM were positive for p63 and ABCG2 and BrdU label-retaining studies on flat mount preparation. When the ex vivo-expanded LSCs with AM were transplanted into a subcutaneous layer of nude mice, they formed multiple layers of cells. Only the basal layer of cells was positive for p63 and BrdU. The cells over the suprabasal layers were positive for K12/K3. The pathologic studies of corneal specimen of successful LSC transplantation after penetrating keratoplasty demonstrated that P63-positive cells were noticed all over the basal layer of central cornea and AM could be identified at 10 months after LSC transplantation. CONCLUSIONS: These results indicate that the AM provided the niche function for cultured LSCs and maintained the limbal-like environment for the transplanted area of cornea. The survival of cases depends on the severity of the disease entity, culture technique, and maintenance of the niche environment for LSCs in the culture and after clinical transplantation.

Effects of aging on anterior and posterior corneal astigmatism.

PURPOSE: To evaluate age-related changes in astigmatism of both corneal surfaces and the whole cornea. METHODS: The right eyes of 370 subjects were measured with a rotating Scheimpflug camera (Pentacam). Astigmatisms of the anterior and posterior corneal surfaces were determined. The total corneal astigmatism was derived using power vector summation and vergence tracing. Age-related changes to corneal astigmatism were evaluated using polar value analysis (both in diopter and millimeter). RESULTS: For the anterior and total cornea, the proportion of with-the-rule astigmatisms decreased and those of oblique and against-the-rule astigmatisms increased with age. For the posterior cornea, most eyes displayed against-the-rule astigmatisms in all age groups. There was a significant trend toward against-the-rule astigmatism associated with increasing age for both anterior and total corneal astigmatisms (mean changes of -0.18 and -0.16 diopters/5 years, respectively), and toward with the rule in posterior corneal astigmatism (a mean change of 0.022 diopters/5 years). Regarding shape changes, a "flat meridian toward a more vertical orientation" trend with increasing age for both the anterior and posterior corneal surfaces was observed (mean changes of 0.0295 and 0.0224 mm/5 years, respectively). The posterior corneal surface compensated for the astigmatism arising from the anterior corneal surface in 91.4% and 47.7% of eyes in the 21-30 and > or =71 years groups, respectively. CONCLUSIONS: There were age-related shifts toward against-the-rule and with-the-rule astigmatisms for the anterior and posterior corneal surfaces, respectively. The compensating effects of the posterior corneal surface on anterior corneal astigmatism decreased with advancing age.

Bioengineered corneas for transplantation and in vitro toxicology.

Bioengineered corneas have been designed to replace partial or the full-thickness of defective corneas, as an alternative to using donor tissues. They range from prosthetic devices that solely address replacement of the cornea's function, to tissue engineered hydrogels that permit regeneration of host tissues. In cases where corneal stem cells have been depleted by injury or disease, most frequently involving the superficial epithelium, tissue engineered lamellar implants reconstructed with stem cells have been transplanted. In situ methods using ultraviolet A (UVA) crosslinking have also been developed to strengthen weakened corneas. In addition to the clinical need, bioengineered corneas are also rapidly gaining importance in the area of in vitro toxicology, as alternatives to animal testing. More complex, fully innervated, physiologically active, three-dimensional organotypic models are also being tested.

Estimation of the effective lens position using a rotating Scheimpflug camera.

