Browsing by Author "Yasar, T"

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Bcg Vaccination To Prevent Implantation of Endometriosis
(Elsevier Sci Ireland Ltd, 2001) Gül, A; Yasar, T; Ugras, S
To investigate whether BCG vaccination can prevent endometrial implantation in a rat model. Forty sexually mature virgin Wistar-Albino rats weighing 185-215 g were randomly assigned (double-blind) to two groups. The first group (n = 20) were injected with BCG 3 weeks before endometrial implantation to the eye. The second group (n = 20) with BCG not injected before endometrial implantation was the control. Photobiomicroscopy observation was done weekly and 6 weeks post endometrial implantation all eyes were investigated histologically. Five implants grew in the anterior surface of the iris of the first (vaccinated) group and 17 in the second (control) group. The difference was statistically significant. Systemic prophylaxis with BCG can exert an inhibitory effect on endometrial transplantation. (C) 2001 Elsevier Science Ireland Ltd. All rights reserved.
A Comparative Study on the Effect of Radial Keratotomy in Patients Who Live at Sea Level and High Altitude
(Royal Coll Ophthalmologists, 1999) Çinal, A; Yasar, T; Demirok, A; Simsek, S; Yilmaz, ÖF
Purpose To compare the refractive and keratometric results of matched pairs of patients who underwent radial keratotomy (RK) at sea level and high altitude. Methods The results of 30 eyes that underwent RK procedures in two clinical centres at different altitude were analysed. One centre was at sea level (Istanbul) and the other at an altitude of 1720 m (Van). The patients in the two centres were matched regarding gender, age, degree of myopia, number of incisions and optic zone size. There were 15 eyes in each group. All operations were performed with a diamond blade using a Russian technique by the same surgeon. Results The mean pre-operative spherical equivalent cycloplegic refractions (SECR) were -6.33 +/- 1.15 D and -6.32 +/- 1.01 D in the Istanbul and Van groups, respectively (p = 0.96). The mean post-operative SECRs were -1.93 +/- 1.03 D and -0.28 +/- 0.57 D in the Istanbul and Van groups, respectively (p < 0.001). The mean SECR changes were 4.40 +/- 0.92 D and 6.03 +/- 1.13 D in subjects who had undergone RK at sea level and at 1720 m, respectively (p < 0.001). Conclusion These results show that a higher myopic correction can be provided in patients who undergo RK at high altitude compared with those operated on at sea level. The RK nomograms used by refractive surgeons performing RK surgery at high altitude may need to be redesigned in the light of future studies with long-term follow-up.
The Effect of 0.25% Apraclonidine in Preventing Intraocular Pressure Elevation After Nd:yag Laser Posterior Capsulotomy
(Wichtig Editore, 1998) Simsek, S; Ertürk, H; Demirok, A; Cinal, A; Yasar, T; Karadenizli, G
Purpose. The efficacy and adverse effects of 0.25% apraclonidine on intraocular pressure (IOP) after Nd: YAG laser posterior capsulotomy were investigated, and the results were compared with placebo, 0.50% timolol maleate and 1% apraclonidine. Methods. Eighty eyes were randomly assigned to four groups of 20 eyes. In a double-masked design, the groups were treated with placebo (group I), 0.50% timolol maleate (group 2), 1% apraclonidine (group 3), 0.25% apraclonidine (group 4) one hour before and five minutes after Nd:YAG laser posterior capsulotomy. IOP was measured by applanation tonometry I hour before (baseline IOP) and 1, 3, 24 hours after capsulotomy. Results. The average baseline IOP increased respectively 3.90 +/- 5.35, 5.95 +/- 5.32, 1.15 +/- 3.20 mmHg in the first group 1, 3 and 24 hours post-treatment. There were significant differences between baseline IOP and 1 and 3 hours but not at 24 hours (p=0.004, p=0.001, p=0.13). IOP increased 0.40 +/- 4.08, 0.75 +/- 5.33, 0.80 +/- 6.03 mmHg in the second group at the same times. The differences between the average baseline IOP and the 1, 3 and 24 h measurement were not significant (p=0.83, p=0.65, p=0.93). In the third group, IOP decreased 3.70 +/- 2.40, 3.30 +/- 2.47, 2.65 +/- 1.56 mmHg at the measurement times, with significant differences between the average baseline IOP and the 1, 3 and 24 hour measurements (p=0.001, p=0.0001, p=0.01). In the fourth group IOP increased 0.35 +/- 3.32 mmHg at 1 hour, but decreased 1.25 +/- 3.41, 0.90 +/- 2. 07 mmHg at 3 and 24 hours. The differences were not significant (p = 0.94, p = 0.16, p = 0.08). When the 0.25% and 1% apraclonidine groups were compared, there were significant differences between the average IOP at 1 hour in both groups but not at 3 and 24 hours (p=0.01, p = 0.17, p = 0.21). Similarly, there were no significant differences between the average IOP at the same times when the 0.25% apraclonidine group was compared with the timolol group (p = 0.30, p = 0.08, p = 0.16). Some systemic and local side effects were seen in the timolol and 1% apraclonidine groups, but none with 0.25% apraclonidine. Conclusions. It was concluded that 0.25% apraclonidine is effective in preventing the early elevation of IOP after Nd:YAG laser posterior capsulotomy and may offer an alternative to 0.50% timolol maleate and 1% apraclonidine.
