Researcher: Müftüoğlu, Orkun
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Publication Metadata only Persistence of the cone on the posterior corneal surface affecting corneal aberration changes after intracorneal ring segment implantation in patients with keratoconus(2018) Aydın, Rukiye; Müftüoğlu, İlkay Kılıç; N/A; Müftüoğlu, Orkun; Faculty Member; School of Medicine; 188588Purpose: To analyze the changes in anterior and posterior corneal surfaces and aberrations in patients who underwent intracorneal ring segment (ICRS) implantation for the treatment of keratoconus. Methods: Eighty-nine eyes of 59 patients with keratoconus who underwent ICRS implantation were analyzed. All eyes were evaluated using a tomography system combining a Placido disc and Scheimpflug photography before and at least 6 months after surgery. Total, anterior, and posterior corneal aberrations, anterior and posterior sagittal and tangential anterior and posterior curve analysis, keratometry (K), minimum corneal thickness, and anterior chamber depth were analyzed before and after surgery. Results: Flattening with a decrease in the cone shape on the anterior corneal surface and steepening in the paracentral area with persistence of cone appearance on the posterior corneal surface were noted in all cases after ICRS implantation. The total corneal higher-order aberrations (HOAs) significantly decreased from 1.09 +/- 0.43 to 0.71 +/- 0.32 mm, and anterior corneal HOAs significantly decreased from 0.98 +/- 0.46 to 0.81 +/- 0.37 mm, whereas the posterior corneal HOAs increased from 0.53 +/- 0.29 to 0.66 +/- 0.25 mm after ICRS implantation (P < 0.05). There was a significant decrease in anterior maximum keratometry, but there was a significant increase in posterior maximum keratometry after ICRS implantation (P < 0.05). Conclusions: The cone shape persists on the posterior corneal surface despite its correction on the anterior corneal surface, leading to a decrease in anterior corneal aberrations and an increase in posterior corneal aberrations after ICRS implantation in eyes with keratoconus.Publication Metadata only Cataract surgery in patients with corneal disease(Medical Network, 2017) N/A; N/A; Müftüoğlu, Orkun; Taş, Ayşe Yıldız; Faculty Member; Faculty Member; School of Medicine; School of Medicine; 188588; 200905Preexisting corneal disease can be exacerbated by cataract surgery and may prevent well tolerated cataract extraction. Thisarticle describes how corneal epithelial, stromal, endothelial disease may impact and be impacted by cataract surgery whilehighlighting recommendations for perioperative management and surgical technique. / Kornea problemleri varlığında katarakt cerrahisi, hastanın mevcut bulgularını kötüleştirebilmekte ya da cerrahi basamaklarını zorlaştırabilmektedir. Bu yazının amacı korneal epitelyal, stromal, endotelyal problemlerin katarakt cerrahisinden nasıl etkilendiğini ve katarakt cerrahisi basamaklarını nasıl etkilediğini göz önüne sermektir.Publication Metadata only Results of ethanol-assisted epithelium-on corneal cross-linking with and without intrastromal corneal ring implantation(Springer, 2019) Ayar, Orhan; Akdemir, Mehmet Orcun; Ozmen, Mehmet Cuneyt; N/A; Müftüoğlu, Orkun; Faculty Member; School of Medicine; 188588PurposeTo evaluate the topographic, refractive, and pachymetric changes after ethanol-assisted transepithelial corneal cross-linking (CXL) to stabilize progression of keratoconus (KC).Patients and methodsThis study retrospectively evaluated the long-term topographic, refractive, and pachymetric changes in patients diagnosed with KC who underwent corneal cross-linking and/or intrastromal corneal ring segment (ICRS) implantation. The subjects were divided into three groups, corresponding to eyes treated with CXL alone (group1), CXL and ICRS at the same time (group2), and CXL after ICRS implantation (group3). Corrected visual acuity and refraction, steep keratometry (SteepK) values, steepest keratometry reading on sagittal curvature map, and corneal thickness were recorded preoperatively and at each visit. Changes