Simultaneous Bilateral “Malignant Glaucoma” Attack in a Patient with no Antecedent Eye Surgery or Miotics

Malignant glaucoma is a term commonly used to describe a condition characterized by a sudden increase in intraocular pressure, usually occuring after eye surgery. This report describes a case of malignant glaucoma simultaneously presenting in both eyes, with no antecedent eye disease, medication or surgery. As far as we know this is the first report of spontaneous bilateral glaucoma. Both eyes were operated on according to the technique described by Chandler et al. (1), and the condition was solved. We suggest that, despite its rarity in eyes with no antecedent disease or ocular therapy, a surgeon should be aware of this condition.

[Tonic pupil, pupil Adie syndrome Adie Holmes: current reassessment of terminology -- a clinical case]

The benign syndrome of pupillotonia and absence of deep reflexes is not uncommon. It was clearly and accurately described by Adie (1932), although incompletely recognized many years, before. The pupillary abnormality was reported by ophthalmologists at the turn of the century (Saenger, 1902, Strasburger 1902), and the associated deep reflex change was described by Markus (1906), Roemheld (1921) and Parkes Weber (1923). Holmes (1932) was fully aware of the association of "partial iridoplegia" with diminished reflexes. Tonic pupils react poorly to light but constrict during viewing of a near stimulus. Adie's name is typically used in association with tonic pupils, but a review of Adie's articles reveals that he described the syndrome of tonic pupils and absent reflexes and not the pupillary abnormality per se. Therefore, it would be more appropriate to refer to a tonic pupil as simply a 'tonic pupil" and leave Adie's name for the syndrome. We report a typical case of tonic pupil.

Effect of vehicle on pilocarpine-induced miosis

To determine the effect of 1.4% polyvinyl alcohol (PVA) and castor oil vehicles on the pilocarpine-induced miosis, we studied the miotic effect of 2% pilocarpine-PVA and oily drops on 4 young and 10 elderly people and the miotic effect of 4% pilocarpine-PVA and oily drops on 13 elderly people. The miosis developed fast within 15 min, and maximum miosis was rached within 1 h. Oily drops of pilocarpine induced stronger maximum miosis than corresponding PVA-drops. The pupil remained contracted to less than 50% of its starting diameter after pilocarpine-PVA drops for 3-4 h and after oily drops for 9 h and returned to its starting diameter after pilocarpine-PVA drops 9-10 h and after oily drops 20-24 h following administration. The difference in the effect between pilocarpine-PVA and oily drops was independent of the subjects' age.

Effect of vehicle on pilocarpine-induced ocular hypotension

The effect of 1.4% polyvinyl alcohol and castor oil vehicles on pilocarpine-induced hypotension was studied in 50 patients with open-angle glaucoma. Diurnal tension curves showed that the mean intraocular pressure was lower and the maximum diurnal variation smaller during the treatment with oily drops of 2% and 4% pilocarpine instilled 2-3 times daily than when 2% and 4% pilocarpine in polyvinyl alcohol was instilled 3-4 times daily. The differences were statistically significant. In long-term treatment no marked pilocarpine tolerance developed in cases treated with oily drops of pilocarpine. It is concluded that in the treatment of patients with open-angle glaucoma, the hypotensive effect of pilocarpine in an oily vehicle instilled 2-3 times daily is greater and more even than that of pilocarpine of corresponding strength in polyvinyl alcohol administered 3-4 times daily.

Pupillary changes among Nigerian adults following the instillation of Garcinia kola nut extracts: multicentric studies

BACKGROUND

A multi-centre, open, within-patient controlled study was performed on 106 adult volunteers to investigate the effects of Garcinia kolanut extracts on the pupillary sizes.

STUDY DESIGN

106 participants in three Nigerian Ophthalmic Centres with no pupillary defects and associated ocular or systemic co-morbidities had their pupillary diameters measured at 0, 15, 30 and 45 minutes respectively with a pupillometer (Neuroptics model # 586009). Using the left eyes as control, Garcinia kolanut extract was instilled into the right eyes at 15 minutes intervals.

