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At least 955 records · Page 53Linked to original sources
PubMed1990

Effect of illuminance on the directions of chromostereopsis and transverse chromatic aberration observed with natural pupils.

The direction of chromostereopsis observed with a natural pupil and the direction of the monocularly perceived disparity between coloured targets (F and C lines - 486 and 656 nm) have been measured in a sample of 30 subjects at 10 and 1000 lx. At both illumination levels approximately equal numbers of subjects perceived positive and negative chromostereopsis. When the ambient illumination was increased, a reversal in the direction of the chromostereopsis occurred for 16 subjects. For six of them a change from a positive to a negative chromostereopsis was observed, a pattern not reported in previous studies. In most cases at both high and low illuminance, there was an absence of perception of a monocular disparity (transverse chromatic aberration), although chromostereopsis was reported, indicating that binocular information can be obtained from sub-threshold monocular disparities. At low illuminance, the lack of correlation between the direction of chromostereopsis and transverse chromatic aberration (TCA) may indicate that there may be a supplementary binocular factor in chromostereopsis.

Adult↗
PubMed1990

[Initial experience with the combined use of YAG and argon lasers in the area of the pupil].

The authors analyze the advantages of the opportunity to use two types of lasers located on a single slit lamp, as tested in a group of 17 patients. The authors give an account of suitable combined interventions in the area of the pupil. If the indication is correct and based on knowledge of the risk of the action of the two lasers, the complications of the procedure are rare and readily managed. According to the authors' experience it is a useful therapeutic method, in particular in complicated posttraumatic, post-inflammatory and postoperative conditions.

Humans↗
PubMed1989

[Effects of combined instillation of dapiprazole and epinephrine on human anterior chamber depth, intraocular pressure and pupil diameter].

Pilocarpine, a first choice drug for primary angle closure glaucoma (PACG), is reported to produce shallow anterior chamber and posterior synechia and consequently a small immobile pupil. In this paper, dapiprazole, a newly synthesized alpha 1 blocker, was given topically in combination with epinephrine eye drops to 15 healthy volunteers and 10 patients with PACG. In both volunteers and patients, the treated eyes revealed deeper anterior chambers, thinner lenses and significant IOP reduction after the combined instillation of dapiprazole and epinephrine. Though light reaction was preserved, mild miosis was observed in volunteers, but no pupillary change in patients. The conjunctival hyperemia induced by dapiprazole was reversed by additional instillation of epinephrine. Burning sensation was the only side effect observed after instillation of dapiprazole. In conclusion, the combined instillation of dapiprazole and epinephrine appears to be a good choice for the therapy of PACG.

Adrenergic alpha-Antagonists↗
PubMed1989

Surgical dilation of the pupil during pars plana vitrectomy.

Adequate pupillary dilation is essential to dissect and excise peripheral tractional proliferative tissue during vitreous surgery. Most surgical dilating procedures involve an incision or excision of iris tissue, that is either inadequate or irreversible. We describe a modification of a previously devised technique for stretching the pupil that ensures an excellent view of the peripheral retina. The technique has been used in aphakic and pseudophakic eyes in over 50 cases with no postoperative morbidity or problems with glare or poor cosmesis.

Dilatation↗
PubMed1977

Results after intracapsular extraction: the atonic pupil.

Satisfactory visual results are reported in a series of 80 consecutive patients who underwent intracapsular cataract extraction with a four- or three-loop Binkhorst lens replacement. Nearly 50% of patients could see 20/30 or better unaided. However, results in the under 70 age group tend to be marred by macular edema, and in the over 80 age group by corneal edema, the latter occasionally being the result of lens instability because of an atonic pupil.

Aged↗
PubMed1986

Image tracking observed with a pupil-centring device.

A brief report is given of some observations made during an extended investigation into the subjective image quality of telescopes. For part of the work, a device was required that would indicate directly to an observer the accuracy of eye position, both laterally and longitudinally, with respect to an artificial pupil. This device is described. During use it was observed that the point image produced by the device approximately tracked the eye rotation. This unanticipated property is explained and a different optical arrangement is suggested in order to exploit and enhance this tracking property. The reason for drawing attention to the technique is not only that there may be similar situations in which such devices may be used but also that the tracking property may have other applications, perhaps in a teaching or clinical context.

Cornea↗
PubMed1985

Tonic pupils following oculomotor nerve palsies.

Four patients developed a unilateral tonic pupil following ipsilateral oculomotor nerve palsy. The probable basis for this phenomenon is misdirection of injured oculoparasympathetic fibers in the oculomotor nerve proximal to the ciliary ganglion.

Accommodation, Ocular↗
PubMed1982

The Marcus Gunn pupil in incomplete optic tract hemianopias.

Three patients with optic tract lesions, incomplete homonymous hemianopias, and good vision in both eyes are presented. All three had a Marcus Gunn pupil in the eye with temporal field loss (eye contralateral to the tract lesion). This pupillary sign may serve to differentiate acute optic tract from acute geniculostriate lesions when the characteristic infrageniculate optic atrophy has not had time to develop.

Adult↗
PubMed1984

Decreased sympathetic stimulation to the pupils in two patients with myotonic dystrophy.

Abnormalities discussed in previous papers on myotonic dystrophy suggested that there are no defects in the sympathetic nervous system, and the pupillary abnormalities were probably of peripheral origin. The pupils of two patients with myotonic dystrophy were examined and were determined to have findings suggesting a lack of preganglionic sympathetic stimulation, which has never been reported before. Other findings of Horner's syndrome such as anhidrosis and lack of sympathetic stimulation to the Muller's muscle were not present.

