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Dilated, miotic-resistant pupil and laser iridotomy in primary angle-closure glaucoma.

We analyzed 22 eyes with primary angle-closure glaucoma that underwent initial laser iridotomy to determine which factors could lead to subsequent trabeculectomy. Twenty-two eyes were divided into two groups: (1) the eyes in which intraocular pressure (IOP) could be controlled by iridotomy and/or topical medication (iridotomy success group, 15 eyes) and (2) the eyes that underwent trabeculectomy to control IOP in spite of a patent opening (iridotomy failure group, 7 eyes). The clinical variables between the two groups were analyzed. Age, sex, visual field defect, presenting IOP and cup/disk ratio were not significantly different between the iridotomy success and failure groups. However, presence of peripheral anterior synechiae (PAS) greater than 50% was found more frequently in the iridotomy failure group as compared with the iridotomy success group (4/7 vs. 1/15, p = 0.02). Dilated, miotic-resistant pupils were observed only in the iridotomy failure group (4/7 vs. 0/15, p = 0.004). PAS greater than 50% and dilated, fixed pupils were observed in these same cases (4 eyes). Our results suggest that laser iridotomy may not be helpful in cases with dilated and miotic-resistant pupils with formation of extensive PAS.

Aged↗

The effects of phaco-emulsification-aspiration and intra-ocular lens implantation on the pupil: pupillographic and pharmacologic study.

The authors report postoperative change in pupil diameter and pupil dynamics after phaco-emulsification-aspiration and intra-ocular lens implantation by comparing the operated eye and non-operated eye in 20 patients who received unilateral surgery. Miosis was noted in the operated eye throughout the postoperative period in the dark, and also in the light at an early stage after the operation. Both the maximal constriction velocity and maximal dilatation velocity of the light reflex decreased postoperatively, but the constriction velocity alone was accelerated 1 or 2 weeks after the operation. In the drug instillation test, pupillary responses to both neosynephrine and pilocarpine were decreased, indicating damage both to the dilator and sphincter muscles. Since no hypersensitivity of the pupil was noted, lesions in the axonal fibres and denervation were judged to be absent. Postoperative miosis is believed to be explained by irreversible damage to the dilator muscle, as well as by the transient effects of inflammatory substances.

Aged↗

The Behr pupil revisited. Anisocoria following cerebrovascular accidents.

Three hundred and sixty-three cases of cerebral infarction were reviewed: 19 had anisocoria. Eighty percent had the larger pupil contralateral to the hemispheric lesion. The mydriasis was associated with long tract signs in all instances. If the abnormal pupil and long tract signs are not on the same side, the long tract signs are the most accurate evidence of the side of thhe hemispheric lesions. When the pupil was 4 mm or larger and reacted sluggishly, the prognosis was poor. The mechanism of the production of the anisocoria is still uncertain; the lesion is probably "cortical" and in the contralateral hemisphere.

Cerebrovascular Disorders↗

Reversible posterior leukoencephalopathy and Adie's pupil after measles vaccination.

Reversible posterior leukoencephalopathy syndrome is an increasingly recognized disorder with typical radiologic findings of bilateral gray- and white-matter abnormalities in the posterior regions of the cerebral hemispheres. The majority of patients with reversible posterior leukoencephalopathy syndrome are adults, and it is rare in children. Previously reported associations of reversible posterior leukoencephalopathy syndrome include hypertension, vasculitis, nephrotic syndrome, severe hypercalcemia, hemolytic uremic syndrome, eclampsia, renal failure, and use of immunosuppressive drugs. Adie's pupil is described as the presence of a large unilateral or bilateral tonic pupil related to virus infections or trauma. In this article, we describe a case of reversible posterior leukoencephalopathy and Adie's pupil association that occurred after measles vaccination. To our knowledge, this association has not been reported.

Brain Diseases↗

Reversal of fixed pupils after spontaneous intraventricular hemorrhage with secondary acute hydrocephalus: report of two cases treated with early ventriculostomy.

Rapid reversal of fixed pupils, complete external 3rd nerve ophthalmoplegia, and coma occurred after early ventriculostomy in two hypertensive male patients with spontaneous intraventricular hemorrhage and secondary acute hydrocephalus. Putative pathophysiology of fixed pupils secondary to transtentorial herniation from obstructive hydrocephalus is discussed. Cases such as the present ones are unsettling because they are exceptions to the usually reliable negative prognosis indicated by fixed pupils. Nonetheless, it is important to report these cases to delineate which patients with this important clinical sign may benefit from aggressive management.

Acute Disease↗

Application of the pupil astigmatism criteria in optical design.

We developed the pupil astigmatism criteria for correcting the quadratic field-dependent aberrations. These criteria provide an elegant way to determine and correct aberrations that have quadratic field dependence and arbitrary pupil dependence in the same way that the Abbe sine condition is used for aberrations with linear field dependence. Like the sine condition, the pupil astigmatism criteria involve only the properties of the rays originating from the on-axis object point, so it is convenient to implement them in optical design. We introduce an algorithm to apply the criteria in designing new well-corrected optical systems. Some example designs are presented.

