Biomedical subjects

Ibrahim F Hepsen

Publications and source records attributed to Ibrahim F Hepsen.

5 recordsLinked to original sources

PubMed2006

Myopic shift from the predicted refraction after sulcus fixation of PMMA posterior chamber intraocular lenses.

BACKGROUND: To evaluate the refractive results of sulcus-fixated polymethylmethacrylate (PMMA) posterior chamber intraocular lenses (PC IOLs) after cataract surgery with and without posterior capsule complications. METHODS: The charts of patients who had undergone cataract surgery were reviewed, and eyes that had received sulcus-fixated PMMA PC IOLs were included in the study. Postoperative refraction, predicted postoperative refraction for in-the-bag IOL with the same diopter, intraoperative posterior capsular complications and vitrectomy, axial eye length, incision type (corneal or scleral), and surgery type were recorded and analyzed. The difference between actual postoperative refraction and predicted refraction for the in-the-bag lens was calculated for each patient. RESULTS: Of 143 patients (84 men and 59 women), 162 eyes with a sulcus-fixated posterior chamber intraocular lens were investigated. Mean age was 63.7 +/- 12.1 years. A mean myopic shift of -1.02 +/- 0.96 D from the predicted in-the-bag refraction was found. There were no significant differences between eyes with or without vitreous loss-vitrectomy (p = 0.8), eyes with scleral or corneal incisions (p = 0.11), and eyes having phacoemulsification or extracapsular cataract extraction (p = 0.93). In terms of axial length, there were no significant differences between long, normal, or short eyes (p = 0.85). INTERPRETATION: Sulcus fixation of a PMMA IOL originally planned for in-the-bag fixation caused approximately -1.00 D myopic shift in this study. We recommend that when sulcus fixation is necessary PMMA IOL power should be approximately 1.25 to 1.50 D less than the power for in-the-bag fixation. Axial length, incision type, vitreous loss and use of vitrectomy, and type of the surgery do not appear to alter the postoperative refraction significantly in eyes with sulcus fixation.

Adolescent↗

PubMed2004

The comparison of topical ibopamine 2% with tonography to identify the outflow resistance in eyes with ocular hypertension.

BACKGROUND: To evaluate the ability of topical ibopamine 2% to detect outflow resistance by comparing it with the tonography test in eyes with ocular hypertension (OHT). METHODS: 62 eyes with OHT and 33 control eyes were included in this prospective study. Tonography was done manually as a standard outflow facility measurement. We used a C value of 0.18 mul/min/mm Hg or less and a P(o)/C value of 100 and above as a positive tonographic test. The ibopamine test performed on the following day was considered positive if there was an intraocular pressure (IOP) change of at least 3 mm Hg. RESULTS: The sensitivity of the tonography and ibopamine tests was 69 and 53%, respectively, in eyes with OHT. The specificity of both tests was 97%. Although the sensitivity of the tonography test is higher than that of the ibopamine test, the difference between both was not statistically significant in these eyes (p = 0.409). Positive results in tonography were associated with higher IOP, while the results were not dependent on the IOP in the ibopamine test. Both tests together were positive in 33.87% (21 eyes) and negative in 11.29% (7 eyes) in 62 eyes with OHT. CONCLUSION: This study revealed that the ibopamine provocation test can detect outflow system resistance in eyes with OHT comparable with tonography which is a traditional outflow facility measurement. Ibopamine, however, can detect the eye with outflow impairment by a different and IOP-independent way, while tonography depends on IOP.

Administration, Topical↗

PubMed2004

Preventive effect of lacrimal occlusion on topical timolol-induced bronchoconstriction in asthmatics.

AIM: To evaluate the potential preventive role of lacrimal occlusion on the topical timolol-induced bronchoconstriction in asthmatics. METHODS: This was a prospective and single-masked study. Fourteen volunteer subjects with asthma were included. Collagen plugs were inserted into both canaliculi on one side to inhibit lacrimal drainage. The effect of lacrimal occlusion on lung function tests was measured before and 60 min after the instillation of a timolol drop in unplugged and plugged eyes. The spirometric measurements include forced vital capacity (FVC), forced expiratory volume in 1 s (FEV1), FEV1/FVC, and mid expiratory flow-rate (FEF25-75). RESULTS: The timolol (0.5%) drop administration into the eye caused a significant decrease in pulmonary functions in patients with asthma in whom the lacrimal punctae had not been occluded by collagen plug. P values were 0.008 for FVC and 0.001 for FEV1 and FEF25-75. The occlusion of the lacrimal duct by intracanalicular plugs significantly reduced this decrease in pulmonary function. P values were 0.6 for FVC, 0.8 for FEV1, and 0.5 for FEF25-75. The lacrimal occlusion did not affect heart rate and blood pressures. Three subjects complained of epiphora. CONCLUSIONS: Lacrimal occlusion with intracanalicular collagen plugs may almost completely prevent the bronchoconstriction caused by topical timolol in asthmatics by inhibiting or decreasing systemic absorption of the medication.

Administration, Topical↗

PubMed2003

The relationship between serum trace element changes and visual function in heavy smokers.

PURPOSE: The aim of this prospective study was to evaluate serum manganese (Mn), zinc (Zn) and copper (Cu) levels and visual functions including visual acuity, colour vision, pattern visual evoked potentials (PVEPs), and contrast sensitivity in heavy smokers and to compare these with the equivalent levels and functions in non-smokers. METHODS: Data were recorded in 24 healthy, chronic and heavy cigarette smokers and 16 healthy, non-smoking control subjects. Serum Zn, Cu and Mn concentrations in all subjects were measured by atomic absorption spectrophotometry. RESULTS: Both study and control subjects had normal visual acuity and colour vision. Pattern visual evoked potentials were normal in all study and control subjects. Contrast sensitivity was significantly reduced in heavy smokers compared to non-smokers (p < 0.023), despite the fact that central vision and PVEP responses were not affected. Mean serum Mn and Zn levels were significantly lower in smokers than in non-smokers (p < 0.0001 and p < 0.005, respectively). CONCLUSIONS: Reduced contrast sensitivity values associated with low levels of serum Mn and Zn, which function as cofactors of superoxide dismutase in erythrocyte and other nucleated cells, suggest a possible role of trace elements in smoking-induced early retinal toxicity.

Adult↗

PubMed2003

Hammer-chisel technique in endoscopic dacryocystorhinostomy.

We performed a prospective evaluation of endoscopic hammer-chisel dacryocystorhinostomy (DCR) procedures on 62 eyes of 44 patients (40 female and 4 male) with chronic epiphora or dacryocystitis (26 unilateral and 18 bilateral). The technique included chisel removal of bone over the lacrimal sac. The follow-up period was 12 to 54 months (mean, 28 months), and the patients' ages ranged from 17 to 67 years (mean, 35.5 years). The success rate of the consecutive endoscopic hammer-chisel DCR procedures was 87%. During operation, 8 patients had mild mucosal hemorrhage, which did not prevent the successful completion of the operation. Excellent patient tolerance was observed, with minimal morbidity and no major complications. As compared to the external approach, endoscopic hammer-chisel DCR is less traumatic, is less time-consuming, and is practical and cosmetically convenient, with minimal perioperative and postoperative complications. It also allows the simultaneous correction of any intranasal disease. It requires minimal instrumentation and is a relatively easy and fast technique.

Adolescent↗