between measurements were assessed during follow-up.ResultsCorrected distant visual acuity (CDVA) values improved in all groups compared with baseline, but the differences were not statistically significant except for the first year (p>0.05). In groups1 and 3, SteepK values did not change statistically significantly during the entire follow-up (p>0.05). In group2, SteepK values statistically significantly decreased at all follow-up examinations compared with baseline, determined as the first month after ICRS implantation (p<0.05). Complication rates were acceptable without any need for surgical intervention.ConclusionsSingle-session ethanol-assisted transepithelial CXL with or without ICRS implantation was a safe and effective procedure to halt progression of KC.Publication Metadata only Keratopigmentation: is it a miracle or an adventure?(Kare Yayıncılık, 2020) N/A; N/A; Karslıoğlu, Melisa Zişan; Taş, Ayşe Yıldız; Kesim, Cem; Şahin, Afsun; Müftüoğlu, Orkun; Doctor; Faculty Member; Doctor; Faculty Member; Faculty Member; N/A; School of Medicine; N/A; School of Medicine; School of Medicine; Koç University Hospital; Koç University Hospital; Koç University Hospital; N/A; N/A; N/A; 200905; 387367; 171267; 188588Objectives: this study is an analysis of the cosmetic and functional results of patients who underwent keratopigmentation (KTP). Methods: sixteen eyes of 16 patients, 7 females (43.75%) and 9 males (56.25%) were included in the study. Intrastromal and superficial manual KTP were performed under general anesthesia. Patients with no light perception or with only light perception but total corneal opacification, prosthetic contact lens intolerance, or unwillingness to use a contact lens were studied. The main outcomes were postoperative patient’s satisfaction, cosmetic results, pigment stabilization and surgical complications. A grading system (0-5 points) was used to assess patient satisfaction and the cosmetic results. Results: the mean age of the patients was 30.5±12.06 years (range: 16-53 years). Black pigment was used in 10 patients (62.5%), a brownish color in 5 patients (31.25%) and a greenish, yellow, blue, and black color pigmentation was used for 1 patient (6.25%). The mean follow-up was 29.31±15.45 months (range: 8-52 months). In 2 of 16 patients, mild to moderate pigment loss was seen 12 months after the surgery and superficial KTP was repeated. Minimal pigment loss was seen in 5 patients, but the cosmetic results were satisfactory and no secondary surgical procedure was required. Pigment leakage underneath the conjunctiva was seen in only 1 patient. Otherwise, there were no complications associated with keratopigmentation. The postoperative mean patient satisfaction score was 4.18±0.75 points (range: 3-5 points). Conclusion: KTP is a safe surgical procedure that is easy to learn and perform, does not require expensive materials, and avoids more extensive and invasive reconstructive ocular procedures. Corneal KTP may have a great impact on future ophthalmic surgical practice from both therapeutic and cosmetic perspectives.Publication Open Access Capecitabine-induced bilateral ectropion: a rare ocular manifestation requiring surgical intervention(Medknow Publications, 2018) N/A; N/A; Tatar, Sedat; Yalçın, Can Ege; Sezgin, Billur; Taş, Ayşe Yıldız; Müftüoğlu, Orkun; Özmen, Selahattin; Faculty Member; Faculty Member; Faculty Member; Faculty Member; School of MedicineIt has been established that many chemotherapeutic agents are associated with a variety of ocular side effects. As an antineoplastic agent, 5-fluorouracil (5-FU) is the chemotherapeutic agent that is frequently linked with cicatricial ectropion. Capecitabine is a prodrug of 5-FU and has a more favorable side effect profile than 5-FU. Frequent side effects of capecitabine include gastrointestinal events and hand-foot-mouth syndrome; cicatricial ectropion is rather uncommon. Enzyme deficiencies affecting the capecitabine metabolism have been reported to be associated with exaggerated generalized systemic and cutaneous side effects; however, there are no cases in the