Handan Bardak

In vivo biometric evaluation of Schlemm's canal with spectral-domain optical coherence tomography in pseuduexfoliation glaucoma.

To perform in vivo imaging of the Schlemms canal (SC) with anterior segment spectral‐domain optical coherence tomography [AS‐spectral‐domain (SD)‐OCT] and also to measure its biometric parameters including the SC length and SC area in patients with pseudoexfoliation (PEX) glaucoma.

Evaluation of Refractive Errors and Ocular Biometric Outcomes after Intravitreal Bevacizumab for Retinopathy of Prematurity

ABSTRACT Purpose: To assess ocular biometric outcomes following intravitreal bevacizumab (IVB) monotherapy for retinopathy of prematurity (ROP) and compare these results with those of laser photocoagulated infants and with the ones with spontaneously regressed ROP. Materials and methods: Premature infants including those who underwent IVB monotherapy (Group 1) or laser photocoagulation (Group 2) for ROP and infants with spontaneously regressed ROP (Group 3) were recruited for the study. Refractive errors and ocular biometric parameters (Axial length [AL], anterior chamber depth [ACD], and lens thickness [LT]) were measured at adjusted 1 year of age in all subjects. Results: There was no significant difference of spherical equivalent (SE) value between the groups (P = 0.781). The incidence of high myopia was 7.4% in Group 1 and 12.7% in Group 2 (P = 0.081). No infants exhibited high myopia in Group 3. LT was greater in Group 2 when compared to Group 1 and Group 3 (P = 0.011). Lower SE was significantly correlated to longer AL in Group 1 (r = −0.656, P = 0.015). There was a significant positive correlation between SE and ACD values in Group 2 (r = 0.391, P = 0.005). Conclusion: The study showed no significant difference of SE between the groups. High myopia was only present among the treated infants either with IVB or laser. Infants who received laser treatment significantly had thicker lenses.

Effect of Single Intravitreal Bevacizumab on Ophthalmic and Middle Cerebral Arterial Blood Flow in Retinopathy of Prematurity

Purpose: To evaluate the effect of a single intravitreal bevacizumab (IVB) injection on blood flow parameters in the ophthalmic artery (OA) and middle cerebral artery (MCA) in infants with retinopathy of prematurity (ROP). Materials and Methods: This prospective and interventional study included 15 infants with ROP who were treated with IVB. Peak systolic velocity (PSV), end-diastolic velocity, mean velocity (MV) and resistivity index were measured using pulse wave Doppler ultrasonography (Philips En Visor C, Amsterdam, The Netherlands) in the OA and MCA, before IVB injection and 1 day, 1 week and 1 month after IVB injection. Results: Measurements of PSV-OA, MV-OA and PSV-MCA showed significant changes after IVB treatment (p = 0.01, p = 0.02, p = 0.02, respectively). The PSV-OA measurements at 1 week and 1 month were significantly lower than the baseline PSV-OA measurement (p = 0.03 and p = 0.01, respectively). The MV-OA measurement was significantly lower at 1 month following IVB as compared to the baseline MV-OA measurement (p = 0.03). The PSV-MCA showed a significant decline 1 day after IVB injection (p = 0.03). Conclusions: The study demonstrated that IVB causes significant alterations in blood flow parameters in the OA and MCA predicted by Doppler ultrasonography in infants with ROP.

Effect of Single Administration of Coffee on Pupil Size and Ocular Wavefront Aberration Measurements in Healthy Subjects

No study has so far evaluated the impact of coffee drinking on ocular wavefront aberration (OWA) measurements. This study presents novel findings regarding the OWA of the eye following coffee intake. We aimed to evaluate the acute changes in pupil size and OWA of the eye after single administration of coffee. A total of 30 otherwise healthy participants were included in this prospective study. All subjects drank a cup of coffee containing 57 mg caffeine. Measurements of pupil size, total coma (TC), total trefoil (TF), total spherical aberration (TSA), and total higher order aberration (HOA) were performed before and at 5 minutes, at 30 minutes, and at 4 hours after coffee drinking using a wavefront aberrometer device (Irx3, Imagine Eyes, Orsay, France). The mean age of the study population was 20.30 ± 2.74 years. Pupil size did not show a significant change during the measurements (p > 0.05). A significant increase was observed in TF and HOA measurements following coffee intake (p = 0.029 and p = 0.009, resp.). Single administration of coffee results in significant increase in TF and total HOAs in healthy subjects without any effect on pupil diameter. Ultrastructural changes in the cornea following coffee intake might be of relevance to the alterations in ocular aberrations in healthy subjects.

