Inhibition of form-deprivation myopia by a GABAAOr receptor antagonist, (1,2,5,6-tetrahydropyridin-4-yl) methylphosphinic acid (TPMPA), in guinea pigs

Purpose To investigate the effects of the relatively selective GABAAOr receptor antagonist (1,2,5,6-tetrahydropyridin-4-yl) methylphosphinic acid (TPMPA) on form-deprivation myopia (FDM) in guinea pigs. Methods A diffuser was applied monocularly to 30 guinea pigs from day 10 to 21. The animals were randomized to one of five treatment groups. The deprived eye received daily sub-conjunctival injections of 100 μl TPMPA at a concentration of (i) 0.03 %, ( ii) 0.3 %, or (iii) 1 %, a fourth group (iv) received saline injections, and another (v) no injections. The fellow eye was left untreated. An additional group received no treatment to either eye. Prior to and at the end of the treatment period, refraction and ocular biometry were performed. Results Visual deprivation produced relative myopia in all groups (treated versus untreated eyes, P < 0.05). The amount of myopia was significantly affected by the drug treatment (one-way ANOVA, P < 0.0001); myopia was less in deprived eyes receiving either 0.3 % or 1 % TPMPA (saline = −4.38 ± 0.57D, 0.3 % TPMPA = −3.00 ± 0.48D, P < 0.01; 1 % TPMPA = −0.88 ± 0.51D, P < 0.001). The degree of axial elongation was correspondingly less (saline = 0.13 ± 0.02 mm, 0.3 % TPMPA = 0.09 ± 0.01 mm, P < 0.01, 1 % TPMPA = 0.02 ± 0.01 mm, P < 0.001) as was the VC elongation (saline = 0.08 ± 0.01 mm, 0.3 % TPMPA = 0.05 ± 0.01 mm, P < 0.01, 1 % TPMPA = 0.01 ± 0.01 mm; P < 0.001). ACD and LT were not affected (one-way ANOVA, P > 0.05). One percent TPMPA was more effective at inhibiting myopia than 0.3 % (P < 0.01), and 0.03 % did not appreciably inhibit the myopia (0.03 % TPMPA versus saline, P > 0.05). Conclusions Sub-conjunctival injections of TPMPA inhibit FDM in guinea pig models in a dose-dependent manner.

Ocular refractive and biometric characteristics in patients with tilted disc syndrome

BACKGROUND Tilted disc syndrome (TDS) is associated with characteristic ocular findings. The purpose of this study was to evaluate the ocular, refractive, and biometric characteristics in patients with TDS. METHODS This case-control study included 41 eyes of 25 patients who had established TDS and 40 eyes of 20 healthy control subjects. All participants underwent a complete ocular examination, including refraction and analysis using Fourier transformation, slit lamp biomicroscopy, pachymetry, keratometry, and ocular biometry. Corneal topography examinations were performed in the syndrome group only. RESULTS There were no significant differences in spherical equivalent (P = 0.13) and total astigmatism (P = 0.37) between groups. However, mean best spectacle-corrected visual acuity (Log Mar) was significantly worse in TDS patients (P = 0.003). The lenticular astigmatism was greater in the syndrome group, whereas the corneal component was greater in controls (P = 0.059 and P = 0.028, respectively). The measured biometric features were the same in both groups, except for the lens thickness and lens-axial length factor, which were greater in the TDS group (P = 0.007 and P = 0.055, respectively). CONCLUSIONS Clinically significant lenticular astigmatism, more oblique corneal astigmatism, and thicker lenses were characteristic findings in patients with TDS.