literature reporting capecitabine-induced isolated bilateral-progressive ectropion. Although cessation of the agent is frequently sufficient for the treatment of ectropion, close follow-up is indicated in such patients as permanent damage may occur if the problem is left untreated. We report a case of capecitabine-induced bilateral cicatricial ectropion refractory to treatment cessation, ultimately requiring surgical treatment.Publication Open Access Comparison of three different diffractıve multifocal intraocular lenses with a +2.5, +3.0, and +3.75 diopter additıon power(Elsevier, 2019) Altınkurt, Emre; N/A; Müftüoğlu, Orkun; Faculty Member; School of MedicinePurpose: to compare the functional outcomes and astigmatic tolerability after implantation of multifocal intraocular lenses (IOLs) with a +2.5, +3.0, and +3.75 diopter (D) addition power. Methods: this study included 122 eyes of 61 patients who had bilateral cataract extraction and implantation of diffractive aspheric multifocal acrylic IOLs with +2.5 D (+2.5 group), +3.0 D (+3.0 group), and +3.75 D (+3.75 group) addition powers. 1-year after surgery, distance corrected near (DNVA) and intermediate (DIVA) visual acuities at 32, 40, 45, 50, 55, and 60 cm; and contrast sensitivity measurements under photopic, mesopic and mesopic with glare conditions; spherical and astigmatic defocus testing; distance-intermediate-near vision patient satisfaction levels; spectacle dependance; patient-reported outcomes were assessed binocularly. Results: the +2.50 D group had better DIVA than both +3.0 group and +3.75 groups at 45 cm, 50 cm, 55 cm, and 60 cm (p < 0.05). The +3.75 group had better DNVA than both +2.5 and +3.0 IOL groups at 32 cm (p < 0.05). There was no significant difference in mean contrast values at all frequencies between three IOL groups (p > 0.05). The +2.50 D group showed better astigmatic tolerability than +3.00 group (at 2.00 D) and +3.75 group (at 1.50 D, and at 2.00 D) (p < 0.05). Conclusion: multifocal IOLs with +2.5 add power have better intermediate vision, but worse near vision compared to multifocal IOLs with +3.00 D and +3.75 D add power. Multifocal IOLs with +2.50 D add power tend to have better astigmatic defocus tolerability than multifocal IOLs with +3.00 D and +3.75 D add powers.Publication Open Access Computer-based tutorial to enhance the informed consent process for cataract surgery in Serbian or Turkish speaking patients(Karger Publishers, 2021) Ruiss, M.; Findl, O.; Prinz, A.; Kahraman, G.; Barisic, S.; Hirnschall, N.; Müftüoğlu, Orkun; Faculty Member; School of Medicine; 188588Introduction: this study analyses if a translated version of the CatInfo tool increases the knowledge of Serbian-and Turkish-speaking patients about cataract surgery. Methods: in total, 61 cataract patients, literate in Serbian or Turkish, were randomly allocated into two groups. Via an interactive computer-based tool (""CatInfo""), patients either saw a detailed audio-visual presentation about cataract surgery (study group) or a ""placebo""video (control group). Afterwards, all participants had a face-to-face discussion with an ophthalmologist. Immediately after the interview and on the day of surgery, all patients had to fill out a questionnaire including knowledge and demographic questions. Patients in the study group were further asked about their satisfaction with the CatInfo tool and the usefulness of such a device before other interventions. Results: patients in the study group answered significantly more questions correctly compared to the control group, and this information gain remained stable over a 1-week period. There was a significant low negative correlation between educational level and the test results, whereas age and computer habits of the participants did not have an influence on correct answers. Satisfaction with the CatInfo tool was high in the Serbian and the Turkish group (96% and 84%, respectively), and 92% of Serbian patients as well as 62% of the Turkish patients rated that they could imagine to use such a device before any other surgery. Discussion/Conclusion: