Comparison of salivary flow rate and pH between healthy subjects and tobacco and areca nut chewers.

Introduction: Tobacco and areca nuts release carcinogens, which cause alterations in saliva. Evaluation of these changes through estimation of salivary flow rate and pH was performed in tobacco and areca nut chewers and apparently healthy subjects. Material and Methods: The study group for this comparative study comprised 60 subjects with 20 areca nut chewers (group 1), 20 tobacco chewers (group 2), and 20 non-tobacco and areca nut chewers (group 3) in the ages between 18 and 75 years. After collection of saliva from each subject, the salivary flow rate (SFR) was measured by using graduated tubes, whereas salivary pH was measured using a digital salivary pH meter. Tukey HSD post hoc test was performed for comparison of mean SFR and mean pH between study group subjects. Analysis of variance (ANOVA) test was used to find the mean difference in SFR and pH in duration, intensity, and frequency among various types of areca nut and tobacco users. A "P" value of less than 0.05 was considered as statistically significant. Results: The mean age among groups 1, 2, and 3 was 37.70 ± 10.44, 39.75 ± 10.16, and 37.90 ± 10.52 years, respectively, with a statistically insignificant difference. The mean salivary flow rate (ml/20 min) was maximum in group 3 (13.23), followed by group 2 (11.75) and group 1 (10.48), with the statistically significant difference as P < 0.05. The mean salivary pH was maximum in group 3 (7.07), followed by group 2 (6.86) and group 1 (6.49), with the statistically significant difference as P < 0.05. Conclusion: Long-term use of tobacco and areca nuts in a chewable form can significantly reduce the salivary flow rate and salivary pH. Hence, these measurements can be used as chair side, non-invasive measures for assessing pathological changes in oral mucosa linked to vulnerable effects among people addicted to these adverse habits; thereby, early re-organization can prevent mobility and mortality.

Socioeconomics of retinopathy of prematurity screening and treatment in the United States.

BACKGROUND: Retinopathy of prematurity (ROP) screening, an integral part of pediatric ophthalmology, can be time consuming and resource intensive. The purpose of this study was to evaluate the economic landscape of ROP screening and treatment among pediatric ophthalmologists in the United States. METHODS: An online survey was distributed to US pediatric ophthalmologists through a pediatric ophthalmology email listserv. Survey results were compiled, and responses were deidentified and analyzed, with particular focus on factors affecting financial compensation. RESULTS: A total of 97 responses were collected. Almost half of respondents worked in private practice settings. Over 80% of respondents had a formal contract to perform ROP care, but only 26% enlisted the assistance of an attorney to negotiate their contract. Just over half of respondents believed themselves adequately compensated for their services. Respondents that had retained an attorney for contractual negotiations were more likely to have a higher mean annual compensation rate ($126,545 ± $145,133 vs $70,214 ± $50,671; P = 0.05). Physicians who believed themselves adequately compensated were more likely to be in academic practice settings (78% academic vs 55% combo/other vs 24% private; P < 0.001) and were more likely to have contracts to perform ROP care (68% with contracts vs 15% without; P = 0.001). Average annual compensation was $82,968 ± $84,132, approximately $24,000 higher than reported in 2013. CONCLUSIONS: More pediatric ophthalmologists among our respondents obtained contracts for their services, and compensation rates have increased since 2013. Nevertheless, concerns regarding under-compensation and time commitment persist, raising concerns about the long-term sustainability of current models for providing ROP services.

Comparison of histologic findings in age-related macular degeneration with RPE flatmount images.

Purpose: To visualize and analyze ex vivo flatmounted human RPE morphology from patients with age-related macular degeneration (AMD), and to compare the morphology with histologic findings. To establish whether the sub-RPE structures identified en face in RPE flatmount preparations are drusen with histopathological registration in serial sections. To detect characteristic patterns found en face in RPE with the same structures in histological cross sections from eyes from cadavers of patients with AMD. Methods: Twenty-eight postmortem eyes from 14 patients (16 eyes with AMD and 12 age-matched control eyes) were oriented and microdissected yielding a RPE-choroid preparation. The tissues were flatmounted, stained with Alexa Fluor 635 Phalloidin (AF635-phalloidin) for f-actin and propidium iodide for DNA, and imaged using confocal microscopy. Portions of tissue from macular regions were processed for electron microscopic examination. After confocal imaging, the samples were remounted for histologic processing, embedded in paraffin, and serially sectioned perpendicular to the plane of the RPE-choroid sheet. Scaled two-dimensional (2D) maps of drusen locations found with the histological cross sections were constructed and correlated with the en face confocal microscopic images. Results: Twenty-eight postmortem eyes with a mean time of death to tissue preservation of 23.7 h (range 8.0­51 h) from 14 donors (seven women and seven men) with an average age of 78 years (range 60­93 years) were evaluated. Eight donors had AMD, and six served as controls. Scattered small, hard drusen were present in the periphery of the eyes with AMD and the healthy eyes. The macular region of the eyes with AMD contained small (<63 µm), medium (63.0­124 µm), and large ( ≥ 125 µm) drusen. The RPE was arranged in rosette-like structures overlying small drusen, attenuated overlying medium-sized drusen, and consisted of large multinucleated cells overlying large drusen. The RPE in the area of geographic atrophy was attenuated and depigmented. Conclusions: Confocal images of flatmounts from eyes with AMD showed RPE patterns overlying various types of drusen and geographic atrophy that correlated with histologic characteristics. We propose RPE repair mechanisms that may result in the patterns that we observed.

