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2. Frequency of obsessive-compulsive disorder in schizophrenic patients according to structural clinical interview (SCID)

Author

Pakravan M, Ghalebandi MF, Alavi K, and Afkham Ebrahimi A

Subjects
OCD, Schizophrenia, Clinical Interview, Medicine, Medicine (General), R5-920
Abstract

Background&Objective: The life time prevalence of schizophrenia is estimated about 1%-1.5% in United States and various studies have shown that between 7.8-46.6% of these patients suffer from OCD. The differences in these statistics are partly due to the assessment and treatment methods. The purpose of this study was to measure the frequency of OCD in hospitalized schizophrenic patients. Materials&Methods: The study was cross-sectional. 96 inpatients (56 men and 40 women) with DSM-IV schizophrenia diagnostic criteria were selected from Iran Psychiatry Hospital by simple non-random sampling Results: The age range of the patients were 17-73 with a mean age of 35 ±12.6. The majority of patients (88.5%) suffered from paranoid schizophrenia. 47 patients (49%) were diagnosed to have obsessive-compulsive symptoms on interview. The mean age of schizophrenia onset was 24.7 ±8.8 and the mean age of OCD onset in schizophrenic patients was 20.2 ±6.7. In 8 (17%), the two disorders were began simultaneously and in 20 (20.8%), schizophrenia was started earlier. Conclusion: Obsessive-compulsive symptoms are completely prevalent in schizophrenia. The co morbidity of these two clinical entities has both etiological and therapeutic importance.

Published
2007

4. Nutritional messages in Iranian newspapers: a content analysis

Author

Mohammad Pour- Ahranjani B, Abdollahi M, and Pakravan M

Subjects
nutritional messages, content analysis, newspapers, health education, Medicine, Medicine (General), R5-920
Abstract

Objectiv(s): To evaluate the nutritional messages in Iranian newspapers. Material & Methods: A content analysis study was conducted on 192 issues of 8 largest national daily newspapers using a systematic monthly content analysis from March 1999 to March 2000. A coding form was devised to tabulate information. All messages related to food and nutrition was recorded by 5 trained nutritionists and double-checked by a senior nutritionist and a communication expert. Results: In total, 122 nutritional messages were found with a mean of 0.65 messages per issue and total printed surface of0.3%. In terms of style, 64.8, 1.6, 4.9 and 28.7% of messages classified as news, reports, articles and as others, respectively. The most frequent topic was food safety (35.3%), followed by nutrition related disorders (17.6%) and food properties (14%). While about 70% of messages were scientific-based, 17% identified as ambiguous. About 40% of messages were written by a nutritionist or an allied expert. The target audience for 75% of messages was the general public. Only 1 message was written in a non-popular language. About 30% of messages contained promotional statements, while 47.5% presented bleak news. Messages cited from different resources, from which Islamic Republic of Iran News Agency (18.9%), four major news agencies (UP, AP, Reuters and France Press) (1.6%), international and national organizations (23%) and Internet (1.6%) were foremost. Conclusion: According to this study, it seems that both quantity and quality of nutritional messages in most popular newspapers are not public - oriented.

Published
2003

5. Coordinated multivoxel coding beyond univariate effects is not likely to be observable in fMRI data

Author

Ali Ghazizadeh and Pakravan M

Subjects
Multivariate statistics, medicine.diagnostic_test, business.industry, Computer science, Univariate, Pattern analysis, Observable, Cognition, Pattern recognition, computer.software_genre, Voxel, medicine, Artificial intelligence, business, Functional magnetic resonance imaging, computer, Coding (social sciences)
Abstract

Simultaneous recording of activity across brain regions can contain additional information compared to regional recordings done in isolation. In particular, multivariate pattern analysis (MVPA) across voxels has been interpreted as evidence for distributed coding of cognitive or sensorimotor processes beyond what can be gleaned from a collection of univariate responses (UVR) using functional magnetic resonance imaging (fMRI). Here, we argue that regardless of patterns revealed, conventional MVPA is merely a decoding tool with increased sensitivity arising from considering a large number of ‘weak classifiers’ (i.e. single voxels) in higher dimensions. We propose instead that ‘real’ multivoxel coding should result in changes in higher-order statistics across voxels between conditions such as second-order multivariate responses (sMVR). Surprisingly, analysis of conditions with robust multivariate responses (MVR) revealed by MVPA failed to show significant sMVR in two species (humans and macaques). Further analysis showed that while both MVR and sMVR can be readily observed in the spiking activity of neuronal populations, the slow and nonlinear hemodynamic coupling and low spatial resolution of fMRI activations make the observation of higher-order statistics between voxels highly unlikely. These results reveal inherent limitations of fMRI signals for studying coordinated coding across voxels. Together, these findings suggest that care should be taken in interpreting significant MVPA results as representing anything beyond a collection of univariate effects.

Published
2021
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9. Ranunculus polyrhizos as a new record for Iran, with ecological and micromorphological evidence

Author

Bidarlord M., Gahremaninejad F., and Pakravan M.

Subjects
Ranunculus polyrhizos, flora, lcsh:Botany, Talesh Mountains, new record, autoecology, lcsh:QK1-989
Abstract

Ranunculus polyrhizos is reported as a new noteworthy record for the flora of Iran. This species was collected from alpine dry gravelly slope in Talesh Mountains. Taxonomic remarks and notes geographical distribution and habitat for this species are provided. Moreover nectar scale, pollen and achene micromorphological characters of the species are added and compared with related species.