RESULTS

There were 63 females and 43 males ranging in age from 18 to 58 years with the mean age of 34.9 years. Average pupillary diameter measured among participants was 4.1 - 8.4 mm with the mean value of 6.0 mm prior to garcinia kola nut extract instillation. There was a gradual reduction in the baseline pupillary size with age in years at 0.2mm per decade without garcinia extract instillation. There was a significant higher baseline pupillary diameter in males than females with males and females mean values of 6.29mm (6.00 - 6.56mm) and 5.85mm (5.60 - 6.11mm) in the right eye (p=0.026) and mean pupillary diameters 6.16mm (5.90 - 6.42mm) and 5.80mm (5.56 - 6.04mm) in the left eyes (p=0.05) respectively. There were consistent significant miosis in the right eyes with instilled Garcinia kola nut extract compared to the left eyes at 15, 30 and 45 minutes (p=0.0000).

CONCLUSION

4% Garcinia kola nut extract drop has a transient miotic effect on human pupils not sustainable for more than 45 minutes.

Lens diameter and thickness as a function of age and pharmacologically stimulated accommodation in rhesus monkeys

Uncertainty exists regarding accommodative and age changes in lens diameter and thickness in humans and monkeys. In this study, unaccommodated and accommodated refraction, lens diameter, and lens thickness were measured in rhesus monkeys across a range of ages. Iridectomized eyes were studied in 33 anesthetized monkeys aged 4-23 years. Refraction was measured using a Hartinger coincidence refractometer and lens thickness was measured with A-scan ultrasound. Lens diameters were measured with image analysis from slit-lamp images captured via a video camera while a saline filled, plano perfusion lens was placed on the cornea. Accommodation was pharmacologically stimulated with 2% pilocarpine via the perfusion lens in 21 of the monkeys and lens diameters were measured until a stable minimum was achieved. Refraction and lens thickness were measured again after the eye was accommodated. Unaccommodated lens thickness increased linearly with age by 0.029 mm/year while unaccommodated lens diameter showed no systematic change with age. Accommodative amplitude decreased by 0.462 D/year in response to pilocarpine. The accommodative increase in lens thickness decreased with age by 0.022 mm/year. The accommodative decrease in lens diameter declined linearly with age by 0.021 mm/year. Rhesus monkeys undergo the expected presbyopic changes including increasing lens thickness and a decreasing ability of the lens to undergo changes in thickness and diameter with accommodation, however without an age-related change in unaccommodated lens diameter. As in humans, the age-related decrease in accommodative amplitude in rhesus monkeys cannot be attributed to an age-related increase in lens diameter.

Anhidrosis: A clue to an underlying autonomic disorder

We describe a patient with Ross syndrome who had the classic triad of segmental anhidrosis, tonic pupils and hyporeflexia. Dilute pilocarpine (0.1%) instillation in both eyes revealed parasympathetic denervation hypersensitivity. There was evidence of cardiac dysautonomia in the form of a decrease in heart rate variability with deep breathing and an abnormal Valsalva response. A thermoregulatory sweat test showed the presence of sweating in the right cheek, neck and upper one-third of the left arm and shoulder only. Sympathetic skin responses were absent in the affected segments of the upper limb. Ross syndrome is a degenerative disorder that progressively involves different fibre populations, starting with autonomic fibres and then involving the unmyelinated and myelinated sensory fibres. A careful clinical examination and simple bedside autonomic tests can confirm the diagnosis.

Phenylephrine and pilocarpine eye drop test for dementia with Lewy bodies and Alzheimer's disease

Pupillary response test using dilute phenylephrine, a sympathetic agonist, and dilute pilocarpine, a cholinergic agonist, were performed in 24 patients with dementia with Lewy bodies (DLB), 40 patients with Alzheimer's disease (AD), and 23 normal elderly subjects. The mydriatic response to 0.5% phenylephrine was significantly greater in the DLB group than in the AD and control groups. The mydriatic change correlated inversely with the reduction in cardiac 123I-metaiodobenzylguanidine uptake. In contrast, miotic response to 0.0625% pilocarpine was significantly greater in the DLB and AD groups than in the control group. The pupil assay using combined phenylephrine and pilocarpine eye drop test may be useful in the detection of patients with DLB and AD and in distinguishing between them.

