Diagnostic Ability of Macular Ganglion Cell Layer Measurements in Glaucoma Using Swept Source Optical Coherence Tomography

PURPOSE: To evaluate diagnostic ability of macular ganglion cell complex (mGCC), macular ganglion cell inner plexiform layer (mGCIPL) measurements in glaucoma using swept source deep range imaging optical coherence tomography (DRI OCT-1, Topcon Co., Tokyo, Japan). METHODS: From August of 2014 to July of 2015, 109 eyes of 109 subjects were assessed for the average thickness and sectional thickness of both mGCC and mGCIPL to determine whether there exists any significant difference among advanced stage glaucoma group, early stage glaucoma group and normal group in Swept source OCT. Comparisons were also made between the above measurements and circumpapillary retinal nerve fiber layer (cpRNFL) thickness measurements in their diagnostic accuracy, sensitivity, and specificity. RESULTS: The diagnostic ability of mGCC based-mean thickness value (area under the curve [AUC] = 0.78/0.99) in detecting early stage glaucoma group as well as advanced stage group was not significantly different from that of cpRNFL thickness measurement. However, there was a significant difference in thickness between mGCIPL (AUC = 0.70) and cpRNFL in early stage glaucoma groups (p = 0.018). The sensitivities and specificities of mGCC were 0.95/0.97, and those of mGCIPL were 0.92/0.97, respectively. CONCLUSIONS: The two swept source OCT based methods measuring retinal ganglion cell layer thickness appeared to have a good diagnostic accuracy, high sensitivity and specificity in detecting glaucomatous eyes. Nevertheless, of the two methods, mGCC thickness measurement was more efficient in detecting early glaucomatous changes.

Effect of Dominant Eye and Contextual Background on Binocular Rivalry

PURPOSE: We investigated the effects of dominant eye and contextual background on predominance during binocular rivalry. METHODS: 10 subjects were recruited for the present study. Dominant eye was determined using the hole-in-the-card test. In experiment 1, subjects viewed the stimuli through anaglyph filters and reported the predominance of color. The subject's responses were compared with the color on the dominant eye. To investigate the influence of color dominance and contextual color, we conducted the experiment with added contextual color information target through switched-anaglyph filters. In experiment 2, the subject viewed the stimuli through the polarized filters and reported the predominance of orientation. The subject's responses were compared with the grating on dominant eye. To rule out the effect of stimulus size, we conducted the experiment with a smaller target. We designed the additional experiment to investigate the influence of contextual grating information on binocular rivalry. RESULTS: 10 subjects were evaluated. In experiment 1, 8 of 10 subjects reported that eye preference was highly correlated with dominant eye. This finding is significant without reference to color. In experiment 2, 7 of 10 subjects reported that eye preference was highly correlated with dominant eye. This finding is significant without reference to size. In experiment 1-2 and 2-2, all subjects reported that predominance of context contradictory target increased. CONCLUSIONS: We found the relationship between the dominant eye and eye preference. Experiment 1-2 and 2-2 showed that contradictory contextual information increases target predominance during binocular rivalry. Overall, our results indicate that the contextual background reduce the stimulus strength of the context-congruent target; it would correspond to an increase in the dominance duration of the context-contradictory target.

Infant and toddler vision care: a supplement to the Manual of Infant Health Screening conducted by Korean National Health Insurance Corporation

Since 2008, a nationwide infant and toddler vision screening program has been initiated as a part of the Infant Health Screening Project of the Korean National Health Insurance Corporation. Because children's visual system is in the process of development and they can hardly be treated after its maturation, their vision problems must be screened for and treated in their early age. The program screens for frequent and important eye problems from the age of 4 months to 6 years. The vision screening part consists of history questionnaire section and examination section. The history questionnaire section was devised to screen the symptoms of the target diseases that frequently occur in their due age. The examination section comprises penlight examination up to the age of 2 and visual acuity testing afterward. Amblyopia is by far the most important target disease in all screening sessions. Unilateral or bilateral vision problems, strabismus, other intraocular blinding conditions, blepharoptosis, abnormal head posture of ocular origin, and refractive errors are other important target diseases. Proper knowledge of target diseases and methods is essential for the successful screening. This article is intended to supplement the vision screening of the Doctor's Manual for Infant Health Screening.