Published
2016

10. Mitomycin-C Trabeculectomy versus Ahmed Glaucoma Implant in Pediatric Aphakic Glaucoma

Author

Pakravan, M., Homayoun Nikkhah, Baradaran-Rafii, A., and Yazdani, S.

Subjects
lcsh:Ophthalmology, lcsh:RE1-994
Abstract

PURPOSE: To compare the outcomes and complications of mitomycin-C trabeculectomy (MMC-T) versus the Ahmed glaucoma implant (AGI) for treatment of pediatric aphakic glaucoma. METHODS: In a randomized clinical trial, 30 eyes of 28 children < 16 years of age who had undergone anterior lensectomy-vitrectomy for congenital cataract were assigned to MMC-T (15 eyes of 13 children) or AGI (15 eyes of 15 children). Surgical success was classified as complete (IOP 6-21 mmHg without any antiglaucoma medication) and partial (IOP 6-21 mmHg with < 2 topical antiglaucoma agents) in the absence of any sight-threatening complication or need for further glaucoma surgery, stable cup/disc ratios and visual loss < 2 Snellen lines. Overall success was defined as the sum of complete and partial success. RESULTS: Mean patient age was 9.1±4.1 and 10.9±5.1 years in the MMC-T and AGI groups, respectively (P=0.29). After a mean follow up of 14.8±11 and 13.1±9.7 months; complete, partial and overall success rates were 33.3%, 40% and 73.3% in the MMC-T vs 20%, 66.7% and 86.7% in the AGI groups, respectively (P= 0.361). Complication and failure rates were 40% and 26.7% in the MMC-T group vs 26.7% and 13.3% in the AGI group, respectively (P= 0.439). CONCLUSION: MMC-T and AGI seem to be comparable in terms of success and complications as the initial surgical procedure in pediatric aphakic glaucoma. Choice of either technique depends on surgeon's experience and conjunctival quality and mobility.

Published
2008

12. Genetic association study of exfoliation syndrome identifies a protective rare variant at LOXL1 and five new susceptibility loci

Author

Aung, T., Ozaki, M., Lee, M.C., Schlotzer-Schrehardt, U., Thorleifsson, G., Mizoguchi, T., Igo, R.P., Jr., Haripriya, A., Williams, S.E., Astakhov, Y.S., Orr, A.C., Burdon, K.P., Nakano, S., Mori, K., Abu-Amero, K., Hauser, M., Li, Z., Prakadeeswari, G., Bailey, J.N., Cherecheanu, A.P., Kang, J.H., Nelson, S., Hayashi, K., Manabe, S.I., Kazama, S., Zarnowski, T., Inoue, K., Irkec, M., Coca-Prados, M., Sugiyama, K., Jarvela, I., Schlottmann, P., Lerner, S.F., Lamari, H., Nilgun, Y., Bikbov, M., Park, K.H., Cha, S.C., Yamashiro, K., Zenteno, J.C., Jonas, J.B., Kumar, R.S.S., Perera, S.A., Chan, A.S.Y., Kobakhidze, N., George, R., Vijaya, L., Do, T., Edward, D.P., Juan Marcos, L. de, Pakravan, M., Moghimi, S., Ideta, R., Bach-Holm, D., Kappelgaard, P., Wirostko, B., Thomas, S., Gaston, D., Bedard, K., Greer, W.L., Yang, Z, Chen, X., Huang, L., Sang, J., Jia, H., Jia, L., Qiao, C., Zhang, H., Liu, X., Zhao, B., Wang, Y.X., Xu, L., Leruez, S., Reynier, P., Chichua, G., Tabagari, S., Uebe, S., Zenkel, M., Berner, D., Mossbock, G., Weisschuh, N., Hoja, U., Welge-Luessen, U.C., Mardin, C., Founti, P., Chatzikyriakidou, A., Pappas, T., Anastasopoulos, E., Lambropoulos, A., Ghosh, A., Shetty, R., Porporato, N., Saravanan, V., Venkatesh, R., Shivkumar, C., Kalpana, N., Sarangapani, S., Kanavi, M.R., Beni, A.N., Yazdani, S., Hollander, A.I. den, Pasutto, F., Khor, C.C., Aung, T., Ozaki, M., Lee, M.C., Schlotzer-Schrehardt, U., Thorleifsson, G., Mizoguchi, T., Igo, R.P., Jr., Haripriya, A., Williams, S.E., Astakhov, Y.S., Orr, A.C., Burdon, K.P., Nakano, S., Mori, K., Abu-Amero, K., Hauser, M., Li, Z., Prakadeeswari, G., Bailey, J.N., Cherecheanu, A.P., Kang, J.H., Nelson, S., Hayashi, K., Manabe, S.I., Kazama, S., Zarnowski, T., Inoue, K., Irkec, M., Coca-Prados, M., Sugiyama, K., Jarvela, I., Schlottmann, P., Lerner, S.F., Lamari, H., Nilgun, Y., Bikbov, M., Park, K.H., Cha, S.C., Yamashiro, K., Zenteno, J.C., Jonas, J.B., Kumar, R.S.S., Perera, S.A., Chan, A.S.Y., Kobakhidze, N., George, R., Vijaya, L., Do, T., Edward, D.P., Juan Marcos, L. de, Pakravan, M., Moghimi, S., Ideta, R., Bach-Holm, D., Kappelgaard, P., Wirostko, B., Thomas, S., Gaston, D., Bedard, K., Greer, W.L., Yang, Z, Chen, X., Huang, L., Sang, J., Jia, H., Jia, L., Qiao, C., Zhang, H., Liu, X., Zhao, B., Wang, Y.X., Xu, L., Leruez, S., Reynier, P., Chichua, G., Tabagari, S., Uebe, S., Zenkel, M., Berner, D., Mossbock, G., Weisschuh, N., Hoja, U., Welge-Luessen, U.C., Mardin, C., Founti, P., Chatzikyriakidou, A., Pappas, T., Anastasopoulos, E., Lambropoulos, A., Ghosh, A., Shetty, R., Porporato, N., Saravanan, V., Venkatesh, R., Shivkumar, C., Kalpana, N., Sarangapani, S., Kanavi, M.R., Beni, A.N., Yazdani, S., Hollander, A.I. den, Pasutto, F., and Khor, C.C.

