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In nine cases of botulism B infection due to food poisoning acute onset of accommodation paresis, mydriasis, and dry-eye symptoms were the prominent clinical findings. Impairment of salivary secretion as a further effect upon cholinergic autonomic innervation was detectable for months. Guanidine treatment had a beneficial effect, whereas administration of antitoxin in the late and benign form was not effective.
A number of hypotheses has been advanced during the last 130 years to explain the progressive loss of accommodation of the human crystalline lens. None has dealt with the high initial value of accommodation which enables infants to form sharp retinal images of objects as close as 6 or 7 cm. This paper attempts to relate the initial value to the overall loss in terms of evolution and biological cost.
AIM: Theoretically myopes are required to exert more accommodation and vergence when wearing single vision contact lenses compared to glasses and hypermetropes less. This study aims to quantify the effects clinically. METHOD: Thirty subjects (21 female, nine male, average age 21.0+/-2.2 years) with a range of refractive errors (-7.87 D to +3.50 D) viewed in a random order, static targets at 0.1, 0.5, 1.0, 2.0, 3.0, 4.0 and 5.0 D accommodative demand that were matched for angular subtense. The subjects were fully corrected with spectacles and daily disposable contact lenses to their full prescription. Accommodation was monitored objectively with the PowerRefractor and Shin-Nippon SRW5000 and vergence and pupil size with the PowerRefractor. RESULTS: Myopes exerted greater accommodative effort for viewing near targets with contact lenses than glasses and hypermetropes less (r(2)=0.35, p=0.001 PowerRefractor). Myopes also exerted greater vergence effort for viewing near targets with contact lenses than glasses and hypermetropes less (r(2)=0.22, p<0.01). CONCLUSION: Theoretical calculation of the accommodative and vergence requirements with glasses compared to contact lenses reflect clinical findings, although there is reasonable variability between individuals.
BACKGROUND: Botulism is a rare but potentially lethal disease in which ophthalmic signs and symptoms are among the very earliest manifestations. The aim of this study was to investigate the epidemiological and clinical features of botulism-infected patients admitted to a general hospital in Porto, Portugal. METHODS: We performed a retrospective chart review of all botulism patients admitted to São João Hospital between January 1998 and January 2003. We excerpted data on epidemiology, ophthalmic and non-ophthalmic manifestations, and treatment. RESULTS: We identified 18 patients in nine registered outbreaks. In two patients (11%), ophthalmic manifestations preceded systemic manifestations; in six patients (33%), ophthalmic and systemic manifestations occurred simultaneously; in ten patients (56%), systemic manifestations occurred first. Ophthalmologists had examined only seven patients and made the correct diagnosis in five. The most common ocular symptoms were blurred near vision (100%), blurred distant vision (94%), and diplopia (44%). Accommodation impairment was documented in all seven patients examined by ophthalmologists. CONCLUSIONS: Ophthalmic manifestations were among the earliest and most prominent manifestations of botulism in this series, as in earlier reports. The diagnosis should be suspected when impaired accommodation and gastrointestinal symptoms occur together.
Congenital aplasia of the iris sphincter and dilator muscles is rare. We describe a 3-month-old boy with a patent ductus arteriosus who had this anomaly, with no other ocular or systemic abnormalities. The child, whom we followed for over 7 years, had reduced accommodative amplitudes. This anomaly, although it bears some similarity to Gillespie's syndrome, circumpupillary aplasia and aniridia, is an isolated, nonprogressive condition that general physicians need to differentiate from the neurologically dilated pupil so that misdirected, unnecessary investigations can be avoided.
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Neuro-optometry is evolving as an optometric clinical specialty focusing on neurological dysfunctions of the visual system. Initially, we focused upon abnormalities of ocular movements, and our investigations have now broadened to include static and dynamic measurements of eye movements, accommodation, and the pupil. We feel the clinic serves three fundamental purposes: (1) to provide service to the patient, (2) to perform clinical research, and (3) to broaden the scope of the students' clinical experience. Operation of the clinic, technical methods of measurement, the testing protocol, and examples of interesting clinical recordings are described.
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The authors describe a syndrome occurring in people learning fundus photography. This entity comprises the following: decrease of vision due to accomodative spasm, signs of anxiety and the finding of an improperly set ocular on the instrument used by the trainee.
