Browsing by Author "Akova, Yonca A."

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    Does topical bevacizumab prevent postoperative recurrence after pterygium surgery with conjunctival autografting?
    (2014) Karalezli, Aylin; Kucukerdonmez, Cem; Akova, Yonca A.; Koktekir, Bengu Ekinci
    AIM: To assess the effect of topical bevacizumab use on postoperative pterygium recurrence in eyes who underwent pterygium excision with limbal -conjunctival autograft transplantation (LCAT). METHODS: eighty -eight eyes of 88 patients with primary pterygium were included. Pterygia were graded preoperatively from type 1 to type 3 (type 1 atrophic, type 3 inflamed) according to the inflammatory status. The eyes were preoperatively randomized to receive topical steroid and antibiotic treatment (group 1, 46 eyes) and additional topical bevacizumab (5 mg/mL; group 2, 42 eyes) in the postoperative period. All eyes underwent pterygium excision and LCAT. Medications were tapered and discontinued at one month. Postoperative complications and recurrence rates were recorded. RESULTS: The mean follow -up duration was 29.3 +/- 4.2mo (24-52mo) and 28.5 +/- 3.4 (24-48mo) in group 1 and 2, respectively (P>0.05). There were no statistically significant differences regarding the age or gender between groups (P>0.05). Also, the difference between groups with respect to pterygium type was not significant. During the follow -up period, recurrence developed in 2 eyes (4.3%) in group 1, whereas in one eye (2.4%) in group 2. No statistically significant difference between groups was found in recurrence rates (P>0.05). No re-operation for recurrence was necessary during the follow-up period in both groups. CONCLUSION: Topical bevacizumab seems to have no additonal effect on pterygium recurrence after LCAT.
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    Does Topical Bevacizumab Prevent Postoperative Recurrence After Pterygium Surgery with Conjunctival Autografting?
    (2014) Karalezli, Aylin; Kucukerdonmez, Cem; Akova, Yonca A.; Koktekir, Bengu Ekinci; 24967201
    AIM: To assess the effect of topical bevacizumab use on postoperative pterygium recurrence in eyes who underwent pterygium excision with limbal -conjunctival autograft transplantation (LCAT). METHODS: eighty -eight eyes of 88 patients with primary pterygium were included. Pterygia were graded preoperatively from type 1 to type 3 (type 1 atrophic, type 3 inflamed) according to the inflammatory status. The eyes were preoperatively randomized to receive topical steroid and antibiotic treatment (group 1, 46 eyes) and additional topical bevacizumab (5 mg/mL; group 2, 42 eyes) in the postoperative period. All eyes underwent pterygium excision and LCAT. Medications were tapered and discontinued at one month. Postoperative complications and recurrence rates were recorded. RESULTS: The mean follow -up duration was 29.3 +/- 4.2mo (24-52mo) and 28.5 +/- 3.4 (24-48mo) in group 1 and 2, respectively (P>0.05). There were no statistically significant differences regarding the age or gender between groups (P>0.05). Also, the difference between groups with respect to pterygium type was not significant. During the follow -up period, recurrence developed in 2 eyes (4.3%) in group 1, whereas in one eye (2.4%) in group 2. No statistically significant difference between groups was found in recurrence rates (P>0.05). No re-operation for recurrence was necessary during the follow-up period in both groups. CONCLUSION: Topical bevacizumab seems to have no additonal effect on pterygium recurrence after LCAT.
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    Subconjunctival Bevacizumab in The Impending Recurrent Pterygia
    (2014) Bayar, Sezin Akca; Kucukerdonmez, Cem; Oner, Ozlem; Akova, Yonca A.; https://orcid.org/0000-0001-5109-755X; 24026871; AAJ-2406-2021
    The aim of this study is to evaluate the efficacy and safety of subconjunctival bevacizumab injection(s) in the treatment of impending recurrent pterygia. Twenty-three eyes of 23 patients who developed impending recurrence after pterygium surgery with conjunctival autografting and were treated with subconjunctival bevacizumab injection(s) (2.5 mg/0.1 mL) were included in the study. Anterior segment photographs were taken prior to and at 1 week, 1, 3 and 6 months after the injection, and at the end of the follow-up period. Image analysis was performed using an image processing and analysis software program. Recurrence rate and complications were recorded. The mean age and follow-up time of the patients were 51.2 +/- A 6.2 (31-60 years) and 16.8 +/- A 3.1 (12-22 months), respectively. The average number of injections was 2 +/- A 0.78 (1-3). Sixteen eyes required re-injection (two injections in nine eyes, three injections in seven eyes), due to progression of vascularization. There were significant differences between size percentage of lesions before injection and at 1 week, 1, 3 and 6 months after the injection (p < 0.05 for all). Corneal recurrence developed in only one patient and no ocular or systemic side-effects of bevacizumab were observed. Repeated injections of bevacizumab may help to prevent the high recurrence rate of residual impending pterygium, due to its adjuvant role in decreasing lesion size, especially in the first year after surgery.