Abstract

Item does not contain fulltext, Exfoliation syndrome (XFS) is the most common known risk factor for secondary glaucoma and a major cause of blindness worldwide. Variants in two genes, LOXL1 and CACNA1A, have previously been associated with XFS. To further elucidate the genetic basis of XFS, we collected a global sample of XFS cases to refine the association at LOXL1, which previously showed inconsistent results across populations, and to identify new variants associated with XFS. We identified a rare protective allele at LOXL1 (p.Phe407, odds ratio (OR) = 25, P = 2.9 x 10-14) through deep resequencing of XFS cases and controls from nine countries. A genome-wide association study (GWAS) of XFS cases and controls from 24 countries followed by replication in 18 countries identified seven genome-wide significant loci (P < 5 x 10-8). We identified association signals at 13q12 (POMP), 11q23.3 (TMEM136), 6p21 (AGPAT1), 3p24 (RBMS3) and 5q23 (near SEMA6A). These findings provide biological insights into the pathology of XFS and highlight a potential role for naturally occurring rare LOXL1 variants in disease biology.

Published
2017

13. Predictive value of early postoperative IOP and bleb morphology in Mitomycin-C augmented trabeculectomy

Author

Loewen, NA, Esfandiari, H, Pakravan, M, Yaseri, M, Loewen, NA, Esfandiari, H, Pakravan, M, and Yaseri, M

Abstract

Background: To determine the predictive value of postoperative bleb morphological features and intraocular pressure (IOP) on the success rate of trabeculectomy. Methods: In this prospective interventional case series, we analyzed for one year 80 consecutive primary open angle glaucoma patients who underwent mitomycin-augmented trabeculectomy. Bleb morphology was scored using the Indiana bleb appearance grading scale (IBAGS). Success was defined as IOP ≤15 mmHg at 12 months. We applied a multivariable regression analysis and determined the area under the receiver operating characteristic curve (AUC). Results: The mean age of participants was 62±12.3 years in the success and 63.2±16.3 years in the failure group (P= 0.430) with equal gender distribution (P=0.911). IOPs on day 1, 7 and 30 were similar in both (P= 0.193, 0.639, and 0.238, respectively.) The AUC of IOP at day 1, day 7 and 30 for predicting a successful outcome was 0.355, 0.452, and 0.80, respectively. The AUC for bleb morphology parameters of bleb height, extension, and vascularization, on day 14 were 0.368, 0.408, and 0.549, respectively. Values for day 30 were 0.428, 0.563, and 0.654. IOP change from day 1 to day 30 was a good predictor of failure (AUC=0.838, 95% CI: 0.704 to 0.971) with a change of more than 3 mmHg predicting failure with a sensitivity of 82.5% (95% CI: 68 to 91%) and a specificity of 87.5% (95% CI: 53 to 98%). Conclusions: IOP on day 30 had a fair to good accuracy while bleb features failed to predict success except bleb vascularity that had a poor to fair accuracy. An IOP increase more than 3 mmHg during the first 30 days was a good predictor of failure.

Published
2017

14. Indoor Wireless Infrared Channel Characterization by Measurements

Author

Pakravan, M. R., Kavehrad, Mohsen, and Hashemi, H.

Subjects
Wireless communication systems -- Research, Infrared communications -- Research, Business, Electronics, Electronics and electrical industries, Transportation industry
Abstract

Use of infrared light for indoor wireless communications has received considerable attention recently. In this paper, we present results obtained from a large set of measurements performed at the University of Ottawa. We investigate impacts of receiver rotation and shadowing on the properties of indoor infrared channels. This paper contains a description of a measurement system developed and used throughout the experiments. Measurement results are used to find and present methods to estimate variations of channel path loss for small changes in the receiver direction, using statistical techniques. This would be useful for generating samples of channel path loss for system performance simulations and modulation analysis. Using the measurement results, it is shown that variations of channel path loss are smooth and a simple curve-fitting algorithm can be used to accurately interpolate intermediate values. It is also shown that for a receiver changing its elevation angle from 0 [degrees] to 180 [degrees], five points along the entire path are sufficient to predict variation of channel path loss for the entire rotation range. The results also demonstrate a correlation between the channel delay spread and channel path loss for both diffuse and line-of-sight configurations. A simple formula can provide an estimate of channel delay spread for a known path loss of a given configuration. It is demonstrated that variations of channel path loss for small changes of receiver rotation can be described by a Gamma distribution. This enables generation of samples of channel path loss under general conditions for system-level simulation algorithms. Measurements have also been performed to investigate effects of shadowing on indoor infrared channel characteristics. Some important parameters that specify the impact of shadowing on the channel characteristics are included in the measurement plans. Variations of channel path loss due to shadowing and due to these parameters are investigated and detailed results are reported. It is shown that shadowing affects the channel delay spread. For the measured shadowing results, it is shown that channel path loss and delay spread are correlated and their relationship is provided.