PURPOSE: To describe a no-history method of estimating the effective lens position (ELP) for double-K intraocular lens (IOL) power calculation in eyes that had previous refractive surgery. SETTING: Departments of Ophthalmology, Taipei Medical University Hospital and Taipei City Hospital, Taipei, Taiwan. METHODS: The corneal height (H(m)) and anterior chamber diameter (AG(m)) in 106 unoperated eyes were measured using a rotating Scheimpflug camera. The theoretical anterior corneal radius (R(rt)) was then derived from H(m) and AG(m) by regression and rearrangement of the Fyodorov equation. The ELP estimate was then calculated from R(rt). The performance of this ELP estimation method in double-K IOL power calculation and the performance of other methods were compared retrospectively in 11 eyes having cataract surgery that had previous refractive surgery. The refractive results 9 to 12 weeks after cataract surgery were selected for data analysis. RESULTS: The new ELP estimation method, combined with the BESSt formula or the Savini et al. method for estimating post refractive-surgery corneal power (K(post)) in the double-K SRK/T formula, provided the best IOL power prediction results. The mean arithmetic and absolute IOL prediction errors were -0.05+/-0.62 diopters (D) and 0.49+/-0.34 D, respectively, when combined with the BESSt formula and 0.03+/-0.73 D and 0.60+/-0.36 D, respectively, when combined with the Savini et al. method. With either combination, all 11 eyes were within+/-1.00 D of the refractive prediction error. CONCLUSION: This ELP estimation method may be helpful for IOL power calculation in post refractive-surgery eyes when historical data are unavailable.

Intraocular lens power calculation after automated lamellar keratoplasty for high myopia.

PURPOSE: To report intraocular lens (IOL) power calculation in 2 eyes that were highly undercorrected by previous myopic automated lamellar keratoplasty (ALK). METHODS: A 35-year-old man underwent bilateral myopic ALK, which caused high residual myopia (-9.0 -4.0 x 171 and -9.5 -4.5 x 74). The patient then underwent cataract surgery with IOL implantation for cataract development. The double-K clinical history method was utilized, and satisfactory IOL power prediction results were obtained. Two no-history IOL power calculation methods (Rosa correcting factor method and Ferrara theoretical variable refractive index method), which involved axial length-dependent modification of the keratometer-measured corneal radius, and 1 no-history IOL power calculation method (Shammas' method), which involved axial length-independent modification of the keratometer-measured corneal power, were tested on these 2 eyes. RESULTS: In both eyes, the double-K SRK-T clinical history method gave small IOL prediction errors (-0.66 and -0.81 D). The Shammas' no-history method gave a slightly higher IOL prediction error in the right eye (-1.67 D) and a small IOL prediction error in the left eye (-0.74 D). Unacceptable IOL power prediction errors would have resulted if Rosa's correcting factor method (-8.07 and -8.35 D) or Ferrara's theoretical variable refractive index method (-17.56 and -18.51 D) had been applied. When we utilized Rosa's method for the IOL power calculation by assuming that the previous ALK had fully corrected the refractive error, the predicted IOL powers were very close to the benchmark IOL powers (IOL power prediction errors: 1.16 and 0.37 D). When we utilized Ferrara's method with the same assumption, the IOL power prediction errors remained high (-6.32 and -7.16 D). CONCLUSIONS: For patients who have had previous myopic ALK (and whose eyes are highly undercorrected) and who require cataract surgery and for whom the pre-ALK history is available, the double-K method appears to yield excellent predictive results. However, if the pre-ALK history is not available, the Shammas' no-history method appears to yield better results than the Rosa's or the Ferrara's method. High undercorrection by the previous ALK might have been one of the major reasons why Rosa's method resulted in a high IOL prediction error in these 2 eyes. The cause for the marked IOL prediction error by Ferrara's method in this case, however, remains to be determined.

Seasonal variations in the occurrence of retinal vein occlusion: a five-year nationwide population-based study from Taiwan.

PURPOSE: To determine whether seasonal variation exists in the incidence of retinal vein occlusion. DESIGN: Retrospective, nationwide population-based administrative database study. METHODS: We collected data on outpatient and emergency visits for the period from January 1999 through December 2003 from the Taiwan National Health Insurance Research Database, a source that covers more than 96% of Taiwan's 23 million citizens. In total, 20,792 patients with a first-time diagnosis of either central retinal vein occlusion or branch retinal vein occlusion (The International Classification of Disease, Ninth Revision, Clinical Modification [ICD-9-CM] code 362.35 or 362.36, respectively) were identified. Monthly incidence of retinal vein occlusion was obtained for each age group, each gender group, and for the entire sample. The autoregressive integrated moving average method of analysis was adopted to examine seasonality in the monthly incidence of retinal vein occlusion. RESULTS: The monthly incidence rates of retinal vein occlusion revealed significant seasonality, with a clear peak in January for each age group and each gender group, as well as for the total sample. CONCLUSIONS: Our study demonstrates significant seasonal variations in the retinal vein occlusion incidence, with the peak occurrence in the winter month of January.

