Portable pupillography of the swinging flashlight test to detect afferent pupillary defects

OBJECTIVE: To investigate the ability of a portable, personal computer-driven, pupillometer to record the pupillary response curve during the swinging flashlight test. Also, to determine whether these response curves can be used to identify and quantify relative asymmetry in the pupillary light reflex between eyes in healthy volunteers with simulated afferent pupil defects (APDs) and patients with optic neuropathies. DESIGN: Comparative, observational case series and instrument validation. PARTICIPANTS: Healthy volunteers with no known ocular disease and patients (n = 20) with various optic neuropathies noted to have relative APDs on examination. METHODS: Pupillary response curves of the right eye were recorded with a portable, electronic, infrared pupillometer from healthy volunteers (with and without simulated APDs) and patients with APDs while the light stimulus alternated between eyes, simulating the swinging flashlight test. Simulated APDs in healthy volunteers were created with increasingly dense neutral density filters in front of the left eye. MAIN OUTCOME MEASURES: Differences in constriction amplitude, latency, and constriction velocity of the pupillary response with right eye stimulation versus left eye stimulation in both groups of subjects. RESULTS: A significant correlation between neutral density filter strength and intereye differences was seen for all measurement parameters in volunteers with simulated APDs. Depending on the measurement parameter and stimulus intensity, simulated APDs of 0.6 log units or more could be distinguished from normal responses. Clinically graded true APDs had intereye differences similar to simulated APDs of the same density. Those with real and simulated APDs of 0.9 log units or more could be distinguished from healthy volunteers with 80% sensitivity and 92% specificity. Responses from those with real and simulated small APDs of 0.3 to 0.6 log units could not be distinguished reliably. CONCLUSIONS: Portable, personal-computer driven, electronic, infrared pupillography can record the swinging flashlight test accurately and identify large afferent pupillary defects. An affordable, portable, reliable device for identifying relative APDs would be useful in the identification and follow-up of patients with neurogenic vision loss.     

Detection of glaucomatous damage using multifocal ERG

The first‐order kernel analysis in multifocal electroretinogram (mfERG) using low contrast stimulation is suggested as a way to detect the inner retinal responses in animal studies. In this case report, this protocol is applied to human patients with glaucoma to demonstrate the possibility of using mfERG as a tool to detect glaucomatous damage. Two patients with glaucoma were recruited and had mfERG measurements with the 103‐scaled hexagonal stimulus pattern at low (50 per cent) contrast. Their responses were analysed and compared with those from normal subjects with the mfERG measured under the same condition. In the normal subjects, there were obvious oscillatory components on the ascending and descending limbs of the first‐order kernel response to 50 per cent contrast. In the glaucomatous patients, the oscillatory component on the descending limb was obviously diminished. In addition, this component was significantly diminished in the quadrant with a glaucomatous visual field defect. This suggests that the low‐contrast stimulation condition in mERG measurement may provide a good way to detect glaucomatous damage and this may help in clinical diagnosis of glaucoma.     

Correlation of asymmetric glaucomatous visual field damage and water-drinking test response

PURPOSE: To determine whether there is a correlation between asymmetric glaucomatous visual field (VF) damage and water-drinking test (WDT) response. METHODS: A retrospective analysis was conducted of VF and WDT data from 101 patients with glaucoma in clinical therapy, who were receiving treatment with the same topical medication in both eyes, and asymmetric VF defect. Eyes were classified according to mean deviation (MD) into "better" and contralateral "worse" eyes. Maximum mean difference in basal IOP was 2 mm Hg between both eyes. The peak IOP and fluctuation obtained with the WDT were compared between both groups. For the statistical analysis, the Tukey post hoc multiple comparison test and paired t-test were used. RESULTS: Better and contralateral worse eyes presented mean MDs of -4.6 +/- 5.3 and -9.0 +/- 7.4 dB, respectively (P < 0.001). Mean basal IOPs were 13.9 +/- 3.3 and 13.9 +/- 3.1 mm Hg, respectively (P = 0.67). Mean maximum IOPs after water ingestion were 16.5 +/- 3.8 mm Hg in the group with less severe VF defect and 17.2 +/- 4.1 mm Hg in the contralateral group with worse visual fields (P < 0.001). Mean fluctuation (maximum IOP - minimum IOP after water ingestion) was 3.6 +/- 1.8 and 4.4 +/- 2.2 mm Hg (P < 0.001), respectively. CONCLUSION: Eyes with worse MDs presented higher IOP peaks and fluctuation after water ingestion. This study demonstrates a lower capacity of eyes with worse glaucomatous lesion to respond to a stimulus that leads to a transitory elevation of IOP.     

