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Biomedical subjects

M Orhan

Publications and source records attributed to M Orhan.

At least 19 recordsLinked to original sources

Autogenous versus allograft fascia lata in frontal sling surgery --long-term results.

PURPOSE: Either autogenous or allograft fascia lata frontal sling procedures can be used for the treatment of severe ptosis. We retrospectively evaluated the late outcomes of both approaches. METHODS: Medical records of patients who underwent frontal sling ptosis surgery between 1978 and 2000, with a follow-up of one year or more were included in the study. Success rates and the complications of the surgery for autogenous and allograft fascia lata were recorded. The results were compared statistically. RESULTS: Surgeries were performed with 82 autogenous or 43 allograft fascia lata. At last follow-up there were 71 eyes (86.6%) with good, 8 eyes (9.7%) with moderate, 3 eyes (3.7%) with poor results after autogenous fascia lata and 35 (81.4%), 3 (7%) and 5 (11.6%) after the allograft fascia lata frontal sling procedure. There was no significant difference between the two groups. Repeat surgery was carried out on three patients after autogenous and five after allograft fascia lata surgery. Two cases of preseptal cellulitis were observed, one abscess after autogenous and one lagophthalmus after allograft fascia lata sling surgery. All patients had slight edema early after surgery which resolved in a few days. Only one patient developed a hematoma at the site of the leg incision. CONCLUSIONS: Although the long-term success rate with the autogenous fascia lata is slightly higher and this remains the first choice, allograft fascia lata is a good alternative in patients in whom fascia could not be harvested.

Adolescent↗

The evaluation of retinal nerve fiber layer in pigment dispersion syndrome and pigmentary glaucoma using scanning laser polarimetry.

PURPOSE: To measure the retinal nerve fiber layer thickness in patients with pigment dispersion syndrome (PDS) using scanning laser polarimetry and to compare these measurements with those of normal subjects and patients with pigmentary glaucoma (PG). METHODS: Age-, sex-, and refractive error-matched subjects--18 patients with PDS, 18 patients with PG, and 20 healthy subjects--were evaluated by scanning laser polarimetry (Nerve Fiber Analyzer [NFA] GDx). The NFA did not have a compensator for corneal polarization. One randomly selected eye from each patient was included in the statistical analysis. The NFA measurements of patients with PDS and PG and healthy subjects were compared statistically using analysis of variance, Tukey multiple comparisons, chi-square, and independent t-tests. RESULTS: The mean values for average thickness, superior and inferior maximum, superior and inferior average, ellipse average thickness, and superior integral were found to be lower in the patients with PDS (p < 0.02) and PG (p < 0.005) compared to the normal subjects. The mean values for maximum modulation, superior ratio, inferior ratio, and superior/nasal ratio in PDS were in between those of the PG and control groups (p > 0.05). The ellipse modulation was significantly lower in the PG group when compared to the other two groups (p < 0.03). CONCLUSIONS: Retinal nerve fiber loss is present to some extent in patients with PDS and this loss is not age or sex dependent. Parameters of modulation might be more representative of significant damage of the nerve fiber layer.

Adult↗

Retinal nerve fiber layer analysis and interpretation of GDx parameters in patients with tilted disc syndrome.

This study was conducted to determine abnormalities of the GDx Glaucoma Scanning System parameters in patients with tilted discs, in order to set guidelines for the evaluation of glaucomatous damage in this situation. The objective was to determine which GDx parameters displayed the highest level of variation, and which remained unchanged in tilted disc syndrome. RNFA was polarimetrically conducted on 45 eyes from 26 subjects with tilted discs, and 43 normal eyes with Nerve Fiber Analyzer II (Laser Diagnostic Technologies). All parameters except inferior maximum, average thickness, ellipse average, and inferior average displayed a significant difference between the two groups (p < 0.05). Although NFA is useful in glaucoma diagnosis, the majority of the GDx parameters, as shown in our study, are unreliable in tilted disc syndrome in this respect.

Adult↗

Polarimetric nerve fiber analysis in patients with peripapillary myelinated retinal nerve fibers.