Published
2001

16. Pattern electroretinography in glaucoma suspects and early primary open angle glaucoma

Author

Jafarzadehpour, E., Radinmehr, F., Pakravan, M., Mirzajani, A., and Shahin Yazdani

Subjects
lcsh:Ophthalmology, genetic structures, lcsh:RE1-994, Glaucoma Suspect, Original Article, sense organs, Primary Open Angle Glaucoma, Pattern Electroretinography, eye diseases
Abstract

Purpose: To explore retinal ganglion cell (RGC) dysfunction in glaucoma suspects and patients with early primary open angle glaucoma (POAG) using pattern electroretinography (PERG). Methods: Twenty glaucoma suspects (glaucomatous optic disc appearance), 15 early POAG (based on abnormal discs and abnormal visual fields) and 16 normal controls were enrolled. Transient PERG was recorded in response to 0.8΀ and 16΀ black and white checkerboard stimuli. Amplitude and peak time (latency) of the P50 and N95 components of the PERG response, and the ratio of N95 amplitude in response to 0.8΀ and 16΀ checks were measured. Results: N95 peak time (latency) was significantly increased in both early manifest POAG and glaucoma suspects as compared to normal controls (P

Published
2013

19. Effect of glucosamine on intraocular pressure: a randomized clinical trial

Author

Esfandiari, H, Pakravan, M, Zakeri, Z, Ziaie, S, Pakravan, P, and Ownagh, V

Abstract

PurposeThe purpose of the study was to investigate ocular hypertensive effect of exogenous glucosamine in comparison with placebo in patients with osteoarthritis.Patients and methodsIn this double-masked randomized clinical trial, 88 patients with osteoarthritis were included. Forty-four patients were randomized into either glucosamine sulfate or the placebo group.Comprehensive ophthalmologic exam including intraocular pressure (IOP) at baseline, month 1, and 3 was performed. Ocular response analyzer parameters were also checked at baseline and month 3.ResultsThe mean IOP at the time of presentation was 12.4±2.7 mm Hg in glucosamine and 13±2.8 mm Hg in the placebo group (P=0.329). At month 1 the corresponding values were 12.6±2.4 and 12.9±2.4 mm Hg (P=0.868), and at 3 months follow-up were 13.5±2.3 and 13±2.7 mm Hg (P=0.002), respectively. About 34.1% in treatment and 12.5% in the placebo group had clinically significant (defined as ≥ 2 mm Hg) rise in IOP at final follow-up (P=0.023). Mean age in those with significant rise in IOP was 66 vs 57.7 years in patients with <2 mm Hg (P=0.034). The ORA parameters remained unchanged in both the groups during the course of study.ConclusionGlucosamine supplement therapy causes statistically significant rise of IOP, which is more pronounced in elderly patients. Clinical implication of this finding needs further evaluation.

Published
2017
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30. Assessment of reproducibility of Geometric Distortion in MRI based on phantom measurements.

Author

Kim, Sun I., Suh, Tae Suk, Magjarevic, R., Nagel, J. H., Ashkanmehr, M., Riyahi-Alam, Nader, Oghabian, M. A., Ghasemzadeh, A., Bakhtiary, M., Ghanaati, H., and Pakravan, M.

Abstract

Image distortion is one of the major deficits of magnetic resonance (MR) imaging for use in 3DMRI, velocity MRI, fMRI and radiotherapy treatment planning (RTTP). It is widely known the most obviously effect of inhomogenity of magnetic fields and the nonlinearity of gradient is the Geometric Distortion of MR tomograms. In this study, the accuracy of MR images considered by phantom study and the reproducibility of images evaluated by repeated phantom measurements. A cube-shaped Perspex phantom, 20×20×5 cm, was designed for measurement of geometric distortion. There is a grid pattern inside the phantom, with grid space of 10 mm, the thickness grids of 2 mm and the depth of 40 mm contains 4mM/l magnevist solution. MR scans were performed with two 1.5 Tesla super-conductive MR systems (Picker VISTA TM HPQ & GE Signa Echo Speed), using head coil. For Geometric Distortion reproducibility the T1W, PDW and T2W SE protocols with TR/TE=500ms/20ms, 1000ms/20ms, 1000ms/100ms respectively and ST/FOV/MATRIX/NEX=5mm/24cm/256×256/1 were used. The Geometric Distortion was measured manually and by an edge detection program in MATLAB. The geometric distortion generally tended to be large in peripheral area of the images than in central area in all images. Average of displacements in Picker MRI were 3 pixel in y and 1 pixel in x direction and in GE MRI were 1 pixel in x and y directions for 24 cm FOV (1 pixel=0.9mm). Since the positional variation were within 1 to 3 pixels for head coil, it will be possible to use this MR system in 3DMRI, velocity MRI, FMRI and RTTP. For decreasing of geometric distortion use of suitable coil and protocol are expected. [ABSTRACT FROM AUTHOR]

Published
2007
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34. Posterior ischemic optic neuropathy following percutaneous nephrolithotomy

Author

Pakravan, M., Kiavash, V., and Siamak Moradian

Subjects
lcsh:Ophthalmology, lcsh:RE1-994
Abstract

PURPOSE: To report a case of posterior ischemic optic neuropathy (PION) following percutaneous nephrolithotomy (PCNL). CASE REPORT: A 57-year-old man with history of diabetes mellitus, hyperlipidemia and mild anemia underwent PCNL for treatment of nephrolithiasis. He noticed painless visual loss in both eyes immediately after the procedure. Visual acuity was light perception, however ophthalmologic examinations were unremarkable and the optic discs were pink with no swelling. Visual fields were severely affected, but neuro-imaging was normal. Within three months, visual acuity and visual fields improved dramatically but the optic discs became slightly pale. CONCLUSION: This is the first report of PION following PCNL. PION is a rare cause of severe visual loss following surgery. Severe blood loss, hypotension, anemia and body position during surgery are the most important risk factors. Ophthalmologists, urologists and anesthesiologists should be aware of this condition and this rare possibility should be considered prior to surgery.