Phosphorylation of the alpha subunit of translation initiation factor-2 by PKR mediates protein synthesis inhibition in the mouse brain during status epilepticus

In response to different cellular stresses, a family of protein kinases phosphorylates eIF2alpha (alpha subunit of eukaryotic initiation factor-2), contributing to regulation of both general and genespecific translation proposed to alleviate cellular injury or alternatively induce apoptosis. Recently, we reported eIF2alpha(P) (phosphorylated eIF2alpha) in the brain during SE (status epilepticus) induced by pilocarpine in mice, an animal model of TLE (temporal lobe epilepsy) [Carnevalli, Pereira, Longo, Jaqueta, Avedissian, Mello and Castilho (2004) Neurosci. Lett. 357, 191-194]. We show in the present study that one eIF2alpha kinase family member, PKR (double-stranded-RNA-dependent protein kinase), is activated in the cortex and hippocampus at 30 min of SE, reflecting the levels of eIF2alpha(P) in these areas. In PKR-deficient animals subjected to SE, eIF2alpha phosphorylation was clearly evident coincident with activation of a secondary eIF2alpha kinase, PEK/PERK (pancreatic eIF2alpha kinase/RNA-dependent-protein-kinase-like endoplasmic reticulum kinase), denoting a compensatory mechanism between the two kinases. The extent of eIF2alpha phosphorylation correlated with the inhibition of protein synthesis in the brain, as determined from polysome profiles. We also found that C57BL/6 mice, which enter SE upon pilocarpine administration but are more resistant to seizure-induced neuronal degeneration, showed very low levels of eIF2alpha(P) and no inhibition of protein synthesis during SE. These results taken together suggest that PKR-mediated phosphorylation of eIF2alpha contributes to inhibition of protein synthesis in the brain during SE and that sustained high levels of eIF2alpha phosphorylation may facilitate ensuing cell death in the most affected areas of the brain in TLE.

Pupila tônica bilateral como seqüela oftálmica isolada da doença de Lyme: relato de caso

Lyme disease is a multisystemic disorder caused by Borrelia burgdorferi spirochete, transmitted by ticks. Mainly described in the northern hemisphere and rarely in Brazil. The purpose of this report is to describe a patient with Lyme disease who developed bilateral tonic pupil as the only remaining sign. A 13-year-old female with Lyme disease, presented with bilateral peripheral facial and oculomotor paralysis. After recovery from neurological abnormalities the patient sustained anisocoria, reduced fotomotor reflex, less than normal amplitude of accommodation, tonic pupil constriction for near objects and slow redialation in both eyes. Dilute 0.1% pilocarpine test was positive in both eyes, confirming the suspicion of bilateral tonic pupil. This is the first case report of bilateral tonic pupil caused by Lyme disease.

Isolated anisocoria from an endodermal cyst of the third cranial nerve mimicking an Adie's tonic pupil

We present only the second reported case in the literature of a neuroenteric cyst involving the third cranial nerve. Our case is highlighted by the initial presentation of an isolated anisocoria, initially believed to represent an Adie's tonic pupil as interpreted by pharmacologic testing. False-positive results may occur with the dilute pilocarpine test.

[Atypical tonic pupil as a complication of chickenpox infection]

BACKGROUND

Pupillary disorders following varicella infections are rare and few cases have been reported which were only partially pharmacologically tested.

MATERIALS AND METHODS

A 5-year-old boy presented with a left-sided dilated and unreactive pupil, 3 months before he had suffered from chickenpox and in the course of the acute disease developed anterior uveitis which was treated with local prednisone and mydriatics. The pupil remained dilated despite discontinued medication, light reaction was absent and accommodation was impaired. Pilocarpine supersensitivity was an indication against a lesion of the sphincter muscle and reduced response to cholinesterase inhibitors (physostigmine) pointed towards a postganglionic lesion.

CONCLUSIONS

It is probable that a varicella virus infection of the short ciliary nerves and the ciliary ganglion caused anterior uveitis and a postganglionic parasympathetic nerve lesion, clinically presenting as a tonic pupil. According to cases previously reported an irreversible nerve lesion has to be assumed.