Progression of glaucomatous visual field damage detected by short-wavelength automated perimetry

The efficacy of short-wavelength automated perimetry (SWAP) and conventional automated perimetry (CAP) in detecting the progression of glaucomatous visual field loss was compared. After 3 years, CAP detected progressive visual field damage in 3 (13.6%) of 22 eyes, while SWAP detected progressive visual field damage in 8 (36.6%) of 22 eyes. Thus, SWAP was more efficient than CAP in detecting progressive visual field losses in glaucomatous patients with incipient defects. The authors have stated that they do not have a significant financial interest or other relationship with any product manufacturer or provider of services discussed in this article.     

Detection of glaucomatous damage in patients with osteo-odontokeratoprosthesis.

BACKGROUND--Osteo-odontokeratoprosthesis (OOKP) is an autologous transplantation procedure in which the cornea is replaced by an optical cylinder glued to a biological support. Patients undergoing OOKP surgery may develop a secondary glaucoma whose diagnosis, by means of standard diagnostic procedures, is often doubtful. METHODS--In the present study pattern electroretinograms (PERGs), visual evoked potentials (VEPs), contrast sensitivity, and automated threshold perimetry (Humphrey 30-2) were evaluated in 19 OOKP treated patients with postoperative visual acuities > or = 0.8. Nine patients had had a preoperative secondary glaucoma, while the remaining 10 had no history of glaucoma and normal posterior pole. RESULTS--Results were compared with those obtained from either normal control subjects or from ordinary glaucoma patients. PERG amplitudes and contrast and perimetric sensitivities were reduced in both groups of OOKP patients when compared with normal controls. However, these losses were significantly greater in OOKP patients with glaucoma compared with those with normal posterior pole. VEPs were reduced, compared with controls, only in OOKP patients with glaucoma. These VEP losses were similar to those found in ordinary glaucoma patients. CONCLUSION--Among the tests employed, VEPs showed the best accuracy (79%) in discriminating between glaucomatous and non-glaucomatous OOKP treated eyes. The present results suggest a possible use of the VEP technique for detecting glaucomatous dysfunction after OOKP.     

Detecting early to mild glaucomatous damage: a comparison of the multifocal VEP and automated perimetry

PURPOSE: To gain better understanding of the relationship between abnormalities detected by the multifocal VEP (mfVEP) compared with those detected by static achromatic, automated perimetry in patients with glaucoma. METHODS: Fifty patients were studied who had open-angle glaucoma that met the following criteria: (1) a mean deviation (MD) of better than -8 dB in both eyes on the 24-2 Humphrey visual field (HVF) test (Carl Zeiss Meditec, Dublin, CA); and (2) glaucomatous damage in at least one eye, as defined by a glaucomatous optic disc and an abnormal 24-2 HVF test result (pattern standard deviation [PSD] <5% and/or glaucoma hemifield test [GHT] results outside normal limits). Monocular mfVEPs were obtained from each eye by using a pattern-reversal dartboard array, 44.5 degrees in diameter, which contained 60 sectors. Recording electrodes were placed at the inion (I) and I+4 cm, and also at two lateral locations up 1 cm and over 4 cm from I. Monocular and interocular mfVEP probability plots were derived by comparing the results with those of normal control subjects. For both the HVF and mfVEP probability plots, a hemifield was classified as abnormal if three or more contiguous points were significant at less than 5%, with at least one at less than 1%. RESULTS: Of the 200 hemifields tested (50 patients x two eyes x two hemifields), 75 showed significant clusters on the HVF, and 74 (monocular probability plot) and 93 (monocular or interocular plot) showed significant clusters on the mfVEP. Overall, the HVF and mfVEP results agreed on 74% of the hemifields, and 90 hemifields were normal and 58 were abnormal on both the mfVEP (interocular and/or monocular abnormal) and HVF cluster tests. Of the 52 disagreements, 35 hemifields had a significant cluster on the mfVEP, but not on the HVF, whereas the reverse was true of 17 hemifields. A case-by-case analysis indicated that misses and false-positive results occurred on both the HVF and mfVEP tests. CONCLUSIONS: As predicted from a theoretical analysis, under these conditions (i.e., the signal-to-noise level) the HVF and monocular mfVEP tests showed a comparable number of defects, and, with the addition of the interocular test, the mfVEP showed more abnormalities than the HVF. However, although there were abnormalities detected by the mfVEP that were missed by the HVF, the reverse was true as well.     

