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1.
Vet Res Commun ; 2024 Mar 26.
Artigo em Inglês | MEDLINE | ID: mdl-38528300

RESUMO

Equine influenza (EI) is a highly contagious acute respiratory disease of equines caused by the H3N8 subtype of Influenza A virus i.e. equine influenza virus (EIV). Vaccination is an important and effective tool for the control of EI in equines. Most of the commercial influenza vaccines are produced in embryonated hen's eggs which has several inherent disadvantages. Hence, subunit vaccine based on recombinant haemagglutinin (HA) antigen, being the most important envelope glycoprotein has been extensively exploited for generating protective immune responses, against influenza A and B viruses. We hypothesized that novel vaccine formulation using baculovirus expressed recombinant HA1 (rHA1) protein coupled with bacteriophage will generate strong protective immune response against EIV. In the present study, the recombinant HA1 protein was produced in insect cells using recombinant baculovirus having cloned HA gene of EIV (Florida clade 2 sublineage) and the purified rHA1 was chemically coupled with bacteriophage using a crosslinker to produce rHA1-phage vaccine candidate. The protective efficacy of vaccine preparations of rHA1-phage conjugate and only rHA1 proteins were evaluated in mouse model through assessing serology, cytokine profiling, clinical signs, gross and histopathological changes, immunohistochemistry, and virus quantification. Immunization of vaccine preparations have stimulated moderate antibody response (ELISA titres-5760 ± 640 and 11,520 ± 1280 for rHA1 and rHA1-phage, respectively at 42 dpi) and elicited strong interferon (IFN)-γ expression levels after three immunizations of vaccine candidates. The immunized BALB/c mice were protected against challenge with wild EIV and resulted in reduced clinical signs and body weight loss, reduced pathological changes, decreased EIV antigen distribution, and restricted EIV replication in lungs and nasopharynx. In conclusion, the immune responses with moderate antibody titer and significantly higher cytokine responses generated by the rHA1-phage vaccine preparation without any adjuvant could be a novel vaccine candidate for quick vaccine preparation through further trials of vaccine in the natural host.

2.
Indian J Palliat Care ; 23(3): 293-299, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28827933

RESUMO

OBJECTIVE: The Self-administered Leeds Assessment of Neuropathic Symptoms and Signs (S-LANSS) is a 7-item self-report scale developed to identify pain which is of predominantly neuropathic origin. The aim of this study was to develop a Malayalam version of the LANSS and to test its validity and reliability in chronic pain patients. METHODOLOGY: We enrolled 101 Malayalam-speaking chronic pain patients who visited the Division of Palliative Medicine, Regional Cancer Centre, Thiruvananthapuram, Kerala, India. The translated version of S- LANSS was constructed by standard means. Fifty-one neuropathic pain and fifty nociceptive pain patients were identified by an independent pain physician and were subjected to the new pain scale by a palliative care nurse who was blinded to the diagnosis. The "gold standard diagnosis" is what the physician makes after clinical examination. Its validation, sensitivity, specificity, and positive and negative predictive values were determined. RESULTS: Fifty-one neuropathic pain and fifty nociceptive pain patients were subjected to the Malayalam version of S-LANSS pain scale for validity testing. The agreement by Cohen's Kappa 0.743, Chi-square test P < 0.001, sensitivity 89.58, specificity 84.91, positive predictive value 84.31, negative predictive value 90.00, accuracy by 87.13, and likelihood ratio 5.94. CONCLUSION: The Malayalam version of S-LANSS pain scale is a validated screening tool for identifying neuropathic pain in chronic pain patients in Malayalam-speaking regions.

