Retinal Ganglion Cell Layer Thicknesses and Visual Functions in Patients with Bilateral Temporal Optic Atrophy

PURPOSE: To investigate correlations between macular retinal ganglion cell (RGC) layer thickness and best-corrected visual acuity (BCVA) and visual field parameters in patients with bilateral temporal optic atrophy.METHODS: Thirty eyes of 15 patients with bilateral temporal optic atrophy and 30 eyes of 15 normal subjects that were age- and sex-matched were included in the study. We measured the thicknesses of the RGC layers of posterior poles using optical coherence tomography volume scanning. The RGC layer was divided into nine zones based on the Early Treatment of Diabetic Retinopathy Study baseline. Possible correlations of the RGC layer with the BCVA and visual field parameters were determined.RESULTS: The RGC layer thickness was significantly thinner in all patients compared to those in the control group (p = 0.001). The RGC layer thicknesses in the inner superior, inner temporal, inner inferior, and inner nasal areas were significantly correlated with the BCVA (r = −0.650, r = −0.626, r = −0.616, and r = −0.636, respectively; p = 0.000). The RGC layer thicknesses in the outer superior, outer temporal, outer inferior, and outer nasal areas were significantly correlated with the mean deviation of the visual field test (r = 0.470, r = 0.349, r = 0.496, and r = 0.469, respectively; p < 0.05).CONCLUSIONS: In patients with bilateral temporal optic atrophy, the RGC layer thickness in the medial region was correlated with the BCVA, and the RGC layer thickness in the lateral region was correlated with the mean deviation of the visual field test.

A Case of Moyamoya Syndrome Diagnosed by Ophthalmic Examination in a Patient with Moyamoya Disease

PURPOSE: To report a case of moyamoya syndrome after an additional diagnosis of neurofibromatosis type 1 (NF 1) using an ophthalmic examination in a middle-aged patient with moyamoya disease. CASE SUMMARY: A 60-year-old male with no specific past medical history except moyamoya disease visited our hospital for an ophthalmic examination. Two years prior, he had been diagnosed with moyamoya disease by brain imaging performed after a head trauma. At the first visit, his best corrected visual acuity was no light perception in the right eye (OD) and 20/25 in the left eye (OS). The intraocular pressure was 8 mmHg (OD) and 10 mmHg (OS). On fundus examination, the right eye showed a dense opacity of an ocular media and the left eye showed no abnormality except an increased cup-to-disc ratio. However, infrared imaging showed multiple whitish lesions in the left eye. Fluorescein angiography showed a patchy choroidal filling delay. During the follow-up, slit-lamp microscopy revealed Lisch nodules and multiple café au lait spots and neurofibromas were found in the skin which led to the diagnosis of NF 1. CONCLUSIONS: When examining patients with moyamoya disease, ophthalmologists should check not only ocular comorbidity associated with moyamoya disease but also ocular comorbidity with other systemic diseases that can accompany moyamoya disease. NF 1 is the most common systemic disease associated with moyamoya syndrome. In this case, appropriate follow-up was essential to monitor the development of ocular or systemic vasculopathies and their complications.

A Case of Retinal Herniation through Peripapillary Pit Resulting in Retinal Nerve Fiber Layer Defect

PURPOSE: To report a case of glaucoma suspect with peripapillary pit, which enlarged in size with retinal herniation through the pit, and resulted in retinal nerve fiber layer defect and corresponding visual field defect. CASE SUMMARY: A 34-year-old male was referred to our glaucoma clinic for glaucoma evaluation. The intraocular pressure was 15 mmHg in the right eye and 14 mmHg in the left eye. The refractive error in spherical equivalence was −12.75 diopters (D) in the right eye and −11.50 D in the left eye. The axial length was 28.70 mm in the right eye and 28.15 mm in the left eye. On optical coherence tomography (OCT), the retinal nerve fiber layer thickness was within normal limits in both eyes. A peripapillary pit was found in both eyes, which measured 155 µm in the right eye and 625 µm in the left eye in maximal horizontal diameters. Two year follow-up OCT images showed that the peripapillary pit in the right eye enlarged to 239 µm and retinal herniation occurred through the pit, resulting in a retinal nerve fiber layer defect and a corresponding visual field defect. However, the peripapillary pit in the left eye had no significant change. CONCLUSIONS: Glaucoma patients or suspects, with peripapillary pits need close observation because of the possibility of a retinal nerve fiber layer defect in the direction of the pit.