Validity of the keratometric index: evaluation by the Pentacam rotating Scheimpflug camera.

PURPOSE: To determine the keratometric index based on actual measurements of the anterior and posterior corneal surfaces using a rotating Scheimpflug camera (Pentacam, Oculus) and evaluate the accuracy of this keratometric index in estimating total and posterior corneal powers. SETTING: Departments of Ophthalmology, Taipei Medical University Hospital and Taipei City Hospital, Taipei, Taiwan. METHODS: The right eye of 221 subjects was measured with the Pentacam system. The radius of the best-fit sphere for the anterior corneal surface (rant) and posterior corneal surface (rpost), mean radius of simulated keratometry (rsimK), and central corneal thickness were obtained. The ratio of rant to rpost (AP ratio) and keratometric index were calculated in each eye. RESULTS: The means for rant, rpost, rsimK, and AP ratio were 7.75 mm +/- 0.28 (SD), 6.34 +/- 0.28 mm, 7.75 +/- 0.27 mm, and 1.223 +/- 0.034 mm, respectively. These parameters were normally distributed. The mean calculated keratometric index (Ncal) was 1.3281 +/- 0.0018. Using the keratometric indices of 1.3281 (Ncal), 1.3315 (Gullstrand schematic eye), and 1.3375 (conventional), the mean arithmetic and absolute estimation errors for the total corneal power were, 0.00 +/- 0.24 diopter (D) and 0.17 +/- 0.17 D, 0.43 +/- 0.23 D and 0.45 +/- 0.21 D, and 1.21 +/- 0.24 D and 1.21 +/- 0.24 D, respectively. The total corneal power was predicted to within +/-0.50 D of the actual value in 95.0%, 60.2%, and 0.9% of eyes, respectively. The mean arithmetic and absolute estimation errors for the posterior corneal power using an AP ratio of 1.223 (this study) or 1.132 (Gullstrand schematic eye) were 0.00 +/- 0.17 D and 0.13 +/- 0.12 D and 0.47 +/- 0.18 D and 0.47 +/- 0.17 D, respectively. The posterior corneal power was estimated to within +/-0.50 D of the actual value in 97.7% and 60.2% of eyes, respectively. CONCLUSION: Using the Pentacam-derived keratometric index improved the prediction accuracies of total and posterior corneal powers.

Reduction of indocyanine green-associated photosensitizing toxicity in retinal pigment epithelium by sodium elimination.

OBJECTIVE: To determine if eliminating sodium affects indocyanine green (ICG) photosensitizing toxicity and uptake in cultured human retinal pigment epithelial (RPE) cells. METHODS: Cultured human RPE cells were exposed to ICG (2.5 mg/mL) in balanced salt solution and sodium-free balanced salt solution for 2 minutes. Afterwards, ICG was removed, and the cells were irradiated with a light beam (4 x 10(4) lux) for 40 minutes. Toxicity was monitored using light microscopy, calcein AM-ethidium homodimer 1 staining, trypan blue exclusion test, and 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium viability assay. Indocyanine green uptake was measured by optical absorption at 790 nm. RESULTS: Photoreactive changes occurred in RPE cells exposed to ICG and light. These changes included cell shrinkage, cell death, pyknotic nuclei, reduced viability, and reduced mitochondrial dehydrogenase activity. These changes were less severe when ICG was dissolved in sodium-free balanced salt solution. In addition, ICG uptake was reduced when the solvent was sodium-free balanced salt solution. CONCLUSION: Indocyanine green and intense light exposure in RPE cells caused photosensitizing toxicity that was reduced when sodium in the solvent was eliminated and replaced with other cations. CLINICAL RELEVANCE: Eliminating sodium from the solvent reduced ICG uptake into RPE and its associated photosensitizing toxicity. This reconstitution method of ICG may be helpful for safer intravitreal ICG use in macular hole surgery.