PURPOSE: The aim of this study was to compare the RNFL thickness in eyes with myelinated retinal nerve fibers (MRNF) and age, sex-matched controls using scanning laser polarimetry. METHODS: Seventeen patients with MRNF underwent a comprehensive ophthalmological examination including automated visual field testing, and scanning laser polarimetry with Nerve Fiber Analyser (NFA II). Twenty eyes with MRNF from 17 patients were available for the study. Sixteen healthy, age and sex-matched subjects were taken as controls. Retinal nerve fiber thickness measurements of the four sectors (superior, inferior, nasal, temporal) and along the whole circumference of the optic disc were obtained for affected and control eyes, and compared. RESULTS: Inferior average and inferior integral parameters of the NFA revealed significantly thinner RNFL thickness measurements in eyes with inferiorly located MRNF compared to controls. CONCLUSION: Retinal myelination alters the birefringent property of the RNFL, and results in diminished thickness measurements. Hence, NFA measurements in patients with MRNF may not be reliable.

Adult↗

Inclinometer method for recording and transferring natural head position in cephalometrics.

The purposes of this study were (1) to construct a device to record natural head position and transfer it to the cephalostat, (2) to assess its clinical use, and (3) to evaluate the reproducibility of lateral cephalograms taken with the device. The device, incorporated into a pair of eyeglass frames, included 2 tilt sensors to measure pitch and roll of the head. The natural head positions of 20 subjects were established 10 times by self balance and mirror position, recorded with the device, and reproduced in the cephalostat by using the average of these 10 measurements. Three lateral cephalograms were obtained in this manner at 30-minute intervals. The first 2 films were made with the subject wearing the device to assess the reproducibility of the recorded position in the cephalostat by the inclinometer. During exposure of the third film, the device was not worn, and this film was used to determine the stability of the established position when the inclinometer was removed. The results revealed method errors of 0.6 degrees (SD, 0.9) between the first 2 sets of radiographs with a correlation coefficient of 0.985. Method errors between the first and third and the second and third sets were 0.6 degrees (SD, 0.8) and 0.7 degrees (SD, 1), respectively, with correlation coefficients of 0.989 and 0.982. The reproducibility of the method was high, and the system was clinically practical for both recording and transferring natural head position in cephalometrics. This technique should make it possible to measure and reproduce head position accurately. Minimizing the size of the device, making it radiolucent, and integrating it into the radiographic device will make it more versatile and decrease error.

Adolescent↗

Polarimetric nerve fiber analysis in patients with visible optic nerve head drusen.

OBJECTIVE: To evaluate the effect of visible optic nerve head drusen (ONHD) on retinal nerve fiber layer (RNFL) thickness retardation by using scanning laser polarimetry. METHODS: Twenty-three eyes of 13 patients with visible ONHD and 26 eyes of 13 age- and sex-matched control subjects were involved in the study. Ophthalmologic examination, scanning laser polarimetry with nerve fiber analyser (NFA) type II GDX, automated Humphrey visual field testing, and red-free fundus photography were performed. Eyes with ONHD were classified from grade 0 to III according to the amount of visible drusen. Thus, grade 0 discs had no clinically visible ONHD and grade III discs represented the presence of dense drusen. RESULTS: Measurements with NFA of RNFL thickness retardation showed significant decrease in eyes with visible ONHD compared with control eyes (P < 0.05). Although no significant difference was found between grade I and grade II discs regarding NFA measurements, grade III discs had significantly lower values, indicating the greater amount of RNFL loss with higher grade ONHD. Documentation of increased percentage of visual field defects with higher grade drusen was also in accordance with this finding. CONCLUSIONS: NFA can quantitatively detect the decrease in retardation of RNFL thickness in eyes with visible ONHD and can be used as an indicator of nerve fiber layer loss in these cases.

Adolescent↗

Long-term results and reasons for failure of intranasal endoscopic dacryocystorhinostomy.

The aim of this study was to evaluate the long-term results and the factors influencing the success in patients with nasolacrimal duct obstruction treated with intranasal endoscopic dacryocystorhinostomy (DCR) and silicone tube intubation (STI). We prospectively investigated 158 patients with lacrimal obstruction in two groups, one of which comprised 108 patients treated primarily with intranasal endoscopic DCR by experienced surgeons and the other comprised 50 patients who were operated on by inexperienced surgeons. In a mean follow-up time of 49 months the surgical success was 94.4% in experienced hands and 58.0% in inexperienced hands. The endoscopic examination of six patients with failure in the first group revealed granulation tissue around the tube in four, atonic sac in one and persistence of bone that was supposed to have been excised in the nasal cavity in one. There were 21 failures out of 50 patients in the second group: granulation tissue in 2 cases, fenestration to the nasolacrimal duct instead of the sac in 6 cases, synechia between the lateral nasal wall and the middle turbinate in 2 cases, bony spicles causing obstruction in 5 cases and fenestration anterior to the sac in 2 cases. In 4 cases no reasons were found for failure, but perhaps the small fenestration and failure to remove the medial half of the membranous sac wall was the reason. DCR and STI can be performed for primary treatment in lacrimal obstruction. There is a learning curve for the operation. False localization of the lacrimal sac, granulation tissue formation around the tubes, retained bony spicles, inadequate removal of the medial wall of the sac and the synechia between the lateral wall and the middle turbinate are the most common causes of failure.