the translated version of the CatInfo tool improved patients' knowledge, and this information gain remained stable until the day of the surgery.Publication Open Access Comparison of postoperative corneal astigmatism induced by two different corneal incisions during microincisional cataract surgery(Kare Yayıncılık, 2022) Hasanreisoğlu, Murat; Karslıoğlu, Melisa Zişan; Kesim, Cem; Taş, Ayşe Yıldız; Müftüoğlu, Orkun; Şahin, Afsun; Faculty Member; Teaching Faculty; Faculty Member; Faculty Member; Faculty Member; School of Medicine; Koç University Hospital; 182001; N/A; N/A; N/A; 188588; 171267Introduction: Clear corneal incision (CCI) architecture in modern microincision cataract surgery (MICS) plays an undeniable role in postoperative refraction. The goal of this study was to evaluate the effect of hinge incision prior to two-step CCI on postoperative refractive astigmatism after cataract surgery and to demonstrate the schematic presentation of these postoperative astigmatic changes via double-angle polar plots. Methods: this study involved a consecutive case series of patients who had MICS. The first incision was performed as a two-step CCI, whereas the second was made as a hinge incision prior to 2-step CCI. The preoperative corneal and postoperative refractive astigmatism and surgically induced astigmatism (SIA) were calculated by vectorial analysis. Hotelling’s T2 test was performed to compare the centroid values of preoperative and postoperative corneal astigmatism. Results: a total of 63 eyes from 57 subjects were evaluated. Group I consisted of 27 eyes with the two-step CCI, and Group II included 36 eyes with the hinge incision prior to two-step CCI. No significant difference was found between the groups in terms of age, sex, axial length, keratometry readings, implanted intraocular lens power, and postoperative spherical equivalent. The centroids of corneal astigmatism postoperatively increased to 0.21 D at 87.6°±0.61 with no significance in Group I (p=0.525) and to 0.70 D at 90.6°±0.47 with significance in Group II (p=0.032). The difference in postoperative centroids between the two groups was also significantly different (p=0.043). Finally, the centroids of SIA were 0.12 D at 85.5°±0.50 and 0.22 D at 91.1°±0.49 for Group I and Group II, respectively, with no significance. Discussion and conclusion: A hinge incision did not have an unfavorable effect on postoperative refractive astigmatism; therefore, it may be preferred for controlled entrance to the anterior chamberPublication Open Access The effect of anterior segment depth on the accuracy of 7 different intraocular lens calculation formulas(Galenos Yayınevi, 2022) Kesim, Cem; Taş, Ayşe Yıldız; Karslıoğlu, Melisa Zişan; Hasanreisoğlu, Murat; Müftüoğlu, Orkun; Şahin, Afsun; Teaching Faculty; Faculty Member; Doctor; Faculty Member; Faculty Member; Faculty Member; School of Medicine; Koç University Hospital; N/A; 200905; N/A; 182001; 188588; 171267Objectives: to evaluate the effect of anterior segment depth (ASD; sum of anterior chamber depth and lens thickness) on the accuracy of 7 intraocular lens formulas calculated in patients with axial length (AL) between 22.5 and 24.5 mm.Materials and Methods: in this retrospective study, patients who underwent cataract surgery were divided into three groups based on their ASD measurements (Group I: ASD <7.30 mm, Group II: ASD between 7.30-7.90 mm, Group III: ASD >7.90 mm). The mean predictive error (MPE), mean absolute error (MAE), and median absolute error (MedAE) values of each group were compared. The effect of ASD on the predictive error (PE) of each lens formula was additionally tested in subgroups based on mean keratometry (K) values (Subgroup I: K <42.0 D, Subgroup II: K between 42.0-44.5 D, Subgroup III: K >44.5 D). Results: the study included 184 eyes of 184 patients. In Group I, all formulas except Olsen OLCR and Barrett II had clinically myopic MPEs. In Group II, the MPEs of all lens formulas except Barrett II were statistically non-different from zero (p>0.05). In Group III, the MPEs of all lens formulas were found