Optic Cup Slope as a Numeric Representative of Glaucomatous Cupping

PURPOSE: To objectively define the degree of cupping, the authors extracted 3-dimensional slope surface maps from Cirrus HDTM-OCT data and assessed their differentiating characteristics between normal subjects and glaucomatous patients. METHODS: One eye from each of 40 normal subjects and 1 eye from each of 39 patients with glaucoma were examined using automated visual field perimetry and Cirrus HDTM-OCT. The Optic Disc Cube 200 x 200 protocol was performed. The individual OCT data were reconstructed as the 3-dimensional surface maps of the optic disc cup and the slope of each contour was calculated using custom-developed software. Several disc cup slope parameters were derived. The parameters measuring the internal features of the optic disc cup were calculated and compared between groups. RESULTS: Sum of cup slope, sum of thresholded cup slope, and sum of thresholded cup slope / thresholded cup area parameters were differentiating factors between the normal and glaucoma groups (p < 0.05). The area under the receiver operating characteristic curve (AUROC) value of the slope parameters ranged from 0.718 to 0.753. The sum of thresholded cup slope / thresholded cup area parameter was well correlated with visual field mean deviation (r = -0.250, p = 0.028). CONCLUSIONS: The optic disc cup slope parameter obtained with OCT may be a useful parameter for representing glaucomatous cupping.

A Case of Intracavernous Carotid Aneurysm Presenting with Visual Loss with No Oculomotor Disturbance

PURPOSE: Oculomotor disturbance is the common manifestation of intracavernous carotid aneurysm cases. Intracavernous carotid aneurysms causing compressive optic neuropathy with no oculomotor disturbance are relatively rare due to their anatomical characteristics. We experienced a case of intracavernous carotid aneurysm which resulted in a shifted supraclinoid segment of the internal carotid artery, presenting with visual loss and visual field defect with no oculomotor disturbance. CASE SUMMARY: A 40-year-old woman presented with loss of vision in the right eye. A relative afferent pupillary defect was observed in this eye. Visual field test showed quadranopsia in the right eye. Magnetic resonance imaging revealed that the intracavernous carotid aneurysm had shifted the supraclinoid segment of the internal carotid artery to the superomedial position. The right optic nerve was directly molded by the shifted supraclinoid segment of the internal carotid artery at the point of the bifurcation between the anterior cerebral artery and the middle cerebral artery. A Guglielmi detachable coil (GDC) embolization was performed successfully with no operational complications. Six months after coiling, best corrected visual acuity of the right eye was 1.0, and the visual field defect had recovered in all except the superior temporal field. CONCLUSIONS: Oculomotor disturbance is frequently associated with intracavernous carotid aneurysms. Nevertheless, optic neuropathy without oculomotor disturbance may be the only sign in patients with an intracavernous carotid aneurysm that causes shifting of the supraclinoid segment of the internal carotid artery.

Amblyogenic Risk Factors in Primary Family Members of Patients with Exotropia

PURPOSE: To investigate the prevalence of amblyogenic risk factors in the primary family members (parents, siblings) of patients with exotropia. METHODS: The authors of the present study examined primary family members including parents and siblings of 58 exotropia patients in our clinic. Best corrected visual acuity, refractive error, and cover-uncover test were performed. A total of 49 normal children's family members (control group) were examined in a similar manner. The prevalence of significant ocular findings were determined and compared to the control group. RESULTS: In 58 eligible families (153 subjects except proband), 65.4% had significant ocular findings: In parents, anisometopia, astigmatism, hyperopia, and strabismus were found at a rate of 18.1%, 31.1%, 2.5%, and 11.2%, respectively. In siblings, anisometropia, astigmatism, hyperopia, and strabismus were found at a rate of 24.3%, 24.3%, 5.4%, and 18.9%, respectively. Compared to the control group, in parents of exotropia patients, anisometropia, astigmastim, and strabismus were observed at a higher rate. In siblings, anisometropia, and strabismus were observed at a higher rate. CONCLUSIONS: Primary family members of exotropia patients have a high prevalence of amblyogenic risk factors. The present study offers rationale for providing comprehensive eye exams for parents and children with a family history of exotropia.