Adult↗

Role of tear inflammatory mediators in contact lens-associated giant papillary conjunctivitis in soft contact lens wearers.

Contact lens-associated giant papillary conjunctivitis (CL-GPC) caused by mechanical and immune mechanisms is a significant problem resulting in contact lens intolerance and discontinuation of contact lens wear. In the present study, tear fluid leukotriene C4 (LTC4) level was evaluated in soft contact lens wearers with and without CL-GPC using ELISA. Statistical analysis showed no significant difference in tear fluid LTC4 between contact lens wearers without GPC and normal controls (p>0.05), but a significant increase in tear LTC4 level in CL-GPC patients (p<0.05). On the basis of this finding, it might be possible to explain redness, conjunctival edema, increased mucoid secretion, and papillary changes by the effect of LTC4 on eye tissues. Effective treatment of CL-GPC might be possible in the future by employing inhibitors of leukotriene synthesis and action.

Adult↗

Tear functions in patients with pterygium.

PURPOSE: In the etiology of pterygium abnormalities in tear functions have also been emphasized. In this study, tear function tests are evaluated in patients with pterygium. METHODS: Schirmer's test 1, tear film break-up time and mucus fern patterns were evaluated in 70 eyes with pterygium and in 70 eyes of the age matched control group. Marginal tear films were also assessed. RESULTS: Tear film break-up time was significantly reduced in the pterygium group. Mucus fern patterns and marginal tear films were found to be markedly abnormal in the eyes with pterygium, however, there was no significant difference in Schirmer's test 1. CONCLUSION: Tear function tests disclosed disrupted tear film stability which is more likely to be due to the altered mucin. This change may either be the primary factor inducing pterygium formation or reflect an existing pathology in the cells lining the ocular surface.

Adult↗

Effects of lodoxamide, disodium cromoglycate and fluorometholone on tear leukotriene levels in vernal keratoconjunctivitis.

PURPOSE: We compared tear leukotriene B4 (LTB4) and leukotriene C4 (LTC4) levels of vernal keratoconjunctivitis (VKC) patients with those of age-matched controls and evaluated the effects of disodium cromoglycate (DCG) 2%, lodoxamide 0.1% and fluorometholone 0.1% on the tear LTB4 and LTC4 levels of the VKC patients. METHODS: Thirty VKC patients were divided into three groups and their tear LTB4 and LTC4 levels measured with an enzyme-linked immunoassay technique before and after treatment with either lodoxamide 0.1%, DCG 2% or fluorometholone 0.1%. The results were compared with the tear LTB4 and LTC4 levels of 10 healthy control subjects. During this trial period, clinical scores for signs and symptoms of VKC were also evaluated. RESULTS: In the VKC patients median tear LTB4 and LTC4 levels were 349.0 pg/ml (range 213.3-707.7 pg/ml) and 225.2 pg/ml (range 196.1-241.1 pg/ml) respectively--significantly higher than the control group (p = 0.0065 for LTB4 and p = 0.0003 for LTC4). After treatment, LTB4 levels decreased significantly in all treatment groups when compared with baseline (for the lodoxamide group, p = 0.01; for the DCG group, p = 0.008; for the fluorometholone group, p = 0.045). LTC4 levels were also significantly reduced after treatment in all three treatment groups (for the lodoxamide group, p = 0.0209; for the DCG group, p = 0.0284; for the fluorometholone group, p = 0.0109). CONCLUSIONS: Tear LTB4 and LTC4 levels are significantly higher in VKC patients than controls, which points to a possible role of lipoxygenase pathway products in the pathophysiology of ocular allergic disorders. Lodoxamide 0.1%, DCG 2% and fluorometholone 0.1% were all effective in reducing LTB4 and LTC4 levels in VKC.

