Hidayet Erdöl

Simple methods for segmentation and measurement of diabetic retinopathy lesions in retinal fundus images

Diabetic retinopathy (DR) is one of the most important complications of diabetes mellitus, which causes serious damages in the retina, consequently visual loss and sometimes blindness if necessary medical treatment is not applied on time. One of the difficulties in this illness is that the patient with diabetes mellitus requires a continuous screening for early detection. So far, numerous methods have been proposed by researchers to automate the detection process of DR in retinal fundus images. In this paper, we developed an alternative simple approach to detect DR. This method was built on the inverse segmentation method, which we suggested before to detect Age Related Macular Degeneration (ARMDs). Background image approach along with inverse segmentation is employed to measure and follow up the degenerations in retinal fundus images. Direct segmentation techniques generate unsatisfactory results in some cases. This is because of the fact that the texture of unhealthy areas such as DR is not homogenous. The inverse method is proposed to exploit the homogeneity of healthy areas rather than dealing with varying structure of unhealthy areas for segmenting bright lesions (hard exudates and cotton wool spots). On the other hand, the background image, dividing the retinal image into high and low intensity areas, is exploited in segmentation of hard exudates and cotton wool spots, and microaneurysms (MAs) and hemorrhages (HEMs), separately. Therefore, a complete segmentation system is developed for segmenting DR, including hard exudates, cotton wool spots, MAs, and HEMs. This application is able to measure total changes across the whole retinal image. Hence, retinal images that belong to the same patients are examined in order to monitor the trend of the illness. To make a comparison with other methods, a Naïve Bayes method is applied for segmentation of DR. The performance of the system, tested on different data sets including various qualities of retinal fundus images, is over 95% in detection of the optic disc (OD), and 90% in segmentation of the DR.

Cyclosporine Effects on Clinical Findings and Impression Cytology Specimens in Severe Vernal Keratoconjunctivitis

Purpose: To investigate the possible effects of topical cyclosporine eye drops 2% (CsA) on conjunctival immune cells obtained by impression cytology technique and to determine the clinical relevance of this effect if present. Methods: Ten consecutive patients with severe, resistant, and active vernal keratoconjunctivitis (VKC) were included in this study. All of them were treated with 2% of topical CsA drops. Symptom and clinical scores and conjunctival impression cytology specimens were obtained both before and following treatment. Impression cytology specimens were stained with anti-CD8+, CD4+, CD45RA+, and CD23+ antibodies and the percentages of positive cells were counted. The results were compared and correlation analyses were performed between clinical and laboratory data. Results: Significant reductions were observed with respect to the percentages of CD4+ and CD23+ cells in the conjunctival impression cytology specimens and clinical and symptom scores following treatment with topical CsA, while no change occurred in the percentages of CD8+ and CD45RA+ cells. The percentages of CD4+ and CD23+ cells showed good correlations with symptom and clinical scores. Conclusion: Topical CsA treatment is a very effective alternative in severe VKC cases in clinical ground and clinical efficacy of topical CsA treatment in severe, resistant VKC cases can be (at least partly) related to reduction of the CD23+ and CD4+ cell populations on the conjunctival surface.

Long-term follow-up of external dacryocystorhinostomy and the factors affecting its success.

Aim: To evaluate the long-term follow-up results of external dacryocystorhinostomy (Ex-DCR) and to assess the role of some factors in its success. Patients and Methods: Between January 1990 and November 2002, 437 nasolacrimal systems of 387 patients were operated on and included in the study. The success rates were determined on the basis of the last examinations of the patients, and the correlations between success rates and factors such as age, gender, the duration of obstruction, history of acute dacryocystitis, the side of obstruction, and the postoperative follow-up period were calculated. Results: The mean follow-up period was 5.9 ± 2.5 years. Fifty cases (12.9%) were operated bilaterally. The initial success rate was 91.5% and the last success rate was 98.4% after reoperations. We found meaningful correlations between success and duration of obstruction, age of the patient, and the duration of postoperative follow-up (r = 0.18, 0.17 and −0.14, p = 0.036, 0.001 and 0.002, respectively). Discussion: In comparison to newly developed surgical techniques for the treatment of nasolacrimal duct obstruction, Ex-DCR still appears to offer higher success rates, even after long-term follow-up. In addition to being a cost-effective procedure, it requires no sophisticated instruments. In our opinion, the high success rates may be explained by the nature of the operation, which creates a fistula between the sac and the nasal mucosa.

Parry-Romberg syndrome associated with Adie’s pupil and radiologic findings

We describe Adies pupil and radiologic changes related to Parry-Romberg syndrome in a child who presented with facial hemiatrophy with no neurologic deficit. We suggest that cerebral lesions in Parry-Romberg syndrome without neurologic symptoms must be carefully investigated.

MYO15A (DFNB3) mutations in Turkish hearing loss families and functional modeling of a novel motor domain mutation.

