Omer Karti

The Evaluation of Choroidal Vascular Changes Associated with Vascular Dysregulation in Patients with Multiple Sclerosis Using Enhanced Depth Imaging Optical Coherence Tomography

Purpose: To evaluate the choroidal thickness (CT) in patients with Multiple Sclerosis (MS) using enhanced depth imaging optical coherence tomography (EDI-OCT) and comparing it with healthy subjects. Material/Methods: Sixty-four eyes of 32 patients with MS (22 women, 10 men, mean age: 37.5 ± 8.21 years) were enrolled in this study. Their choroidal thickness was measured using EDI-OCT, and compared with healthy subjects. CT was measured at fovea and at four extrafoveal points. Results: The mean subfoveal choroidal thickness was 327.01 ± 64.60 μm in MS patients and 365.3 ± 99.14 μm in controls ( p=0.019 ). Significant differences were found at points temporal 500 μm, temporal 1000 μm and nasal 500 μm to the fovea between patients and control group ( p=0.018, 0.003 and 0.03, respectively). Conclusions: Patients with MS had thinner choroids when compared to normal subjects. The decrease in mean choroidal thickness in MS patients compared to controls may be related to vascular dysregulation or inflammatory pathology of MS. Further prospective studies are needed to evaluate the choroidal thickness in MS patients.

The Effect of Age, Gender, Refractive Status and Axial Length on the Measurements of Hertel Exophthalmometry

Purpose : To evaluate the normal distribution of exophthalmometric values in Turkish adult population and the effect of age, gender, refractive status and axial length on globe position. Methods : One hundred and twenty-two males and 114 healthy females with age ranging from 18 to 87 years were included in the study. The study population was recruited from patients presenting to our institution for routine refractive examination. Hertel exophthalmometer was used to measure the degree of ocular protrusion. Effect of age, refractive error, interpupillary distance, and axial length on globe position was detected with linear regression analyses. Results : The mean Hertel exophthalmometric size was 15.7+2.6 mm (range; 11 to 21 mm). The mean value for males was 16.1±2.6 mm (range; 11 to 21 mm), and for females 15.5±2.6 mm (range; 11 to 20 mm). The mean distance between the lateral rims of the orbit was 102 + 5.1 mm (range; 88 to 111mm). The mean exophthalmometric values were not statistically different in males and females. Age and mean spherical equivalents were negatively correlated with exophthalmometric measurements. Axial length was positively correlated with exophthalmometric measurements. Conclusion : The exophthalmometric measurement of the eye is affected by the age, spherical equivalent and the axial length. Standard normative values of the Hertel exophthalmometric measurements should be reevaluated with larger samples.

Evaluation of Corneal Thickness, Anterior Chamber Depth, and Iridocorneal Angle Following Scleral Buckling Surgery With AS-OCT

BACKGROUND AND OBJECTIVE To evaluate the changes in central corneal thickness (CCT), anterior chamber depth (ACD), and iridocorneal angle (ICA) with anterior segment optical coherence tomography (AS-OCT) following scleral buckling surgery. PATIENTS AND METHODS Thirty-one eyes with rhegmatogenous retinal detachment that underwent scleral buckling were included in this prospective study. Changes in CCT, ACD, and ICA were measured with AS-OCT. RESULTS There was a significant increase in the CCT at 1 day and 1 week postoperatively. CCT became slightly thinner than the preoperative values at 1 month postoperatively. The ACD was relatively shallow at all visits after the surgery. The decrease in the ICA 0° and 180° values was statistically significant at 1 day, 1 week, and 1 month postoperatively. CONCLUSION Changes in the CCT and ICA after scleral buckling were mild and almost returned to their preoperative levels within 6 months. However, ACD shallowing persisted even after 6 months.

Evaluation of Macular Perfusion in Healthy Smokers by Using Optical Coherence Tomography Angiography