Annual database of intraocular lens power in a Taiwanese population.

BACKGROUND: To derive a unique database of intraocular lens (IOL) power for Taiwanese, an ethnic group with a strikingly high prevalence of myopia. METHODS: A retrospective series of 3068 cases visiting Chang Gung Memorial Hospital, Linkou for cataract removal and posterior chamber IOL implantation between July 1999 and June 2000 was reviewed. The distribution of IOL powers and a possible age-correspondence was analyzed by one-way analysis of variance (ANOVA) test and multiple regression. RESULTS: Using the SRK/II linear regression formula, with an "A" constant of 118.5, the mean predicted IOL power required for emmetropia was 20.0 +/- 5.1 diopter (D). The mean IOL power for males was 19.8 +/- 5.1 D. The mean IOL power for females was 20.1 +/- 5.1 D. Moreover, ANOVA results documented a statistically significant tendency of age-dependence for IOL power distribution in the 3 groups (male, female, and male and female; F=24.53, p<0.05; F=16.39, p<0.05; F=40.54; p<0.05, respectively). In particular, it statistically significantly differed among decades over 40 years indicating that IOL power increased with age. However, the implanted IOL power decreased with age in patients younger than 40 years old. Multiple regression analysis showed that age, but not gender, was statistically significantly correlated to the IOL power distribution (p<0.05). CONCLUSION: We provide a unique database of IOL power for cataract surgeries in Taiwan. An age-related correspondence of the database of IOL powers was also documented in this study, which can therefore be regarded further cross-sectional evidence for the age-dependence prevalence of myopia.

GDNF gene therapy attenuates retinal ischemic injuries in rats.

PURPOSE: To examine the protective effects of glial cell line-derived neurotrophic factor (GDNF) on retinal ischemia-reperfusion injury by using gene delivery. METHODS: Gene delivery to retinal cells was achieved through intravitreal injections of recombinant adeno-associated virus expressing GDNF (rAAV-GDNF) in the right eyes and AAV expressing Escherichia coli LacZ (rAAV-LacZ) in the left eyes of Sprague-Dawley rats. Ischemic injury was introduced three weeks after gene delivery. The synthesis and accumulation of GDNF within the retina were determined using immunohistochemistry and enzyme-linked immunosorbent assay (ELISA) three weeks after gene delivery. The neuroprotective effects of GDNF were evaluated by determining the preservation of the inner retina thickness and the cell counts in the retinal ganglion cell (RGC) layer one week after reperfusion. In addition, eletroretinograms (ERGs) were performed to determine the functionality of the retinas. Finally, the levels of RGC apoptosis were measured using the TdT-dUTP terminal nick-end labeling (TUNEL) method 6 h after reperfusion. RESULTS: Gene expression of GDNF was demonstrated through immunohistochemistry and ELISA. Thinning of the inner retina and decreased numbers of cells in RGC layer were noted after ischemia in all of the eyes. However, the thickness of the inner retina and the numbers of cells in RGC layer were better preserved in rAAV-GDNF treated eyes than in rAAV-LacZ treated eyes seven days after reperfusion (p=0.028 and p<0.001, respectively). Also, seven days after reperfusion, the rAAV-GDNF treated eyes had retained larger b-wave amplitudes than rAAV-LacZ treated eyes (p=0.003). Finally, rAAV-GDNF treated eyes had statistically fewer apoptotic cells in the RGC layer than the control eyes (p=0.011). CONCLUSIONS: In these experiments, GDNF moderately protected rat retina from ischemia-reperfusion injury, possibly by preventing apoptosis in retinal cells.