Child↗
PubMed1983

The pupil cycle time in familial dysautonomia. Further evidence for denervation hypersensitivity.

The pupil cycle time (PCT) was prolonged in 11 subjects with familial dysautonomia. In the younger age group (10-19 years), mean PCT was 872 +/- 88 msec as compared to 15 normal age matched controls (728 +/- 88). In the 3 oldest patients (30-39 years) mean PCT was 980 +/- 133 msec as compared to 13 age matched normals (748 +/- 56). It is proposed that prolongation of PCT in familial dysautonomia may be due to functional denervation of the iris or that it is a result of a structural abnormality of its musculature and/or its neuromuscular junctions.

Adolescent↗
PubMed1983

Lack of effect of a new spasmolytic agent, rociverine, on intraocular pressure, pupil size and iridocorneal angle in patients with angle-closure glaucoma.

Twenty patients with angle-closure glaucoma (38 glaucomatous eyes - 17 surgically operated, 21 non-operated) were treated with rociverine (60 mg orally per day for 7 days), a new direct myolitic and mildly anticholinergic antispasmodic drug. Intraocular pressure, pupil size, iridocorneal angle, blood pressure and heart rate were checked before and during treatment. No clinically significant variations were observed in the parameters tested. It is suggested, therefore, that rociverine may be administered, if necessary, even to patients with angle-closure glaucoma.

Adult↗
PubMed1978

Absence of an effect of timolol on the pupil.

Timolol, a relatively new beta-adrenergic blocker which has been found to lower the intraocular pressure in man, has not been observed to have any side effects upon the visual system. This study utilized pupillography to determine the effect of conjunctival instillation of 0.5% timolol ophthalmic solution upon pupillary size and reaction. No clinically significant effect was observed, but a statistically significant decrease in the amplitude of redilation of the pupil was found in the eye that received timolol.

Conjunctiva↗
PubMed1982

Use of annular artificial pupil in the determination of modulation transfer function of the eye.

According to Ref. [1] primary spherical aberration of the schematic eye would be completely absorbed by an annular aperture when its obstruction ratio epsilon is greater than or equal to 0.60. Consequently the contrast sensitivity function, Tcs, determined with the use of such an annulus, Tcs (A), is the MTF of the retina-brain system, Trb, weighted by the MTF of the annulus, T. . Trb thus obtained can be used to determine the MTF of the eye, Te. Annular apertures of various sizes and obstruction ratios used for the determination of Te have been analysed. It is shown that there are several factors other than incomplete absorption of primary spherical aberration that would prevent the use of annular pupil to derive Trb under unrestrained conditions. This is due to the fact that the apparent T.'s of annuli used in the actual determination of Tcs(A) usually deviate from the theoretical T.'s for the passive eye to different extents. However, it is found that the T. for annulus of o.d. = 2.7 mm and epsilon = 0.60 conforms more or less to the theoretical T. and can be used to derive reasonably accurate Te(2.7). It is also possible to estimate Te(less than 2.7) from Te(2.7) by some empirical correction.

Adaptation, Ocular↗
PubMed1982

Effects of N-demethylated carbachol on intraocular pressure and pupil in ocular hypertensive patients.

The effects of N-demethylated carbachol on intraocular pressure and pupil size were studied in 18 ocular hypertensive patients. Topical administration of N-demethylated carbachol in 9%, 15% and 30% solutions has been demonstrated to bring about miosis which was found to be dose-dependent. No significant change of intraocular pressure clearly attributable to this drug has been demonstrated.

Administration, Topical↗
PubMed1981

Effectlessness of a new spasmolytic (rociverine) on intraocular pressure, pupil size, and iridocorneal angle in ophthalmically healthy subjects.

Thirty-seven subjects without eye diseases were treated with rociverine, a new direct myolytic and parasympatholytic antispasmodic: 15 by intravenous injection (20 mg) and 22 by oral administration (20 mg three times daily for four days). Intraocular pressure, pupil size, iridocorneal angle, blood pressure, and heart rate were checked before and during treatment. No clinically significant variations were observed in the parameters tested.

Adult↗
PubMed1979

Effects of prostaglandins and norepinephrine on ocular pressure and pupil size in rabbits following bilateral cervical ganglionectomy.

We wish to report an early (10 to 30 min) 6 to 7 mm Hg increase in IOP above predrug levels following topical norepinephrine (NE) (5mumol) administration in conscious normal rabbits. This early elevation in IOP was significantly more pronounced in bilateral superior cervical ganglionectomized (BG) rabbits. The time course for peak IOP elevation slightly preceded the accompanying peak mydriatic effect in all groups. IOP returned to baseline levels in about 60 min in the BG rabbits, but the mydriasis persisted. Pretreatment with topical indomethacin significantly reversed the early hypertonic NE effect on IOP in the BG animals implying the involvement of prostaglandin synthesis. The IOP continued to fall significantly after 60 min in the BG group with indomethacin pretreatment. This latter result suggests a predominant long-lasting NE effect. The indomethacin pretreatment had no effect on pupil size of any group, but phenoxybenzamine (PBA) reduced the mydriatic effect, implying a direct or a predominant role of NE on iris muscle.

Animals↗
PubMed1995

Blur due to pupil area when using progressive addition spectacles.

The progression zone of a progressive addition spectacle lens cannot provide a sharp retinal image as it presents the pupil with a range of powers through which to view an object. The resulting blur is explored mathematically. The nature of this blur is extraordinary but its visual significance is very slight and is less than previously believed. Peripheral astigmatism, found in all such lenses, may lower their visual performance.

Astigmatism↗