介绍一种青光眼视盘损伤估测法

目的介绍青光眼视盘损伤可能性估测法(DiskDamageLikelihoodScale,DDLS),应用于同一检查者及不同检查者间,评估其对青光眼视盘损伤估测值的变异度及一致性。方法同一检查者及不同检查者分别对10例(20眼)原发性开角青光眼(primaryopen-angleglaucoma,POAG)进行3次视盘大小测量值(垂直径)及DDLS分期。结果在10例(20眼)POAG中,2位检查者的视盘垂直径测量值的变异系数分别为3.30%和4.41%。2位检查者3次估测DDLS视盘损伤分期的一致性为75%;检查者1自身3次DDLS分期的一致性为90%;检查者2自身3次分期的一致性为85%。结论DDLS对于分析青光眼性视盘损害具有变异度低及不同检查者间一致性高的特点。     

Detection of eyeshine by flashlight fishes of the family Anomalopidae.

Flashlight fishes of the family Anomalopidae live in clear tropical waters and are nocturnally active. They have luminescent organs located just below the pupils of their eyes. The relation of the luminescent organ to the pupil of the anomalopid eye is similar to that of the illumination and pupil system of the ophthalmoscope and identical to that of some photoretinoscopes. Indeed, one species of flashlight fish, Anomalops katoptron, actually moves its luminous organ away from its pupils in the process of occluding its light organ, making a retinoscopic-like movement. By photographing the eyeshine of a number of fishes with a photoretinoscope and by analyzing the optics of light organs of fish of the family Anomalopidae as well as the optics of reflecting eyes, we show under what light conditions and ranges flashlight fishes may reasonably be able to detect eyeshine from other fishes in the environment. Further, we suggest that flashlight fishes may be able to communicate with each other by altering the accommodation of their eyes. In such a communication system, the sender radiates no energy and communicates only with the interrogating receiver of the information. To our knowledge, this utilization of eyeshine, both for detection and for communication, is unique in the animal kingdom.     

Detection of optic neuropathy in glaucomatous eyes with normal standard visual fields using a test battery of short-wavelength automated perimetry and pattern electroretinography