35. Scheimpflug imaging criteria for identifying eyes at high risk of acute angle closure

Author

Pakravan, M., Sharifipour, F., Shahin Yazdani, Koohestani, N., and Yaseri, M.

Subjects
Scheimpflug Imaging, genetic structures, lcsh:Ophthalmology, lcsh:RE1-994, Acute Angle Closure, Glaucoma, Original Article, sense organs, eye diseases
Abstract

Purpose: To compare anterior segment and ocular biometric parameters in unaffected fellow eyes of patients with a previous attack of acute angle closure (AAC), primary angle closure suspect (PACS) eyes, and normal eyes; and to identify eyes at high risk of AAC among primary angle closure suspects. Methods: In this case-control study, 16 unaffected fellow eyes of patients with a previous attack of AAC (group I), 20 PACS eyes (group II) and 18 normal eyes (group III) underwent Pentacam and A-scan echography. Results: Mean anterior chamber volume was 72±18, 77±18 and 176±44 μl in groups I, II, and III, respectively (P0.05). Conclusion: Eyes with anterior chamber volume ≤100 μl, depth ≤2.1 mm and angle ≤26° may be considered at high risk for developing AAC. These criteria could be helpful for making decisions regarding prophylactic laser peripheral iridotomy.

36. Single versus two-site phacoemulsification and mitomycin-C trabeculectomy

Author

Baradaran-Rafiee, A., Shahin Yazdani, Feizi, S., and Pakravan, M.

Subjects
genetic structures, lcsh:Ophthalmology, lcsh:RE1-994
Abstract

PURPOSE: To compare the outcomes of single-site versus two-site mitomycin-C (MMC) augmented phacotrabeculectomy. METHODS: This matched randomized clinical trial included 34 eyes of 30 patients with visually significant cataracts and poorly controlled glaucoma. Equal numbers of eyes were randomly assigned to the single-site and two-site groups. In the single-site approach, phacoemulsification was performed under a superior scleral tunnel followed by trabeculectomy. The two-site approach included a temporal clear corneal phaco-emulsification combined with a separate superior trabeculectomy. MMC 0.2 mg/ml was similarly applied for one minute in both groups. RESULTS: Patients were followed for a mean period of 13±1.4 (range, 12 to 15) months. Mean best corrected visual acuity one year after surgery was 0.6±0.4 LogMAR in the single-site group and 0.4±0.28 LogMAR in the two-site group (P=0.12). In the single-site group, mean preoperative intraocular pressure (IOP) was 26.4±6.6 mmHg which was decreased to 14.8±2.5 mmHg, one year after the operation (P < 0.001). Corresponding figures for the two-site group were 22.9±3.3 and 13.6±1.7 mmHg respectively (P < 0.001). At final follow up no significant difference in IOP existed between the study groups. Mean number of anti-glaucoma medications was 0.06±0.24 in the two-site group vs 0.43±0.5 in the single-site group (P=0.014). The rate of complications was not different between the study groups (P=1). CONCLUSIONS: Both single-site and two-site phacotrabeculectomy improved visual acuity which was slightly, but not significantly, better with two-site surgery. Final IOP was comparable with both techniques; however, the two-site group required fewer antiglaucoma medications.

37. Corneal biomechanical changes following trabeculectomy, phaco-trabeculectomy, Ahmed Glaucoma Valve implantation and phacoemulsification

Author

Pakravan, M., Afroozifar, M., and Shahin Yazdani

Subjects
genetic structures, lcsh:Ophthalmology, Ocular Response Analyzer, Corneal Biomechanics, Corneal Hysteresis, Glaucoma Surgery, lcsh:RE1-994, Original Article, sense organs, eye diseases
Abstract

Purpose: To determine corneal biomechanical changes following major glaucoma procedures. Methods: In a prospective comparative case series, corneal biomechanical properties were assessed using the Ocular Response Analyzer (ORA, Reichert Inc., Depew, New York, USA) before and 3 months after surgery in 89 eyes of 89 patients undergoing trabeculectomy + mitomycin C (MMC) (23 eyes, group 1), phacotrabeculectomy + MMC (23 eyes; group 2), Ahmed glaucoma valve (AGV) implantation (17 eyes; group 3) or phacoemulsification (PE) alone (26 non-glaucomatous eyes; group 4). Patients with history of contact lens use, previous intraocular surgery, any chronic corneal disease, central corneal thickness ≥580 microns or ≤500 microns, post-operative intraocular pressure (IOP) > 21 mmHg or ≤ 5 mmHg, and any surgical complication were excluded. Main outcome measures included changes in corneal hysteresis (CH) and corneal resistance factor (CRF). Results: Preoperatively, CH was lower in glaucomatous versus non-glaucomatous eyes (5.4, 5.3, 5.2 and 8.1 mmHg in groups 1, 2, 3 and 4 respectively, p

38. Astigmatic outcomes of temporal versus nasal clear corneal phacoemulsification

Author

Pakravan, M., Homayoun Nikkhah, Yazdani, S., Shahabi, C., and Sedigh-Rahimabadi, M.