The Effect of Altitude on Radial Keratotomy
(Elsevier Science inc, 1998) Simsek, S; Demirok, A; Cinal, A; Yasar, T; Yilmaz, OF
The authors analyzed refractive results of patients who underwent radial keratotomy (RK) at sea level and high altitude and evaluated the effects of the altitude. A total of 102 eyes undergoing RK procedures performed in two clinical centers having different altitude were analyzed. The results compared between subjects who had undergone RK at sea level (Istanbul/Turkey) and at an altitude of 5750 feet (Van/Turkey) were compared. Subjects were 19-42 years old with myopia from -4.00 to -12.00 diopters (D). The average preoperative spherical equivalent cycloplegic refractions (SECR) were -8.01 +/- 1.86 D and -6.99 +/- 2.15 D in the istanbul and Van groups, respectively. These were divided into subgroups according to myopia degree and number of incisions and optic zone size. The RK procedures were performed by the same surgeon with diamond blade in standard Russian style. The average changes in SECR were 5.09 +/- 1.29 D and 6.50 +/- 2.24 D in subjects who had undergone RK at sea level and at 5750 feet, respectively. There was a significant difference between the subgroups (P < 0.0002). This difference was especially higher in the high myopia subgroups. Additionally, we obtained a partial relation between increase of RK incision number and SECR change at high altitude but not at sea level. No notable regression and progression were seen in the 3 months of follow up at high altitude. These results support hy potheses suggesting both corneal hypoxic expansion in the area of RK incisions, which may lead to central corneal flattening, and barometric pressure directly altering corneal shape, which is responsible for the hyperopic shift induced by altitude. Ophthalmologists performing RK surgery at high altitude had better consider redesigning their RK nomograms in light of these findings. However, when the nomogram used at sea level was used at high altitude, the subjects became hyperopic. (C) 1998 Japanese Ophthalmological Society.
The Effect of Pterygium Surgery on Corneal Topography
(Slack inc, 2001) Cinal, A; Yasar, T; Demirok, A; Topuz, H
OBJECTIVE: The aim of this prospective randomized clinical study was to evaluate the effect of pterygium surgery on the corneal topography using a computerized corneal topography system. PATIENTS AND METHODS: Computerized corneal topography was performed on 27 patients with primary pterygium before and after pterygium excision surgery. The topographical changes that occurred following surgery were evaluated using paired and unpaired two-tailed t-test and Pearson coefficient of correlation analyses. Simulated keratometric astigmatism at the central 3 mm and the total mean refractive powers of the whole cornea were measured before and after surgery. Following surgery, fattened or steepened corneal areas were determined. RESULTS: Simulated keratometric astigmatism at 3 mm was found to be 2.30 +/- 2.08 D (0.2 - 7.63) preoperatively and 0.82 +/- 0.74 D (0.06 - 2.79) postoperatively. The difference between these two values was statistically significant (t = -3.46, P = 0.002). Total mean refractive power of the whole cornea was found to be 42.26 +/- 0.63 (40.80 - 43.64) preoperatively and 43.69 +/- 0.88 (41.50 - 44.90) postoperatively and the difference was 1.42 +/- 0.87. There was a statistically significant high difference (t = 28.36, P < 0.001). When preoperative and postoperative corneal topographies were compared, the whole cornea was found steeper at the postoperative period except a little region in the superior nasal quadrant. CONCLUSION: We believe that corneal topographical changes caused by the pterygium are almost reversible after surgical treatment, and postoperatively the cornea becomes steeper.