3.
Exp Eye Res ; 162: 79-85, 2017 09.
Artigo em Inglês | MEDLINE | ID: mdl-28712540

RESUMO

Antibiotics such as fluoroquinolones (FQLs) are commonly used to treat ocular infections but are also known to cause dermal melanocyte toxicity. The release of dispersed pigments from the iris into the aqueous humor has been considered a possible ocular side effect of the systemic administration of FQLs such as Moxifloxacin, and this condition is known as bilateral acute iris transillumination (BAIT). Bilateral acute depigmentation of iris (BADI) is a similar condition, with iris pigment released into the aqueous, but it has not been reported as a side effect of FQL. Iris pigments are synthesized by the melanogenic enzyme tyrosinase (TYR) and can be detected but not quantified by using slit-lamp biomicroscopy. The correlation between dispersed pigments in the aqueous and the extent of melanocyte toxicity due to topical antibiotics in vivo is not well studied. Here, we aimed to study the effect of topical FQLs on iris tissue, the pigment release in the aqueous humor and the development of clinically evident iris atrophic changes. We evaluated this process by measuring the activity of TYR in the aqueous humor of 82 healthy eyes undergoing cataract surgery following topical application of FQLs such as Moxifloxacin (27 eyes, preservative-free) or Ciprofloxacin (29 eyes, with preservative) or the application of non-FQL Tobramycin (26 eyes, with preservative) as a control. In addition, the patients were questioned and examined for ocular side effects in pre- and post-operative periods. Our data showed a significantly higher mean TYR activity in the aqueous humor of Ciprofloxacin-treated eyes compared to Moxifloxacin- (preservative free, p < 0.0001) or Tobramycin-treated eyes (p < 0.0001), which indicated that few quinolones under certain conditions are toxic to the iris melanocytes. However, the reduced TYR activity in the aqueous of Moxifloxacin-treated eyes was possibly due to the presence of a higher drug concentration, which inhibits TYR activity. Consistently, immunoblotting analysis of the aqueous humor from both Ciprofloxacin- and Moxifloxacin-treated eyes showed the presence of soluble TYR enzyme, thus reflecting its toxicity to iris melanocytes and corresponding to its activity in the aqueous humor. Intriguingly, none of these patients developed any clinically appreciable ocular side effects characteristic of BAIT or BADI. Overall, our results suggest that topical antibiotics cause different levels of iris melanocyte toxicity, releasing dispersed pigments into the aqueous humor, which can be measured through TYR enzyme activity. Hence, we conclude that topical FQLs may cause subclinical toxicity to the iris melanocytes but may not be the sole cause of the development of BAIT or BADI.


Assuntos
Humor Aquoso/enzimologia , Fluoroquinolonas/efeitos adversos , Iris/patologia , Melanócitos/efeitos dos fármacos , Monofenol Mono-Oxigenase/metabolismo , Administração Tópica , Adulto , Idoso , Idoso de 80 Anos ou mais , Antibacterianos/administração & dosagem , Antibacterianos/efeitos adversos , Cromatografia Líquida de Alta Pressão , Relação Dose-Resposta a Droga , Feminino , Fluoroquinolonas/administração & dosagem , Humanos , Iris/efeitos dos fármacos , Iris/metabolismo , Masculino , Melanócitos/metabolismo , Melanócitos/patologia , Pessoa de Meia-Idade , Soluções Oftálmicas , Estudos Prospectivos
4.
J Refract Surg ; 33(5): 330-336, 2017 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-28486724

RESUMO

PURPOSE: To quantify keratometry and wavefront aberration of the anterior corneal surface and epithelium-Bowman's layer interface using anterior segment optical coherence tomography (OCT). METHODS: Twenty-five normal eyes and 25 eyes with keratoconus were retrospectively analyzed. The anterior corneal edge and epithelium-Bowman's layer interface were segmented from 12 distortion-corrected OCT B-scans. Axial tangential curvatures and wavefront aberration were calculated by ray tracing and 6th order Zernike analyses. All eyes underwent simultaneous imaging with Pentacam (Oculus Optikgeräte GmbH, Wetzlar, Germany). The Pentacam elevation data were used for aberration analyses using the same ray-tracing method. The paired t test was used to compare the variables. RESULTS: In normal eyes, mean steep axis and maximum keratometry of OCT of the anterior corneal surface and epithelium-Bowman's layer interface were significantly greater than the same of the Pentacam anterior corneal surface (P < .05). Mean root mean square of higher order aberrations of the OCT surfaces was greater than the same of the Pentacam surface by a factor of 4. In eyes with keratoconus, mean steep axis and maximum keratometry of the OCT epithelium-Bowman's layer interface was the greatest (P < .05). Mean root mean square of the higher order aberrations and vertical coma of the OCT epithelium-Bowman's layer interface was the greatest (P < .05). In general, the aberrations of the OCT epithelium-Bowman's layer interface were significantly greater than those of the Pentacam anterior corneal surface. CONCLUSIONS: A noncontact method to quantify the topography and aberrations of corneal surfaces with OCT was presented. OCT measurements yielded greater curvature and aberrations than Pentacam in both normal and keratoconic eyes. [J Refract Surg. 2017;33(5):330-336.].