Adolescent↗

Effect of lodoxamide on tear leukotriene levels in giant papillary conjunctivitis associated with ocular prosthesis.

Leukotrienes have been shown to play a role in the pathogenesis of ocular inflammatory and allergic reactions like vernal keratoconjunctivitis and contact lens-associated giant papillary conjunctivitis. This study was designed to determine leukotriene B4 (LTB4) and leukotriene C4 (LTC4) levels in the tears of patients with ocular prosthesis-associated giant papillary conjunctivitis (OP-GPC) and to evaluate the effects of lodoxamide 0.1% on tear LTB4 and LTC4 levels of OP-GPC patients. Tear LTB4 and LTC4 levels were determined by an ELISA technique in the tears of ten OP-GPC patients before and after treatment with lodoxamide 0.1% for one month. The results were compared with that of ten healthy control subjects. The mean tear LTB4 and LTC4 levels of the OP-GPC patients were significantly higher than those of the control group. After treatment with lodoxamide 0.1%, tear LTB4 and LTC4 levels of the OP-GPC patients decreased significantly. This is the first report of elevated LTB4 and LTC4 levels in tears of OP-GPC patients and it points to the possible role of leukotrienes in the immunopathogenesis of OP-GPC. The results also indicate that lodoxamide 0.1%, a mast cell membrane stabilizer, is effective in significantly reducing tear LTB4 and LTC4 levels in OP-GPC patients.

Adolescent↗

Multiple orbital intraosseous hemangiomas.

The case of a 36-year-old healthy, asymptomatic man who was monitored for a slowly growing subcutaneous mass under his right inferior orbital rim for more than ten years is presented. The mass was hard, immobile, and nontender. Computed tomography (CT) documented a lytic lesion at the frontal process of the right maxilla. Four years later, magnetic resonance imaging (MRI) of the orbits revealed distinct lesions in the right zygoma, maxillary, and greater wing of the sphenoid bones. These lesions were hypointense with respect to orbital fat on T1-weighted images and hyperintense on T2-weighted series. There was moderate enhancement after contrast agent administration. These findings combined with the clinical features of the patient were suggestive of presumed multiple orbital intraosseous hemangiomas. Differential diagnosis between other osseous tumors of the orbit can be reasonably made based on imaging characteristics.

Adult↗

Surface deposits on frequent replacement and conventional daily wear soft contact lenses: a scanning electron microscopic study.

PURPOSE: We performed a prospective study to compare the surface deposits on frequent replacement soft contact lenses with deposits on conventional daily wear soft contact lenses. METHODS: We fit two groups of young myopic patients with either conventional daily wear or frequent replacement soft contact lenses. Subjects in both groups wore their lenses on a daily wear basis and used a hydrogen peroxide/catalytic disk based care system. Contact lenses were obtained from patients in the frequent replacement group after 1 month of wear and from the conventional contact lens group after 12 months. Contact lenses from each group were examined with scanning electron microscopy and surface deposits were compared. RESULTS: Frequent replacement lenses were covered with significantly fewer deposits than conventional daily wear soft contact lenses (P = 0.0003). No microorganisms were seen on frequent replacement contact lenses. Bacteria in the form of coccus on two contact lenses were seen in the other group. CONCLUSIONS: Surface deposits occur less often on frequent replacement lenses but they cannot be totally prevented. Surface deposit related contact lens complications may be expected to occur less frequently with the use of frequent replacement lenses.

Adolescent↗

Intranasal endoscopic silicone intubation for congenital obstruction of the nasolacrimal duct in children.

Aim of the present study was to determine the efficacy of intranasal endoscopic silicone intubation to treat congenital nasolacrimal duct obstruction in children who failed conventional lacrimal system probing. Silicone intubation with intranasal endoscopic visualization was performed in 18 eyes of 16 patients with an age range of 18-48 months (mean, 25 months) to treat congenital nasolacrimal duct obstruction. Out of 16 patients, ten had already undergone previous probings with failure, the other six were primary intubation cases without any previous probings. The tubes were left in place an average of 6 months. Follow-up ranged from 4 months to 2 years (mean, 12 months) following removal of the silicone tubing. Intranasal endoscopic silicone intubation is effective in the treatment of congenital nasolacrimal duct obstruction as a primary procedure in children over 18 months of age and, it is also recommended as the next step in the management of epiphora which fails to resolve after probing.

Child, Preschool↗