Algorithms↗

Microlens-array-based exit-pupil expander for full-color displays.

Two-dimensional arrays of microlenses can be used in wearable display applications as numerical aperture expanders or exit-pupil expanders (EPEs) to increase the size of the display exit pupil. A novel EPE approach that uses two microlens arrays (MLAs) is presented. The approach is based on cascading two identical microlens arrays spaced precisely at one focal-length distance with submicrometer registration tolerances relative to each other. The ideal MLA for this application requires a 100% fillfactor, sharp seams between microlenses, and a perfect spherical profile. We demonstrate a dual-MLA-based EPE that produces excellent exit-pupil uniformity and better than 90% diffraction efficiency for all three wavelengths in a color-display system. Two-MLA registration is performed with submicrometer precision by use of far-field alignment techniques. Fourier optics theory is used to derive the analytical formulas, and physical optics beam propagation is used for numerical computations. Three MLA fabrication technologies, including gray-scale lithography, photoresist reflow, and isotropic etching, are evaluated and compared for an EPE application.

Color↗

Foveal optical modulation transfer function of the human eye at various pupil sizes.

We determined the foveal optical modulation transfer functions of the human eye (O) for pupil sizes of 1-8 mm by using two simple psychophysical techniques. O as a function of spatial frequency f could be described by exp[-(f/fc)n] at any pupil size in our data as well as in the data available in the literature [J. Physiol. (London) 186, 558 (1966); Opt. Acta 21, 395 (1974); Vision Res. 33, 15 (1993); J. Opt. Soc. Am. A 11, 246 (1994)]. When all these estimates of fc and n were pooled the parameters were found to depend on the pupil diameter as fc = 16.6 - 1.49p and n = exp(0.840/p - 0.318). This result indicates that at 1 mm O(f) is close to the diffraction-limited system.

Contrast Sensitivity↗

[The pupil in the chronic phase of Chagas disease and the reaction to pilocarpine and phenylephrine].

To develop a method to analyse pupillary disturbances in patients with chronic Chagas disease in an endemic area, ten chagasic and ten normal subjects were matched according to sex, age and race. Pupillary diameter and area were determined using projection and topography techniques and compared between groups. Both pupils were visualised simultaneously. In each case three photographs were taken under standardised illumination. The first photo was obtained without medication, the second, 30 minutes after instillation of 0,1% pilocarpine and the last 30 minutes after instillation of 3% phenylephrine (60 minutes after pilocarpine). Pupils of chagasic patients had a statistically significant greater initial diameter and area, irregularity of the pupil border, greater percentual reduction in diameter and area after pilocarpine 0.1% and greater percentual increase in diameter and area after 3% phenylephrine eyedrops. The method developed for this study was considered satisfactory. The results suggest ocular autonomic nervous system disturbances in chagasic patients.

Chagas Disease↗

Guillain-Barré syndrome with bilateral tonic pupils.

A 53-year-old patient with Guillain-Barré syndrome preceded by herpes simplex virus infection developed bilateral tonic pupils with light-near dissociation. Pharmacological tests for pupils suggested postganglionic involvement of the parasympathetic and sympathetic nerves. A demyelinating process of peripheral autonomic nerves was suspected to be the cause of the tonic pupils and autonomic dysfunction.

Epinephrine↗

The influence of age, duration of diabetes, cataract, and pupil size on image quality in digital photographic retinal screening.

OBJECTIVE: To evaluate the effect of age, duration of diabetes, cataract, and pupil size on the image quality in digital photographic screening. RESEARCH DESIGN AND METHODS: Randomized groups of 3,650 patients had one-field, non-mydriatic, 45 degrees digital retinal imaging photography before mydriatic two-field photography. A total of 1,549 patients were then examined by an experienced ophthalmologist. Outcome measures were ungradable image rates, age, duration of diabetes, detection of referable diabetic retinopathy, presence of early or obvious central cataract, pupil diameter, and iris color. RESULTS: The ungradable image rate for non-mydriatic photography was 19.7% (95% CI 18.4-21.0) and for mydriatic photography was 3.7% (3.1-4.3). The odds of having one eye ungradable increased by 2.6% (1.6-3.7) for each extra year since diagnosis for nonmydriatic, by 4.1% (2.7-5.7) for mydriatic photography irrespective of age, by 5.8% (5.0-6.7) for non-mydriatic, and by 8.4% (6.5-10.4) for mydriatic photography for every extra year of age, irrespective of years since diagnosis. Obvious central cataract was present in 57% of ungradable mydriatic photographs, early cataract in 21%, no cataract in 9%, and 13% had other pathologies. The pupil diameter in the ungradable eyes showed a significant trend (P < 0.001) in the three groups (obvious cataract 4.434, early cataract 3.379, and no cataract 2.750). CONCLUSIONS: The strongest predictor of ungradable image rates, both for non-mydriatic and mydriatic digital photography, is the age of the person with diabetes. The most common cause of ungradable images was obvious central cataract.

Adult↗

The pupil dark response in narcolepsy.