Assuntos
Lâmina Limitante Anterior/patologia , Topografia da Córnea/métodos , Ceratocone/diagnóstico , Tomografia de Coerência Óptica/métodos , Adulto , Feminino , Seguimentos , Humanos , Ceratocone/fisiopatologia , Masculino , Reprodutibilidade dos Testes , Estudos Retrospectivos , Fatores de Tempo , Acuidade Visual , Adulto Jovem
5.
J Matern Fetal Neonatal Med ; 30(7): 849-853, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-27165812

RESUMO

OBJECTIVE: To quantify cell free fetal DNA (cffDNA) with fetal specific epigenetic marker, hypermethylated RASSF1A, in maternal plasma of normal pregnant women from 20 weeks of gestation and to assess its relationship with maternal age, height, pre-pregnancy weight and body mass index (BMI). METHODS: Hundred normal pregnant women within the gestational age of 21-40 weeks were randomly selected and grouped into five (n = 20). Group 1: 21-24, Group 2: 25-28, Group 3: 29-32, Group 4: 33-36 and Group 5: 37-40 weeks. Maternal plasma DNA was extracted, digested with methylation-sensitive restriction enzyme, BstUI and the fetal specific DNA (cffDNA) was quantified by Real-time polymerase chain reaction (qRT-PCR). RESULTS: The mean hypermethylated RASSF1A concentrations in different gestational groups were Group 1: 30.1 ± 14.9, Group 2: 52.6 ± 22.18, Group 3: 93.2 ± 19.08, Group 4: 172.8 ± 26.81 and Group 5: 337.8 ± 52.9 copies/ml. Pearson's correlation analysis showed highly significant positive correlation between cffDNA and gestational age (r = 0.899, p < 0.001). BMI was also found to be positively related to cffDNA (r = 0.217, p < 0.05). However, it did not show any correlation with maternal age, height and pre-pregnancy weight. CONCLUSIONS: The gestational age-dependent increase of hypermethylated RASSF1A; the fetal specific epigenetic marker in maternal plasma was demonstrated, in an Indian study group of normal pregnant women. Findings would form the basis of future studies involving pregnancy complications that would aid in the early diagnosis of placental pathologies with hypermethylated RASSF1A.


Assuntos
Metilação de DNA , Feto/metabolismo , Proteínas Supressoras de Tumor/genética , Adulto , Feminino , Idade Gestacional , Humanos , Índia , Idade Materna , Gravidez , Complicações na Gravidez/genética , Diagnóstico Pré-Natal/métodos , Proteínas Supressoras de Tumor/metabolismo
7.
Indian Pediatr ; 53 Suppl 2: S107-S111, 2016 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-27915317

RESUMO

OBJECTIVE: To compare the benefits of initiating Retinopathy of Prematurity (ROP) screening at first contact with the admitted infant prior to hospital discharge ('early screening') with screening performed between 21 and 28 days after birth ('conventional screening') in rural India. DESIGN: Prospective study. SETTING: Two Level II neonatal intensive care units (NICU), from two district headquarters in Karnataka state. PARTICIPANTS: Participants: 329 infants admitted in the two NICUs. INTERVENTION: One NICU was randomly selected for 'early' and the other for 'conventional' screening. Infants <2000 g at birth were targeted for enrolment. Both centres were visited once a week by a dedicated ROP team. MAIN OUTCOME MEASURE(S): The yield of enrolment, and the magnitude of treatment-requiring cases that would be missed in each scenario were estimated and compared. RESULTS: 107 of 329 admitted infants were eligible for ROP screening. In the study period of 4 months, 42 and 65 infants were eligible for enrolment in the early and conventional group, respectively. In the early group, 88.1% of eligible infants got screened, compared to 38.5% in the conventional group (P=0.03). CONCLUSION: Early enrolment of infants for ROP screening in the NICU itself ensures a superior yield compared to conventional age of initiating screening. The recorded information of mothers allowed pre-counselling, improved enrolment and better compliance to the scheduled examinations. These results suggest the need to re-look at the screening guidelines in India and other regions with similar demographics.


Assuntos
Triagem Neonatal , Retinopatia da Prematuridade/diagnóstico , Peso ao Nascer , Diagnóstico Tardio , Feminino , Humanos , Índia , Recém-Nascido , Recém-Nascido Prematuro , Recém-Nascido de muito Baixo Peso , Unidades de Terapia Intensiva Neonatal , Masculino , Alta do Paciente , Estudos Prospectivos , População Rural
8.
Pregnancy Hypertens ; 6(4): 306-312, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27939474