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    Topikal ve subkonjonktival bevacizumab (avastin) uygulamasının deneysel korneal neovaskülarizasyon modelindeki inhibitör etkisinin araştırılması ve karşılaştırılması
    (Başkent Üniversitesi Tıp Fakültesi, 2008) Öner, Veysi; Akova, Yonca A.; Küçükerdönmez, Cem
    Bu çalısma yüksek ve düsük doz topikal ve subkonjonktival bevacizumab (Avastin, Genentech Inc., San Fransisco, Ca, USA) uygulamasının sıçan modelinde korneal neovaskülarizasyondaki inhibitör etkilerinin arastırılması ve karsılastırılması amacıyla yapılmıstır. Sprague-Dawley türü, 20 erkek sıçanın korneaları gümüs nitrat çubukları kullanılarak kimyasal olarak koterize edildi. Sıçanlar 4 gruba ayrıldı: düsük doz (grup 1) ve yüksek doz (grup 2) topikal bevacizumab (Avastin) gruplarına sırasıyla günde 2 defa 4 mg/ml ve 12.5 mg/ml topikal bevacizumab (Avastin), subkonjonktival enjeksiyon grubuna (grup 3) 1. 3. 5. ve 7. günlerde 0.05 ml/1.25 mg subkonjonktival bevacizumab ve kontrol grubuna (grup 4) günde 2 defa topikal suni gözyası uygulandı. Dijital fotoğraflar çekildi ve bir bilgisayar programı (Pixcavator Image Analyzer, Intelligent Perception,WV, USA) kullanılarak incelendi. Onuncu günde bütün sıçanlar sakrifiye edilerek gözleri enüklee edildi. Korneal kesitler alınarak histopatolojik değisiklikler incelendi. Ortalama neovasküler korneal alan kontrol grubunda % 63.32 ± 13.10 (ortalama ± SS), grup 3’te (subkonjonktival injeksiyon) % 50.22 ± 15.73 , grup 1’de (düsük doz topikal bevacizumab) % 26.76 ± 10.23 ve grup 2’de (yüksek doz topikal bevacizumab ) % 25.52 ± 12.45 olarak bulundu. Kontrol grubu ile grup 1 (düsük doz topikal bevacizumab) ve grup 2 (yüksek doz topikal bevacizumab) arasındaki fark istatistiksel olarak anlamlı bulundu (p1,p2<0.01). Fakat grup 3 (subkonjonktival enjeksiyon grubu) ile kontrol grubu arasındaki fark istatistiksel olarak anlamlı bulunmadı (p>0.05). Korneal kesitlerin histopatolojik incelemesinde düsük ve yüksek doz topikal bevacizumab ile tedavi edilen gözlerde kontrol grubuna göre daha az neovasküler korneal alan ve korneada daha az sayıda eritrosit içeren damar olduğu görüldü.Topikal bevacizumab (Avastin) uygulaması deneysel korneal neovaskülarizasyonu azaltmaktadır ancak subkonjonktival bevacizumab (Avastin) enjeksiyonunun bu konudaki etkisi yetersiz görünmektedir. Sonuçlar topikal bevacizumab uygulamasının doz arttırılmasına gerek kalmadan ( 4 mg/ml veya 12.5 mg/ml) korneal anjiyojenezi inhibe ettiğini göstermektedir. Topikal bevacizumab (Avastin), klinik kullanımda korneal neovaskülarizasyon tedavisine katkı sağlayabilir. This study was carried out to evaluate and compare the inhibitory effects of topical high dose, low-dose and subconjunctival bevacizumab (Avastin, Genentech Inc., San Francisco, Ca, USA) on corneal vascularization in a rat model. Corneas of 20 Sprague-Dawley male rats were chemically cauterized with silver nitrate sticks. Animals were divided in four groups: low-dose (group 1) and high-dose (group 2) topical bevacizumab groups that received twice daily instillation of 4 mg/ml and 12.5 mg/ml bevacizumab, subconjunctival injection group (group 3) that received 0.05 ml (1.25mg) of bevacizumab on day 1, 3, 5 and 7; control group (group 4) that received only topical artificial tear drops twice daily, respectively. Digital photographs of the corneas were taken and analyzed using an image analysis software (Pixcavator Image Analyzer, Intelligent Perception,WV, USA). On day 10, all animals were sacrificed and the eyes were enucleated. Corneas were excised and examined for changes in histology. The mean percentage of neovascularized corneal area in the control group was 63.32 % ± 13.10 (mean ± SD), 50.22 % ± 15.73 in group 3 (subconjunctival injection), 26.76 % ± 10.23 in group 1 (low dose topical bevacizumab) and 25.52 % ± 12.45 in group 2 (high dose topical bevacizumab). The differences between control group and group 1 (low dose topical bevacizumab) and group 2 (high dose bevacizumab) were found to be statistically significant (p1,p2 < 0.01). However, there was no statistically significant difference of mean percentage values between group 3 ( subconjunctival injection ) and control group (p > 0.05). In histopathological examination of the excised corneas, treated eyes with low and high dose bevacizumab (Avastin) showed significantly less neovascular area and number of vessels than the control group.Topical application of bevacizumab (Avastin) reduces experimental corneal vascularization compared with the control group, but the effect of subconjunctival injection of bevacizumab (Avastin) seems to be insufficient. These results suggest that topical bevacizumab is able to inhibit corneal angiogenesis, without increasing the dosage (4mg/ml or 12.5mg/ml for topical form). Clinical use of topical bevacizumab may have an additional effect in the treatment for corneal neovascularization.