Specific Spectral Domain Optical Coherence Tomographic Findings of Oguchi Disease

PURPOSE: To report specific spectral domain OCT findings of Oguchi disease diagnosed with fundoscopic examination and electrophysiological study. CASE SUMMARY: A 14-year-old patient visited our clinic with a complaint of night blindness for ten years. Fundoscopic examination showed a golden-yellow fundus reflex. After three hours of dark adaptation, the fundus color returned to normal (Mizuo-Nakamura phenomenon). In full-field ERG, rod b-wave was not detectable. The a-wave amplitude in maximal combined response increased after three hours of dark adaptation, although the b-wave amplitude was similar to the amplitude before dark adaptation, demonstrating a negative waveform. In the spectral domain OCT images of the perifoveal area, no gap between the retinal pigment epithelium and the inner segment/outer segment (IS/OS) junction was detected before prolonged dark adaptation, and a highly reflective band was shown. However, the gap appeared after three hours of dark adaptation, and two highly reflective bands were detected in the OCT images. CONCLUSIONS: The characteristic OCT finding in addition to the specific fundoscopic finding and full-field ERG results may be useful to diagnose Oguchi disease.

Orbit Magnetic Resonance Imaging Images of Bilateral Dacryocele

In this study, we present a case of bilateral dacryocele with orbit magnetic resonance imaging (MRI) images. Otherwise healthy, full term, 46-day-old boy was referred for the evaluation of bilateral orbital mass with both eye discharge. External examination revealed palpable bluish mass on both medial canthus. On orbit MRI images, bilateral cystic masses were visible in his both nasolacrimal duct on T2 weighted MRI images with fluid level on left side. The size of masses had decreased after 3 days of diagnosis. There are only few previous articles describing on MRI findings of dacryocele, especially in bilateral cases. Therefore, we are here to present orbit MRI images of bilateral dacryocele that may be valuable to clinicians interested in congenital nasolacrimal anomalies.

Supermaximal Recession and Resection in Large-Angle Sensory Exotropia

In cases of extropia with an exodeviation angle over 50 prism diopter (PD), a 3- or 4-muscle surgery is a rational option. But, in patients with sensory exotropia, there is usually a strong preference for a monocular procedure to avoid surgery on the single seeing eye. Thus, we confined surgery to visually poor eyes, and performed a medial rectus muscle resection with a mean of 10.3 mm (range, 9-11 mm) and a lateral rectus muscle recession with a mean of 12.8 mm (range, 10-14 mm) in 4 adult sensory exotropia patients who had a mean deviation of 82.3 PD (range, 75-90 PD). The mean postoperative angle of exodeviation was 2.0 PD (range, ortho-8 PD). The limitation on abduction was not disfiguring. Other expected disfigurements, such as narrowing of the palpebral fissure or enophthalmos, were not conspicuous. The mean follow-up period was 4.5 months (range, 3-7 months). In large-angle sensory exotropia, instead of additive surgery on the seeing eye, supermaximal medial rectus resection and lateral rectus recession only on the visually poor eye is a clinically feasible surgical option.

Study for Analysis of the Multifocal Visual Evoked Potential

PURPOSE: To introduce the clinical utility of the absolute value of the reconstructed waveform method in the analysis of multifocal visual evoked potential (mfVEP). METHODS: The mfVEP with 4-channel recording was performed using RETIscan(R) on 10 eyes of 10 normal subjects. Amplitudes were obtained from ring-shaped 6 areas and 4 sectors. The best visual evoked potential (VEP) response method and the absolute value of the reconstructed waveform method were compared in terms of analysis of the amplitudes. In order to assess the false positive rate of the examination, stimuli were administered with one-half of the cathode ray tube (CRT) monitor completely covered and the results were compared using 2 methods. RESULTS: The amplitudes in 6 areas and 4 sectors analyzed with the best VEP response method and the absolute value of the reconstructed waveform method showed no statistical difference (p > 0.05). The amplitude in the stimuli-blocked area of the absolute value of the reconstructed waveform method was smaller than that of the best VEP response method (p 0.05). CONCLUSIONS: The absolute value of the reconstructed waveform method has similar reproducibility and lower level of false positives relative to the best VEP response method. Therefore, it can be considered as a useful method in the analysis of the mfVEP.