RESUMO

OBJECTIVES: Cell free fetal DNA (cffDNA) and its hypermethylated RASSF1A gene signify a recent advancement in non-invasive prenatal diagnosis of feto-placental anomalies like pre-eclampsia. The study uses hypermethylated RASSF1A gene to quantify cffDNA and to assess its relationship with placental and urine proteins in pre-eclampsia cases. DESIGN AND METHODS: DNA was isolated from plasma samples of clinically diagnosed cases of pre-eclampsia (n=103) and normal pregnancy (n=616) from 21weeks of gestation. Through methylation sensitive enzyme (BstUI) digestion; followed by real time-polymerase chain reaction (RT-PCR), quantification of hypermethylated RASSF1A was done. Immunoassays determined: placental protein-13 (pp-13) and pregnancy associated plasma protein A (PAPP-A) and pyrogallol red molybdate assay for 24h urine protein. RESULTS: Highly significant differences between control and pre-eclampsia cases for hypermethylated RASSF1A concentrations were found; Group I: 33±7.35 vs 74.46±16.71, Group II: 53.75±16.65 vs 244.22±35.68, Group III: 93.25±19.08 vs 412.31±80.18, Group IV: 144.30±18.13 vs 1056.89±153.78, Group V: 307.55±40.76 vs 2763.76±259.76copies/ml. Multivariate Pearson's correlation analysis of hypermethylated RASSF1A with pp-13, PAPP-A and urine proteins showed positive and very highly significant (P<0.001) associations. CONCLUSIONS: Diagnostic potential of fetal specific, hypermethylated RASSF1A was evaluated. Its positive relationship with placental and urine proteins submit the case for considering it as a reliable marker for pre-eclampsia.


Assuntos
Metilação de DNA , Pré-Eclâmpsia/sangue , Pré-Eclâmpsia/diagnóstico , Diagnóstico Pré-Natal/métodos , Proteínas Supressoras de Tumor/genética , Adulto , Estudos de Casos e Controles , Feminino , Feto/metabolismo , Galectinas/sangue , Humanos , Gravidez , Proteínas da Gravidez/sangue , Proteína Plasmática A Associada à Gravidez/metabolismo , Proteinúria/urina , Adulto Jovem
9.
Oman J Ophthalmol ; 9(3): 157-159, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27843230

RESUMO

The purpose of this case report is to bring forth a rare clinical scenario where preclinical cataract mimics post-LASIK regression and to describe the role of aberrometry in detecting higher order aberrations (HOAs) and early lens changes. A 36-year-old female presented with blurring of vision since 1 year after having undergone an uneventful LASIK surgery 3 years prior. Corneal topography and aberrometry were within normal limits. Although the lens was morphologically normal on slit lamp examination, increased HOAs and lenticular density were detected. Since there were no cataractous changes, the patient was advised regular follow-up. A year later, the patient had developed lenticular changes along with a further increase in aberrations and worsening of scatter on densitometry. Increase in aberrations and lenticular density may serve as a marker for cataract development before clinically detectable lenticular changes. This report shows how preclinical cataract can mimic post-LASIK regression with a change in spherical and cylindrical power of the eye. This could result in patients undergoing re-correction in eyes where the primary pathology is in the lens.

10.
J Ophthalmic Inflamm Infect ; 6(1): 36, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27714662

RESUMO

BACKGROUND: Psycho-immunology is an emerging branch of science which studies the interaction between the brain and the immune system. The purpose of this study is to identify the types of personality factors in patients with non-infectious uveitis and to find its association with a particular uveitic entity if any. This is a prospective, observational, case-control study of 186 patients with non-infectious uveitis (group A) and controls from general ophthalmology outpatient department (group B). "Global 5/SLOAN" personality questionnaire was used which is based on the five-factor theory of personality which describes personality factors based on the presence or absence of five primary dimensions, viz extroversion, orderliness, emotional stability, accommodation, and intellectual curiosity. Personality factors of patients from groups A and B were compared. History of present illness, clinical diagnosis, details of systemic ailment, and demographic information were collected. RESULTS: Group A comprised HLA-B27-related uveitis (n = 30), uveitis due to sarcoidosis (n = 10), Vogt-Koyanagi-Harada syndrome (n = 5), sclero-kerato-uveitis due to rheumatoid arthritis (n = 5), and idiopathic uveitis in rest. Forty-five patients with uveitis had associated systemic ailment. Uveitis patients (n = 56) showed positive personality trait: S (social), C (calm), O (organized), A (accommodative), and I (inquisitive). In contrast, the control group (group B) which mainly comprised patients with non-pathological refractive error and visually insignificant cataract showed more number of negative personality traits (n = 62): R (reserved), L (limbic), U (unstructured), E (egocentric), and N (non-curious). This difference between the uveitis and control group was found to be statistically significant (p ≤ 0.001). The difference was also statistically significant for O (p = 0.008), U (p = 0.004), and C (p = 0.022) with chi-square test. Calm personality was found to be significantly associated with HLA-B27-related uveitis (p = 0.002). N, S, and A traits were seen almost equal in numbers in both the groups. U trait was absent in group A, whereas I trait had negligible presence in group B. CONCLUSIONS: Our finding of an association between organized personality type and uveitis and calm personality and HLA-B27-related uveitis warrants further studies to understand the complex mechanism of psycho-immunology in uveitis.