BACKGROUND AND OBJECTIVE To investigate the macular perfusion changes in healthy smokers by using optical coherence tomography angiography (OCTA). PATIENTS AND METHODS OCTA measurements were taken for the right eyes of 40 smokers (Group 1) and age- and sex-matched control cases (Group 2). Group 1 underwent OCTA scanning with the XR Avanti AngioVue OCTA (Optovue, Fremont, CA) at baseline and at 5 minutes, 30 minutes, and 60 minutes after one standard cigarette smoking. The same scanning protocol was applied without smoking in Group 2. Macular vessel area density, flow index of the choriocapillaris, foveal avascular zone (FAZ), and central macular thickness were evaluated in both groups. RESULTS Group 1 consisted of 28 men and 12 women with a mean age of 41.2 years ± 9.1 years (range: 24 years to 63 years). The mean age of Group 2 was 42.6 years ± 8.4 years (range: 21 years to 65 years), which consisted of 28 men and 12 women. The mean baseline vessel area density, flow index of the choriocapillaris, FAZ, and central macular thickness showed no statistically significant differences between Groups 1 and 2. Although the flow index of choriocapillaris values were similar at the repetitive OCTA measurements in the control group (P > .05), it was decreased from 1.94 ± 0.06 to 1.89 ± 0.08, 1.90 ± 0.08, and 1.91 ± 0.07 at 5 minutes, 30 minutes, and 60 minutes following smoking, respectively, in Group 1 (P < .001). CONCLUSION Smoking causes a significant decrease in the blood flow index of the choriocapillary area by the acute effects of nicotine and other chemical substances in cigarettes on peripheral vascular structure, as evaluated by OCTA. [Ophthalmic Surg Lasers Imaging Retina. 2017;48:617-622.].

Retinal Ganglion Cell Loss in Children With Type 1 Diabetes Mellitus Without Diabetic Retinopathy

BACKGROUND AND OBJECTIVE Early diabetic retinal changes in children with type 1 diabetes mellitus (T1DM) without diabetic retinopathy (DR) were examined using spectral-domain optical coherence tomography (SD-OCT). PATIENTS AND METHODS Sixty children with T1DM without DR and 60 normal children were enrolled in the study. SD-OCT was used to measure the ganglion cell-inner plexiform layer (GC-IPL) and retinal nerve fiber (RNFL) thicknesses in all participants. RESULTS The GC-IPL thickness was significantly decreased in all quadrants except the superior-nasal quadrant in children with diabetes (P < .05). However, the RNFL thickness in all quadrants was not significantly different between the groups (P > .05). CONCLUSIONS There was a decreased GC-IPL thickness in children with T1DM without DR, suggesting that T1DM has an early neurodegenerative effect on retinal ganglion cells that occurs when the vascular component of DR is absent. SD-OCT may be more useful than ophthalmoscopic evaluation for detecting the earlier retinal structural changes of diabetes. [Ophthalmic Surg Lasers Imaging Retina. 2017;48:473-477.].

Risk factors for multiple retinal tears in patients with acute posterior vitreous detachment

PurposeTo evaluate possible risk factors for multiple retinal tears in patients with acute posterior vitreous detachment.Materials and methodsThree hundred and seventy-six consecutive patients presenting with symptoms of floaters and/or flashes were examined. The associations of retinal tears with the duration of symptoms, multiple floaters, flashing, a family history of retinal detachment, peripheral retinal degeneration, lens status, myopia, tobacco dust, and retinal or vitreous hemorrhage were analyzed.ResultsFifty-four (14.4%) of the 376 patients had 71 initial retinal tears. Forty of the 54 eyes had one retinal tear, and 14 eyes had multiple retinal tears. The presence of retinal or vitreous hemorrhage increased the risk of multiple retinal tears 6.1 times using univariate analysis and 7.0 times using multivariate analysis.ConclusionUnrecognized retinal tears in patients with acute posterior vitreous detachment can cause subsequent retinal detachment. It is therefore important to consider multiple retinal tears, especially in patients with retinal or vitreous hemorrhage.

Effect of 1- and 6-Hour-Delayed Corneal Collagen Cross-Linking on Corneal Healing in a Rabbit Alkali-Burn Model: Clinical and Histological Observations.

Purpose: To study the effect of 1- and 6-hour-delayed corneal collagen cross-linking (CXL) on wound-healing of experimental alkali burns of the cornea. Methods: Twenty-four albino rabbits were used. Alkali burns were created using 1 M NaOH. The animals were divided randomly into 2 groups: group 1 (control group, n = 6) and group 2 (experimental group, n = 18). The experimental group was further divided into 3 subgroups as follows: group 2A, untreated (non-CXL) subgroup; group 2B, 1-hour-delayed CXL treatment subgroup; and group 2C, 6-hour-delayed CXL treatment subgroup. All rabbits were examined periodically for 21 days after treatment and then killed. The corneas were excised and histologically examined. Results: Corneal ulceration, edema, and opacity scores were 4.0 ± 1.64, 1.6 ± 0.65, and 3.5 ± 1.21 in group 2A, 1.5 ± 1.76, 1.3 ± 0.87, and 3.1 ± 1.12 in group 2B, and 2.0 ± 1.90, 1.5 ± 0.79, and 3.3 ± 1.09 in group 2C, respectively. These scores were significantly less in groups 2B and 2C than in group 2A (P = 0.023, P = 0.043, and P = 0.034, respectively). Corneal epithelialization, evident upon staining, was best in group 2B and worst in group 2A (P = 0.012). Histopathology revealed that destruction of corneal collagen fibers and infiltration of inflammatory cells into corneal tissue were reduced in groups 2B and 2C compared with group 2A. Conclusions: We found that CXL treatment exerted positive effects on severe alkali-induced corneal burns. However, the effects were more pronounced in the 1-hour treatment group. We believe that CXL treatment may be a possible treatment for corneal alkali burn.