Myosin XVA is an unconventional myosin which has been implicated in autosomal recessive nonsyndromic hearing impairment (ARNSHI) in humans. In Myo15A mouse models, vestibular dysfunction accompanies the autosomal recessive hearing loss. Genomewide homozygosity mapping and subsequent fine mapping in two Turkish families with ARNSHI revealed significant linkage to a critical interval harboring a known deafness gene MYO15A on chromosome 17p13.1‐17q11.2. Subsequent sequencing of the MYO15A gene led to the identification of a novel missense mutation, c.5492G → T (p.Gly1831Val) and a novel splice site mutation, c.8968 − 1G → C. These mutations were not detected in additional 64 unrelated ARNSHI index patients and in 230 Turkish control chromosomes. Gly1831 is a conserved residue located in the motor domains of the different classes of myosins of different species. Molecular modeling of the motor head domain of the human myosin XVa protein suggests that the Gly1831Val mutation inhibits the powerstroke by reducing backbone flexibility and weakening the hydrophobic interactions necessary for signal transmission to the converter domain.

The One-Month Effects of Topical Betaxolol, Dorzolamide and Apraclonidine on Ocular Blood Flow Velocities in Patients with Newly Diagnosed Primary Open-Angle Glaucoma

Purpose: This double-masked, prospective and randomized clinical trial was planned to investigate with color Doppler imaging the 1-month vascular effects of betaxolol, dorzolamide and apraclonidine treatment on patients with newly diagnosed primary open-angle glaucoma (POAG). Methods: 22 consecutive patients with newly diagnosed POAG between the ages of 46 and 72 years were enrolled in this study. All patients were newly diagnosed cases and had not received any antiglaucoma medication before. Patients who had a systemic vascular disease (including systemic hypertension) or were taking β-blockers, nitrates or calcium channel blockers were excluded from the study. The patients were randomly divided into three groups. Groups A and B contained 7 patients, group C contained 8 patients. Group A patients were treated with topical betaxolol, group B patients received topical dorzolamide eye drops, and group C patients were treated with topical apraclonidine eye drops. Peak systolic velocities (PSV), end-diastolic velocities (EDV) and resistive indices (RI) in the right ophthalmic arteries (OA), central retinal arteries (CRA) and posterior ciliary arteries (PCA) were measured at baseline by using color Doppler imaging on a masked basis. On days 15 and 30 of treatment, the same measurements were repeated. The inter- and intragroup results were compared statistically. Results: Compared to pretreatment measurements, topical betaxolol therapy significantly decreased PSV only in the PCA and only on day 30 of treatment (p = 0.011). On days 15 and 30, dorzolamide decreased RI measurements in the PCA compared to pretreatment measurement (p = 0.013 and p = 0.011, respectively). Apraclonidine also decreased PSV in the OA on days 15 and 30 of treatment when compared to pretreatment values (p = 0.013 and p = 0.012, respectively). When 15-day measurements were compared between the groups, PSV in the OA were significantly higher in dorzolamide-treated patients compared to other groups (p = 0.01 and p = 0.011). On day 30 of treatment, PSV in the OA was also higher in the dorzolamide-treated group than the other groups (p = 0.012 and p = 0.01). Additionally, apraclonidine-treated patients had a significantly lower EDV in the OA than the other groups (p = 0.013 and p = 0.01). The RI in the OA was also significantly lower in the apraclonidine-treated group compared to the other groups (p = 0.01 and p = 0.011). Conclusion: Our study suggests that dorzolamide has the most advantageous 1-month effects on blood flow velocity in the retrobulbar arterial circulation of POAG patients. Betaxolol seems superior to apraclonidine in this regard. Our data may help the clinician when treating patients with POAG medically. Further studies using a larger population size may clarify our results.

The relationship between diabetic retinopathy and serum levels of ischemia-modified albumin and malondialdehyde.

Purpose: To establish the correlation between ischemia-modified albumin (IMA) and malondialdehyde (MDA) and the development of diabetic retinopathy (DRP) in patients with diabetes mellitus. Methods: Seventy Type 2 diabetic patients, 35 with DRP, and 36 healthy controls were enrolled in this study. Serum IMA and MDA levels were compared statistically. Receiver operating characteristic curve analysis was also performed to calculate the value of IMA and MDA in distinguishing DRP. Results: Mean serum IMA levels were 0.658 ± 0.128 absorbance units in the non-DRP group, compared with 0.767 ± 0.074 absorbance units in the DRP group and 0.619 ± 0.044 absorbance units in the control group. Mean serum MDA levels were 0.325 ± 0.172 nmol/mL, 0.244 ± 0.152 nmol/mL, and 0.178 ± 0.131 nmol/mL, respectively. The differences in IMA and MDA levels were statistically significant for all groups (P < 0.05 for all). The areas under the receiver operating characteristic curves for the determination of DRP in diabetic patients were 0.789 (95% confidence interval, 0.682-0.896) for IMA and 0.3 (95% confidence interval, 0.175-0.426) for MDA. Conclusion: Both serum IMA and serum MDA levels were higher in the diabetic patients compared with the control group. In particular, the high sensitivity of IMA toward DRP showed that it reflected retinal vascular complication better than MDA. Ischemia-modified albumin may be a useful marker in monitoring the risk of DRP development.