11.
J Cataract Refract Surg ; 42(4): 577-81, 2016 04.
Artigo em Inglês | MEDLINE | ID: mdl-27113881

RESUMO

PURPOSE: To assess the repeatability of a new swept-source optical coherence tomography (SS-OCT) biometer (IOLMaster 700) and evaluate the agreement with an optical low-coherence reflectometry (OLCR) biometer (Lenstar 900) in cataractous eyes. SETTING: Tertiary eyecare facility. DESIGN: Prospective evaluation of a diagnostic test. METHODS: Eyes of patients had 3 consecutive scans acquired by the same operator. The repeatability of measurements was assessed using the within-subject standard deviation and coefficient of variation (CoV). Agreement between the mean measurements of each machine was evaluated. RESULTS: The study comprised 100 eyes of 100 patients. The median lens thickness and axial length (AL) measurements were significantly greater (P < .001) with SS-OCT (4.29 mm and 23.5 mm, respectively, versus 4.25 mm and 23.4 mm, respectively); anterior chamber depth (ACD) was greater with OLCR (2.72 mm versus 2.70 mm, respectively) (P < .001). The within-subject standard deviation and CoV of the AL (0.01 and 0.05, respectively) and the ACD (0.04 and 1.22, respectively) measurements showed lower variability with SS-OCT (0.05 and 0.21, respectively, for AL; 0.06 and 1.99, respectively, for ACD) than with OLCR. Good agreement was seen for anterior segment measurements between the 2 devices. The 95% limits of agreement of most parameters fell within the test-retest variability of the parameters. The SS-OCT biometer also showed better penetration in dense posterior subcapsular cataracts, measuring AL successfully in 96% of cases. CONCLUSIONS: The new SS-OCT biometer showed good repeatability and agreement with the OLCR biometer. The SS-OCT biometer measured the AL with fewer dropouts compared with the OLCR even in dense cataracts. FINANCIAL DISCLOSURE: None of the authors has a financial or proprietary interest in any material or method mentioned.


Assuntos
Córnea/diagnóstico por imagem , Tomografia de Coerência Óptica , Câmara Anterior , Comprimento Axial do Olho , Biometria , Humanos , Interferometria , Estudos Prospectivos , Reprodutibilidade dos Testes
12.
Curr Eye Res ; 41(9): 1223-8, 2016 09.
Artigo em Inglês | MEDLINE | ID: mdl-26765040

RESUMO

PURPOSE: To study whether there exists a relationship between retinal nerve fiber layer thickness and oxygen saturation and to identify whether perivascular thickness (pRNFL) or quadrant thickness (qRNFL) has a stronger correlation. METHODS: Patients without any detectable ocular abnormality on complete ophthalmic evaluation underwent non-invasive photo-spectrometric retinal oximetry on the Oxymap T1 retinal oximeter (Oxymap hf, Reykjavik, Iceland) and spectral-domain optical coherence tomography to determine if the pRNFL (Spectralis, Heidelberg, Germany) and the qRNFL (RtVue, Optovue) correlated with the measured light intensities and the calculated retinal oxygen saturations. RESULTS: 30 eyes of 30 patients (120 arterioles, 120 venules) were included in the study. The mean arteriolar saturations (%) were temporal: 84.5 (95% CI 82.7-86.3) and nasal: 93.5 (95% CI 91.0-95.8); venous saturations were temporal: 54.4 (95% CI 52.9-55.9) and nasal: 59.9 (95% CI 58.3-61.4). The mean pRNFL thickness (µm) around arterioles was temporal: 153.1 (95% CI 146-159) and nasal: 109.4 (95% CI 103-115); around venules it was temporal: 147.4 (95% CI 140-154) and nasal: 101.2 (95% CI 95-107). The oxygen saturations correlated significantly with pRNFL (arteriolar r = -0.514; p < 0.001 and venous r = -0.513; p < 0.001) but did not show a significant correlation with qRNFL values. CONCLUSION: This relationship between perivascular RNFL could be physiological or artifactual. If physiological, it would explain and form the basis of altered oxygen saturation in a multitude of diseases. If artifactual, it would necessitate the incorporation of a pRNFL correction. However, the results of this study enable us to expect increased saturation in areas of thinner RNFL or vice versa with the current methodology of retinal vessel oximetry as obtained by dual-wavelength photo-spectrometric fundus imaging.


