Pingelapese achromatopsia: correlation between paradoxical pupillary response and clinical features

AIM: To evaluate the paradoxical pupillary constriction in darkness in patients with Pingelapese achromatopsia (PA), and to describe a connection between this phenomenon and the clinical features. METHODS: 27 patients with PA were examined. All underwent a full ophthalmic examination which included Snellen visual acuity and ophthalmoscopy. Colour vision examination was performed with Ishihara pseudoisochromatic plates and also with a colour plate consisting of five basic colours (red, green, purple, yellow, and orange). Paradoxical pupillary response was examined and documented with a special infrared video camera. Pupils' images were analysed using the Scion Image program and the ratio of pupil size in darkness to its size in light was calculated and recorded. RESULTS: Mean visual acuity was 20/400 (range 20/80-20/800). Colour vision examination showed a mean of 3.2 (SD 1.5) (range 1-5) of Ishihara colour plates, and 0.5 (0.75) (0-3) of basic colour plates. 23 patients (85%) had paradoxical pupillary constriction in darkness. Mean dark/light ratio of pupillary area was 0.86 (range 0.5-1.6). In patients with marked paradoxical pupillary constriction there was a significant correlation of visual acuity and Ishihara score. CONCLUSIONS: Clinical manifestations of achromatopsia include total colour blindness, low visual acuity (mean of 20/400), horizontal pendular or rotatory nystagmus, and photophobia. Most patients have paradoxical pupillary constriction in darkness. When this response is brisk it seems to correlate with lower visual acuity and lower Ishihara score.     

Human psychophysical analysis of receptive field-like properties: V. Adaptation of stationary and moving windmill target characteristics to clinical populations

This paper describes the application of several key parameters of a windmill-shaped target (used in determinations of the psychophysical transient-like function) to clinical populations as a diagnostic tool for static perimetry. A technique for independently analyzing sustained- (Westheimer function) and transient-like retinally-based psychophysical responses is outlined, and stimulus characteristics, reliability and diagnostic potential of the tests are examined. Several particularly interesting clinical cases (one closure of a branch retinal arteriole and two senile macular degeneration patients) are presented for illustrative purposes. In addition, a tentative working hypothesis is presented as a basis for extensive future analysis of various clinical populations.This research has been supported in part by National Eye Institute Research Grant No. EY-01418-03 (to JME), National Eye Institute Postdoctoral Fellowship No. EY-00173-02 (to CAJ), and by National Eye Institute Research Grant No. EY-01084-02 (to CRF). The National Eye Institute is part of the National Institutes of Health, Bethesda, MD.     

Waldenstrom's macroglobulinemia,a hyperviscosity manifestation of venous stasis retinopathy

Waldenstrom's macroglobulinemia is characterized by hyperviscosity. This is usually the result of an increased serum concentration of IgM molecules; this paraprotein has a high molecular weight and unusual shape. The changes in shear rate associated with increased IgM concentrations produces maximal viscosity in the venous circulation.One of the major causes of retinal venous occlusion is venous stasis retinopathy. The typical patient with this disorder is a young individual with a periphlebitis. However, the hyperviscosity in Waldenstrom's macroglobulinemia is an ideal representative of a venous stasis that is without associated vascular pathology. To illustrate this situation, two cases are described and their etiologic features are discussed.This work was supported, in part, by a National Institutes of Health Training Grant ( 5T 32 EY 07007), and an unrestricted grant from Research to Prevent Blindness.     

Differentiation of ischemic from non-ischemic central retinal vein occlusion during the early acute phase

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 fourfunctional tests [visual acuity, visual fields, relative afferent pupillary defect (RAPID), electroretinography (ERG)] and twomorphologic 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: RAPID was most reliable in uniocular CRVO (with a normal fellow eye), followed closely by ERG in all cases; combined information from RAPID 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.A preliminary summary of this was presented at the Macula Society Meeting, Cannes, France (June, 1987) and at the XVIth Meeting of the Club Jules Gonin, Bruges, Belgium, 4–8 September 1988. This investigation was supported by grant EY-1151 from the National Institutes of Health and, in part, by unrestricted grants from Research to Prevent Blindness, Inc., and from Alcon Research Institute     

Electroretinography in central retinal vein occlusion

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 60% or by 1 SD from the normal mean value, or 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 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%.Presented in part at the Annual Meeting of the Association for Research in Vision and Ophthalmology, Sarasota, Florida, USA, 2 May 1988Supported by grant EY-1151 from the National Institutes of Health, and in part by unrestricted grants from Research to Prevent Blindness, Inc., and from Alcon Research Institute     