Nephropathy and retinopathy in type 2 diabetic patients living at moderately high altitude and sea level.

Background: High-altitude-induced hypoxia results in various diseases, such as chronic mountain sickness and high altitude retinal edema, and may affect severity and incidence of some cardiovascular diseases. In order to evaluate the effects of moderately high altitude on diabetic nephropathy and retinopathy, a cross-sectional study was planned. Material Method: Long-term type II diabetic residents of sea level (n = 75, 38 male, 37 female, mean age 51.9 ± 10.5 in Trabzon and Zonguldak cities) and moderately high altitude (h = 1,727 m, n = 73, 28 male, 45 female, mean age 48.3 ± 12.1, Van city) were compared. Results: No difference was observed in terms of age, gender, diabetes duration, body mass index, smoking, systolic, diastolic, and mean arterial blood pressure values, serum glucose levels, cholesterol, high-density lipoprotein (HDL)-cholesterol, low-density lipoprotein (LDL)-cholesterol, hemoglobin, HbA1C, hypertension control, or blood pressure medications and retinopathy incidence. Mean 24 h protein excretion (210.0 ± 139.9, 127.8 ± 112.1 mg; P = 0.00), proteinuria prevalence (57.5% versus 33.3%, p = 0.003), and serum creatinine levels (1.04 ± 0.22 versus 0.84 ± 0.21, p = 0.00) were significantly higher in the highlanders, glomerular filtration rate (GFR) was significantly lower in sea level (SL) patients (90.9 ± 26.5 versus 83 ± 21.1, p = 0.05). Conclusion: Tendency to diabetic nephropathy as indicated by higher proteinuria and creatinine levels is increased among type 2 diabetic patients living at moderately high altitude. Prospective studies are needed to confirm these findings.

The results of intravitreal bevacizumab injections for persistent neovascularizations in proliferative diabetic retinopathy after photocoagulation therapy.

Purpose: The purpose of this study was to evaluate the effectiveness of intravitreal bevacizumab on persistent retinal neovascularizations in proliferative diabetic retinopathy. Methods: Thirty-three eyes of 24 patients (mean age, 52.75 ± 8.2 years) with proliferative diabetic retinopathy showing recurrences or no regressions in neovascularizations were evaluated in this study. After the intravitreal injection of 1.25 mg/0.05 mL of bevacizumab, the first examination was performed within 3 days and repeated at 1 week, 1 month, 3 months, and 6 months. In these examinations, localization and dimensions of neovascularizations were evaluated with red-free photographs and/or fluorescein angiography. Results: All patients had type II diabetes for a period of 12 ± 4.4 years (range, 2–20 years). After a single dose of bevacizumab, complete resolution rate of neovascularizations was 78.8% at 1 month, 63.6% at 3 months, and 45.4% at 6 months. When evaluated together with 9 eyes that had a second injection at 3 months, the complete resolution rate was 60.6% at 6 months. Mean best-corrected visual acuity and macular volume were 1.06 logarithm of the minimum angle of resolution (20/225 in Snellen) and 11.65 mm3 before treatment. Six months after treatment, these were 0.73 logarithm of the minimum angle of resolution (20/108 in Snellen) and 8.92 mm3 (P = 0.048 and 0.003, respectively). Conclusion: Bevacizumab can be used safely and successfully in patients with proliferative diabetic retinopathy who do not experience any resolution or experience recurrences after panretinal photocoagulation.

Neurofibromatosis type 1 associated with pheochromocytoma: A case report and a review of the literature

Pheochromocytoma (PHEO) occurs in 0.1–5.7% of patients with neurofibromatosis type 1 (NF1). We report a case of adrenal PHEO in a patient with NF1. A 30-yr-old Turkish man was admitted to our hospital for further examinations of a right adrenal mass, that was incidentally discovered by abdominal ultrasonography during examinations for acute hepatitis B infection in another hospital. In his past medical history, the patient had only had one palpitation, sweating and headache episode 4 yr before. On admission, his blood pressure was 110/ 70 mmHg. Physical examination revealed signs of NF1. He had multiple neurofibromas over the entire skin, café-au-lait spots on the trunk and extremities and skinfold freckling. Bilateral opthalmic examination revealed multiple Lisch nodules. The 24-h ambulatory blood pressure monitoring revealed paroximal hypertension attacks (190/148 mmHg). Urinary catecholamines were markedly increased. Magnetic resonance imaging (MRI) revealed a solid round tumor approximately 5 cm in diameter, located in right adrenal gland. A 131Iodine-metaiodobenzylguanidine (131I-MIBG) scan showed uptake in the right adrenal gland. The pre-operative treatment with an α-blocker (phenoxybenzamine) was performed. Right adrenalectomy was performed; the surgical specimen revealed PHEO. Urine catecholamines and their metabolites returned to normal ranges on post-operative day 7. In conclusion, an adrenal mass can be incidentally discovered in any patient. After diagnosis of NF1, patients who have episodes of hypertension, sweating, headache and palpitation should be evaluated for PHEO.