Assuntos
Fibras Nervosas/metabolismo , Consumo de Oxigênio , Oxigênio/metabolismo , Células Ganglionares da Retina/citologia , Tomografia de Coerência Óptica/métodos , Adulto , Arteríolas , Feminino , Seguimentos , Humanos , Masculino , Oximetria/métodos , Estudos Prospectivos , Células Ganglionares da Retina/metabolismo , Vênulas
13.
Indian J Ophthalmol ; 63(5): 423-6, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-26139804

RESUMO

AIM: To assess the variations in cone mosaic in myopia and its correlation with axial length (AL). SUBJECTS AND METHODS: Twenty-five healthy myopic volunteers underwent assessment of photoreceptors using adaptive optics retinal camera at 2° and 3° from the foveal center in four quadrants superior, inferior, temporal and nasal. Data was analyzed using SPSS version 17 (IBM). Multivariable regression analysis was conducted to study the relation between cone density and AL, quadrant around the fovea and eccentricity from the fovea. RESULTS: The mean cone density was significantly lower as the eccentricity increased from 2° from the fovea to 3° (18,560 ± 5455-16,404 ± 4494/mm 2 respectively). There was also a statistically significant difference between four quadrants around the fovea. The correlation of cone density and spacing with AL showed that there was a significant inverse relation of AL with the cone density. CONCLUSION: In myopic patients with good visual acuity cone density around the fovea depends on the quadrant, distance from the fovea as well as the AL. The strength of the relation of AL with cone density depends on the quadrant and distance.


Assuntos
Comprimento Axial do Olho/patologia , Fóvea Central/patologia , Miopia/patologia , Óptica e Fotônica , Células Fotorreceptoras Retinianas Cones/patologia , Tomografia de Coerência Óptica/instrumentação , Adulto , Contagem de Células , Feminino , Humanos , Masculino , Adulto Jovem
14.
Indian J Ophthalmol ; 63(5): 432-7, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-26139806

RESUMO

PURPOSE: To report the impact of transient, self-resolving, untreated "macular edema" detected on spectral domain optical coherence tomography in Asian Indian premature infants with retinopathy of prematurity (ROP) on visual acuity (VA) and refraction at 1-year of corrected age. MATERIALS AND METHODS: Visual acuity and refraction of 11 infants with bilateral macular edema (Group A) was compared with gestational age-matched 16 infants with ROP without edema (Group B) and 17 preterms infants without ROP and without edema (Group C) at 3, 6, 9 and 12 months of corrected age using Teller Acuity Cards and cycloplegic retinoscopy. Sub-group analysis of the previously described pattern A and B macular edema was performed. RESULTS: Visual acuity was lower in infants with macular edema compared with the other two control groups throughout the study period, but statistically significant only at 3 months. Visual improvement in these infants was highest between the 3 rd and 6 th month and plateaued by the end of the 1 st year with acuity comparable to the other two groups. The edema cohort was more hyperopic compared to the other two groups between 3 and 12 months of age. Pattern A edema had worse VA compared to pattern B, although not statistically significant. CONCLUSION: Macular edema, although transient, caused reduced VA as early as 3 months of corrected age in Asian Indian premature infants weighing <2000 g at birth. The higher hyperopia in these infants is possibly due to visual disturbances caused at a critical time of fovealization. We hypothesize a recovery and feedback mechanism based on the principles of active emmetropization to explain our findings.


Assuntos
Recém-Nascido Prematuro , Edema Macular/etnologia , Refração Ocular , Retinopatia da Prematuridade/etnologia , Acuidade Visual , Ásia/etnologia , Feminino , Seguimentos , Idade Gestacional , Humanos , Incidência , Índia/epidemiologia , Lactente , Recém-Nascido , Edema Macular/etiologia , Edema Macular/fisiopatologia , Masculino , Prevalência , Retinopatia da Prematuridade/complicações , Retinopatia da Prematuridade/fisiopatologia , Fatores de Tempo , Tomografia de Coerência Óptica
15.
J Mech Behav Biomed Mater ; 48: 173-182, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25955559