Protective effects of melatonin and memantine in human retinal pigment epithelium (ARPE-19) cells against 2-ethylpyridine-induced oxidative stress: implications for age-related macular degeneration

Abstract Purpose: To investigate the possible protective effects of melatonin and memantine (MMT) against 2-ethylpyridine (2-EP)-induced oxidative stress and mitochondrial dysfunction in human RPE (ARPE-19) cells in vitro. Materials and methods: The ARPE-19 cells were divided into seven groups. Oxidative stress was triggered by incubating the ARPE-19 cells with 30 μM of 2-EP for 24 h. Then, 200 μM of melatonin was administered over three days and 20 μM of MMT over six hours prior to the experiment. The effects of melatonin and MMT on the intracellular calcium release mechanism, reactive oxygen species production, caspase-3 and caspase-9 activities, as well as vascular endothelial growth factor levels were measured. Results: Melatonin and MMT were found to significantly decrease apoptosis levels. The intracellular calcium release was regulated by both melatonin and MMT. Further, melatonin and MMT significantly decreased both caspase-3 and caspase-9 activities, as well as pro-caspase and poly(ADP-ribose) polymerase expression, in ARPE-19 cells. Moreover, melatonin significantly increased the protective effect of MMT. The combination of melatonin and MMT significantly decreased 2-EP-induced oxidative toxicity and apoptosis by inhibiting the intracellular reactive oxygen species production and mitochondrial depolarization levels. Conclusions: These notable findings are the first to demonstrate the synergistic protective effects of melatonin and MMT against 2-EP-induced oxidative stress in ARPE-19 cells.

Characteristics of Severe Retinopathy of Prematurity in Infants with Birth Weight above 1500 Grams at a Referral Center in Turkey

Purpose To demonstrate the clinical characteristics and treatment outcomes of severe retinopathy of prematurity (ROP) in preterm infants with birth weight (BW) above 1500 g in Turkey. Methods A retrospective review of 5920 ROP records was performed in Zeynep Kamil Maternity and Children’s Diseases Training and Research Hospital. The records were obtained from ROP treatment center of the same institute between 2011 and 2016. The data comprised the demographic and clinical characteristics including, gestational age, BW, systemic risk factors, zone and stage of ROP, ROP type, treatment modality, treatment outcomes and inborn/outborn status of the babies. Results A total of 36 infants (71 eyes) with severe ROP and BW> 1500 g were retrieved. There were 30 infants (83.3%) with type 1 ROP and 6 infants (16.7%) with aggressive posterior ROP (APROP). 3 infants (8.3%) were born at our hospital whereas 33 (91.7%) were referred from outer private neonatal intensive care unit (NICU) centers. Zone I APROP was detected during the initial screening. 21 infants (58.3%) underwent laser treatment while 15 (41.7%) received intravitreal bevacizumab (IVB) injections. No unfavorable structural outcome was observed following either treatment modality. Conclusion Severe ROP may occur in heavier preterm infants. Laser treatment and IVB injections were useful in selected cases. Presence of APROP at first examination suggests an earlier screening in heavier babies. Standardization of private NICU centers as well as establishing a national ROP protocol is necessary in Turkey.

Retinal and choroidal thicknesses measured with swept-source optical coherence tomography after surgery for idiopathic macular hole.

Purpose To evaluate the changes in retinal nerve fiber layer thickness (RNFLT), ganglion cell layer thickness (GCLT), retinal thickness (RT), and subfoveal choroidal thickness (SFCT) in eyes that received pars plana vitrectomy (PPV) with internal limiting membrane (ILM) peeling for idiopathic macular hole (IMH) and to compare these data with data from fellow eyes and healthy controls. Methods This cross-sectional study included 49 subjects. Eighteen eyes that underwent surgery for IMH, 18 fellow eyes, and 31 eyes of the healthy controls were designated as group 1, group 2, and group 3, respectively. The RNFLT, GCLT, RT, and SFCT were measured by using the swept-source optical coherence tomography (SS-OCT) device at last postoperative visit. Results The RNFLT was significantly lower in group 1 than group 2 and group 3 (p<0.05). The GCLT was significantly reduced in all sectors in group 1 as compared to group 2 and group 3 (p<0.05). The RT was found to be significantly lower (except in central field) in group 1 than group 2 and group 3 (p<0.05). The SFCT was significantly decreased in group 1 as compared to group 2 and group 3 (p<0.05). Conclusions A reduction in the RNFLT, GCLT, RT, and SFCT was observed following PPV with ILM peeling for IMH detected by SS-OCT.

