Search

Purpose: To examine systematically how prechiasmal, chiasmal, and postchiasmal lesions along the visual pathway affect the respective pupillary responses to specific local monochromatic stimuli., Methods: Chromatic pupil campimetry (CPC) was performed in three patient groups (10 subjects with status after anterior ischemic optic neuropathy, 6 with chiasmal lesions, and 12 with optic tract or occipital lobe lesions (tumor, ischemia)) using red, low-intensity red, and blue local stimuli within the central 30° visual field. Affected areas - as determined by visual field defects revealed using conventional static perimetry - were compared with non-affected areas. Outcome parameters were the relative maximal constriction amplitude (relMCA) and the latency to constriction onset of the pupillary responses., Results: A statistically significant relMCA reduction was observed in the affected areas of postchiasmal lesions with red (p = 0.004) and low-intensity red stimulation (p = 0.001). RelMCA reduction in the affected areas seemed more pronounced for low-intensity red stimulation (46.5% mean reduction compared to non-affected areas; 36% for red stimulation), however statistically not significant. In prechiasmal lesions, a statistically significant latency prolongation could be demonstrated in the affected areas with low-intensity red stimulation (p = 0.015)., Conclusion: Our results indicate that the choice of stimulus characteristics is relevant in detecting defects in the pupillary pathway of impairment along the visual pathway, favoring red stimuli of low intensity over blue stimuli. Such knowledge opens the door for further fundamental research in pupillary pathways and is important for future clinical application of pupillography in neuro-ophthalmologic patients., (© 2021. The Author(s).)

Purpose: The photopic negative response (PhNR) is a negative wave following the b-wave of the photopic electroretinogram (ERG). The PhNR originates from the retinal ganglion cells (RGCs), and it can be used to assess the function of RGCs noninvasively and objectively. The purpose of this study was to determine whether the relative amplitudes (affected/normal eye) of the PhNR are significantly correlated with the degree of the relative afferent pupillary defect (RAPD) in eyes with unilateral or asymmetrical damage of the optic nerve., Methods: The PhNRs of the full-field photopic ERGs were measured. In addition, videopupillography and automated perimetry were performed on 27 cases with asymmetrical optic nerve disorders including glaucoma. The differences of these assessments were expressed by the relative amplitudes of the PhNRs of the two eyes, the neutral density (ND) filter required to equate the amplitudes of the pupillary light reflexes between the two eyes, and differences of the mean defects (ΔMDs) of the sensitivities of the Humphrey visual fields. The correlations between these values were determined by linear regression analyses., Results: The relative PhNR amplitudes were significantly and negatively correlated with the ΔMDs (R 2  = 0.58, P = 0.0001). In addition, the relative PhNR amplitudes were moderately but significantly and positively correlated with the RAPDs (R 2  = 0.36, P = 0.002)., Conclusion: The relative amplitudes of the PhNR of the affected eyes to the contralateral eyes indicate an asymmetric alteration of the RGCs, and they can be used to monitor the physiology of the RGCs objectively.

Background: Detection of a relative afferent pupillary defect (RAPD) by the swinging-light test can be challenging in clinical practice (dark eyes, anisocoria, dark environment). We developed a new method of RAPD quantification based on the recording of the infrared pupillary asymmetry (IPA) with a standard optical coherence tomography (OCT) device., Methods: The diagnostic value of the IPA for detection of the RAPD was determined by receiver-operating characteristic (ROC) curves and area under the curve (AUC)., Results: Twenty-nine subjects were included in this study (17 controls and 12 unilateral optic neuropathies). The IPA was significantly greater in unilateral optic neuropathies (0.39) compared to controls (0.18, p = 0.001). The diagnostic value was good with a ROC-AUC of 0.843. Importantly, the IPA correlated significantly with the inter-eye percentage difference of the macular ganglion cell-inner plexiform layer (mGCIPL) thickness (R = 0.53, p = 0.01). Assessment of the IPA took less than 30 s., Conclusion: The present data show that the IPA is a practical and rapid test that can be applied in a clinical setting. The IPA may be a valuable functional outcome measure for clinical trials, complementing structural retinal OCT data in a biological meaningful way. The IPA should be further investigated for suitability for optic neuritis treatment trials.

Background: The purpose of the study was to describe a simple infrared photography technique to aid in the diagnosis and documentation of pupillary abnormalities., Methods: An unmodified 12-megapixel "point and shoot" digital camera was used to obtain binocular still photos and videos under different light conditions with near-infrared illuminating frames. The near-infrared light of 850 nm allows the capture of clear pupil images in both dim and bright light conditions. It also allows easy visualization of the pupil despite pigmented irides by augmenting the contrast between the iris and the pupil., Results: The photos and videos obtained illustrated a variety of pupillary abnormalities using the aforementioned technique., Conclusions: This infrared-augmented photography technique supplements medical education, and aids in the more rapid detection, diagnosis, and documentation of a wide spectrum of pupillary abnormalities. Its portability and ease of use with minimal training complements the education of trainees and facilitates the establishment of difficult diagnoses.