The pupil dark response and maintenance of pupil area in darkness were compared in seven narcoleptic patients and 14 age-matched normal volunteers. Onset and degree of miosis after maximal pupil dilation in darkness were similar in the two groups, although three narcoleptic patients and no normal volunteers fell asleep during the experiment. The results of this study contradict earlier suggestions that pupillography can be used to distinguish normal individuals in family studies of narcoleptic patients.

Adolescent↗

Comparison of the Colvard pupillometer and the Zywave for measuring scotopic pupil diameter.

PURPOSE: To evaluate the accuracy and repeatability of two pupillometers. METHODS: Two pupillometers, the Colvard and Zywave, were used to measure scotopic pupil diameter for 64 consecutive patients. Accuracy and repeatability were assessed by two independent examiners and statistical analysis was performed using the comparison method described by Bland and Altman. RESULTS: Mean scotopic pupil diameter was 5.96 +/- 0.69 mm with the Colvard pupillometer and 5.77 +/- 0.85 mm with the Zywave. The difference between the Colvard and Zywave measurements was 0.21 +/- 0.56 mm (P < .001). The coefficient of interrater repeatability was smaller for the Colvard (0.59) than for the Zywave (1.17). The mean difference between the pupillometers for each examiner was 0.17 +/- 0.47 mm (P < .01) for examiner 1 and 0.26 +/- 0.64 mm (P < .01) for examiner 2. CONCLUSIONS: Scotopic pupil diameter measured with the Zywave was statistically but not clinically significantly smaller than that measured with the Colvard pupillometer. The Zywave produced an inter-rater repeatability comparable to other devices although not as good as the Colvard pupillometer.

Adult↗

A case of ocular neuromyotonia with tonic pupil.

A 48-year old woman with hypertension experienced painful oculomotor nerve palsy. After surgery for a giant aneurysm of the internal carotid artery in the cavernous sinus, phasic constrictions of the pupil developed. Two years later, this phenomenon disappeared and was replaced by intermittent involuntary cyclic spasms elevating the ptosed lid. These cyclic lid movements were not elicited with any eye movement or by increased accommodation. The pupil now manifested the pharmacologic features of a tonic pupil. The explanation for this unique case of ocular neuromyotonia is based on a misdirection phenomenon, possibly caused by ephaptic transmission.

Carotid Artery Diseases↗

Accommodation microfluctuations and pupil size during sustained viewing of visual display terminals.

Accommodation microfluctuations comprise two dominant frequencies; a low frequency component (LFC < or = 0.6 Hz) and a high frequency component (1.0 Hz < HFC < 2.1 Hz). In the present experiment we examine accommodation microfluctuations and steady-state pupil responses during sustained viewing of visual display terminals (VDTs). Steady-state accommodation and pupil responses were measured continuously and simultaneously using a modified Canon Autoref R-1 infra-red objective optometer and an Hamamatsu C3160 Perceptscope Video Area Analyser. Measurements were obtained at three time intervals (0, 10 and 20 min) during a 20 min reading task presented on five different displays. With the displays placed at 50 cm, the task was to locate and identify typographical errors in one of five sets of standard text. Five young visually-normal emmetropic subjects with a mean age of 22.5 +/- 3.0 years participated in the study. Two-way ANOVA revealed no significant variation in the magnitude of the accommodation microfluctuations with either display or task duration, nor was there any significant interaction between these two factors. There was no significant variation in mean pupil diameter with either display or task duration. These measures may have the potential to provide objective information about visual display quality.

Accommodation, Ocular↗

Endophthalmitis after cataract surgery in eyes with small pupils managed by sector iridectomy and polypropylene suture closure.

Two patients with small pupils developed endophthalmitis following cataract surgery during which the small pupils were managed by sector iridectomy and closed with a polypropylene suture. Prior studies have reported that implantation of intraocular lenses (IOLs) with haptics made of polypropylene is associated with a higher risk of postoperative endophthalmitis than the use of IOLs with polymethylmethacrylate haptics. Endophthalmitis in the two patients reported herein was managed successfully without removal of the polypropylene suture; vision returned to 20/60 in one patient and 20/30 in the other patient. Iris retractors may represent a faster and safer alternative management option for small pupils than sector iridectomy closed with a polypropylene suture.

Aged↗

Continuous recording of accommodation and pupil size using the Shin-Nippon SRW-5000 autorefractor.

A newly released commercial autorefractor, the Shin-Nippon SRW-5000 (Japan), has been found to be valid compared to subjective refraction and repeatable over a wide prescription range. Its binocular open field-of-view allows the accommodative state to be monitored while a natural environment is viewed. In conventional static mode, the device can take up to 45 readings in 1 min using digital image analysis of the reflected retinal image of a measurement ring. Continuous on-line analysis of the ring provides high (up to 60 Hz) temporal resolution of the refractive state to an accuracy of < 0.001 D. Pupil size can also be analysed to a resolution of < 0.001 mm. The measurement of accommodation and pupil size was relatively unaffected by eccentricity of viewing up to +/- 10 degrees and instrument focusing inaccuracies of +/- 5 mm. The resolution properties of the analysis are shown to be ideal for measurement of dynamic accommodation and pupil responses.

Accommodation, Ocular↗