Effect of Sex in Branch Retinal Vein Occlusion
(Wichtig Editore, 1998) Simsek, S; Demirok, A; Çinal, A; Yasar, T
Purpose. To evaluate the effect of sex in relation to crossing numbers, arterial overcrossings and occlusion sites in patients with branch retinal vein occlusion (BRVO). Methods. Fifty-one eyes with BRVO (study group) and 48 eyes with retinal problems other than BRVO (control group) were investigated All venous occlusions were examined in detail with regard to their anatomical positions, sites and arteriovenous crossings on the retinal surrounding area two disc diameters nasally, four disc diameters temporally three disc diameters superiorly and three inferiorly from the optic disc, in the arteriovenous phase of fundus fluorescein angiography and fundus color photography. Results. The study group comprised 29 women (56.86%) and 22 men (43.14%). All occlusions were unilateral and located at the crossing areas. BRVO had arterial overcrossing in 28 eyes (96.6%) in females and 22 eyes (95.5%) in males (p > 0.005). The average numbers of crossings were 7.79 +/- 1.57 in females and 7.82 +/- 1.05 in males in the study group (p > 0.05), and respectively 7.30 +/- 1.19 and 6.95 +/- 1.13 (p > 0.05) in the control group. The average arterial overcrossing ratios were 75% in females and 71% in males in the study group (p > 0.05), and 74% and 65% in the control group (p > 0.05). Conclusions. Our data suggest that females ha ve a higher risk than males because of their arterial overcrossing ratio and BRVO prefer arterial overcrossing. However the insignificant difference between the female and male patients leads us to assume that the effect of sex on BRVO cannot be explained only by local anatomical factors since their effect is only slight.
Effect of Superior and Temporal Clear Corneal Incisions on Astigmatism After Sutureless Phacoemulsification
(Elsevier Science inc, 1998) Simsek, S; Yasar, T; Demirok, A; Cinal, A; Yilmaz, OF
Purpose: To evaluate the effect of superior and temporal clear corneal incisions on astigmatism after sutureless, small incision phacoemulsification. Setting: World Eye Hospital, Istanbul, Turkey. Methods: This prospective study evaluated 40 eyes of 20 patients with cataract having bilateral, sutureless, small incision phacoemulsification by the same surgeon. A superior clear corneal incision was used in all right eyes and a temporal clear corneal incision in ail left eyes. Mean preoperative astigmatism was 0.63 diopter(D) +/- 0.21 (SD) and 0.65 +/- 0.20 D, respectively. Mean patient age was 66.45 years. Patients were examined preoperatively and 1 day, 1 week and 1 and 3 months postoperatively. Results: Three months postoperatively, mean astigmatism was 1.60 +/- 0.37 D in the superior incision group and 0.83 +/- 0.19 D in the temporal incision group. Induced astigmatism calculated by vector analysis was 1.44 +/- 0.31 D and 0.62 +/- 0.28 D, respectively. The temporal incision group had significantly lower astigmatism at all follow-ups (P = .000). Conclusion: Upper lid pressure on the superior corneal incisions led to fluctuating, against-the-rule astigmatism that was significantly higher than that induced by temporal incisions.
Effects of 0.5% and 0.25% Apraclonidine on Postoperative Intraocular Hypertension After Cataract Extraction
(Wichtig Editore, 1998) Simsek, S; Demirok, A; Yasar, T; Çinal, A; Bayram, A; Yilmaz, ÖF
Purpose. We conducted a double-masked, prospective study to evaluate the effect of 0.5% and 0.25% apraclonidine on postoperative intraocular pressure (IOP) in patients undergoing extracapsular cataract extraction (ECCE) with intraocular lens (IOL) implantation. Methods. Fifty-four patients scheduled for ECCE were randomly divided into three groups of 18. The first group received one drop of 0.50% apraclonidine topically one hour before surgery and immediately after the end of the procedure. The second group received the same regimen but with 0.25% apraclonidine. The third group received artificial fears as the control group. IOP was measured 12 h preoperatively and 6 and 24 h postoperatively. All the measurements were made using the same Goldmann applanation tonometer by the same surgeon who did not know to which group the patient belonged. Results. Preoperative mean IOP was 13.66 +/- 2.76 mmHg in the first group, 14.27 +/- 2.24 mmHg in the second and 14.5 +/- 1.34 mmHg in the control group. The differences were not significant (p = 0.398). Mean IOP at the early postoperative visit (6 h) was significantly lower in the first group (17.44 +/- 4.95 mmHg) than the second (21.78 +/- 7.19 mmHg) and the control group (24.55 +/- 5.65 mmHg) (p < 0.001). Mean postoperative IOP at 24 h was again significantly lower in the first group (14.33 +/- 3.75 mmHg) than the second (17.11 +/- 14.16 mmHg) and the control group (19.61 +/- 3.20 mmHg) (p < 0.001). Conclusions. Our findings indicate that topical 0.5% apraclonidine controlled early postoperative intraocular hypertension after cataract extraction without any side effects, while the 0.25% drops were not effective.