Cardinal points and image-object magnification with an accommodative lens implant (1 CU)

A simple mathematical method for the determination of the cardinal points of pseudophakic eyes after implantation of an accommodative intraocular lens [posterior chamber intraocular lenses (PCIOL)] is presented. The purpose of this study was to explore the changes during pseudophakic accommodation (PAC) in (1). the positions of the cardinal points, (2). the distance of the object conjugate with the retina, and (3). the image-object magnification. These theoretical accommodation data are compared with clinical measurements.

METHODS AND PATIENTS

Using biometrical measurements of the axial length, equivalent power of the cornea and the anterior chamber depth (ACD) in the non-accommodated state we used linear geometric optics for determination of the cardinal points and object distance as well as lateral magnification (the ratio of image to object size). With the measurement of ACD decrease (following pharmacological stimulation of the ciliary muscle with 2% pilocarpine eye drops) we determined the changes of the cardinal points and magnification to assess PAC amplitude from the shortening of the object distance. Calculated values of PAC amplitude were compared with the respective measured values derived from amplitude measures by accommodometer, defocusing and streak retinoscopy. We analysed the results of a prospective study on 35 eyes of 28 patients after cataract surgery (target refraction: -0.2 D) and accommodative PCIOL implantation (1 CU, Human Optics AG, Erlangen, Germany) 3 months after surgery.

RESULTS

After pilocarpine eye drops, ACD (mean +/- S.D., range; median) decreased by 0.88 +/- 0.48 mm (0.51-1.91; 0.66). Distance of the in-focus object decreased from the non-accommodated state (-5.62 +/- 1.83 m, -25 to -1.1; -4.83 m) to the accommodated state (ACD decrease) (-0.81 +/- 0.21, -2.11 to -0.65; -0.79 m). For a theoretical ACD decrease of 1.0 mm (the intrinsic limitation of the PCIOL design) it was -0.59 +/- 0.28, -1.31 to -0.51; -0.63 m and resulted in an objective accommodative response of 1.49 +/- 0.16, 1.21-1.81; 1.46 D, depending on the actual geometry of the individual eye. On average, magnification as induced by PAC in contrast to that induced by adequate spectacle addition differed by only about 1%. Accommodation measured with defocusing and the accommodometer correlated significantly with the theoretical value based on IOLMaster measurement of ACD decrease (r = 0.752, p = 0.005 and r = 0.676, p = 0.02). Likewise, accommodation measured with streak retinoscopy correlated weakly with the theoretical value based on IOLMaster ACD decrease (r = 0.465, p = 0.05).

CONCLUSIONS

Using geometrical optics, PAC can be derived from the biometric data of the eye and the measured ACD decrease. This approach may be an additional indicator for the accommodative response in pseudophakic patients and may allow a subdivision of the measured accommodation into true PAC and pseudoaccommodation, for example, because of increased depth of focus induced by pupillary constriction.

The effects of new topical treatments on management of glaucoma in Scotland: an examination of ophthalmological health care

BACKGROUND

The management of glaucoma has been changed in the past decade by the introduction of new drugs. The impact of these changes on clinical care of patients was examined by examining operation and prescribing rates for glaucoma in four geographical areas of Scotland for the years 1994 to 1999.

METHODS

A retrospective analysis of national health statistics: primary care prescribing data, hospital derived operation rates, consultant numbers, optometrist numbers, and eye test data, expressed by estimated population at risk of glaucoma. The outcome measures were prescribing volume and cost for glaucoma medications, and operation rates, corrected for population estimated to be at risk of glaucoma (PEG), for trabeculectomy, for Scotland as a whole, and for four geographical "regions" (north east, south east, central, and south west Scotland).