Ocular refractive and biometric characteristics in patients with tilted disc syndrome

Purpose: To evaluate the ocular refractive and biometric characteristics in patients with tilted disc syndrome (TDS). Methods: This case-control study comprised 41 eyes of 25 patients with established TDS and forty eyes of 20 age- and sex-matched healthy control subjects. All had a complete ocular examination including refraction and analysis using Fourier transformation, slit lamp biomicroscopy, pachymetry keratometry, and ocular biometry. Corneal topography examinations were performed in the syndrome group only. Results: There were no significant differences in spherical equivalent (p = 0.334) and total astigmatism (p= 0.246) between groups. However, mean best spectacular corrected visual acuity was significantly worse in TDS patients (P < 0.001). The lenticular astigmatism was significantly greater in the syndrome group, while the corneal component was greater in the controls (p = 0.004 and p = 0.002, respectively). The measured biometric features were the same in both groups, except for the lens thickness, relative lens position, and lens-axial length factor which were greater in the TDS group (p = 0.002, p = 0.015, and p = 0.025, respectively). Conclusions: Clinically significant lenticular astigmatism, more oblique corneal astigmatism, and thicker lens were characteristic findings in patients with TDS.

Comprehensive evaluation of dehydration impact on ocular tissue during Ramadan fasting

Purpose The present study aimed to review the effect of dehydration during Ramadan fasting on the health and ocular parameters leading to changes in eye function. Methods Articles included in the study were taken from PubMed, Ovid, Web of Science and Google Scholar up to 2014. Related articles were also obtained from scientific journals on fasting and vision system. Results Dehydration and nutrition changes in Ramadan cause an increase in tear osmolarity, ocular aberration, anterior chamber depth, IOL measurement, central corneal thickness, retinal and choroidal thicknesses, and also a decrease in IOP, tear secretion, and vitreous thickness. Conclusion Much research related to the effect of dehydration on ocular parameters during Ramadan fasting exists. The findings reveal association with significant changes on ocular parameters. Thus, it seems requisite to have a comprehensive study on "fasting and ocular parameters”, which will be helpful in making decisions and giving plan to the patients.

Regional changes in choroidal thickness associated with accommodation

Purpose. To characterize the changes occurring in choroidal thickness (ChT) across the posterior pole during accommodation using enhanced-depth imaging optical coherence tomography (OCT). Methods. Forty participants (mean age 21 ± 2 years) had measures of ChT and ocular biometry taken during accommodation to 0, 3, and 6 diopter (D) stimuli, with the Spectralis OCT and Lenstar biometer. A Badal optometer and cold mirror system was mounted on both instruments, allowing measurement collection while subjects viewed an external fixation target at varying accommodative demands. Results. The choroid exhibited significant thinning during accommodation to the 6 D stimulus in both subfoveal (mean change, −5 ± 7 μm) and parafoveal regions (P < 0.001). The magnitude of these changes varied by parafoveal meridian, with the largest changes seen in the temporal (−9 ± 12 μm) and inferotemporal (−8 ± 8 μm) meridians (P < 0.001). Axial length increased with accommodation (mean change, +5 ± 11 μm at 3 D, +14 ± 13 μm at 6 D), and these changes were weakly negatively associated with the choroidal changes (r2 = 0.114, P < 0.05). Conclusions. A small, but significant thinning of the choroid was observed at the 6 D accommodation demand, which was greatest in the temporal and inferotemporal parafoveal choroid, and increased with increasing eccentricity from the fovea. The regional variation in the parafoveal thinning corresponds to the distribution of the nonvascular smooth muscle within the uvea, which may implicate these cells as the potential mechanism by which the choroid thins during accommodation.

Straylight, lens yellowing and aberrations of eyes in type 1 diabetes

Straylight, lens yellowing and ocular aberrations were assessed in a group of people with type 1 diabetes and in an age matched control group. Most of the former had low levels of neuropathy. Relative to the control group, the type 1 diabetes group demonstrated greater straylight, greater lens yellowing, and differences in some higher-order aberration co-efficients without significant increase in root-mean-square higher-order aberrations. Differences between groups did not increase significantly with age. The results are similar to the findings for ocular biometry reported previously for this group of participants, and suggest that age-related changes in the optics of the eyes of people with well-controlled diabetes need not be accelerated.