RESUMO

With the advent of newer techniques to correct refraction such as flapless laser procedure and collagen crosslinking, in vivo estimation of corneal biomechanical properties has gained importance. In this study, a new 3-D patient specific inverse finite element method of estimating corneal biomechanical properties from air-puff applanation was developed. The highlight of the model was inclusion of patient-specific corneal tomography, fiber dependent hyperelastic model, cross links between collagen lamellae and epithelium layer. A lumped mass, spring and dashpot model was included to model the resistance to motion and deformation of the eye globe caused by air-puff applanation. 10 normal eyes of 10 human subjects were used for the study. 3-D finite element models were constructed and custom routines were scripted for performing the inverse calculations. The model for each eye was perturbed to estimate the effect of measured intraocular pressure on the estimated biomechanical variables. The study demonstrated that the inverse method was effective in quantification of material properties and was sensitive to intraocular pressure alterations. Specifically, in vivo fiber dependent hyperelastic biomechanical properties of human corneas were estimated for the first time.


Assuntos
Córnea/fisiologia , Modelos Biológicos , Fenômenos Biomecânicos/fisiologia , Elasticidade , Análise de Elementos Finitos , Humanos , Pressão Intraocular , Tonometria Ocular
17.
Indian J Ophthalmol ; 62(1): 23-8, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24492498

RESUMO

PURPOSE: To create a nomogram for the insertion of intrastromal corneal ring segments (ICRS) (Intacs) in eyes with keratoconus. SETTING: Tertiary eye care center in South India. MATERIALS AND METHODS: This prospective, non-randomized, interventional case series used a self-designed decision-making nomogram for the selection of ICRS in keratoconus patients based on the centration of the cone, mean refractive spherical equivalent (MRSE), and mean keratometry (Km) values. The 3, 6, and 12 months clinical outcomes were compared to historical controls. Primary endpoints were improvement in uncorrected and best-corrected vision and change in the keratometric values. RESULTS: Group A comprised of 52 eyes of 50 patients that followed the nomogram, while Group B comprised of 25 eyes of 23 non-nomogram historical controls matched for baseline parameters.In Group A, the uncorrected distance visual acuity (UDVA) improved from 0.16 ± 0.15 to 0.25 ± 0.16 (P < 0.001), corrected distance visual acuity (CDVA) from 0.58 ± 0.2 to 0.69 ± 0.21 (P = 0.022), MRSE from -5.41 ± 4.94 to -1.71 ± 2.88 (P < 0.001), Km from 51.77 ± 5.45 to 48.63 ± 4.37 (P < 0.001), and astigmatism reduced from 5.86 ± 2.61 to 4.91 ± 2.72 diopters (P < 0.001).In Group B, improvement in the average MRSE was from -6.44 ± 5.32 to -3.26 ± 2.82 (P < 0.013) and in the average Km from 53.64 ± 5.32 to 50.31 ± 5.02 (P < 0.001). Other parameters did not improve significantly.A statistically significant difference was present in the percentage of patients achieving a good clinical outcome between the two groups (P < 0.001; Chi-square). CONCLUSION: The nomogram provides a means to choose the appropriate ICRS, hence improving the outcome in patients with keratoconus.


Assuntos
Substância Própria/cirurgia , Tomada de Decisões , Ceratocone/cirurgia , Próteses e Implantes , Adulto , Substância Própria/patologia , Topografia da Córnea , Feminino , Seguimentos , Humanos , Ceratocone/patologia , Ceratocone/fisiopatologia , Masculino , Nomogramas , Estudos Prospectivos , Refração Ocular , Acuidade Visual , Adulto Jovem
18.
Indian J Ophthalmol ; 62(1): 41-9, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24492500

RESUMO

AIM: To report the Karnataka Internet Assisted Diagnosis of Retinopathy of Prematurity (KIDROP) program for retinopathy of prematurity (ROP) screening in underserved rural areas using an indigenously developed tele-ROP model. MATERIALS AND METHODS: KIDROP currently provides ROP screening and treatment services in three zones and 81 neonatal units in Karnataka, India. Technicians were trained to use a portable Retcam Shuttle (Clarity, USA) and validated against ROP experts performing indirect ophthalmoscopy. An indigenously developed 20-point score (STAT score) graded their ability (Level I to III) to image and decide follow-up based on a three-way algorithm. Images were also uploaded on a secure tele-ROP platform and accessed and reported by remote experts on their smart phones (iPhone, Apple). RESULTS: 6339 imaging sessions of 1601 infants were analyzed. A level III technician agreed with 94.3% of all expert decisions. The sensitivity, specificity, positive predictive value and negative predictive value for treatment grade disease were 95.7, 93.2, 81.5 and 98.6 respectively. The kappa for technicians to decide discharge of babies was 0.94 (P < 0.001). Only 0.4% of infants needing treatment were missed.The kappa agreement of experts reporting on the iPhone vs. Retcam for treatment requiring and mild ROP were 0.96 and 0.94 (P < 0.001) respectively. CONCLUSIONS: This is the first and largest real-world program to employ accredited non-physicians to grade and report ROP. The KIDROP tele-ROP model demonstrates that ROP services can be delivered to the outreach despite lack of specialists and may be useful in other middle-income countries with similar demographics.