RESULTS

Prescribed items per 1000 population estimated to have glaucoma (PEG) increased by 24.9% between 1994 and 1999. This was above the general increase in prescribing in Scotland (17.8%). This increase varied in the four health regions evaluated (14.3% to 31.9%). Prescribing of topical beta blockers increased little (6.4%), but there was a large increase in the use of new products (topical prostaglandins, carbonic anhydrase inhibitors, and alpha(2) agonists), at the expense of miotics (47.7% fall), and older sympathomimetics. This change in prescribing pattern was accompanied by a 61.5% increase in cost (range 42.2% to 73.4% in the four regions). New drugs accounted for more than half of total glaucoma expenditure in 1999. Operation rates (corrected for PEG) fell by 45.9% (range 43.1 to 58.6%) between 1994 and 1999. Other indicators suggested increased activity in ophthalmic areas (for example, cataract operations, eye tests, numbers of optometrists and ophthalmic surgeons all increased). Within north east Scotland operation rates decreased and prescribing increased less than in other regions, both from lowest regional baseline in 1994.

CONCLUSIONS

The introduction of new drug classes has had dramatic effects on the prescribing of glaucoma treatments. There has been a decline in older treatments and an increase in new agents, which has been associated with a large reduction in operation rates for glaucoma in Scotland over 6 years. Comparison of prescribing and operation data indicates regional differences in healthcare delivery for glaucoma.

Enhanced miotic response to topical dilute pilocarpine in patients with Alzheimer's disease

To determine whether miotic response to dilute (0.0625%, two drops) topical pilocarpine could be useful in detecting Alzheimer's disease (AD), we assessed the response in 14 AD patients and 10 control subjects. The miotic response to pilocarpine was significantly greater in AD patients than in control subjects (p < 0.001). In contrast, mydriatic response to the anticholinergic tropicamide (0.01%, one drop) failed to show a difference between the groups (p = 0.54). There was no significant correlation between the miotic and mydriatic responses in individuals. We conclude that dilute pilocarpine could be useful as a diagnostic tool in early AD.

Scanning laser polarimetry of the retinal nerve fibre layer in primary open angle and capsular glaucoma

AIMS

To evaluate the clinical value of scanning laser polarimetry with the nerve fibre analyser type II in primary open angle glaucoma (POAG) and capsular glaucoma.

METHODS

Scanning laser polarimetry was performed on one eye of 30 patients suffering from POAG, 25 patients suffering from capsular glaucoma, and on 35 healthy control subjects. The retinal nerve fibre layer (RNFL) thickness values were compared among the groups. Reproducibility of the measurements was calculated and the influence of pilocarpine induced miosis on the results was investigated.

RESULTS

RNFL thickness in the superior and inferior sectors, as well as along the total circumference was significantly lower in both glaucoma groups than in the control eyes (p < 0.05). None of the thickness values differed between the two glaucoma groups. Reproducibility was comparable in all groups; the coefficient of variation varied between 3.0% and 8.9% for the different sectors investigated. Miosis had no significant impact either on the thickness values or on the reproducibility (p > 0.05).

CONCLUSION

The results suggest that scanning laser polarimetry is a useful method for nerve fibre layer analysis in glaucoma, and that it is not influenced by the pupil size.

In-vivo genotoxicity of the alkaloid drug pilocarpine nitrate in bone marrow cells and male germ cells of mice

Pilocarpine nitrate, an alkaloid drug of plant origin induces spindle disfunction in bone marrow cells of mice. Further studies were carried out to investigate its mutagenic effects in somatic and germ cells of mice by assessing chromosome aberrations at mitotic metaphase and as micronuclei in bone marrow cells and sperm-shape abnormality in cauda epididymides. The dose and time yield effects of the drug were investigated. The statistically significant results that were obtained for both chromosomal aberrations and micronucleus test but not for the sperm-shape abnormality test, indicated the genotoxicity of this compound in somatic cells but not in germ cells.