Validation of a partial coherence interferometry method for estimating retinal shape

To validate a simple partial coherence interferometry (PCI) based retinal shape method, estimates of retinal shape were determined in 60 young adults using off-axis PCI, with three stages of modeling using variants of the Le Grand model eye, and magnetic resonance imaging (MRI). Stage 1 and 2 involved a basic model eye without and with surface ray deviation, respectively and Stage 3 used model with individual ocular biometry and ray deviation at surfaces. Considering the theoretical uncertainty of MRI (12-14%), the results of the study indicate good agreement between MRI and all three stages of PCI modeling with <4% and <7% differences in retinal shapes along horizontal and vertical meridians, respectively. Stage 2 and Stage 3 gave slightly different retinal co-ordinates than Stage 1 and we recommend the intermediate Stage 2 as providing a simple and valid method of determining retinal shape from PCI data.

Light exposure and eye growth in childhood

PURPOSE The purpose of this study was to examine the relationship between objectively measured ambient light exposure and longitudinal changes in axial eye growth in childhood. METHODS A total of 101 children (41 myopes and 60 nonmyopes), 10 to 15 years of age participated in this prospective longitudinal observational study. Axial eye growth was determined from measurements of ocular optical biometry collected at four study visits over an 18-month period. Each child’s mean daily light exposure was derived from two periods (each 14 days long) of objective light exposure measurements from a wrist-worn light sensor. RESULTS Over the 18-month study period, a modest but statistically significant association between greater average daily light exposure and slower axial eye growth was observed (P ¼ 0.047). Other significant predictors of axial eye growth in this population included children’s refractive error group (P < 0.001), sex (P < 0.01), and age (P < 0.001). Categorized according to their objectively measured average daily light exposure and adjusting for potential confounders (age, sex, baseline axial length, parental myopia, nearwork, and physical activity), children experiencing low average daily light exposure (mean daily light exposure: 459 6 117 lux, annual eye growth: 0.13 mm/y) exhibited significantly greater eye growth than children experiencing moderate (842 6 109 lux, 0.060 mm/y), and high (1455 6 317 lux, 0.065 mm/y) average daily light exposure levels (P ¼ 0.01). CONCLUSIONS In this population of children, greater daily light exposure was associated with less axial eye growth over an 18-month period. These findings support the role of light exposure in the documented association between time spent outdoors and childhood myopia.

Longitudinal changes in choroidal thickness and eye growth in childhood

PURPOSE To examine longitudinal changes in choroidal thickness and axial length in a population of children with a range of refractive errors. METHODS One hundred and one children (41 myopes and 60 nonmyopes) aged 10 to 15 years participated in this prospective, observational longitudinal study. For each child, 6-month measures of choroidal thickness (using enhanced depth imaging optical coherence tomography) and axial ocular biometry were collected four times over an 18-month period. Linear mixed-models were used to examine the longitudinal changes in choroidal thickness and the relationship between changes in choroidal thickness and axial eye growth over the study period. RESULTS A significant group mean increase in subfoveal choroidal thickness was observed over 18 months (mean increase 13 6 22 lm, P < 0.001). Myopic children exhibited significantly thinner choroids compared with nonmyopic children (P < 0.001), although there was no significant time by refractive group interaction (P ¼ 0.46), indicating similar changes in choroidal thickness over time in myopes and nonmyopes. However, a significant association between the change in choroidal thickness and the change in axial length over time was found (P < 0.001, β = −0.14). Children showing faster axial eye growth exhibited significantly less choroidal thickening over time compared with children showing slower axial eye growth. CONCLUSIONS A significant increase in choroidal thickness occurs over an 18-month period in normal 10- to 15-year-old children. Children undergoing faster axial eye growth exhibited less thickening and, in some cases, a thinning of the choroid. These findings support a potential role for the choroid in the mechanisms regulating eye growth in childhood.

