24 research outputs found
Association between retinal vein occlusion, axial length and vitreous chamber depth measured by optical low coherence reflectometry.
BACKGROUND: Results of ocular biometric measurements in retinal vein occlusion (RVO) eyes are still inconclusive and controversial. The aim of this study was to evaluate the association between ocular axial length (AL), vitreous chamber depth (VCD) and both central (CRVO) and branch retinal vein occlusions (BRVO) using optical low coherence reflectometry (OLCR). METHODS: Both eyes of 37 patients with unilateral CRVO (mean age: 66 +/- 14 years, male:female - 21:16) and 46 patients with unilateral BRVO (mean age: 63 +/- 12 years, male:female - 24:22) were enrolled in this study. The control group consisted of randomly selected single eyes of 67 age and gender matched volunteers without the presence or history of RVO (mean age: 64 +/- 14 years, male:female - 34:33). Optical biometry was performed by OLCR biometer (LenStar LS 900). Average keratometry readings, central corneal thickness (CCT), anterior chamber depth (ACD), lens thickness (LT), AL and VCD of eyes with RVO were compared with those of fellow eyes using paired t-tests and with those of control eyes using independent t-tests. RESULTS: Mean CCT, ACD and LT, average keratometry readings of affected RVO eyes, unaffected fellow eyes and control eyes was not statistically different in either groups. In eyes with CRVO mean AL and VCD of affected eyes were significantly shorter than those of control eyes (p < 0.001, p < 0.05), mean difference in AL and VCD between the affected and control eyes was 0.56 +/- 0.15 mm and 0.45 +/- 0.19 mm, respectively. In eyes with BRVO, mean AL of the affected eyes was significantly shorter with a mean difference of 0.57 +/- 0.15 mm (p < 0.001) and the VCD was significantly shorter with a mean difference of 0.61 +/- 0.15 mm (p < 0.001) comparing with the control eyes. CONCLUSION: Shorter AL and VCD might be a potential anatomical predisposing factor for development either of CRVO or BRVO
Inferior Spear-like Lens Opacity as A Sign of Keratoconus
Purpose: To report 21 cases of typical inferior feather-shape lens opacity associated with keratoconus.
Methods: In this cross-sectional study, we evaluated the association of keratoconus with inferior feather-shape lens opacity in refractive surgery candidates. Visual acuity, demographic, refractive, and topographic characteristics of 26 eyes of 21 patients with inferior feather-shape lens opacity were evaluated in detail. Pedigree analysis was also performed to assess possible inheritance.
Results: Overall, 2122 out of 33,368 cases (6.4%) without lens opacity had keratoconus, while 20 out of 21 patients (95.2%) with peculiar lens opacity had definite keratoconus (P < 0.001). Lens opacity was bilateral in 5 cases (24%), and keratoconus was bilateral in all 20 patients with lens opacity. Nine eyes out of thirty-six with a complete data record (25%) had severe keratoconus and underwent deep lamellar keratoplasty, while 11 (31%) had forme fruste keratoconus. Pedigrees were drawn for eight patients, most families of whom suggested an X-linked recessive inheritance.
Conclusion: The present study was the first to investigate patients with a peculiar inferior feather-shape lens opacity accompanied by bilateral keratoconus, which was observed in 95% of the patients. This finding should raise awareness as to the possibility of diagnosing keratoconus in the eyes of the patients with these characteristics
Corneal Parameters in Healthy Subjects Assessed by Corvis ST
Purpose: To evaluate corneal biomechanics using Corvis ST in healthy eyes from Iranian keratorefractive surgery candidates.
Methods: In this prospective consecutive observational case series, the intraocular pressure (IOP), central corneal thickness (CCT), and biomechanical properties of 1,304 eyes from 652 patients were evaluated using Corvis ST. Keratometric readings and manifest refraction were also recorded.
Results: The mean (±SD) age of participants was 28 ± 5 years, and 31.7% were male. The mean spherical equivalent refraction was –3.50 ± 1.57 diopters (D), the mean IOP was 16.8 ± 2.9 mmHg, and the mean CCT was 531 ± 31 μm for the right eye. The respective means (±SD) corneal biomechanical parameters of the right eye were as follows: first applanation time: 7.36 ± 0.39 milliseconds (ms); first applanation length: 1.82 ± 0.22 mm; velocity in: 0.12 ± 0.04 m/s; second applanation time: 20.13 ± 0.48 ms; second applanation length: 1.34 ± 0.55 mm; velocity out: –0.67 ± 0.17 m/s; total time: 16.84 ± 0.64 ms; deformation amplitude: 1.05 ± 0.10 mm; peak distance: 4.60 ± 1.01 mm; and concave radius of curvature: 7.35 ± 1.39 mm. In the linear regression analysis, IOP exhibited a statistically significant association with the first and second applanation times, total time, velocity in, peak distance, deformation amplitude, and concave radius of curvature.