The trigemino-pupillary reflex: a model of sensory-vegetative integration

Trigeminal stimulation can induce pupillary changes. In vivo and in vitro studies have demonstrated that electrical impulses applied at the trigeminal level can provoke a miotic response, whose nature has been ascribed to the anti-dromic release of neuropeptides (substance P in particular). In order to better define the pupil response to trigeminal stimulation, we investigated the human pupil response to quantified (painless and painful) corneal stimuli by means of a combined (neurophysiological and pharmacological) technique. The response to corneal stimulation was bilateral, direct and consensual. It had a biphasic progression with an initial mydriasis (which directly correlated with the stimulus intensity), followed by a miotic phase. The mydriatic phase disappeared after thymoxamine application, while homatropine pre-treatment prevented occurrence of the miotic phase. The data obtained indicate that the pupillary response to corneal stimulation (trigemino-pupillary reflex) is a multisynaptic reflex with an afferent branch involving the trigeminal system, and an afferent branch involving both the sympathetic and the parasympathetic system. Other pathways, such as the SP-mediated release of acetylcholine, cannot be excluded. Thus the reflex appears to be a potentially useful tool for investigating pain/vegetative interactions in various clinical conditions. In turn, the description of its changes in pathologies characterized by a sympathetic/parasympathetic deficit or by a SP-ergic imbalance will allow us to better describe its inner mechanisms.

[Comparison of the anti-miotic effect of 0.03% flurbiprofen with 1% indomethacin in cataract extraction]

Maintaining successful mydriasis is essential during cataract extraction. The use of nonsteroidal anti-inflammatory drugs in order to inhibit trauma induced miosis has been advocated by many authors. Indomethacin 1% has proved his efficacy since many years. Flurbiprofen has been introduced more recently and has been accepted largely because of a better patient comfort. He proved his efficacy against placebo. We conducted a randomized double blind study in order to verify if there is any difference in efficacy between these two drugs. 40 cases were randomly assigned to a pretreatment, not known by the surgeons, with Indomethacin 1% (Indoptic) or Flurbiprofen 0.03% (Ocuflur). Measurements were taken at the beginning of surgery, after nucleous extraction and after irrigationaspiration of lens cortical material. Sodium hyaluronate and epinephrine were not used during this study. After nucleous extraction, the mean pupillary constriction was 1.53 mm in the Indomethacin group and 1.23 mm in the Flurbiprofen group (p greater than 0.1). After aspiration of cortical material, the mean pupillary constriction was 2.27 mm in the Indomethacin group and 2.00 in the Flurbiprofen group (p greater than 0.1). Cumulative results of patients who constricted the pupil more than 2 and 3 mm showed a better result in the Flurbiprofen group. Flurbiprofen has proved in this study his efficacy compared to an other nonsteroidal anti-inflammatory drug in inhibiting trauma induced miosis.

[The influence of miosis on the central visual field]

We studied the effects of miosis on mean sensitivity in cases of glaucoma and normal subjects. The visual field in 30 degrees was measured by an automated perimeter Octopus. The subjects consisted of 13 cases (24 eyes) with open angle glaucoma and 10 normal subjects (10 eyes). Glaucomas had a 1.8dB reduction of mean sensitivity with a decrease in pupil size from greater than 3mm to less than 2mm with 3% or 4% pilocarpine, regardless of age and mean sensitivity. Normal subjects showed a depression of 1.6-1.8dB with a decrease in pupil size from more than 3mm to less than 2mm with 3% pilocarpine. There were no significant changes of mean sensitivity in pupil size over 3mm in normal. There was no difference in the reduction of mean sensitivity with miosis between cases of glaucoma and normal subjects. The mean sensitivity measured under conditions of pupil size over 3mm before glaucoma surgery could be quantitatively compared with that of the pupil after operation.

Possible non-muscarinic miotic action of echothiophate iodide in humans

The proposed non-muscarinic pupillary action of echothiophate iodide (EI) was investigated in humans. In 10 healthy volunteers the variations of the pupillary area, induced by EI eye drops, were evaluated by using an electronic pupillometer. When instilled alone, as well as after homatropine, EI caused pupillary constriction. The reduction of the homatropine-induced mydriasis by EI was not accompanied by any increase in the almost abolished pupillary response to light, thus excluding that an enhancement of the parasympathetic activity contributes to pupillary constriction. These findings suggest a non-muscarinic component in the EI-induced miosis, the nature of which remains to be elucidated.