Paralelização em CUDA/GLSL do algoritmo SIFT para reconhecimento de íris

Neste trabalho é estudada a viabilidade de uma implementação em paralelo do algoritmo scale invariant feature transform (SIFT) para identificação de íris. Para a implementação do código foi utilizada a arquitetura para computação paralela compute unified device architecture (CUDA) e a linguagem OpenGL shading language (GLSL). O algoritmo foi testado utilizando três bases de dados de olhos e íris, o noisy visible wavelength iris image Database (UBIRIS), Michal-Libor e CASIA. Testes foram feitos para determinar o tempo de processamento para verificação da presença ou não de um indivíduo em um banco de dados, determinar a eficiência dos algoritmos de busca implementados em GLSL e CUDA e buscar valores de calibração que melhoram o posicionamento e a distribuição dos pontos-chave na região de interesse (íris) e a robustez do programa final.

Bothrops aff. Leucurus (Wagler, 1824) populazio irlatar baten deskribapen morfologikoa: suge populazio irlatar baten morfologia

[EUS] Atrox konplexuko espezieen barruan, Bothrops leucurus (Wagler, 1824) Bahia estatuko oihan atlantikoko sugegorri espezie arruntena da. Polimorfikoa da eta ezaugarri geografikoekin, ontogenikoekin eta sexuarekin erlazionatutako kolore aldakortasuna aurkezten du. Jadanik hainbat ikerketa burutu dira kontinenteko populazioei buruz, baina, oraindik ez da lanik egin BTS badiako populazio uhartetarrekin. Lan honen xedea Bothrops aff. leucurus populazio uhartetarraren deskribapena burutzea izan da, orbanen ereduetan, folidosian eta gorputz tamainan oinarriturik. Lagin tamaina erlatiboki txikia izanik (n=20), Student t testeko emaitzak type II erroreen menpe daude eta kontinenteko eta uharteko populazioen arteko ezberdintasunak estatistikoki ikertu izan ez diren arren, gure datuak garrantzia dute. Izan ere, ikerketa sakonagoetan oinarri bezala erabili ahal izango dira. Biometriari dagokionez, gure populazio uhartetarrean batazbesteko MKL txikiagoa ikusi dugu eta balioen tarteak murritzagoak dira. Ez da sexuen arteko ezberdintasun esangarririk topatu gorputzeko neurrientzat. Folidosian (ezkata zenbateka) lortutako datuak, beste autoreek Bothrops leucurus-entzat deskribatutako parametroekin bat datozen arren, gure laginak ezkata tarte mugatuagoak ageri ditu. Orban ereduak ale guztietan behatu eta irudikatu ostean, oro har bi eredu ezberdindu eta deskribatzea posible izan da. Behatuak izan diren ezberdintasunak, uhartetako baliagai-hornidura mugatuen ondorio gisa uler daitezke, izan ere, halako baldintzetan ale txikiagoak positiboki hautatuak izango liratekeelako.

Survey of marine turtles ecobiology in north of Persian Gulf

Sea turtles are counted as rare and extincting species. During the last century the population of sea turtles are drastically reducd and the remaining ones are considerd either threatend or endangerd because of some factors as sea pollution, economic benefits, intense fishing effort, beach man-made structures and so on. So, in recent years, more attention to conserving and surviving them is assumed. After a preliminary studies on some of the biological specifications in northern beach of Persian Gulf, three islands ; Hormoz, Hengam and Larak for the biometry of the turtles, a total number of 179, from 1999 to 2002 (4 years) are chosen. Some of the biological attributes as weight, length and their egg-laying are recorded, these items are then analyzed using SPSS software. The observed results are as follows . The lowest weight of the turtles was 35 kg, the highest 59 kg, and the average 45.24 kg. The lowest carapace length was 64 cm. the highest 86 cm and the average 76.79. the lowest number of laying eggs was 73, the highest 126, and the average 86.79. The results are discussed in three following sections: 1-A contrastive analysis of the biometric characteristics during 1999 in the three mentiond islands. 2-A contrastive analysis of the biometric characteristics in Hormoz island from 1999 to 2002. 3-A contrastive analysis of all the biometric characteristics in the three islands and other parts of the world. The results obtained from the turtles biometry in 1999 shows that the average of the turtles weight in Larak is lower than the other mentioned ones, and the heighest average is observed in Hormoz island. The turtles of Hengm have laid more eggs than the others. The results of Hengani turtles biometry during 1999-2002 indicates that the average of their weight in 2002 is more than the other three years in the same place. The least number of eggs laid during these years are 53 and the most are 126. The most number of eggs are laid in Hormoz in 2002, but the average number does not show any significant change.