Angle Closure and the Acute Rise of Intraocular Pressure after Administration of Methazolamide

PURPOSE: To report a case involving an unexpected increase in intraocular pressure (IOP) and acute angle closure after oral administration of methazolamide. CASE SUMMARY: A 38-year-old male visited the emergency department complaining of decreased visual acuity (VA) and ocular pain. These symptoms developed after he took two tablets of 50 mg methazolamide because his IOP was above normal after a short course of systemic steroid treatment. His uncorrected VA dropped to 0.04 and the refractive error was −6.5 diopters in both eyes. The anterior chamber was very shallow, and the IOPs were 46 mmHg in the right eye and 42 mmHg in the left eye. Macular retinal folds were observed in both eyes in infrared fundus images. The patient was instructed not to take methazolamide, which was suspected as the cause of this idiosyncratic drug reaction. He was prescribed topical anti-glaucoma medications and cycloplegics to relieve the acute angle closure, and all symptoms disappeared after these treatments. CONCLUSIONS: Methazolamide is a sulfa derivative like topiramate, which can cause acute angle closure involving edema of the ciliary body and anterior displacement of the lens-iris diaphragm. Clinicians should consider this possible IOP increase before prescribing methazolamide.

Influence of RNFL Thickness on Visual Acuity and Visual Field in Bilateral Temporal Optic Atrophy

PURPOSE: To investigate the influence of retinal nerve fiber layer (RNFL) thickness on visual acuity and visual field in patients with bilateral temporal optic atrophy. METHODS: Patients with characteristic features of gradual visual loss and temporal atrophy of both optic nerves were enrolled in this study. Among the patients, RNFL thickness of each area was measured with optical coherence tomography, and its influence on the best corrected visual acuity, mean deviation and pattern standard deviation calculated from the refractive test and Humphrey visual field test was analyzed. RESULTS: The present study included 13 patients with bilateral temporal optic atrophy (26 eyes) and 13 normal controls (26 eyes). Optical coherence tomography was performed to calculate RNFL thickness in the 52 eyes. Among 26 eyes of patients with bilateral temporal optic atrophy, the Humphrey visual field test was performed to calculate the mean deviation and pattern standard deviation. The mean age in the patient group was 66.0 ± 12.3 years (37-80 years), and 8 (30.8%) patients were male and 18 (69.2%) female. The mean best corrected visual acuity was 30/50 (20/200-20/20). Simple regression analysis showed that a thinner temporal RNFL thickness was correlated with a lower the best corrected visual acuity (p = 0.015). The mean deviation was low when inferotemporal RNFL was thin (p = 0.005). Pattern standard deviation was high when inferotemporal (p = 0.003), inferonasal (p = 0.04) and nasal (p = 0.008) RNFLs were thin. CONCLUSIONS: Inferotemporal RNFL thickness was significantly correlated with best corrected visual acuity, mean deviation and pattern standard deviation of automated visual field test in patients with bilateral temporal optic neuropathy. Optical coherence tomography can be further used to estimate visual acuity and visual field defects in patients with optic atrophy.

A Study of Foveal Shape in Emmetropia and Myopia Using Spectral Domain Optical Coherence Tomography

PURPOSE: To investigate the shape of normal fovea in Korean subjects in their 20's using spectral domain optical coherence tomography (SD-OCT). METHODS: One hundred-twelve emmetropic eyes of 60 subjects and 100 myopic eyes of 58 subjects between 20 and 29 years of age were included in this study. Central foveal thickness (CFT), regional maximal retinal thickness (MRT), pit diameter, pit depth, and slope were obtained using Spectralis OCT and analyzed according to spherical equivalent and gender. RESULTS: In emmetropic and myopic eyes, MRT was significantly thinner temporally (p < 0.001) than in other regions and pit diameter was wider horizontally than vertically (p < 0.001). The CFT was significantly thicker and all regional MRT was thinner in myopic eyes than in emmetropic eyes (p < 0.001). Foveal pits were narrower and shallower in myopic eyes (p < 0.001). In both groups, CFT and all regional MRT in males were significantly thicker than in females (p < 0.05); however, no difference between the genders in horizontal pit diameter, pit depth, and slope were found. CONCLUSIONS: In normal subjects, statistically significant differences were found in foveal shapes between subjects with different spherical equivalent and gender. These differences should be considered when interpreting a foveal shape. Knowledge of the normal foveal morphology is important when conducting further macular studies.