to be statistically hyperopic. In Group III, all formulas except Olsen OLCR were significantly shifted to more hyperopic results when compared with Groups I and II (p<0.05). ASD was positively correlated with the PEs of the SRK/T, Holladay I, Hoffer Q, Barrett II, Hill-RBF, and Haigis formulas. In cases with mean K greater than 42.0 D, ASD was similarly correlated with PE for all formulas except Olsen OLCR.Conclusion: in eyes with AL between 22.5 and 24.5 mm, the predictions of lens formulas were significantly hyperopic in cases with greater ASD. / Amaç: ön segment derinliğinin (ÖSD; ön kamara derinliği ve lens kalınlığının toplamı), aksiyel uzunlukları (AU) 22,5 ve 24,5 mm arasında olan hastalarda 7 farklı göz içi lens formülü ile hesaplanan değerlerin doğrulukları üzerindeki etkisinin değerlendirilmesi. Gereç ve yöntem: bu retrospektif çalışmada, katarakt cerrahisi geçirmiş hastalar ÖSD ölçümlerine göre üç gruba ayrıldı (Grup 1: ÖSD <7,30 mm, Grup 2: ÖSD 7,30-7,90 mm arası, Grup 3: ÖSD >7,90 mm). Her grubun ortalama prediktif hata (OPH), ortalama mutlak hata (OMH) ve ortanca mutlak hata (OtcMH) değerleri karşılaştırıldı. ÖSD’nin lens formüllerinin prediktif hataları (PH) üzerindeki etkisi, ilaveten ortalama keratometri (K) değerlerine göre belirlenmiş alt gruplarda sınandı (alt Grup 1: K <42,0 D, alt Grup 2: K 42,0-44,5 D arası, alt Grup 3: K >44,5 D). Bulgular: çalışma 184 hastanın 184 gözünü kapsadı. Grup 1’de Olsen OLCR ve Barrett II haricindeki tüm formüller klinik miyopik OPH’ye sahipti. Grup 2’de Barrett II haricindeki tüm formüller istatistiksel olarak sıfırdan farksızdı (p>0,05). Grup 3’te tüm formüllerin OPH’leri istatistiksel olarak hipermetropik bulundu. Grup 3’te Olsen OLCR haricindeki tüm formüllerin Grup 1 ve 2’ye kıyasla istatistiksel olarak daha hipermetropik sonuçlara kaydığı bulundu (p<0,05). ÖSD; SRK/T, Holladay 1, HofferQ, Barrett II Hill-RBF ve Haigis formüllerinin PH’leriyle olumlu korele idi. ÖSD, ortalama K’nin 42,0 D’den büyük olduğu olgularda Olsen OLCR hariç tüm formüllerin PH’leriyle benzer şekilde korele idi. Sonuç: AU’su 22,5 ve 24,5 mm arasında olan gözlerde, daha büyük ÖSD’si olan gözlerin lens formül tahminleri anlamlı derecede hipermetropik idi.Publication Open Access Logistic regression model using Scheimpflug-Placido cornea topographer parameters to diagnose keratoconus(Hindawi, 2021) Altınkurt, Emre; Avcı, Özkan; Uğurlu, Adem; Cebeci, Zafer; Özbilen, Kemal Turgay; Müftüoğlu, Orkun; Faculty Member; School of Medicine; 188588Purpose: diagnose keratoconus by establishing an effective logistic regression model from the data obtained with a Scheimpflug-Placido cornea topographer. Methods: topographical parameters of 125 eyes of 70 patients diagnosed with keratoconus by clinical or topographical findings were compared with 120 eyes of 63 patients who were defined as keratorefractive surgery candidates. The receiver operating character (ROC) curve analysis was performed to determine the diagnostic ability of the topographic parameters. The data set of parameters with an AUROC (area under the ROC curve) value greater than 0.9 was analyzed with logistic regression analysis (LRA) to determine the most predictive model that could diagnose keratoconus. A logit formula of the model was built, and the logit values of every eye in the study were calculated according to this formula. Then, an ROC analysis of the logit values was done. Results: Baiocchi Calossi Versaci front index (BCVf) had the highest AUROC value (0.976) in the study. The LRA model, which had the highest prediction ability, had 97.5% accuracy, 96.8% sensitivity, and 99.2% specificity. The most significant parameters were found to be BCVf (p=0.001), BCVb (Baiocchi Calossi Versaci back) (p=0.002), posterior rf (apical radius of the flattest meridian of the aspherotoric surface in 4.5 mm diameter of the cornea) (p=0.005), central corneal thickness (p=0.072), and minimum corneal thickness (p=0.494). Conclusions: the LRA model can distinguish keratoconus corneas from normal ones with high accuracy without the need for complex computer algorithms.