Study for Analysis of the Multifocal Visual Evoked Potential

PURPOSE: To introduce the clinical utility of the absolute value of the reconstructed waveform method in the analysis of multifocal visual evoked potential (mfVEP). METHODS: The mfVEP with 4-channel recording was performed using RETIscan(R) on 10 eyes of 10 normal subjects. Amplitudes were obtained from ring-shaped 6 areas and 4 sectors. The best visual evoked potential (VEP) response method and the absolute value of the reconstructed waveform method were compared in terms of analysis of the amplitudes. In order to assess the false positive rate of the examination, stimuli were administered with one-half of the cathode ray tube (CRT) monitor completely covered and the results were compared using 2 methods. RESULTS: The amplitudes in 6 areas and 4 sectors analyzed with the best VEP response method and the absolute value of the reconstructed waveform method showed no statistical difference (p > 0.05). The amplitude in the stimuli-blocked area of the absolute value of the reconstructed waveform method was smaller than that of the best VEP response method (p 0.05). CONCLUSIONS: The absolute value of the reconstructed waveform method has similar reproducibility and lower level of false positives relative to the best VEP response method. Therefore, it can be considered as a useful method in the analysis of the mfVEP.

Computed Tomographic Angiogram of an Anterior Communicating Artery Aneurysm Causing Acute Retrobulbar Optic Neuropathy: A Case Report

Three-dimensional computed tomographic (3D-CT) angiography is a widespread imaging modality for intracranial vascular lesions. However, 3D-CT angiograms of an anterior communicating artery aneurysm associated with acute retrobulbar optic neuropathy have not been previously described. We present 3D-CT angiograms of an aneurysm of the anterior communicating artery that caused subarachnoid hemorrhage and vision loss in a 39-year old man. The 3D-CT angiograms were consistent with findings identified directly during surgery.

Relationship Between Visual Acuity and Foveation Window in Infantile Nystagmus by Analyzing Nystagmus Waveforms

PURPOSE: To report herein on Nystagmus Acuity Estimator Function (NAEF) based on the foveation time, obtained by analyzing waveforms of infantile nystagmus patients and comparing the results with the patients' actual visual acuity. METHODS: Electro-oculographic data of 27 patients with infantile nystagmus were reviewed. Data of patients only with jerk type nystagmus and reliable visual acuity were analyzed. The foveation time was measured, and NAEF was calculated and compared with the patients' actual best corrected visual acuity. RESULTS: A correlation analysis of the patients' best corrected visual acuity with NAEF was performed, and the retrieved coefficient was 0.4266. The p-value calculated using the Pearson correlation coefficient was 0.0282, implying that high NAEF correlates positively with visual acuity. CONCLUSIONS: Estimated visual acuity, calculated based on the waveforms, positively correlates with the patients' actual visual acuity with statistical significance. However, since the foveation time can be measured only in the patients with jerk-type nystagmus waveforms, further study should be performed on the measurement of the foveation time with other waveforms. Furthermore, the present study shows that such analysis is possible with electrooculogram settings in most general hospitals.

Intraoperative Adjustment in Horizontal Strabismus Surgery Using Corneal Reflex

PURPOSE: Using corneal reflex, we performed intraoperative adjustments in horizontal strabismus patients who had very poor visual acuities with good compliance and analyzed various aspects of intraoperative adjustment. METHODS: We retrospectively reviewed the records of patients with horizontal strabismus who underwent intraoperative adjustment using corneal reflex from May 1997 to April 2005. We evaluated various aspects of intraoperative adjustment. RESULTS: Fifty-five patients (40 exotropes, 15 esotropes) were included in our study. 11 of 40 extropes (27.5%) and 4 of 15 esotropes (26.7%) eventually underwent operations that were adjusted intraoperatively. Successful results were seen in 35 of 40 exotropes (87.5%) and 8 of 15 esotropes (53.3%). Fifteen patients (27.3%) received intraoperative adjustments, and of these patients 11 (20.0%) who had successful results would have experienced either undercorrection or overcorrection if their operation were performed as scheduled. Four patients underwent operation on one muscle rather than on the scheduled two muscles. All 4 of these patients (100%) would have experienced significantly large overcorrection had they not received intraoperative adjustment. CONCLUSIONS: Patients who would have had difficulty with fixation due to low visual acuity could avoid under- or overcorrection and are expected to have higher success rates because of intraoperative adjustment using corneal reflex.