Assuntos
Diagnóstico por Computador/normas , Internet , Oftalmoscopia/normas , Guias de Prática Clínica como Assunto , Retinopatia da Prematuridade/diagnóstico , Telemedicina/métodos , Seleção Visual/métodos , Humanos , Incidência , Índia/epidemiologia , Recém-Nascido , Projetos Piloto , Retinopatia da Prematuridade/epidemiologia , Telemedicina/normas , Seleção Visual/normas , Tecnologia sem Fio/normas
19.
Indian J Dent Res ; 24(4): 411-7, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24047831

RESUMO

AIM: To evaluate the changes in surface roughness and frictional features of 'ion-implanted nickel titanium (NiTi) and titanium molybdenum alloy (TMA) arch wires' from its conventional types in an in-vitro laboratory set up. MATERIALS AND METHODS: 'Ion-implanted NiTi and low friction TMA arch wires' were assessed for surface roughness with scanning electron microscopy (SEM) and 3 dimensional (3D) optical profilometry. Frictional forces were studied in a universal testing machine. Surface roughness of arch wires were determined as Root Mean Square (RMS) values in nanometers and Frictional Forces (FF) in grams. STATISTICAL ANALYSIS USED: Mean values of RMS and FF were compared by Student's 't' test and one way analysis of variance (ANOVA). RESULTS: SEM images showed a smooth topography for ion-implanted versions. 3D optical profilometry demonstrated reduction of RMS values by 58.43% for ion-implanted NiTi (795.95 to 330.87 nm) and 48.90% for TMA groups (463.28 to 236.35 nm) from controls. Nonetheless, the corresponding decrease in FF was only 29.18% for NiTi and 22.04% for TMA, suggesting partial correction of surface roughness and disproportionate reduction in frictional forces with ion-implantation. Though the reductions were highly significant at P < 0.001, relations between surface roughness and frictional forces remained non conclusive even after ion-implantation. CONCLUSION: The study proved that ion-implantation can significantly reduce the surface roughness of NiTi and TMA wires but could not make a similar reduction in frictional forces. This can be attributed to the inherent differences in stiffness and surface reactivity of NiTi and TMA wires when used in combination with stainless steel brackets, which needs further investigations.


Assuntos
Ligas/química , Níquel/química , Fios Ortodônticos , Titânio/química , Íons , Propriedades de Superfície
20.
Indian J Ophthalmol ; 61(8): 451-5, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23925336

RESUMO

UNLABELLED: Keratoconus is a progressive corneal ectasia, which can be managed both by conservative measures like glasses or contact lenses in non-progressive cases or surgical procedures like collagen crosslinking (CXL) with or without adjuvant measures like intrastromal corneal rings segments (ICRS) or topography guided ablation. Various kinds of ICRS are available to the surgeon, but it is most essential to be able to plan the implantation of the ring to optimize outcomes. AIMS: The aim of this study is to evaluate the visual outcome and progression in patients of keratoconus implanted with ICRS. MATERIALS AND METHODS: Two different types of ICRS-Intacs (Addition Technology) and Kerarings (Mediphacos Inc.) were implanted in 2 different cohorts of patients and were followed-up to evaluate the outcome of the procedure. All patients underwent a complete ocular examination including best spectacle corrected visual acuity, slit lamp examination fundus examination, corneal topography and pachymetry. The ICRS implantation is done with CXL to stop the progression of the disease. Improvement in uncorrected visual acuity (UCVA), best spectacle corrected visual acuity and topographic changes were analyzed. RESULTS: A significant improvement in keratometry and vision was seen in both groups. CONCLUSION: ICRS have been found to reduce corneal irregularity and flatten keratometry with improvement in UCVA and best corrected visual acuity.


Assuntos
Substância Própria/cirurgia , Ceratocone/cirurgia , Polimetil Metacrilato , Próteses e Implantes , Implantação de Prótese , Adulto , Topografia da Córnea , Humanos , Ceratocone/diagnóstico , Ceratocone/fisiopatologia , Masculino , Refração Ocular/fisiologia , Resultado do Tratamento , Transtornos da Visão/reabilitação , Acuidade Visual
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