PURPOSE: To evaluate the clinical use of a test battery of short-wavelength automated perimetry (SWAP), frequency-doubling technology (FDT) perimetry, and pattern-electroretinography (PERG) in patients with definite primary open-angle glaucoma (POAG) but normal results on standard automated perimetry (SAP). STUDY DESIGN: Prospective, comparative, observational case series. PARTICIPANTS: Thirty-six patients with POAG with standard visual field defects in one eye and normal standard visual fields in the contralateral eye and 36 normal controls were enrolled. MAIN OUTCOME MEASURES: SWAP, PERG, FDT, and SAP were performed in all eyes, and global indices and amplitudes were used for statistical analysis. RESULTS: When contralateral POAG eyes with asymmetric glaucomatous damage was compared, a paired t test showed significant differences in SAP mean deviation (MD) (P < 0.0001), SWAP-MD (P = 0.0003), FDT-MD (P = 0.0008), and PERG amplitudes (P < 0.0001). When comparing between POAG eyes with normal results on SAP and normal controls, Student's t test showed significant differences for SWAP-MD (P < 0.0001), FDT-MD (P = 0.0006), PERG N1P1-amplitude (P = 0.0486) and P1N2-amplitude (P < 0.0001); receiver operating characteristic analysis revealed promising accuracy for SWAP-MD of 73.6% (P < 0.0001). SWAP-MD (P < 0.0001) and FDT-MD (P < 0.0001) correlated significantly with SAP-MD and with each other (range, P < 0.0001 to P = 0.0020). Regression analysis revealed that PERG P1N2-amplitude could improve the power of SWAP-MD from 73.6% to detect early POAG in eyes with normal results on SAP to an accuracy of 81.9%. CONCLUSIONS: A test battery of SWAP-MD and PERG P1N2-amplitude could detect glaucomatous optic neuropathy in POAG eyes with normal standard visual fields, whereas FDT-MD and SWAP-MD significantly correlated with each other and with SAP-MD. All tests were able to detect the eye with the more severe glaucomatous optic neuropathy in patients with asymmetric POAG.     

Detection of glaucomatous optic nerve head by using Heidelberg topographic maps

PURPOSE: To evaluate the capacity of a new topographic map analysis to detect abnormal optic discs from healthy ones in a new cohort of subjects. PATIENTS AND METHODS: Only one eye was chosen randomly from each subject included in the study. In total, 20 normal eyes with a normal visual field, an IOP of <22 mmHg and no history of glaucoma in their family, and 20 glaucomatous eyes with an abnormal visual field and an open angle were selected. All the subjects were examined with the Heidelberg Retina Tomograph (HRT, Heidelberg Engineering GMBH, Heidelberg, Germany) and Humphrey Perimeter, program 30-2 (Humphrey Instrument, Inc., San Leandro, CA, USA). Topographic maps analysis was performed to each HRT optic nerve head image. Sensitivity, specificity, and diagnostic precision were calculated. RESULTS: When the topographic map analysis was applied to the group, a sensitivity of 80%, a specificity of 75%, and a diagnostic precision of 77.5% were obtained. CONCLUSION: Using the topographic map analysis, the HRT capacity to differentiate normal optic discs from those with glaucoma was similar to those already published in the literature, but using this technique there is no input from the observer to draw the contourline and reference plane is not necessary.     

Blue-yellow perimetry in the detection of early glaucomatous damage

A perimetric method using blue stimuli on a yellow background was compared with perimetry using white stimulion on a white background as a method of detecting glaucomatous damage. Meridian perimetry was used with an adapted Tübinger perimeter. The difference between the blue-on-yellow meridian and the white-on-white meridian was subdivided into two parts: the general blue sensitivity loss (GBSL), probably due to optical factors, and the corrected blue sensitivity loss (CBSL), probably due to glaucoma. Nine normals, fourteen primary open angle glaucoma (POAG) patients and nine ocular hypertensives (OHT) were tested. All POAG patients and some of the OHT group showed higher CBSL values than the controls. The blue-yellow meridian showed broader and deeper defects than the white-white meridian in all of the POAG group; some of the OHT group had defects in the blue-yellow meridian that were not present in the white-white meridian.In conclusion, blue on yellow perimetry shows promise as a method for more sensitive detection of early glaucomatous damage.     

The use of psychophysical,structural, and electrodiagnostic parameters to identify glaucomatous damage

Fifty-one patients with early glaucoma and 29 patients without the disease had their contrast sensitivity, colour vision, differential light threshold, neuroretinal rim area, retinal nerve fibre layer, pattern-reversal electrogram and visually evoked potential examined. A stepwise discriminant analysis found that the combination of the vertical cup disc ratio, the diffuse nerve fibre layer score and the localized nerve fibre layer score correctly identified 98% of the normals and 84% of the glaucoma patients. Single parameters and various combinations of parameters were also examined for their ability to discriminate between the two groups. Fifty-two glaucoma suspects were similarly examined and were classified into those whose discriminant functions were normal or abnormal.This work was carried out at the Department of Ophthalmology, University of British Columbia