Registration of fluorescein angiography and optical coherence tomography images of curved retina via scanning laser ophthalmoscopy photographs.

Accurate and automatic registration of multimodal retinal images such as fluorescein angiography (FA) and optical coherence tomography (OCT) enables utilization of supplementary information. FA is a gold standard imaging modality that depicts neurovascular structure of retina and is used for diagnosing neurovascular-related diseases such as diabetic retinopathy (DR). Unlike FA, OCT is non-invasive retinal imaging modality that provides cross-sectional data of retina. Due to differences in contrast, resolution and brightness of multimodal retinal images, the images resulted from vessel extraction of image pairs are not exactly the same. Also, prevalent feature detection, extraction and matching schemes do not result in perfect matches. In addition, the relationships between retinal image pairs are usually modeled by affine transformation, which cannot generate accurate alignments due to the non-planar retina surface. In this paper, a precise registration scheme is proposed to align FA and OCT images via scanning laser ophthalmoscopy (SLO) photographs as intermediate images. For this purpose, first a retinal vessel segmentation is applied to extract main blood vessels from the FA and SLO images. Next, a novel global registration is proposed based on the Gaussian model for curved surface of retina. For doing so, first a global rigid transformation is applied to FA vessel-map image using a new feature-based method to align it with SLO vessel-map photograph, in a way that outlier matched features resulted from not-perfect vessel segmentation are completely eliminated. After that, the transformed image is globally registered again considering Gaussian model for curved surface of retina to improve the precision of the previous step. Eventually a local non-rigid transformation is exploited to register two images perfectly. The experimental results indicate the presented scheme is more precise compared to other registration methods.

Effect of Intravitreal Injection of Bevacizumab on Acute Central Serous Chorioretinopathy Patients Who Visited Feiz Hospital during 2014-2015 Period.

BACKGROUND: Aim of this clinical trial is the evaluation of the effect of intravitreal injection of bevacizumab on acute central serous chorioretinopathy (CSC). MATERIALS AND METHODS: In a nonrandomized clinical trial, 36 CSC eyes (with <1-month disease history) were examined. Initially, all the patients underwent posterior and anterior segment examinations as well as complete eye examination to evaluate the best spectacle-corrected visual acuity (BSCVA). Then, optical coherence tomography was performed to confirm the diagnosis. The patients were divided to the two groups each of 18 subjects, which 18 patients received intravitreal injection of bevacizumab (1.25 mg) and the rest of them did not receive any treatment (control group). The patients were health checked by the end of the 1st and 3rd months. Significance level was considered as P < 0.05. RESULTS: In the BSCVA, no significant difference in visual improvement was observed in baseline vision compared to each other (P = 0.481). There was also no significant difference in the vision of intervention and control groups 1 and 3 months after injection (P = 0.379 and P = 0.557). A significant decrement existed in the intervention group compared with the control group in the maximum central macular thickness at 1 month after injection (P = 0.001); however, the difference was not significant when comparing the two groups at baseline and 3 months after injection (P = 0.925 and P = 0.338). CONCLUSION: In general, according to the results of this study, intravitreal injection of bevacizumab was not effective in improvement of patients with acute CSC, although it had no side effects.

Bilateral optic nerve head drusen with chorioretinal coloboma in the right eye.

Chorioretinal coloboma is a congenital defect of the eye caused by improper closure of the embryonic fissure. Optic nerve head drusen (ONHD) are white calcareous deposits that are generally asymptomatic. We report a very rare association of both in a healthy patient with no any systemic syndrome. A 16-year-old man was referred to our clinic from suffering blurred vision. Best corrected visual acuity of the right eye was 6/10 and 10/10 in the left one. External ocular and slit lamp examination were normal. Dilated ophthalmoscopy showed marked swelling in both optic nerves and chorioretinal coloboma in the right eye inferiorly. Ultrasonography showed an echodense structure with acoustic shadowing in both eyes consistent with buried ONHD. Visual field testing showed normal field in the left eye and moderate superior field depression in the right eye corresponding to inferior coloboma in funduscopy. Results of general medical and neurologic, cardiologic, and other examinations were normal. To the best our knowledge combination of bilateral ONHD and unilateral chorioretinal coloboma in a healthy patient with no any systemic syndrome has not been published in the literature. We reported this very rare association and recommended examine eyes and other body organs. In such cases that coloboma is associated with ONHD, we should keep in mind Noonan syndrome. The diagnosis of Noonan syndrome is clinical and confirm by the consultant pediatricians and clinical geneticists.

Post traumatic endophthalmitis: incidence and risk factors.

Post traumatic endophthalmitis is an uncommon but severe complication of ocular trauma. We aimed to identify the incidence of post traumatic endophthalmitis and its contributing risk factors in Feiz hospital (Isfahan, Iran) from 2006 until 2010. Medical records of 1042 patients with open globe injury were analyzed and data were collected including age, sex, location of being injured, visual acuity (VA), time from injury to hospitalization and to repair, site of ophthalmic injury and the presence of foreign body. The frequency of post-traumatic endophthalmitis was about 2.1% (N = 22) of all patients. Nine of 22 cases with endophthalmitis were under 8 years. The visual acuity at the time of admission was seen to be contributed to high rate of endophthalmitis. Intraocular foreign body was detected in 139 patients; and the rate of endophthalmitis was 5% among these patients. Statistical analysis showed significant relationship between presence of foreign body and higher rate of endophthalmitis. Also, duration of hospitalization was significantly different between two study groups (P = 0.019). There were no significant differences between two groups in terms of other studied variables. Patients with low age, low visual acuity at admission, presence of intraocular foreign body and long duration of hospital stay had a higher risk of endophthalmitis after the repair of the globe. Compared to the reports of other large institutions, we can attribute the low incidence rate of endophthalmitis in our institution to the early use of systemic antibiotics such as gentamycin and cephalosporins in the first hour of hospitalization until discharge.