Interferometric resolution determinations in the fovea and parafovea

Foveal and extrafoveal interferometric determinations of retinal resolution were made on two observers. Resolution fell with increasing decentration of fixation. For example, the two subjects exhibited retinal resolution equivalent to Snellen 20/40 respectively at 6.3° and 3.75° from fixation. The test criterion was the ability to distinguish the vertical line (fringe) interferometric pattern formed on the retina. One must conclude that comparable interferometric determinations (resulting in equivalent resolution measurements) do not imply that a patient has central fixation. This finding means that we must use care when interpreting the results of such tests on patients. Of course, if test parameters are altered, or if media are hazy or cloudy, the result may be somewhat different.Observer JE's data follow cone separation data quite well over the range of eccentricities tested. Differences between these data and those of Green (1970) must be resolved (see Appendix).This research has been supported in part by Research Grant EY-00204-13 and Career Development Award No. 5K3-EY 15, 138-10 (to JME) of the National Eye Institute, National Institutes of Health, Bethesda, Maryland and Fight For Sight Grant-in-Aid No. G-466.     

Branch retinal artery occlusion (BRAO) combined with branch retinal vein occlusion (BRVO) and optic disc neovascularization associated with HIV and CMV retinitis

Two vaso-occlusive events, branch retinal artery occlusion (BRAO) and branch retinal vein occlusion (BRVO), were observed in the retina of an HIV-infected patient with cytomegalovirus (CMV) retinitis who developed neovascularization of the disc (NVD). Although BRVO and reversible NVD have been reported in association with CMV retinitis, we have seen no reports of concomitant BRAO. CMV damages endothelial cells and causes an occlusive vasculitis. In HIV-infected individuals, damaged endothelial cells and rheologic problems result in increased blood viscosity. HIV infection has also been associated systemically with elevated levels of cytokines, including tumor necrosis factor alpha (TNF-). In vitro, TNF- exerts effects that decrease fibrinolytic potential; this activity in the circulation of a patient with AIDS may lead to vascular occlusive events. In the patient reported here, the retinal changes were not reversed by induction therapy with ganciclovir and the NVD did not regress.Supported in part by an individual National Research Service Award grant F32-EY06193 (MDC) from the National Eye Institute, National Institutes of Health, Bethesda, Maryland and an unrestricted grant from Research to Prevent Blindness, Inc., New York, NY. Presented in part at the Midwest Fluorescein Conference, Door County, Wisconsin, August, 1992     

Intraocular diathermy coagulation

Previously used transvitreal diathermy systems were found to be less than adequate. A new, safer 1.25 MHz medium frequency bipolar instrument is presented, which obviates most of the earlier drawbacks. Coagulation at the retinal surface can be obtained with as little as 0.15 J.This investigation was supported in part by the Florida Lions Eye Bank, Miami, Florida; the Veterans Administration Medical Center (Project No. 5421-01), Miami, Florida; Public Health Research Grants EY-02180 and EY-02903, from the National Eye Institute, National Institutes of Health, Bethesda, Maryland 21205; and Research to Prevent Blindness, Inc., New York, New York, USA     

Human psychophysical analysis of receptive field-like properties: IV. Further examination and specification of the psychophysical transient-like function

In this paper we examine several key properties of the moving windmill target used in evaluation of the psychophysical transient-like function. Magnitude of the transient-like function, herein defined as the difference in threshold-determining background field luminance between stationary and moving windmill conditions, was greatest for a rate of approximately 6–8 on-off transitions/second for the moving windmill. Increasing the light/dark ratio of the windmill also augmented the magnitude of the transient-like function. The one-, two- and four-section windmill targets exhibited essentially similar results, indicating that the number and length of borders do not influence this response.In conjunction with previous stationary windmill results (Enoch and Johnson, 1976), these data define the relevant transient-like function properties and provide a basis for comparison with findings in the companion paper (Enoch, Johnson & Fitzgerald, 1976a) which describes the application of these properties to clinical populations for diagnostic purposes.This research was supported in part by National Eye Institute Research Grant No. EY-01418 (to JME) and by a National Eye Institute Postdoctoral Fellowship No. EY-00173 (to CAJ). The National Eye Institute is part of the National Institutes of Health, Bethesda, MD.     

Cyclic strabismus — A case study

A hospital study of a patient with well documented cyclic strabismus over a period of seven days did not reveal biologic functions that varied synchronously with the patient's alternate-day esotropia. Forty-eight hour cyclic changes were not found in serially administered psychologic tests, electroencephalograms, analyses of urinary excretory products or other biologic parameters. The ocular deviation maintained its regular periodicity over the seven day study period at the conclusion of which the rhythm was found to be alterable by cycloplegic eye drops, general anesthesia and subsequently by patching. Recessions of the insertions of both medial rectus muscles four months after the hospital study led to a marked decrease in the frequency of crossing. At the time of writing, the patient has reportedly been straight for four consecutive weeks without the aid of glasses or miotics.Supported by a Grant (RR-284) from the General Clinical Research Centers Program of the Division of Research Resources, National Institutes of Health.