Background: Unilateral injury of the optic tract leads to asymmetrical optic atrophy in both eyes derived from the crossing of the nerve fibers at the chiasm. This report demonstrates unique imaging appearances of optic atrophy due to this uncommon condition detected by spectral-domain optical coherence tomography (SD-OCT)., Methods: Cirrus and RTVue measurements were performed in four cases of optic tract syndrome. Circumpapillary retinal nerve fiber layer (cpRNFL) thickness was obtained from both instruments and ganglion cell complex (GCC) integrity was obtained from RTVue. The presumable reduction rates of quadrant cpRNFL thickness were calculated from the published normative database and compared between eyes with temporal hemianopia and those with nasal hemianopia., Results: Both devices showed significant reduction of cpRNFL thickness, but did not have statistical difference in the reduction rates at temporal or nasal quadrant cpRNFL between contralateral and ipsilateral eyes to the lesion. Color-coded maps helped to visualize the unique pattern of cpRNFL and GCC thinning., Conclusions: SD-OCT can be used as a diagnostic tool for the optic tract syndrome.

Pupillary abnormalities are commonly seen in patients presenting with severe traumatic brain injury (TBI). The objectives of this study were to determine the underlying condition responsible, the natural history of recovery of third nerve palsy and the ultimate clinical outcome in 60 patients admitted to a regional neurosurgical centre with a diagnosis of TBI and unilateral or bilateral fixed, dilated pupils (FDP). In approximately three-quarters of cases, some form of road traffic incident was the mechanism of injury. In patients presenting with a unilateral FDP, the CT-defined condition was most commonly diffuse brain injury (49%) with no obvious lateralising condition. In 34% of cases CT demonstrated a lateralising condition ipsilateral to the side of the FDP and in 9% cases the FDP was contralateral to the side of the CT abnormality. Of those patients who survived an FDP, 72% were left with some form of ophthalmological deficit. Most patients with bilateral FDP did not survive (88%); however, of those who did survive, none was left in a persistent vegetative state or with any ophthalmological sequelae. A FDP is a grave prognostic sign following TBI commonly resulting in long term ophthalmological sequelae; however, a favourable outcome is still attainable.

Congenital cranial dysinnervation disorders (CCDDs) are responsible for 1-2% of infant strabismus cases. Insufficient innervation and misinnervation of aberrant nerve fibres lead to motility restrictions and synkinesis. We present the most common CCDDs and explain their pathogenesis and the resulting clinical features. Furthermore, we emphasize essential diagnostic steps and treatment aspects.

Background: A relative afferent pupillary defect (RAPD) is known to develop only when more than 25% of retinal ganglion cells are ablated in monkeys' eyes. However, there was no prior study to estimate biometrically the degree of retinal nerve fiber layer (RNFL) thickness reduction leading to the development of RAPD in live human eyes. The purpose of this study was to examine the correlation between the amount of RNFL thickness reduction and the depth of a clinically detectable RAPD in patients with unilateral optic atrophy., Methods: Enrolled were 20 patients with optic atrophy of various etiologies. We quantified RAPD by performing the swinging flashlight test with log-scaled neutral density filters placed over the unaffected eye. Average RNFL thickness was measured by OCT3000 with the average RNFL thickness program. Linear regression analysis was used in assessing the relationship between RAPD and the ratio of affected to unaffected average RNFL thickness., Results: The mean of average RNFL thickness was 95.6+/-17.3 microm in the unaffected eyes and 50.7+/-19.3 microm in the affected eyes (P<0.001). Regression analysis between RAPD and the ratio of affected to unaffected average RNFL thickness revealed a correlation coefficient R2=0.48 (P=0.0007). The regression line intersected the y-axis at 0.77., Conclusions: RAPD was not clinically detected until at least approximately 25% of the retinal nerve fibers were lost when compared with the unaffected eyes. Substantial retinal ganglion cell damage is required for the development of RAPD.