Subjects
Phacoemulsification, lcsh:Ophthalmology, lcsh:RE1-994, Original Article, Cataract
Abstract

PURPOSE: To compare the astigmatic outcomes of phacoemulsification cataract surgery using temporal versus nasal clear corneal incisions. METHODS: In a clinical trial, consecutive patients with senile cataracts underwent phacoemulsification and implantation of a hydrophobic acrylic foldable intraocular lens through a horizontal clear corneal incision (temporal in right and nasal in left eyes). Outcome measures included keratometric astigmatism and surgically induced astigmatism (SIA) calculated by the vector analysis method using the Holladay-Cravy-Koch formula. RESULTS: The nasal and temporal groups consisted of 20 eyes each. Mean preoperative keratometric astigmatism was 0.63±0.48 D and 0.38±0.39 D in the temporal and nasal incision groups respectively (P=0.09). Data on 10 eyes in each study group was available for the six-month analysis. Mean keratometric astigmatism was as follows in the temporal and nasal groups respectively: 0.85±0.47 D versus 1.95±0.45 D at 1 week (P < 0.001), 0.73±0.46 D versus 1.79±0.55 D at 4 weeks (P < 0.001), and 0.63±0.30 D versus 1.05±0.56 D at 6 months (P=0.053) after surgery. SIA at the same follow-up intervals was 0.71±0.20 D versus 1.80±0.22 D (P < 0.001), 0.63±0.20 D versus 1.65±0.31 D (P < 0.001) and 0.26±0.46 D versus 0.92±0.36 D (P=0.002) in the temporal versus nasal incision groups respectively. CONCLUSION: Temporal clear corneal phacoemulsification induces significantly less astigmatism as compared to similar surgery using the nasal approach.

39. Peripapillary retinal nerve fiber layer thickness measurement by three-dimensional optical coherence tomography in a normal population

Author

Pakravan, M., Aramesh, S., Shahin Yazdani, Yaseri, M., and Sedigh-Rahimabadi, M.

Subjects
genetic structures, Original Article, sense organs, Optical Coherence Tomography, eye diseases, Three-Dimensional Tomography, Retinal Nerve Fiber Layer Thickness
Abstract

Purpose To determine peripapillary retinal nerve fiber layer (RNFL) thickness values by three-dimensional optical coherence tomography (3D-OCT) in a normal Iranian population and to evaluate the concordance of these measurements with those obtained by the second generation of optical coherence tomography (OCT II). Methods In a cross-sectional observational study, 96 normal Iranian subjects 20-53 years old were enrolled. Peripapillary RNFL thickness in one randomly selected eye of each subject was measured by 3D-OCT and also by OCT II. Standard achromatic perimetry, corneal pachymetry and A-scan ultrasonographic biometry were also performed. Other study variables included age, gender, laterality (right versus left eye), refractive error, corneal diameter and disc area. Results Mean peripapillary RNFL thickness measured by 3D-OCT (75.50±8.38) μm was significantly less than that measured by OCT II (144.10±33.32 μm) (P

40. The prevalence of glaucoma in Tehran, Iran

Author

Amini, H., Javadi, M. -A, Yazdani, S., Pakravan, M., Karimian, F., Rezaei, A., Nouri-Mahdavi, K., Zarei, R., Arezoo Miraftabi, Rafiee, A. B., Eslami, Y., Jabarvand, M., and Valaie, N.

Subjects
lcsh:Ophthalmology, lcsh:RE1-994
Abstract

PURPOSE: To determine the prevalence of glaucoma in adults 40 years of age or older in Tehran, Iran. METHODS: This stratified random-sampling cross-sectional population survey was performed on residents of Tehran, the capital of Iran, aged 40 years and older in the year 2001. Refraction, best-corrected visual acuity, slitlamp biomicroscopy, Goldmann applanation tonometry, funduscopy, and gonioscopy were performed in all subjects. Automated perimetry was performed in selected cases. RESULTS: Out of 4418 sampled subjects, 2184 individuals (49.4%) participated in the survey. Eventually data from 2160 individuals including 814 (38%) male and 1346 (62%) female subjects with mean age of 55.1±10.2 (range 40-92) years were analyzed. The overall prevalence of glaucoma was 1.44% (95% confidence interval, 0.94-1.94) including primary open angle glaucoma 0.46%, chronic angle closure glaucoma 0.33%, normal tension glaucoma 0.28%, pseudoexfoliation glaucoma 0.23%, and other types of glaucoma 0.14%. More than 80% of affected subjects were unaware of their condition. CONCLUSION: The prevalence of glaucoma in adults 40 years of age or older in Tehran is 1.44%, which is in the lower range reported in other populations. The large majority of cases are unaware of their condition.

41. Performance Analysis of Slotted ALOHA Random Access Packet-Switching Optical CDMA Networks Using Generalized Optical Orthogonal Codes and M-ary Overlapping PPM Signaling.

Author

Shoaie, M., Khazraei, S., and Pakravan, M.

Abstract

In this paper we study slotted ALOHA random access optical code division multiple access packet-switching networks with a chip-level receiver structure. We use generalized optical orthogonal codes (GOOCs) and the overlapping pulse position modulation (OPPM) signaling technique to improve system performance. The impact of physical layer parameters such as the GOOC cross-correlation value and the OPPM overlapping index on key performance benchmarks such as network throughput and delay are analyzed. We also study the stability of the network based on the number of backlogged users, using the expected state drift. It has been shown that using GOOC instead of strict optical orthogonal codes improves the network average delay and throughput. Moreover, by comparing M-ary OPPM and conventional OOK signaling with a fair criterion we have demonstrated that OPPM signaling can substantially improve both steady state and transient network characteristics. This improvement can be obtained without introducing additional complexity in the receiver and transmitter structure. [ABSTRACT FROM PUBLISHER]

Published
2011
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43. Palynological investigation of some genera of Cichorieae (Asteraceae) in Iran.

