Publications by authors named "Mehmet Hakan Tirhiş"

6 Publications

  • Page 1 of 1

Surgical Indications and Clinical Results of Patients with Exchanged Intraocular Lenses in a Tertiary Eye Hospital.

Turk J Ophthalmol 2016 Aug 15;46(4):156-160. Epub 2016 Aug 15.

Ulucanlar Eye Training and Research Hospital, Ankara, Turkey.

Objectives: To evaluate the demographics, surgical indications and clinical results of patients with repositioned or explanted intraocular lens (IOL) in a tertiary referral eye hospital.

Materials And Methods: Forty-eight eyes of 48 patients that underwent surgery to exchange or reposition the IOL at Ulucanlar Eye Training and Research Hospital between 2009 and 2013 were included in the study. Medical records of patients were evaluated for surgical indications, time elapsed since initial operation, preoperative and postoperative best corrected distance visual acuity and the presence of ocular disease.

Results: The mean age of the 31 male and 17 female patients was 64.91±14.26 years. Median time between the initial and final operations was 36.0 months. Pseudoexfoliation syndrome (PEX) was present in 25% of the patients. There was history of previous vitreoretinal surgery in 18.8% of patients, ocular trauma in 6.3%, high myopia and refractive surgery in 4% of patients. In the first operation the IOL was implanted in the sulcus in 50%, in the bag in 27.1%, and in the anterior chamber in 20.8%; following the final surgery the IOL was in the sulcus in 27.1%, in the anterior chamber in 22.9%, and fixated to the sclera in 10.4% of the patients, while the remaining 29.1% remained aphakic. Indication for the secondary surgery was IOL dislocation in 58%, corneal decompensation in 20.8% and IOL degeneration in 6.3%. In the final surgery, IOL was exchanged in 54.2% of the cases, removed in 31.3% of cases, and repositioned in 14.6%. Visual acuity improved by 1-3 lines in 52.3% and remained stable in 13.6% of the patients postoperatively.

Conclusion: IOL exchange may be necessary at any time following cataract surgery due to surgical complications, IOL dislocation, biometric measurement errors and corneal decompensation. Factors such as vitreoretinal surgery and the existence of PEX increase the risk of IOL exchange surgery.
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August 2016

Evaluation of corneal biomechanical properties using an ocular response analyser to examine aphakic and pseudophakic patients after congenital cataract surgery.

Acta Ophthalmol 2016 May 2;94(3):e198-203. Epub 2015 Nov 2.

Department of Ophthalmology, Hacettepe University, School of Medicine, Ankara, Turkey.

Purpose: We evaluated corneal biomechanical properties in aphakic and pseudophakic patients after congenital cataract surgery and compared the data with those of age-matched normal subjects.

Methods: We included 43 eyes of 43 aphakic or pseudophakic patients treated via congenital cataract surgery. As controls, 42 healthy age- and sex-matched subjects were enrolled. After a complete ophthalmic examination, central corneal thickness (CCT) and intraocular pressure (IOP) were determined. Corneal hysteresis (CH), corneal resistance factor (CRF), corneal-compensated IOP (IOPcc) and Goldmann-correlated IOP (IOPg) were recorded using an ocular response analyser.

Results: In the study group, 18 eyes were aphakic and 25 eyes pseudophakic. We found a significant difference in CCT between the aphakic, pseudophakic and control groups (p < 0.001). No significant among-group differences were detected in CH or CRF (p > 0.05). We found significant differences in IOPcc, IOPg and IOP measured with Goldmann applanation tonometry (IOPGAT ) between the study and control groups (p < 0.001). In contrast, we found no significant differences within the two study groups in terms of these three IOP values (p > 0.05).

Conclusion: Although CCT increased after congenital cataract surgery, corneal biomechanical parameters, including CH and the CRF, were not affected by such surgery. Determination of the IOPcc did not provide any additional information on true IOP, which was independent of CCT in both aphakic and pseudophakic patients after congenital cataract surgery.
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May 2016

Are There Any Changes in Corneal Biomechanics and Central Corneal Thickness in Fuchs' Uveitis?

Ocul Immunol Inflamm 2016 Oct 23;24(5):561-7. Epub 2015 Sep 23.

a Ulucanlar Eye Education and Research Hospital , Ankara , Turkey .

Purpose: To compare corneal biomechanics, intraocular pressure (IOP) and central corneal thickness (CCT) of 38 patients with unilateral Fuchs' uveitis (FU) with 42 healthy controls.

Methods: Corneal hysteresis (CH), corneal resistance factor (CRF), Goldmann-correlated and corneal-compensated IOP (IOPg and IOPcc, respectively) and CCT were measured.