Purpose: The aim of the study was to compare the accuracy and the reproducibility of scotopic pupil measurements using two different methods., Patients and Methods: We developed a simple test to measure scotopic pupil diameters using a narrow slit of light through a green filter of the Haag-Streit slitlamp. A total of 100 eyes from 50 refractive surgery candidates were prospectively examined by 2 independent investigators using both the Colvard pupilometer (Oasis/USA) and Sekundo's slitlamp green light test. Results were compared using all pairwise multiple comparison procedures (Student-Newman-Keuls method, SigmaStat/Jandel Scientific). The mean age of the patients was 36.3 years with a male:female ratio of 16:34. The colour of the iris was considered blue for 36 individuals and brown for the remainder., Results: Reproducibility: the right eye mean pupil diameter using Sekundo's method was 6.4 mm (+/-0.9) measured by both the first (Slit 1R) and the second (Slit 2R) investigator. The left eye mean pupil diameter was 6.5 mm (+/-1) (Slit 1L) and 6.35 mm (+/-1) (Slit 2L), respectively. The following measurements were obtained with the Colvard pupillometer: (Colv1R)=6.25+/-0.85 mm, (Colv2R)=5.99+/-1 mm, (Colv1L)=6.15+/-0.91 mm, (Colv2L)=6.05+/-0.9 mm. There were no statistically significant differences between the two investigators within the same method of examination. Comparability:The data of both investigators were combined to form 4 groups: (Slit R)=6.4+/-0.96 mm, (Slit L)=6.4+/-1 mm, (Colv R)=6.05+/-0.9 mm, (Colv L)=6.1+/-0.93 mm. There was a significant difference ( p=0.024) between the two methods for both right and left eyes. Particularly for large pupils, the slitlamp green light measurements were significantly higher (up to 0.35 mm) than those with Colvard's device., Conclusions: The slitlamp green light test provides similar reproducibility for the measurement of the scotopic pupil diameter as the commercially available Colvard pupilometer.

Background: The purpose of this study is to report a case of superior oblique paresis and contralateral relative afferent pupillary defect (RAPD) with normal vision in a patient with brainstem astrocytoma., Methods: We correlated the patient's clinical findings with anatomical substrates on magnetic resonance imaging (MRI) findings., Results: The patient had right-sided superior oblique paresis. There was a left-sided RAPD, although visual acuities and visual fields were normal in both eyes. T1-weighted, gadolinium-enhanced MRI demonstrated a hyperintense area in the right dorsal midbrain., Conclusion: It is suggested that the lesion damaged both the pretectal afferent pupillary pathway and fascicles of the trochlear nerve, causing a unique combination of neuro-ophthalmologic findings.

An overview how to examine pupillary function and handle pupillary abnormalities is presented. The following issues are discussed: swinging flashlight test, clinical relevance of a relative afferent pupillary defect, anisocoria with normal light reaction, diagnosis and evaluation of Homer's syndrome, differential diagnosis of impaired light reaction, tonic pupil, third nerve palsy, supranuclear pupillary disorders, iris problems, systemic disease, measurement of sleepiness, and pupillography.

We investigated prospectively in 128 patients (140 eyes) the role of six routine clinical tests in the differentiation of ischemic central retinal vein occlusion (CRVO) from non-ischemic CRVO during its early acute phase. There were four functional tests [visual acuity, visual fields, relative afferent pupillary defect (RAPD), electroretinography (ERG)] and two morphologic tests (ophthalmoscopy and fluorescein fundus angiography). We found that none of the six tests had 100% sensitivity and specificity in such a differentiation during the early, acute phase, so that no one test can be considered a "gold standard"; however, combined information from all six is almost always reliable. Overall, the four functional tests proved far superior to the two morphologic tests in differentiating ischemic from non-ischemic CRVO:RAPD was most reliable in uniocular CRVO (with a normal fellow eye), followed closely by ERG in all cases; combined information from RAPD and ERG differentiated 97% of cases; perimetry was the next most reliable, followed by visual acuity. The two morphologic tests performed worst; fluorescein angiography provided either no information at all on retinal capillary nonperfusion (in at least one-third of the eyes during the early, acute phase) because of multiple limitations, or sometimes provided misleading information. Ophthalmoscopic appearance is the least reliable, most misleading parameter.

In 149 eyes with central retinal vein occlusion (CRVO), we prospectively investigated the role of routine, clinical electroretinography (ERG) in differentiating ischemic (60 eyes) from nonischemic CRVO (89 eyes). Single-flash photopic and scotopic ERGs were recorded. Data for the amplitudes and implicit times of a- and b-waves and for the b-/a-wave amplitude ratio were analyzed in detail. The study revealed that the best ERG parameter (for both photopic and scotopic ERG) for differentiating ischemic from nonischemic CRVO was a subnormal b-wave amplitude (reduced to less than or equal to 60% or by greater than or equal to 1 SD from the normal mean value, or less than or equal to 64%-69% of that in the fellow normal eye), with a sensitivity of 80%-90% and a specificity of 70%-80%. ERG findings were correlated with the relative afferent pupillary defect (RAPD). An RAPD of greater than or equal to 0.7 log units showed a sensitivity of 88% and a specificity of 90% in differentiating ischemic from nonischemic CRVO. ERG and RAPD findings showed a good correlation. The combined ERG and RAPD tests could differentiate 97%-100% of ischemic from nonischemic CRVO cases, with a specificity of about 70%.