[Inhibition of acetylcholinesterase at pupil-related central nuclei by organophosphorus pesticide (fenthion)--an experimental study]

An organophosphorus pesticide (OP) inhibits acetylcholinesterase (AChE) of various organs, especially in cholinergically innervated organs. Pupil constriction is a major sign of an ocular symptom in the patient with acute OP intoxication, but the etiology is unknown. The present experiments were intended to elucidate a central mechanism of pupil size in which AChE and OP are involved. Fenthion (dimethyl 4-methylthion-m-tolyl phosphorothionate) of 5mg/day body weight) was subcutaneously administered dorsally in Wistar rats for 14 days consecutively in the longest group. Histochemical staining and microspectrophotometry were used to analyze the intensity of the AChE activity in the iris, the pretectal nucleus and Edinger-Westphal (EW) nucleus on the 2nd, 4th, 6th, 10th and 14th day of administration. The pupil was measured after 20 minutes of dark adaptation. The pupil constricted on the 6th day and most remarkably on the 10th day. The AChE activity in the iris decreased remarkably on the 4th day. Miosis was not seen on the 4th day. The AChE activity in the pretectal nucleus decreased remarkably on the 6th day. The AChE activity in the EW nucleus reduced gradually from the 6th day and 62% reduction of initial value was seen on the 14th day. Intense miosis was seen on the 10th day. In conclusion inhibition of AChE activity was detected first in the iris, thereafter in the pretectal nucleus and the EW nucleus in close correlation with the miotic pupil. Therefore, miosis associated with OP intoxicated patients may parallel the central inhibition of AChE in pupil-related centers.

Pupil size and the steady-state pattern reversal visual evoked cortical potential

30 eye-healthy subjects were being examined, with their pupils reacting, mydriatic or miotic. Their pattern reversal visual evoked cortical potentials (PRVECP's) were recorded under steady-state conditions. Test conditions allowed establishing a statistically significant influence of pupil size on the PRVECP.

Bupranolol, a beta 1- and beta 2-blocker, causes constriction of the pupil in men

Two out of three normal eyes tested with frequent instillation of 30 microliters of drops of 0.5% bupranolol, a beta 1 + beta 2 blocking drug with some intrinsic sympathomimetic and local anesthetic activity, showed a miotic effect of the order of a 25% reduction of pupil area, as estimated by an open-loop iris-videorecorder. A slight contralateral effect was also observed. Blocking by the drug of tonic inhibitory beta-adrenergic activity on the sphincter muscle of the pupil is postulated.

Pupillary constriction by bradykinin and capsaicin: mode of action

The application of bradykinin or capsaicin to the rabbit eye evoked strong miosis. The effect could be prevented by pretreatment of the eye with tetrodotoxin (TTX) or a substance P (SP) antagonist. However, the miotic response could be elicited despite TTX or the SP antagonist if the dose of capsaicin or bradykinin was increased. Bradykinin and capsaicin contracted the isolated rabbit sphincter pupillae muscle. The contraction produced by bradykinin and capsaicin was unaffected by TTX but reduced by specific SP antagonists. This indicates that bradykinin and capsaicin exert their effects on the isolated sphincter muscle through the release of SP but independent of neuronal conduction. In vivo, the situation seems to be different. The finding that TTX is capable of blocking the miotic response to moderate doses of bradykinin and capsaicin suggests that the effect on the eye under these circumstances is dependent upon a normal impulse traffic.

Vehicle effects in ophthalmic bioavailability: an evaluation of polymeric inserts containing pilocarpine

A series of polymeric ophthalmic inserts containing pilocarpine were formulated with four different types of polyvinyl alcohol, PVA, and two types of hydroxypropylcellulose. Pilocarpine was present as the nitrate, or as the salt with polyacrylic acid, PAA. In-vivo miosis vs time experiments on albino rabbits, showed that all inserts increased significantly the bioavailability of pilocarpine, with respect to a standard solution of pilocarpine nitrate. Two PVA inserts, containing the PAA-salt of pilocarpine, were particularly effective. The preparations were also submitted to in-vitro release tests and to differential scanning calorimetry, to ascertain the release mechanism, and to verify, via the thermal behaviour, possible interactions between drug and polymers. The chemical and physiochemical factors, most likely to influence the ophthalmic bioavailability of pilocarpine from the present preparations, are briefly reviewed.