Effects of Fibrovascular Traction and Pooling of Tears on Corneal Topographic Changes Induced by Pterygium
(Nature Publishing Group, 2003) Yasar, T; Ozdemir, M; Cinal, A; Demirok, A; Ilhan, B; Durmus, AC
Aim To investigate the effects of fibrovascular traction and the pooling of tears at the pterygium apex on the corneal topographic changes induced by pterygium. Methods A total of 16 eyes of 14 cases with primary pterygium were included in the study. A computerized corneal topography system was used for corneal topography examinations. Baseline keratographs were taken two times at straight gaze. A repeat corneoscope photograph was immediately obtained in temporal gaze. Then the tears at the pterygium apex were dried with a cellulose sponge, and a new corneoscope photograph was immediately obtained without allowing one to blink. Corneal topographic maps ( numeric maps) were divided into 301 fields in 24 meridians. One colour was allocated to each field, representing its mean refractive power for all groups. In all eyes, keratometric astigmatism at the 3 mm central cornea and total mean corneal refractive power were found. Data were compared using paired-samples two-tailed t-tests. Results Keratometric astigmatism at the 3 mm central cornea was significantly reduced at the temporal gaze (3.10 +/- 2.34 D, t = 3.40, P = 0.027) and dried eyes (2.12 +/- 1.01 D, t = 4.74, P = 0.001) according to the first baseline measurement (4.31 +/- 1.91 D) of the total mean corneal refractive power was found to be 43.45 +/- 1.28 D (39.29-45.87) at the first baseline measurement. There was no change at the temporal gaze (43.54 +/- 1.06 D, P>0.05). However, the total corneal refractive power was significantly higher in dried eyes (44.26 +/- 0.93 D, t = 34.92, P<0.001). The steepest region of corneal topography was a superior quadrant, and the flattest area was a nasal quadrant at the baseline. At the temporal gaze, the cornea was significantly flatter in the superior and inferior sides of the pterygium meridian. After dried pooling of tears, topographic abnormalities returned, and the cornea became more uniform and symmetric. Conclusion We conclude that the pooling of tears at the pterygium apex plays an important role, but fibrovascular traction has no effect on the corneal topographical changes induced by pterygium.
Intraoperative Application of Mitomycin C in the Surgical Treatment of Pterygium
(Wichtig Editore, 1998) Demirok, A; Simsek, S; Çinal, A; Yasar, T
Purpose. To investigate the effectiveness of intraoperative mitomycin C in pterygium surgery. Methods. The effectiveness of intraoperatively administered mitomycin C and the occurrence of postoperative complications were evaluated in 17 patients with two recurrences of pterygium. The authors employed the "bare-sclera technique" and placed a sterile sponge soaked in a 0.02% mitomycin C solution intraoperatively in the episcleral space for 3 minutes. The control group (15 patients) underwent only surgical excision. Patients were followed for 21 to 30 months. Results. The pterygium recurred in one (5.9%) of the 17 patients in group 1 and in six (40%) of the 15 controls. Statistical analysis using Fisher's exact test showed a significant (p=0.027) reduction of recurrences of pterygium in the group treated intraoperatively with mitomycin C. No serious complications or side effects arose during the follow-up period. Conclusions. Mitomycin C administered intraoperatively can be considered an effective treatment to improve the success rate after surgical excision.
Latanoprost Therapy in Patients With Glaucoma and Ocular Hypertension Inadequately Controlled With Carteolol
(Springer Japan Kk, 2004) Yasar, T; Ozdemir, M; Andi, I; Ozdemir, G; Simsek, S
A Newbom With Lipemia Retinalis
(Slack inc, 2003) Ozdemir, M; Bay, A; Yasar, T; Cinal, A
Lipemia retinalis is a rare ocular manifestation of certain types of hyperlipidemia. A case of a newborn with lipemia retinalis evaluated by laboratory and clinical findings is described. A creamy white appearance of all retinal blood vessels was demonstrated by color fundus photographs. The patient had elevated levels of triglycerides (29,000 mg/dL) and cholesterol (1,470 mg/dL). Lipid electrophoresis indicated hyperprebetalipoproteinemia. Type IV primary hyperlipoproteinemia was diagnosed.
Peribulbar Anesthesia: One Versus Two Injections
(Slack inc, 1997) Demirok, A; Simsek, S; Cinal, A; Yasar, T
BACKGROUND AND OBJECTIVE: The authors describe their prospective, randomized study of a single peribulbar injection into the junction of the lateral third and medial two thirds of the lower lid compared with the standard two-injection peribulbar technique. PATIENTS AND METHODS: One hundred twenty patients undergoing elective intraocular surgery were randomly allocated to receive either one or two injections of a mixture of balanced salt solution, 2% lidocaine, 0.5% bupivacaine, and hyaluronidase. Preoperative akinesia was assessed following the injections. At the end of surgery, the patients were asked if they had experienced any pain or discomfort during surgery. RESULTS: There was no significant difference in pain or globe akinesia between the two groups. CONCLUSION: The single peribulbar injection was found to be as effective as the standard two-injection peribulbar technique.