Author

Pakravan M, Safavi SR, Zarei R, Tavakoli Z, Ghahremaninejad F, Noroozi M, Bokaee ZN, Alimadadi M, Ghodusian N, Hosseini F, and Moradi F

Subjects
Iran, Microscopy, Electron, Scanning, Microscopy, Pollen ultrastructure, Pollen anatomy & histology, Pollen classification, Asteraceae classification, Asteraceae anatomy & histology, Asteraceae ultrastructure
Abstract

The pollen morphology of 33 species belonging to the genera Lactuca, Launaea, Cicerbita, Sonchus, Condrilla (tribe Cichorieae: Asteraceae) from Iran were studied with light and electron microscopies. The pollen grains of the investigated taxa are almost oblate-spherical to prolate-spherical, the shapes are circular in equatorial view, hexagonal in polar view, only Sonchus species are triangular or quadrangular in polar view, isopolar, symmetrical and trizonocolporate, except Sonchus and Chondrilla species, which have tri- to tetrazonocolporate pollen grains, and echinolophate. The size and number of spines in the polar area and the number of spines in the paraporal ridges and equatorial ridges proved to be the most taxonomically authentic characteristics in this study. Three pollen types were distinguished, as in alignment with previous studies. Cluster analysis by Ward method based on 10 quantitative morphological characteristics of pollen grains revealed that the species could be grouped based on the pollen characteristics. Moreover, three species of Cicerbita including Cicerbita scoparia (Rech. f. & Köie) Kitam, C. rechingeriana (Tuisl) Coșkunç., M. Güzel & N. Kilian and C. microcephala (DC.) M. Güzel, Coșkunç. & N. Kilian were recorded for the first time in Iran. Although the characteristics of the pollen grains were useful for distinguishing the species in sub-tribes, in some cases, this did not confirm recent phylogenetic results. The pollen characteristics described in this study provide data that may be useful for future systematic studies aiming to complete the knowledge on Cichorieae species. RESEARCH HIGHLIGHTS: In the present study, the pollen morphology of 33 species belonging to five genera of the Cichorieae are investigated with scanning electron microscopy and 12 species are analyzed for the first time. The cluster analysis based on the quantitative morphological characteristics of pollen grains revealed that the species could be grouped based on the pollen characteristics. In addition, three species of Cicerbita are reported for the first time in Iran., (© 2024 Wiley Periodicals LLC.)

Published
2024
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44. Exotropia and Bilateral Internuclear Ophthalmoplegia Following Tuberculous Meningitis.

Author

Carrabba NV, Hummel LA, Pakravan M, Charoenkijkajorn C, and Lee AG

Subjects
Humans, Male, Adult, Female, Tuberculosis, Meningeal complications, Tuberculosis, Meningeal diagnosis, Exotropia etiology, Exotropia diagnosis, Ocular Motility Disorders etiology, Ocular Motility Disorders diagnosis, Ocular Motility Disorders physiopathology, Magnetic Resonance Imaging
Abstract

Competing Interests: The authors report no conflicts of interest.

Published
2024
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45. Delayed Diagnosis of Thymoma in Ocular Myasthenia Gravis.

Author

Noubani LH, Hummel LA, Pakravan M, Charoenkijkajorn C, Mortensen PW, and Lee AG

Subjects
Humans, Female, Middle Aged, Magnetic Resonance Imaging, Male, Myasthenia Gravis diagnosis, Myasthenia Gravis complications, Thymoma complications, Thymoma diagnosis, Thymus Neoplasms complications, Thymus Neoplasms diagnosis, Delayed Diagnosis
Abstract

Competing Interests: The authors report no conflicts of interest.

Published
2024
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46. Strabismus Associated With the Good Syndrome (Immunodeficiency and Thymoma).

Author

Gupta A, Pakravan M, Charoenkijkajorn C, and Lee AG

Subjects
Humans, Immunologic Deficiency Syndromes complications, Immunologic Deficiency Syndromes diagnosis, Magnetic Resonance Imaging, Strabismus etiology, Strabismus physiopathology, Thymoma complications, Thymoma diagnosis, Thymus Neoplasms complications, Thymus Neoplasms diagnosis
Abstract

Competing Interests: The authors report no conflicts of interest.

Published
2024
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47. Delayed Visual Improvement in Neuromyelitis Optica Spectrum Disorder With Severe Optic Atrophy.

Author

Ong J, Mortensen P, Raviskanthan S, Pakravan M, Charoenkijkajorn C, Davila-Siliezar P, Laylani NA, and Lee AG

Subjects
Humans, Female, Magnetic Resonance Imaging, Adult, Vision Disorders physiopathology, Vision Disorders diagnosis, Vision Disorders etiology, Neuromyelitis Optica diagnosis, Neuromyelitis Optica complications, Neuromyelitis Optica physiopathology, Optic Atrophy diagnosis, Optic Atrophy physiopathology, Optic Atrophy etiology, Visual Acuity physiology
Abstract

Competing Interests: The authors report no conflicts of interest.