Photopic ON- and OFF- Responses in Korean Normal Subjects

PURPOSE: To explore the effects of stimulus duration, stimulus intensity, and background luminance on the amplitude and waveform of the ON- and OFF- responses of photopic ERG and to provide standard parameters of ON- and OFF- responses for normal Korean populations. METHODS: Twenty normal subjects (20 eyes) were enrolled to record photopic ON-and OFF-responses using a contact lens electrode with built-in LEDs and an LED-driver. The influence of stimulus duration on wave amplitudes was studied at flash durations that varied from 5 to 200 ms. The influence of stimulus intensity was studied with 0.4, 0.7, 1.1, 1.4, 1.7, 1.9, 2.0, and 2.1 log cd/m2. In addition, the influence of background luminance was studied with 20, 30, 40, and 50 cd/m2. RESULTS: Among 20 normal subjects, the d-waves in 16 subjects were isolated from b-waves with more than 50 ms of stimulus duration. The d-wave was observed for a 30-ms stimulus duration in 3 subjects and for a 100-ms duration in 1 subject. The amplitudes of the b-and d-waves increased as stimulus intensity was increased. The amplitudes of b-and d-waves decreased as background luminance was increased. CONCLUSIONS: Our results suggest that the clinical use of ON-and OFF-response recording can be obtained with stimulus parameters from 100 to 150 ms in duration and a 1.7-2.1 log cd/m2 intensity under 30-40 cd/m2 background luminance.

Occurrence and Risk Factors of Decompensation and Additional Treatment in Refractive Accommodative Esotropia

PURPOSE: To examine the occurrence and risk factors of decompensation and the additional treatment of increased hyperopia in refractive accommodative esotropia. METHODS: Seventy children with refractive accommodative esotropia were followed up for at least 2 years. Time of decompensation and additional treatment, initial refractive error, initial deviation, and controlled deviation were all studied. RESULTS: Decompensation and additional treatment occurred on average at 21.8 months and 22.2 months in eight patients, respectively, and constant survival was achieved after 4 years of full correction of the refractive error, as shown on a Kaplan-Meier survival curve. In the decompensation, additional treatment and control groups, initial refractive errors were 3.97+/-1.07D, 4.06+/-1.92D and 4.60+/-1.29D, respectively; initial deviations were 36.25+/-12.75PD, 31.25+/-10.61PD and 26.02+/-8.62PD, respectively; and controlled deviations were 4.50+/-6.30PD, 4.50+/-4.63PD and 2.65+/-4.10PD, respectively. There was a significant difference in initial deviation between the decompensation and control groups (p=0.011). CONCLUSIONS: The treatment of decompensation and increased hyperopia warranted careful follow-up in the first 4 years after treatment, and patients with large initial deviation risked decompensation.

Clinical Manifestations of Constant Infantile Exotropia

PURPOSE: The purpose of this study is to evaluate the clinical course and surgical outcomes of constant infantile exotopia developed in the first year of life. METHODS: Eighteen patients diagnosed with constant infantile exotropia who underwent surgery between June 1993 and July 2003 were reviewed retrospectively. Age at diagnosis and surgery, refractive error, and preoperative and postoperative prism diopters were evaluated for all patients. RESULTS: The mean age at diagnosis was 7.3+/-2.2 months (2~11 months) and mean deviation was 47.2+/-16.6 prism diopters (PD) (25~90 PD). Inferior oblique muscle overaction was found in 3 (17%) patients. Bilateral lateral rectus muscle recession was performed in all patients and mean amount of recession was 8.0+/-0.9 mm (7.0~9.0 mm). The mean age at surgery was 16.7+/-4.1 months (7~24 months) and the mean postoperative follow-up period was 34.3+/-23.0 months (7~83 months). Thirteen patients (76%) showed stable alignments after the first operation and 3 patients (18%) required reoperation due to undercorrection and recurrence. Among them, one patient (6%) required a third operation. CONCLUSIONS: Early surgical intervention in constant infantile exotropia resulted in good postoperative outcome and stable alignments after the first operation.