Ultrasound biomicroscopy in pigmented conjunctival cystic nevi.

PURPOSE: To report the use of ultrasound biomicroscopy in the clinical diagnosis and management of pigmented conjunctival cystic nevi. METHOD: Two patients, aged 11 and 18 years, with rapidly growing raised conjunctival melanocytic lesions suspected to be inflamed juvenile conjunctival nevus underwent ultrasound biomicroscopic and histopathologic examinations. RESULTS: Ultrasound biomicroscopic examination of the lesions revealed multiple areas of cystic tissue, which is compatible with pathologic finding of compound nevus with epithelial inclusion cysts formation. Furthermore, clear interface was found between the mass and the underlying sclera. CONCLUSION: Pigmented conjunctival nevi may obscure cysts under slit-lamp examination. Ultrasound biomicroscopy is a useful diagnostic adjunct to distinguish cysts in conjunctival lesions. Additionally, this technique may be helpful in delineating the extent of lesions prior to excision biopsy.

A national survey of residents' self-reported work hours: thinking beyond specialty.

PURPOSE: To secure data from residents regarding residency work hours and correlates. METHOD: A national, random sample of postgraduate year 1 (PGY1) and year 2 (PGY2) residents in the 1998-1999 training year was identified using the American Medical Association's Graduate Medical Education database. Residents completed a five-page survey with 44 questions and 144 separate data elements relating to their residency experience. RESULTS: Completed surveys were received from 3,604 of 5,616 (64.2%) residents contacted. PGY1 residents reported working an average of 83 hours a week versus 76.2 hours for PGY2 residents (p <.0001). Total work hours were significantly correlated with reported stress and hours of sleep per week. Residents averaging more than 80 work hours per week were more likely to be involved in a personal accident or injury, a serious conflict with other staff members, and making a significant medical error. Cluster analysis revealed four different types of residency experience: high intensity, moderate intensity, low intensity, and moonlighters, suggesting that residents may have some choice in selecting a residency experience suited to their particular personal and professional needs. CONCLUSION: Nearly half of PGY1 and one third of PGY2 residents reported working more than 80 hours per week. These extended hours are significantly correlated with a number of patient care and personal health variables. Given the variety of program and specialty requirements and demands, it seems unlikely that an arbitrary limit or a simple decrease in work hours will provide a satisfactory solution to many resident and patient care concerns.

Cytotoxicity of indocyanine green on retinal pigment epithelium: implications for macular hole surgery.

OBJECTIVE: To evaluate the potential cytotoxic effects of indocyanine green (ICG) on cultured human retinal pigment epithelium (RPE) and the resultant implications for macular hole surgery. METHODS: Human RPE cells were exposed to ICG in concentrations from 0.001 to 5 mg/mL. The exposure duration ranged from 5 minutes to 3 hours. Light microscopy, MTS viability assay, and calcein AM-ethidium homodimer 1 staining were used to evaluate the cytotoxic effects of ICG. RESULTS: The RPE cells incubated with up to 5 mg/mL of ICG for 5 minutes or less exhibited no morphologic change and no significant decrease in dehydrogenase activity. When RPE cells were exposed to 5 mg/mL of ICG for 10 minutes, 1 mg/mL of ICG for 20 minutes, or 0.01 mg/mL of ICG for 3 hours, cell morphologic features were altered, mitochondrial dehydrogenase activity decreased, and some cells were necrotic. CONCLUSIONS: Indocyanine green caused cytotoxicity in cultured human RPE in a dose- and time-dependent manner. Cell death occurred by necrosis. CLINICAL RELEVANCE: Exposure of RPE cells to ICG concentrations up to 5 mg/mL for 5 minutes or less was not injurious; prolonged exposure to a low ICG concentration was toxic. Since ICG may be retained in the vitreous cavity for a lengthy period, thorough washout of ICG during macular hole surgery is required.