Published
2024
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48. Clinical outcomes of radial optic neurotomy versus pars plana vitrectomy in recent onset non-arteritic anterior ischemic optic neuropathy.

Author

Hassanpour K, Hasanpour H, Pakravan P, Nourinia R, Pakravan M, and Soheilian M

Abstract

Introduction: This study investigated the effect of pars plana vitrectomy (VIT) versus pars plana vitrectomy combined with radial optic neurotomy (RON) on recent onset non-arteritic anterior ischemic optic neuropathy (NAION)., Methods: In this prospective interventional case series, individuals with recent-onset NAION, lower than one month and low vision (lower than 20/200) were recruited. Patients randomly underwent either VIT, or RON., Results: 34 eyes of 34 patients were included in this study. 10, 9, and 15 eyes were randomly included in VIT, RON, and control groups, respectively. The BCVA of the VIT group improved significantly from 1.84 ± 0.5 logMAR at baseline to 1.29 ± 0.67, 0.93 ± 0.53, and 0.77 ± 0.47 logMAR at 1, 3, and 6 months, respectively (Ps < 0.05). The corresponding values for RON group were 1.73 ± 0.53 logMAR at baseline, which improved to 1.04 ± 0.65, 0.64 ± 0.28, and 0.61 ± 0.26 logMAR at the same follow-up visit times ( P  < 0.05).The corresponding values for the control group were 1.6 ± 0.58 log MAR at baseline, which improved to 1.03 ± 0.29, 1.00 ± 0.32, and 0.32 ± 0.83 log MAR at the same follow-up visit times. There was no significant statistical difference in BCVA between the three groups. However, both interventions resulted in statistically significant improvement in mean deviation (MD) of visual field (VF) compared with the control group at the end of 6 months (VIT P  = 0.006, RON P  = 0.043). RNFLT decreased from baseline 235.3 ± 44.01 to 75.6 ± 17.68 at 1 month in the VIT group ( P  < 0.001), from baseline 268.22 ± 65.9 to 76.67 ± 10.59 at 1 month in RON ( P  < 0.001), while it decreased from baseline 179.48 ± 39.02 to 112.92 ± 44.51 at 1 month in the control group., Conclusion: VIT and RON showed promising results in terms of MD of VF, and optic disc edema resolved faster in these groups compared to the control group in recent onset NAION. A larger sample size study is deemed necessary to generalize the results of this study., Competing Interests: Declaration of conflicting interestsThe authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Published
2024
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50. Continuous Wave Transscleral Cyclophotocoagulation and Endoscopic Cyclophotocoagulation in Childhood Glaucoma: A Meta-Analysis.

Author

Elhusseiny AM, Hassan AK, Elsaman AS, Azhari JO, VanderVeen DK, Abdelnaem S, Pakravan M, Chang TC, Khodeiry MM, Khouri AS, Sayed MS, Lee RK, and Sallam AB

Subjects
Humans, Child, Child, Preschool, Ciliary Arteries, Tonometry, Ocular, Intraocular Pressure physiology, Laser Coagulation methods, Sclera surgery, Glaucoma surgery, Glaucoma physiopathology, Ciliary Body surgery, Endoscopy methods
Abstract

Prcis: Transscleral cyclophotocoagulation (TS-CPC) and endoscopic cyclophotocoagulation (ECP) were effective in reducing intraocular pressure (IOP) and glaucoma medications in childhood glaucoma., Objective: To report the outcomes of continuous wave TS-CPC and ECP in childhood glaucoma., Materials and Methods: We performed a systematic search of relevant databases. We collected data on age, follow-up duration, type of glaucoma, previous surgical interventions, preoperative and postoperative IOP, preoperative and postoperative number of glaucoma medications, adverse events, number of sessions, and success rates at different time points. The main outcome measures are the amount of IOP and glaucoma medication reduction., Results: We included 17 studies studying 526 patients (658 eyes); 11 evaluated the effectiveness of TS-CPC (268 patients, 337 eyes), 5 evaluated ECP (159 patients, 197 eyes), and one study compared both techniques (56 patients, 72 eyes for TS-CPC vs 43 patients, 52 eyes for ECP). The median duration of follow-up was 28 months in the TS-CPC group and 34.4 months in the ECP group. The mean number of treatment sessions was 1.7 in the TS-CPC and 1.3 in the ECP. In the TS-CPC group, the mean IOP was significantly reduced from 31.2 ± 8 to 20.8 ± 8 mm Hg at the last follow-up ( P < 0.001). The mean number of glaucoma medications was reduced from 2.3 ± 1.3 to 2.2 ± 1.3 ( P = 0.37). In the ECP group, there was also a significant reduction in the mean IOP from 32.9 ± 8 mm Hg with a mean of 1.7 ± 0.7 glaucoma medications to 22.6 ± 9.8 mm Hg ( P < 0.0001) on 1.2 ± 1.1 medications ( P = 0.009) at the last follow-up., Conclusion: Both TS-CPC and ECP were effective in reducing the IOP and glaucoma medications in childhood glaucoma. Multiple treatment sessions were required., Competing Interests: Disclosure: A.S.K. received grant support from Abbvie, New Jersey Health Foundation, and a fund for the NJ Blind. He is a consultant in Alcon, Glaukos. Also, he is the Speaker Bureau in Abbvie, Bausch & Lomb. The Bascom Palmer Eye Institute is supported by NIH Center Core Grant P30EY014801 and a Research to Prevent Blindness Unrestricted Grant. R.K.L. is supported by the Walter G. Ross Foundation. The remaining authors declare no conflict of interest., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

Published
2024
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