Diagnosis and Management of Congenital Periodic Alternating Nystagmus

PURPOSE: To investigate clinical findings, diagnostic criteria and management for patients with congenital periodic alternating nystagmus (PAN). METHODS: A retrospective analysis of clinical findings and electrooculography (EOG) of patients with congenital PAN was performed. Thirteen patients diagnosed with congenital PAN from March 1992 to December 2002 were included. RESULTS: Of 13 patients, the median age at initial visit was 7 years old (range: 1 to 30 years). Eight patients had abnormal head posture. The mean value for the period of alteration was 265.7 seconds. Six patients who received either the modified Kestenbaum-Anderson procedure or four rectus muscle recession showed a significant decrease in amplitude and/or frequency of nystagmus, and showed statistically significant improvement in visual acuity in LogMAR after the procedures by 0.33+/-0.09 in right eye, 0.34+/-0.11 in the left eye, compared with preoperative acuities of 0.43+/-0.19 and 0.38+/-0.09 respectively. CONCLUSIONS: Congenital PAN requires the evaluation of nystagmus along with a thorough evaluation of eye movement and EOG. Close follow is necessary to evaluate the pattern of nystagmus. Also, either modified Kestenbaum-Anderson procedure or four rectus muscle recession could be effective, depending on the presence of abnormal head posture.

Ictal Nystagmus by Epileptic Activation of Cortical Smooth Pursuit System: Electrophysiological and Neuroimaging Study

BACKGROUND: Epileptic nystagmus is rare. There is no report in Korea about epileptic nystagmus by the activation of cortical smooth pursuit area. We studied a 29-year-male patient with nonconvulsive simple partial status epilepticus presenting as pure ictal nystagmus. METHODS: The EEG including electrooculogram and electronystagmogram during ictus was done. Brain MRI including (99m)Tc-ECD SPECT and 18F-FDG PET were also done during ictus and repeated after complete relief from symptom. Subtraction images obtained from each of SPECT and PET were coregistrated onto MRI. Humphrey visual field test was done for documentation of visual field defect. RESULTS: EEG was compatible with nonconvulsive status epilepticus arising from right mesial occipital area with 9-10 Hz frequency. Compensatory left beating nystagmus with midline crossing feature was noted and characteristic ipsiversive linear slow phase was presented in electronystagmogram. Brain neuroimages from MRI, (99m)Tc-ECD SPECT, and 18F-FDG PET revealed that the right parietotemporooccipital area was relevant area, but the right frontal eye field area was spared, which was much clear in SISCOM image. CONCLUSIONS: Clinical feature and electronystagmogram in this case showed typical epileptic nystagmus by activation of cortical smooth pursuit regions in which the relevant regions was posterior parietotemporooccipital area. The sparing of the frontal eye field area in this case suggested clearly that the epileptic nystagmus by the activation of cortical smooth pursuit regions could occur without involvement of frontal eye field area.

Scanning Electron Microscopic Findings of Removed Supramid Extra II(R) from Recurred Congenital Ptosis Patients

PURPOSE: To identify the cause of frequent recurrence of ptosis after frontalis suspension with Supramid Extra II(R), we investigated the change occurring in the Supramid following implantation. METHODS: We examined the removed Supramid Extra II(R) from recurred congenital ptosis by scanning electron microscopy. RESULTS: Some cracks were noted on its sheath as well as hydrolytic remnant of internal polyfilament. In most cases, the longer the implantation time was, the more the sign of disintegration was observed. CONCLUSIONS: This study showed that hydrolysis and subsequent weakening of Supramid material might have caused the frequent recurrence of ptosis.