Location of the Tube Tip in the Anterior Chamber and Change in Corneal Endothelium after Ahmed Valve Implantation

PURPOSE: To evaluate the impact of location of a silicone tube tip in the anterior chamber on corneal endothelium after Ahmed glaucoma valve implantation. METHODS: We measured the distance from the tip of a silicone tube in the anterior chamber to the posterior surface of the cornea by anterior segment optical coherence tomography (OCT) in 24 eyes of 21 patients who underwent Ahmed glaucoma valve implantation. All surgeries were performed by a single surgeon. The corneal endothelial cells of central, superior, superotemporal, and superonasal area of the cornea were examined by specular microscope before and after surgery. RESULTS: The distance from the tip of the silicone tube in the anterior chamber to the posterior surface of the cornea and the corneal endothelium were measured at 19.2 +/- 11.8 months (2.8-41.2 months) after surgery. At the central corneal area, a statistically significant decrease in the number of corneal endothelial cells (2278 +/- 565/mm2 vs. 2177 +/- 529/mm2, p = 0.043) after surgery was observed, but no relationship was found between the amount of decrease and distance from the tip to the posterior surface of the cornea. At the superotemporal corneal area where the tip of the silicone tube was located in the anterior chamber, there was more significant loss of corneal endothelial cells than in the other areas after surgery (p = 0.006). Moreover, the amount of endothelial cell loss at the superotemporal area was negatively correlated to the distance from the tip to the posterior surface of the cornea (partial correlation coefficient by time -0.558, p = 0.031). CONCLUSIONS: To minimize the loss of corneal endothelial cells after Ahmed glaucoma valve implantation, ensuring a sufficient distance from the tip of the silicone tube to the posterior surface of the cornea is important.

Bursting Fracture of the Proximal Femur during Insertion of Unreamed Femoral Nail for Femur Shaft Fracture: A Case Report

When treating femur shaft fracture in adults, undreamed nail can be an option in order to avoid systemic complications. To appropriately insert unreamed intramedullary nail, an accurate entry point and sufficient reaming of the entry portal is essential. The intramedullary canal of the proximal femur must be reamed over than the diameter of the proximal end of the nail. If the proximal reaming is not sufficient, complications such as bursting fracture of proximal femur can occur. We present two cases of bursting fracture of proximal femur following insertion of undreamed intramedullary nail as well as a literature review.

Circadian Blood Pressure and Intraocular Pressure Patterns in Normal Tension Glaucoma Patients with Undisturbed Sleep

PURPOSE: To investigate and compare the circadian pattern of blood pressure (BP), intraocular pressure (IOP) and mean ocular perfusion pressure (MOPP) while experiencing undisturbed sleep in normal-tension glaucoma (NTG) and non-glaucoma control patient groups. METHODS: Twenty-four eyes from 24 patients diagnosed with NTG and 22 eyes from 22 control group patients were enrolled. Systolic BP, diastolic BP and IOP were measured every two hours except for the period of time from 1 AM to 7 AM in the NTG group and from 11 PM to 7 AM in the control group over a one-day period. IOP and hemodynamic parameters were then compared between the two groups. NTG patients were subdivided according to the degree of morning BP dip and IOP, and hemodynamic parameters and visual field indices (mean deviation and pattern standard deviation) were also compared among these subgroups. RESULTS: There were no significant differences in mean systolic BP, mean diastolic BP and mean arterial pressure (MAP) between the NTG and the control groups. The NTG group showed a significantly large morning BP dip compared to the control group (7.1+/-4.2% vs. 3.8+/-3.4%, p=0.022). However, there were no significant differences in mean or fluctuation of MOPP between the two groups. Morning over-dippers showed significantly large MAP and MOPP fluctuations compared to non-dippers and dippers, while there were no significant differences in visual field indices among the three subgroups. CONCLUSIONS: NTG patients showed significant morning BP dips compared to the control group. The marked morning BP dip was associated with significantly large MAP or MOPP fluctuations but was not associated with visual field indices.