Anti-aquaporin-4 IgG in Patients Presenting with Unilateral Optic Neuritis: A Cohort Study.

BACKGROUND: Optic neuritis (ON) can be the first presentation of multiple sclerosis (MS) or neuromyelitis optica (NMO). Anti-aquaporin-4 IgG (AQP4 IgG) is a highly specific and moderately sensitive biomarker for NMO. This study was designed to assess the rate of seropositivity for AQP4 IgG, and the short-term outcome of patients presenting with single isolated ON (SION). METHODS: A cohort of 41 consecutive patients experiencing severe (< 20 / 200) SION (not fulfilling the diagnostic criteria for MS or NMO), was prospectively recruited. Blood sampling was carried out immediately after the diagnosis of ON, and AQP4 IgG was tested qualitatively, using an indirect immunofluorescence kit. After clinical and paraclinical investigations, all the patients were followed up for a short-term period of at least 18 months. RESULTS: The seroprevalence among the initial ON patients was 9.7% (4 / 41). The short-term conversion rate to MS and NMO was estimated to be about 7.3 and 4.9%, respectively. The conversion rate to NMO in initially seropositive patients was greater than that for the whole cohort [2 / 4 (50%) vs. 2 / 41 (4.9%); P = 0.035; Odds ratio: 19.5, 95% confidence interval: 1.73 to 219.50]. CONCLUSION: AQP4 IgG seropositive SION patients were more likely to develop NMO in comparison to the total SION population. Further studies, with a longer follow-up period and larger sample sizes are warranted to assess the clinical and prognostic value of assessing AQP4 IgG in SION.

Cefazolin-Gentamicin versus Vancomycin-Ceftazidime Eye Drops for Bacterial Corneal Ulcers;a Randomized Clinical Trial.

PURPOSE: To compare the efficacy of topical cefazolin-gentamicin versus vancomycinceftazidime for treatment of bacterial corneal ulcers. METHODS: This randomized double-masked clinical trial was performed on consecutive patients with bacterial corneal ulcers referred to Feiz Hospital, Isfahan, Iran from 2004 to 2005. Patients were randomly assigned to cefazolin-gentamicin or vancomycin-ceftazidime eye drops in a masked fashion. Outcome measures included time for resolution of stromal infiltration, re-epithelization of the epithelial defect, and clearance of anterior chamber inflammation as well as culture results and complications. RESULTS: The study included 89 eyes of 89 patients with bacterial corneal ulcers consisting of 57 (64%) male and 32 (36%) female subjects. Specimens were culturenegative in 46% of cases. Forty-one eyes received cefazolin-gentamicin and 48 eyes were treated with vancomycin-ceftazidime. Time for resolution of stromal infiltration was 17.7± 4.3 days versus 13.8± 3.6 days (P=0.04), time to complete re-epithelization was 13.2± 3.1 days versus 9.6± 2.7 days (P=0.01) and time for clearing of the anterior chamber was 11.6± 2.9 days versus 8.1± 2.3 days (P=0.04) in the cefazolin-gentamicin and vancomycin-ceftazidime groups, respectively. The most common complaint related to the medications was ocular burning in 73.1% of patients treated with cefazolingentamicin and 62.9% of cases receiving vancomycin-ceftazidime (P=0.007). CONCLUSION: Vancomycin-ceftazidime eye drops seem to be more effective than cefazolin-gentamicin eye drops for the treatment of bacterial corneal ulcers and are probably better tolerated locally.

Stereoacuity following LASIK.

PURPOSE: To evaluate the effect of laser in situ keratomileusis (LASIK) on stereoacuity (SA). METHODS: This prospective study includes 200 patients scheduled for LASIK. SA was evaluated preoperatively and one week, one month and three months postoperatively using the Random Dot test. Patients with preoperative SA worse than 480 sec/arc were excluded from the study. RESULTS: The study included 138 female (69%) and 62 male (31%) subjects. Spherical equivalent was -0.5 to -12.0 D. Mean preoperative SA was 124.80±124.64 (range 480-15) sec/arc which deteriorated to 138.30±126.48 sec/arc one week after surgery (P=0.158) but improved to 111.30±112.15 sec/arc (P=0.002) one month and 103.65+112.20 sec/arc (P=0.001) three months postoperatively. Overall, stereoacuity decreased in 9.5%, increased in 32.5% and remained unchanged in 58% of patients (P=0.007). Patients with anisometropia had worse SA; eventually, SA increased in 5 non-amblyopic anisometropic patients. CONCLUSION: Despite the overall improvement in mean SA after LASIK, a minority of patients experienced decreased SA. Anisometropic patients without amblyopia seem to have a chance for improved SA after LASIK.