The effects of intravitreally injected bevacizumab on the retina and retina pigment epithelium: experimental in-vivo electron microscopic study in intact versus vitrectomized eyes

To analyze the retinal toxicity of bevacizumab at various doses both in vitrectomized and non-vitrectomized rabbit models. Twenty- eight rabbits were included in the study. Twenty- four rabbits were assigned to six groups, with 4 of the rabbits in the control group. The animals in Groups 1, 2 and 3 received bevacizumab at a dose of 0.3 mg, 0.5 mg and 1.5 mg /eye, respectively. The rabbits in Groups 4, 5 and 6 received intravitreal bevacizumab of 0.3 mg, 0.5 mg and 1.5mg/eye, respectively, after gas compression vitrectomy. Two weeks after the procedure, the rabbits were euthanized. Retina tissue samples were then obtained and examined with both light and electron microscopes. In Groups 1, 2 and 3 after bevacizumab injection, toxic degeneration in the photoreceptor and retinal pigment epithelium cells was observed via electron microscopic examination. The findings in Groups 4 and 5 were normal as compared to the control group. In Group 6, toxicity in the bipolar neurons and photoreceptor cells was noticed. Increased toxicity and retinal penetration were noticed in all administered doses of bevacizumab in the presence of vitreous. In addition, ocular toxicity occurred through the injection of the highest dose of bevacizumab after vitrectomy. It is possible that the bevacizumab dose and the, vitreous are as important as the drug half-life in the vitreous.

Olfactory Neuroblastoma: A Rare Cause of External Ophthalmoplegia, Proptosis and Compressive Optic Neuropathy

Olfactory neuroblastoma (ONB), which is a neuroectodermal tumor of the nasal cavity, is a rare and locally aggressive malignancy that may invade the orbit via local destruction. In this study, we report a patient with proptosis, external ophthalmoplegia, and compressive optic neuropathy caused by ONB. A detailed clinical examination including ocular imaging and histopathological studies were performed. The 62-year-old female patient presented to our clinic with complaints of proptosis and visual deterioration in the left eye. Her complaints started 2 months prior to admission. Visual acuity in the left eye was counting fingers from 2 meters. There was relative afferent pupillary defect. She had 6 mm of proptosis and limitation of motility. Fundus examination was normal in the right eye, but there was a hyperemic disc, and increased vascular tortuosity and dilation of the retinal veins in the left eye. Computerized tomography and magnetic resonance imaging of the brain and orbits demonstrated a large heterogeneous mass in the left superior nasal cavity with extensions into the ethmoidal sinuses as well as into the left orbit, compressing the medial rectus muscle and optic nerve. Endoscopic biopsy of the lesion was consistent with an ONB (Hyams’ grade III). Orbital invasion may occur in patients with ONB. Therefore, it is important to be aware of this malignancy because some patients present with ophthalmic signs such as external ophthalmoplegia, proptosis, or compressive optic neuropathy.

An Evaluation of the Relationship Between Clinically Unilateral Pseudoexfoliation Syndrome and Age-Related Macular Degeneration

BACKGROUND AND OBJECTIVE To evaluate the relationship between age-related macular degeneration (AMD) and clinically unilateral pseudoexfoliation syndrome (XFS). PATIENTS AND METHODS Seventy-six patients (152 eyes) with bilateral AMD and clinically unilateral XFS were included. Eyes with AMD were divided into three stages (early, intermediate, and late), based on the Beckman Initiative for Macular Research Classification Committee of fundus findings. The distribution of AMD lesions was assessed in both groups, and the subfoveal choroidal thickness (SFCT) was measured using enhanced depth imaging spectral-domain optical coherence tomography (SD-OCT). RESULTS There were significantly more early and intermediate-stage AMD cases in eyes with XFS than in non-XFS fellow eyes (P < .05). In contrast, there were significantly fewer wet AMD cases in XFS eyes than in non-XFS fellow eyes (P < .05). SFCT in all AMD stages was significantly lower in eyes with XFS (P < .05). CONCLUSION XFS was associated with a lower prevalence of wet AMD. Further studies are required to elucidate this association. [Ophthalmic Surg Lasers Imaging Retina. 2018;49:12-19.].