Conclusion: Our study results can be used as a reference for the interpretation of Corvis ST parameters in healthy refractive surgery candidates in the Iranian population. Our results confirmed that IOP is a major determinant of Corvis parameters
In vitro evaluation of actively targetable superparamagnetic nanoparticles to the folate receptor positive cancer cells
Engineering of a physiologically compatible, stable and targetable SPIONs-CA-FA formulation was reported. Initially fabricated superparamagnetic iron oxide nanoparticles (SPIONs) were coated with citric acid (CA) to hamper agglomeration as well as to ameliorate biocompatibility. Folic acid (FA) as a targeting agent was then conjugated to the citric acid coated SPIONs (SPIONs-CA) for targeting the specific receptors expressed on the FAR + cancer cells. Physiochemical characterizations were then performed to assure required properties like stability, size, phase purity, surface morphology, chemical integrity and magnetic properties. In vitro evaluations (MTT assay) were performed on HeLa, HSF 1184, MDA-MB-468 and MDA-MB-231cell lines to ensure the biocompatibility of SPIONs-CA-FA. There were no morphological changes and lysis in contact with erythrocytes recorded for SPIONs-CA-FA and SPIONs-CA. High level of SPIONs-CA-FA binding to FAR + cell lines was assured via qualitative and quantitative in vitro binding studies. Hence, SPIONs-CA-FA was introduced as a promising tool for biomedical applications like magnetic hyperthermia and drug delivery. The in vitro findings presented in this study need to be compared with those of in vivo studies
Radioimmunoscintigraphy of Breast Tumor Xenografts in Mouse Model by 99mTc Direct Radiolabeling of a Monoclonal Antibody PR81
Introduction: The radioimmunoscintigraphy (RIS) has found widespread clinical applications in
tumor diagnosis. Human epithelial mucin, MUC1, is commonly over expressed in
adenocarcinoma including 80% of breast cancers and represents a useful target for RIS. The PR81
is a new murine anti-MUC1 monoclonal antibody that was found to react with the membrane
extracts of several human breast cancerous tissues and the cell surface of some MUC1 positive
cell lines. In this study, a direct method which is very simple, rapid and efficient for the labeling
of this MAb with
99m
Tc, particularly suitable for the development of a ‘kit’, was developed. The
quality control of new radiopharmaceutical and immunoscintigraphy studies in BALB/c mice
bearing breast tumor xenografts were also performed.
Materials and Methods: The Ab reduction was performed with 2-mercaptoethanol (2-ME) at a
molar ratio of 2000:1 (2-ME:MAb) and reduced Ab was labeled with
99m
Tc via methylene
diphosphonate (MDP) as a transchelator. The labeling efficiency was determined by ITLC. The
amount of radiocolloids was measured by cellulose nitrate electrophoresis. The stability of the
labeled product was checked in fresh human serum by gel filtration chromatography (FPLC) over
24 hrs. The integrity of the labeled MAb was checked by the means of SDS-PAGE. Cell-binding
assay was used to test the binding ability of
99m
Tc-PR81 to MCF7 cells. Biodistribution was
studied in normal BALB/c mice at 4 and 24 hrs post-injection. The tumor imaging was performed
in female BALB/c mice with breast tumor xenografts 24 hrs after the new complex injection.
Results: The labeling efficiency was 94.2%±2.3 and radiocolloids were 2.5%±1.7. In vitro
stability was 70%±5.7 in fresh human serum over 24 hrs. There was no significant Ab
fragmentation due to the labeling procedure. Both the labeled and unlabeled PR81 were able to
compete for binding to MCF7 cells. The biodistribution studies in normal BALB/c mice showed
that there was no important accumulation in any organ. The immunoscintigraphy studies
demonstrated definite localization of the preparation at the site of tumors with high sensitivity.
Discussion and Conclusion: The results show that by using the Schwarz method of radiolabeling
MAb PR81, a labeling yield higher than 90% with high stability of the complex in human serum
can be obtained. These findings demonstrated that the new radiopharmaceutical can be considered
as a promising candidate for imaging of human breast cancer