Effect of urea on the activity of certain ophthalmic drugs in man

The role displayed by urea (2-10%) solutions, on the miotic and mydriatic activities of pilocarpine hydrochloride and homatropine hydrobromide respectively, was investigated on the human eye. At different concentrations, urea exerts no effect on the miotic activity of pilocarpine, whereas in the case of homatropine a negative effect is experienced. For the parameters, area under pupil diameter--time curve (AUC) and maximum pupillary response (MPR), a linear relationship exists between response to homatropine and urea concentration. However, the dependency is more pronounced in conjunction with the MPR parameter.

Possible antidotes in severe intoxication with fenitrothion in rats

We investigated antidotal effects of nine drugs against acute fenitrothion poisoning in rats. The antidotal effects were evaluated by a relief from toxic signs, an increased survival ratio and a prolonged surviving time. In the poisoning with approximate LD50 fenitrothion (500 mg/kg), oximes such as 2-PAM (2-pyridine aldoxime methiodide) and TPMM (1-(methyl morphorinium)-3-(4-hydroxyiminomethylpyridinium) propane dibromide), diphenhydramine and parasympatholytics such as atropine, scopolamine and biperiden significantly increased survival ratio and/or prolonged surviving time. These effective drugs did not sufficiently depress the toxic signs, except that the parasympatholytics markedly blocked salivation, miosis and motor ataxia. In contrast, reduced glutathione and central depressants such as diazepam and phenobarbital made the poisoning serious. In the poisoning with 100% lethal dose of fenitrothion (800 mg/kg), the parasympatholytics were more effective than 2-PAM and diphenhydramine, and they elevated the survival ratio up to 20-40%. The best therapy against the severe poisoning with 100% lethal dose of fenitrothion was confirmed to be the repeated and combined treatment with atropine and 2-PAM as established in parathion poisoning, resulting in 90% survival ratio and considerable alleviation from the toxic signs.

[Preliminary study of the topical use of thymoxamine]

In this work the Authors have tried to show the efficacy of TMX, as a miotic drug, and to find out the lowest concentration which can give the best results with the minor complications. Seven patients, in whom TMX was instilled in both eyes at 0.50%, 1%, 2% concentrations, were studied. A mydriatic was instilled before in the right eye, in order to obtain mydriasis whereas the left eye served as control. The 0.5% concentration was as efficacious as 1% and 2% ones, but had less side-effects.

Pupillographic analysis of morphine action in the rabbit: role to the autonomic nervous system

Pupillary response of albino rabbits were recorded using an infrared video pupillometer. The transient response to an i.v. injection of morphine (1-12 mg/kg) consists of three phases. Phase 1 is a brief mydriasis of 20 s duration. Phase 2 is a miosis that reaches a maximum within 2-4 min and is the only dose-related endpoint observed. Time-averaged pupil size is not decreased by morphine in a dose-related manner when measured 5 min after injection. Phase 3 is large amplitude fluctuation that reaches peak amplitude within 20 min and may last for several hours. Thus, dynamic pupillography reveals that the terms "miosis' and "mydriasis' may be insufficient to fully describe opiate-induced pupillary effects. All three phases are blocked by naloxone (0.1 mg/kg i.v.) and by topical pretreatment with scopolamine. These results are consistent with the theory that morphine alters pupil size by interaction with opiate receptors that are involved in the control of parasympathetic output to the iris.

Miosis from echothiophate in patients with total oculomotor nerve paralysis from intracranial abnormalities

Seven subjects with intracranial pathologic abnormalities received bilateral instillations of echothiophate. Six had unilateral third (oculomotor) nerve paralysis; one had unilateral third nerve paresis. All 14 eyes became miotic. Miosis was greater in the defective eye in three subjects, greater in the normal eye in two subjects, and equal in two subjects. The neurons originating in the ciliary ganglion and terminating on the sphincter pupillae muscle may exhibit spontaneous activity. Echothiophate, by preventing acetylcholine hydrolysis, may have allowed this transmitter to accumulate and to produce miosis. The amount of maximal miosis in the abnormal eye after bilateral instillation of echothiophate drops may vary from that in the normal eye. The causes of this variation include denervation supersensitivity of the sphincter pupillae muscle, partial paresis of the dilator pupillae muscle, and increased drug penetration in the abnormal eye.