Optical Coherence Tomography-angiography: Comparison of the Foveal Avascular Zone between Diabetic Retinopathy and Normal Subjects

PURPOSE: To evaluate the effectiveness of optical coherence tomography angiography (OCTA) in investigating changes in the area of the foveal avascular zone (FAZ) in patients with diabetic retinopathy (DR) and normal subjects. METHODS: Eighty-five eyes of 50 DR patients and 50 eyes of 25 normal subjects were included. OCTA images of the FAZ were acquired using the split-spectrum amplitude decorrelation angiography algorithm of Optovue Avanti RTVue XR OCT. Patients were divided into three groups according to DR severity: mild-to-moderate non-proliferative diabetic retinopathy (NPDR) group, severe NPDR group, and proliferative DR group. The area of the FAZ was measured using built-in software and was compared between the patients and normal subjects and among the three groups. RESULTS: The area of the FAZ in patients with diabetic retinopathy (0.46 mm²) was significantly larger than that in normal subjects (0.30 mm², p = 0.001). A significant difference was observed depending on DR severity: 0.40 mm² in the mild-to-moderate NPDR group, 0.45 mm² in the severe NPDR group, and 0.53 mm² in the PDR group (p = 0.03). Correlation between area of the foveal avascular zone and visual acuity showed a tendency toward reduction in visual acuity (p = 0.002). CONCLUSIONS: OCTA effectively detected changes in the FAZ area in DR patients. OCTA has the potential to be used for noninvasive quantification and monitoring of the FAZ.

Combination Therapy with Photodynamic Therapy and Intravitreal Bevacizumab in Idiopathic Macular Telangiectasia Type I

PURPOSE: We investigated the clinical manifestations of combination therapy with photodynamic therapy (PDT) and intravitreal bevacizumab in idiopathic macular telangiectasia type I patients. METHODS: The present study included 7 patients who visited our clinic from May 2008 to February 2011 complaining of decreasing visual acuity and diagnosed as idiopathic macular telangiectasia type I including visible aneurysms at juxtafoveal area and telangiectatic vessels leakage based on fluorescein angiography. Additionally, all patients were treated with combination therapy with PDT and intravitreal bevacizumab. RESULTS: Visual acuity improved from 0.48 ± 0.14 (log MAR) to 0.18 ± 0.17 (log MAR) after the combination therapy, however, there was no change in intraocular pressure between before (17.9 ± 3.1) and after (16.8 ± 2.3) therapy. After combination therapy, fluorescein angiography showed decreased leakage of telangiectatic vessels and optical coherence tomography showed only minimal intraretinal edema. Central subfield macular thickness decreased from 301.9 ± 50.7 μm to 193.6 ± 58.8 μm after the combination therapy. CONCLUSIONS: Combination therapy with intravitreal bevacizumab injection and PDT in patients with idiopathic macular telangiectasia type I can result in a rapid decrease of macular edema, which can lead to rapid visual recovery.

Comparison of the 20-Gauge Conventional Vitrectomy Technique with the 23-Gauge Releasable Suture Vitrectomy Technique

PURPOSE: To compare the efficacy of the transconjunctival releasable suture technique for pars plana vitrectomy using 23-gauge (23G) instruments versus the conventional 20-gauge (20G) technique. METHODS: A retrospective and interventional case series was consecutively performed for 199 eyes of the 192 patients that were a part of this study. Clinical data were reviewed retrospectively regarding the operation time, preoperative and postoperative intraocular pressure, visual acuity and astigmatism for 54 consecutive patients who received a 23G releasable suture vitrectomy and for 98 consecutive patients who received a 20G conventional vitrectomy during the period between April 2007 and September 2010. RESULTS: Mean operation time based on the operation record was 88.5 +/- 20.1 minutes in the 23G releasable suture vitrectomy group and 102.1 +/- 23.1 minutes in the 20G conventional vitrectomy group, respectively (p = 0.01). The last best-corrected visual acuity (BCVA) was significantly better than the preoperative BCVA in both patient groups (p = 0.01, p = 0.01). The 23G releasable suture group showed less surgically induced astigmatism than the 20G conventional vitrectomy group. Vitreous bleeding was observed to be in 6 eyes (5.9%) in the 23G group, and in 8 eyes (8.2%) in the 20G group. In addition, ocular hypertension was noted to be in 3 eyes (3.0%) in the 23G group, and 6 eyes (6.1%) in the 20G group. No serious complications such as postoperative hypotony or endophthalmitis were observed in either group. CONCLUSIONS: The 23G releasable suture technique is as effective as the 20G conventional technique and offers several advantages.