Novel Zinc Finger Protein Gene 469 (ZNF469) Variants in Advanced Keratoconus

ABSTRACT Purpose: Common polymorphic variants upstream of Zinc finger protein gene 469 (ZNF469) have been associated with central corneal thickness. Rare ZNF469 variants have been shown in keratoconus patients. The aim of the current study was to investigate the frequency of ZNF 469 gene variants in rapidly progressive advance keratoconus patients who underwent corneal transplant surgery by the age of 30, compared to their frequency in the normal Turkish population. Methods: A search in a patient database was performed to identify patients with a rapidly progressive keratoconus requiring corneal transplant surgery by the age of 30 in at least one eye. Twenty-six advance keratoconus patients (study group) and 109 health subjects (control group) were included in the study. Blood samples were donated, and genomic DNA was extracted. The entire coding sequence of the ZNF469 gene including the 84 bp of the putative intron was amplified using PCR primers and analyzed using next generation sequencing (NGS). Results: Fifteen single nucleotide polymorphisms previously reported and registered to the dbSNP database were detected in the study group. The allele frequencies of these polymorphisms were higher in the keratoconus group compared to the control group and to the ExAC genome database. Three new missense heterozygote variants and one new synonym variant were detected in keratoconus group. According to prediction software, the P873T and Q2188H variants were shown to be non-tolerated, whereas G3424S could be tolerated. The synonymous variant R1060R is not predicted to lead to abnormal splicing by Human Splicing Finder in silico analysis. Conclusion: New detected ZNF 469 P873T and Q2188H heterozygote coding variants in isolated advance keratoconus patients may be associated with the disease pathogenesis.

Ocular Surface Characteristics in Diabetic Children

ABSTRACT Purpose: To compare tear film osmolarity (TFO) and other dry eye tests between diabetic children and normal healthy children. Materials and Methods: Twenty-six diabetic children (Group 1) and 20 healthy children without any ocular and/or systemic disorder (Group 2) were enrolled in the study. Detailed ocular surface assessment including, ocular surface disease index (OSDI) questionnaire, TFO measurement (Tear Lab Osmolarity System, San Diago, CA, USA), corneal epithelial thickness (CET) measurement using the anterior segment optical coherence tomography (OCT) (RTVue CAM, Optovue Inc, CA, USA), tear film break-up time (TFBUT) test, Schirmer test, meibography, and conjunctival brush cytology were performed. The results were compared between the groups. Results: The mean TFO was significantly higher in Group 1 (328.8 ± 12.8) than Group 2 (313.6 ± 15.1) (p = 0.001). The mean Schirmer test score was significantly lower in Group 1 (16.7 ± 5.1) than Group 2 (23.6 ± 5.6) (p = 0.00). Cytologic analysis revealed grade 0 changes in 11 patients (42.3%), grade 1 changes in 13 patients (50%), and grade 2 changes in 2 patients (7.7%) in Group 1 whereas grade 0 changes in 18 patients (90%) and grade 1 changes in 2 patients (10%) were observed in Group 2 (p = 0.004). The TFO levels were significantly associated with HbA1c levels (r = 0.459, p = 0.018). Conclusion: The study revealed significantly higher TFO, lower Schirmer test scores and changes in conjunctival cytology in diabetic children. Altered ocular surface changes in diabetic children may be due to the result of increased TFO.

Influence of the epiretinal membrane on ranibizumab therapy outcomes in patients with diabetic macular edema

Purpose: To investigate the influence of the epiretinal membrane (ERM) on intravitreal ranibizumab (IVR) therapy for diabetic macular edema (DME). Methods: This retrospective study included 56 eyes of 48 patients with DME divided into two groups: the DME with ERM (study) and only DME (control) groups. Changes in the central macular thickness (CMT) and best-corrected visual acuity (BCVA) were evaluated. Results: In the study group, although the CMT was significantly reduced following the first injection (p<0.001), BCVA did not improve significantly (p=0.296). However, after the first injection, the control group exhibited both a significant decrease in CMT (p<0.001) and improvement in BCVA (p<0.001). However, the improvement in BCVA in the control group was not significantly different from the outcome of the study group. Conclusions: We observed a negative short-term influence of the ERM on IVR treatment for DME.