Analysis of RPE morphometry in human eyes.

PURPOSE: To describe the RPE morphometry of healthy human eyes regarding age and topographic location using modern computational methods with high accuracy and objectivity. We tested whether there were regional and age-related differences in RPE cell area and shape. METHODS: Human cadaver donor eyes of varying ages were dissected, and the RPE flatmounts were immunostained for F-actin with AF635-phalloidin, nuclei stained with propidium iodide, and imaged with confocal microscopy. Image analysis was performed using ImageJ (NIH) and CellProfiler software. Quantitative parameters, including cell density, cell area, polygonality of cells, number of neighboring cells, and measures of cell shape, were obtained from these analyses to characterize individual and groups of RPE cells. Measurements were taken from selected areas spanning the length of the temporal retina through the macula and the mid-periphery to the far periphery. RESULTS: Nineteen eyes from 14 Caucasian donors of varying ages ranging from 29 to 80 years were used. Along a horizontal nasal to temporal meridian, there were differences in several cell shape and size characteristics. Generally, the cell area and shape was relatively constant and regular except in the far periphery. In the outer third of the retina, the cell area and shape differed from the inner two-thirds statistically significantly. In the macula and the far periphery, an overall decreasing trend in RPE cell density, percent hexagonal cells, and form factor was observed with increasing age. We also found a trend toward increasing cell area and eccentricity with age in the macula and the far periphery. When individuals were divided into two age groups, <60 years and ≥60 years, there was a higher cell density, lower cell area, lower eccentricity, and higher form factor in the younger group in the macula and the far periphery (p<0.05 for all measurements). No statistically significant differences in RPE morphometry between age groups were found in the mid-periphery. CONCLUSIONS: Human cadaver RPE cells differ mainly in area and shape in the outer one third compared to the inner two-thirds of the temporal retina. RPE cells become less dense and larger, lose their typical hexagonal shape, and become more oval with increasing age.

Tauroursodeoxycholic Acid Protects Retinal Function and Structure in rd1 Mice.

We explored the potential protective effects of tauroursodeoxycholic acid (TUDCA) on cone photoreceptor survival in a model of rapid retinal degeneration, the ß-Pde6 (rd1) (rd1) mouse model. We injected two strains of rd1 mice (B6.C3-Pde6b (rd1) Hps4(le)/J and C57BL/6J-Pde6b (rd1-2)/J mice) daily from postnatal day (P) 6 to P21 with TUDCA or vehicle. At P21, retinal function was evaluated with light-adapted electroretinography (ERG) and retinal structure was observed with plastic or frozen sections. TUDCA treatment partially preserved function and structure in B6.C3-Pde6b (rd1) Hps4(le)/J mice but only partially preserved structure in C57BL/6J-Pde6b (rd1-2)/J mice. Our results suggest a possible intervention for patients undergoing rapid retinal degeneration.

RPE Cell and Sheet Properties in Normal and Diseased Eyes.

Previous studies of human retinal pigment epithelium (RPE) morphology found spatial differences in density: a high density of cells in the macula, decreasing peripherally. Because the RPE sheet is not perfectly regular, we anticipate that there will be differences between conditions and when and where damage is most likely to begin. The purpose of this study is to establish relationships among RPE morphometrics in age, cell location, and disease of normal human and AMD eyes that highlight irregularities reflecting damage. Cadaveric eyes from 11 normal and 3 age-related macular degeneration (AMD) human donors ranging from 29 to 82 years of age were used. Borders of RPE cells were identified with phalloidin. RPE segmentation and analysis were conducted with CellProfiler. Exploration of spatial point patterns was conducted using the "spatstat" package of R. In the normal human eye, with increasing age, cell size increased, and cells lost their regular hexagonal shape. Cell density was higher in the macula versus periphery. AMD resulted in greater variability in size and shape of the RPE cell. Spatial point analysis revealed an ordered distribution of cells in normal and high spatial disorder in AMD eyes. Morphometrics of the RPE cell readily discriminate among young vs. old and normal vs. diseased in the human eye. The normal RPE sheet is organized in a regular array of cells, but AMD exhibited strong spatial irregularity. These findings reflect on the robust recovery of the RPE sheet after wounding and the circumstances under which it cannot recover.