Population dynamic and stock assessment of lobster resources of Cha-bahar region (with particular ref. to Panulirus homarus)

Amoungst the three spiny lobster species in southern Iranian waters, Panulirus homarus is the only commercial species with a total landings of 20-45 tons per year indicating a decrease in both landings and CPIJE in recent years. Fishing has been regulated according to the no. of fisherman and effort, and trap ha's replaced the gillnef since 1994. Fishing is carried out along the rocky shores of Chah-Bahar region through different landing places by local fisherman for a period of about two months. Most of catch is exported mainly frozen. This research was sposored by the Fisheries Research Dept. and aimed to work on the population dynamics and stock assessment in order to stablish a better understandings of the stock and hence a proper management in this region. Sampling was done for. 10 successive months in _5 major landing places from 1994 to 1995 with no sampling during the monsoon period through June to July. Althogethere, 8500 specimen were collected and the biometry was done accordings to the sex, region and month. Average total length, total weight and carapace length was obtained 216mm., 452 gr. and 75mm. respectively. Total length-weight relationship of both sexes was calculated and follows the cubic law. Regression coefficients for both sexes was 2.8231, males 2.9616, total females 2.7490, berried females 2.6611- and non-berried females

Difflugia mulanensis nov spec., a freshwater testate amoeba from Lake Mulan, China

Testate amoebae are an important and abundant component of aquatic ecosystems. Our knowledge of their distribution and the species inventory in Asia is still limited. This paper describes a new planktonic Difflugia from Lake Mulan, province of Hubei, China. These findings are of taxonomic, as well as biogeographic significance because Difflugia mulanensis nov. spec. is a rare and perhaps the only locally distributed member of the well-known urceolate division within this most species-rich genus of lobose testate amoebae. We have studied its morphology and biometry with light and scanning electron microscopical methods. D. mulanensis differs from related species by its very large wide funnel-shaped apertural collar which normally exceeds the width of the test, a relatively long neck, its rounded apical end and the presence of only one nucleus. All shell parameters are normally distributed with low variability. Only the collar height is more variable. This shows that D. mulanensis is a size-monomorphic species. (c) 2005 Elsevier GrnbH. All rights reserved.

Redescription of Difflugia tuberspinifera Hu, Shen, Gu et Gong, 1997 (Protozoa : Rhizopoda : Arcellinida : Difflugiidae) from China

The freshwater testate amoeba Difflugia tuberspinifera Hu et al. 1997 collected from pond and lake in China, is investigated by light and scanning electron microscopy. This little known taxon is redescribed and its morphology, biometry and ecology are supplied. After carefully comparison with other six similar species including Difflugia bartosi Stepanek, D. corona Wallich, D. corona cashi Deflandre, D. corona tuberculata Vucetich, D. muriformis Gauthier-Lievre et Thomas and Netzelia tuberculata (Wallich) Netzal we believe that the sub-spherical to spherical shell, the mulberry-shaped appearance, the 7-10 apertural tooth-like structures, the short collar and the conical spines numbering from 4 to 8 at the upper equatorial region in D. tuberspinifera set it apart from other species. Besides, statistical analysis indicates that D. tuberspinifera is a size-monomorphic species characterized by a main-size class and a small size range and the shell height is significant correlated with other morphometric characters at p < 0.05 excepting the number of aperture tooth-like structures and the number of spines. Moreover, D. tuberspinifera inhabits not only lotic but also lentic environment.