Results: The mean CH, CRF, and IOPg of the involved FU eyes were significantly lower (9.5 ± 1.6, 9.0 ± 1.9 and 13.1 ± 4.3 mmHg) than contralateral eyes (10.1 ± 1.7, 9.9 ± 1.7 and 14.6 ± 3.4 mmHg), and controls (10.5 ± 1.5, 10.3 ± 1.5 and 14.8 ± 2.5 mmHg), respectively. There was no significant difference for mean IOPcc between involved FU or contralateral eyes and controls (14.8 ± 4.1, 15.5 ± 3.4 and 15.0 ± 2.7 mmHg). The CCT values correlated with CH and CRF in the involved and contralateral eyes.

Conclusions: Involved FU eyes had lower CH, CRF, and IOPg than contralateral eyes and controls, with no difference regarding IOPcc.
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October 2016

Histopathological Analysis of Internal Limiting Membrane Surgically Peeled From Eyes with Epiretinal Membrane.

Curr Eye Res 2016 7;41(2):258-65. Epub 2015 Apr 7.

d Department of Ophthalmology , Atatürk Research and Training Hospital , Ankara , Turkey.

Purpose: To investigate histopathological changes of internal limiting membrane (ILM) in patients with epiretinal membrane (ERM) Materials and Methods: Forty-two eyes of 42 patients who were diagnosed as ERM and enrolled for vitreoretinal surgery were included in this study. Brilliant Blue G (BBG) was used to stain the ILM in all patients. ILM was peeled in all subjects and analyzed by light microscopy (methylene blue-Azur II × 40). ILM samples were then fixed in 2.5% glutaraldehyde solution and examined in JEOL-JEM 1400 and 2100F electron microscope and photographed by CCD camera (Gatan Inc., Pleasanton, CA).

Results: Remained ERM fragments were observed on 80% of ILM's. Vacuolization of ILM was observed in a patient with diabetic ERM. There were cells and cellular fragments observed mostly at retinal side of ILM which was likely to be a fragment of Muller cells of retina.

Conclusions: Most of the ILM's had residual ERM tissue and contained cells and cellular fragments at retinal side of ILM's. ILM peeling might have a role in decreasing ERM recurrence by removal of residual ERM tissues.
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October 2016

Age-related changes in biomechanical parameters of the cornea and intraocular pressure in a healthy Turkish population.

Turk J Med Sci 2014 ;44(4):687-90

Ulucanlar Eye Education and Research Hospital, Ankara, Turkey.

Background/aim: To investigate age-related changes in intraocular pressure (IOP) and biomechanical parameters of the cornea in healthy subjects.

Materials And Methods: There were 404 healthy subjects included prospectively in this study. The subjects were divided into 3 groups (Group 1:93 subjects aged < 18, Group 2:189 subjects aged between 18 and 59, and Group 3:122 subjects aged ≥ 60). Corneal compensated IOP (IOPCC), Goldmann correlated IOP (IOPg), corneal hysteresis (CH), and corneal resistance factor (CRF) were measured by the Ocular Response Analyzer.

Results: When all the study groups were evaluated, a moderately significant negative correlation was found between age and CH and between age and CRF (Spearman's rho = -0.372 and -0.353, respectively; P < 0.0001 for both correlations). There were significant age-related differences among the 3 groups in terms of IOPg, CH, CRF, and central corneal thickness (P = 0.002, P = 0.000, P = 0.000, P = 0.006). There was no confirmation of any difference of IOPcc among the groups (P = 0.427).

Conclusion: The mean values of IOPg, CH, and CRF were lower than the other parameters in Group 3 but no significant differences were determined in IOPcc values in the age groups.
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January 2015

Changes of total antioxidant capacity and total oxidant status of aqueous humor in diabetes patients and correlations with diabetic retinopathy.

Int J Ophthalmol 2013 18;6(4):531-6. Epub 2013 Aug 18.

Department of Ophthalmology, Gazi Mustafa Kemal State Hospital, Ankara 06900, Turkey.

Aim: To measure changes of total oxidant status (TOS) and total antioxidant capacity (TAC) of aqueous humor (AH) in diabetic retinopathy (DR) patients, and to determine if there were any differences in TOS and TAC of AH in diabetic patients without retinopathy compared with non-diabetic patients.

Methods: One hundred and three eyes of 103 patients who were enrolled for cataract surgery were included in this study. Patients were grouped according to presence of diabetes and stage of DR. Prior to cataract surgery, 0.1mL to 0.2mL of AH was aspirated and analyzed for TAC and TOS level using a colorimetric method.

Results: TOS levels were highest among proliferative diabetic retinopathy (PDR) patients and lowest in patients with only cataracts. Results were statistically significant between all groups (P<0.05). Whereas result between diabetic without retinopathy patients and non-proliferative diabetic retinopathy (NPDR) patients was not statistically significant (P=0.757). TAC levels were highest in patients with only cataract and lowest among PDR patients and results were statistically significant between all groups (P<0.05).

Conclusion: Aqueous humor TAC levels are low in diabetic patients and reduced further in DR patients, TOS levels are increased in diabetic patients and this is exacerbated in DR patients.
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August 2013