The Effect of Punctoplasty with Pigtail Probe for Canalicular Intubation in Patients with Punctal Obstruction

PURPOSE: To assess the surgical results of a punctoplasty with insertion of a silicone tube using a pigtail probe for the management of acquired punctal obstruction. METHODS: The medical records of 61 patients who underwent an operation for the management of punctual obstruction were reviewed. After punctal dilation, fluorescein dye disappearance test was performed to evaluate its efficacy. In the case of no functional delay after punctal dilation, three-snip punctoplasty with a silicone tube using a pigtail probe was performed. In the case of a functional delay, three-snip punctoplasty with a silicone tube into the nasolacrimal duct was performed. RESULTS: The surgical success over 1 year was 39.1% in patients who underwent only three-snip punctoplasty, 79.2% in patients who underwent a three-snip punctoplasty with a silicone tube insertion into the nasolacrimal duct, and 85.7% in patients who underwent a three-snip punctoplasty with canalicular intubation using a pigtail probe. CONCLUSIONS: The use of a pigtail probe for canalicular intubation together with a three-snip punctoplasty is useful to prevent the recurrence of punctal obstruction.

Factors Associated with the Direction of Ocular Deviation in Sensory Horizontal Strabismus and Unilateral Organic Ocular Problems

PURPOSE: To evaluate factors associated with the direction of horizontal deviation in the sensory strabismus of patients with unilateral organic amblyopia. METHODS: The medical charts of 53 patients who had been diagnosed with sensory strabismus between 2000 and 2009 were reviewed retrospectively. The underlying ocular disease, time of onset and the duration of vision impairment, refractive error and axial length of the fixing eye, and the direction and angle of deviation were analyzed to determine the distribution of underlying diseases and any factors relevant to determining the direction of the horizontal deviation. RESULTS: Congenital cataracts were the most common underlying disease, found in 33 patients, followed by acquired cataracts, optic nerve disorders, retinal detachment, glaucoma and lens subluxation. Among the 50 patients with horizontal strabismus, 11 had esotropia and 39 had exotropia. The incidence of esotropia was significantly higher when the fixing eye had hyperopia or emmetropia, than when the eye was myopic. Age of onset of vision deterioration and at diagnosis of sensory strabismus, and the axial length of the fixing eye had no relationship to the direction of horizontal deviation. In addition, the duration of visual impairment had no significant relationship with the direction or extent of horizontal deviation. CONCLUSIONS: The most common cause of sensory strabismus was congenital cataracts and the most frequent type of strabismus was exotropia. With respect to the direction of horizontal strabismus, esotropia occurred significantly more often when the refractive error of the fixing eye was hyperopia or emmetropia than when the fixing eye was myopic.

Factors Associated with the Development of Strabismus in Children and Adolescents with Organic Ocular Diseases

PURPOSE: To evaluate risk factors associated with the development of strabismus in children with organic ocular diseases. METHODS: The authors reviewed the medical records of 143 patients diagnosed with organic ocular disease between the ages of six months and 19 years from March 2000 through September 2009. The distributions of etiology, age, visual acuity and visual acuity difference between both eyes at onset of visual loss, spherical equivalent difference between both eyes, duration of visual loss, and nystagmus were analyzed to determine relationships with the development of strabismus. RESULTS: Of 143 patients, strabismus developed in 41 children (28.7%). The causative diseases were congenital cataract (73.2%), developmental cataract (7.3%), uncorrected aphakia (7.3%), retinal detachment (4.9%), lens subluxation (2.4%), optic nerve disorder (2.4%), and corneal opacity (2.4%). The incidence of strabismus increased significantly in the cases of congenital disease, those < or = five years of the age at onset of visual loss, those with < or = 20/200 visual acuity, and those with large interocular spherical equivalent difference. There was no relationship between incidence of strabismus and visual acuity difference between both eyes. However, the incidence of strabismus increased significantly when the visual acuity difference was more than three Snellen lines in congenital ocular disease. CONCLUSIONS: When ocular disease is congenital, an increased risk of onset of strabismus should be considered when the age at onset of visual loss is less than five years, when visual acuity is below 20/200, and when there is a large spherical equivalent difference between both eyes.