OBJECTIVE: To evaluate the effect of laser in situ keratomileusis (LASIK) on ocular alignment and stereopsis in patients with accommodative esotropia. DESIGN: Retrospective, non-comparative, interventional case series. PARTICIPANTS: Since 1998, 27 patients (mean age, 33.3 years; range, 10-52 years) with comitant esophoria or esotropia and hyperopia meeting eligibility requirements underwent bilateral LASIK for correction of refractive error. INTERVENTION: Bilateral hyperopic LASIK was performed using the Technolas Keracor 217 excimer laser (Bausch & Lomb) in 22 patients and using the Nidek 5000 excimer laser in 5 patients. MAIN OUTCOME MEASURES: Visual acuity (best-corrected and uncorrected), refractive error, ocular alignment, and stereopsis were recorded before and after LASIK. Log transformation of each visual acuity was done before data analysis. RESULTS: Using paired t tests, the mean uncorrected esotropia was significantly reduced from 9.0 prism diopters (PD) (range, 0 [esophoria only] to 20 PD; standard deviation [SD], 7.39) before surgery to 3.3 PD (range, 0-15 PD; SD, 6.20) after surgery (P < 0.0001). Most patients (14 patients, 58%) had a reduction in esodeviation after LASIK, but 10 patients (42%) had no response to surgery, and these patients could not be predicted on the basis of preoperative sensorimotor testing. No patient had a worsening sensorimotor status after LASIK. Nine patients subsequently underwent conventional eye muscle surgery. CONCLUSIONS: Hyperopic LASIK was effective in reducing the mean uncorrected esotropia in this group of patients. However, accurately determining those patients most likely to benefit from the procedure was difficult.
BACKGROUND: Dyslexia is defined as a reading and/or writing disability persisting after exclusion of organic causes. Studies show that ocular disorders, especially small refraction errors, hypoaccommodation and symptomatic heterophoria, are often not detected or treated in cases of reading and/or writing problems which were otherwise diagnosed as dyslexia. METHODS: We evaluated the data of patients referred to our department from December 1997 to March 2000 with the diagnosis of dyslexia. RESULTS: We found ocular disturbances in 28 (84.8%) out of 33 children, 26 (78.8%) showed improved reading after therapy. They had mostly accommodative problems: uncorrected hyperopia, hypoaccommodation and/or exophoria compensated by accommodative convergence (pathophoria). CONCLUSIONS: Our results underline the importance of the correction of even small refraction and/or motility errors in the presence of reading and writing difficulties.
It has recently been suggested that correction of the monochromatic aberration of the eye could lead to substantial improvements in visual acuity and contrast sensitivity function. After consideration of the best-corrected visual acuity of normal eyes, the optical and neural limits to visual performance are reviewed. It is concluded that, even if current problems with the accuracy of the suggested techniques of aberration correction, through corneal excimer laser ablation or customised contact lenses, can be overcome, changes in monochromatic ocular aberration over time, the continuing presence of chromatic aberration, errors of focus associated with lags and leads in accommodation, and other factors, are likely to result in only minor improvements in the high-contrast acuity performance of most normal eyes being produced by attempted aberration control. Significant gains in contrast sensitivity might, however, be achievable, particularly under mesopic and scotopic conditions when the pupil is large, provided that correct focus can be maintained. In the immediate future, reduction of the high levels of aberration that are currently found in eyes that have undergone refractive surgery and in some abnormal eyes should bring useful benefits.
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Biofeedback therapy refers to the process of gaining voluntary control over some bodily function by the immediate use of information regarding its physiological state. In this paper we review the use of oculomotor biofeedback therapy in three common ocular disorders: nystagmus, strabismus, and amblyopia. Experimental and clinical test results have been encouraging. We believe oculomotor biofeedback therapy should be attempted, either alone or in conjunction with orthoptic and/or surgical procedures, in these and other ocular disorders manifesting an abnormal oculomotor component.
OBJECTIVE: To study the changes of AC/A ratio of myopia after excimer laser in situ keratomileusis (LASIK). METHODS: 135 myopia patients were treated by LASIK, their AC/A ratios were measured with synoptohore before surgery and 3 months after surgery. RESULTS: The average AC/A ratios of naked eyes or eyes wearing glasses before surgery and the naked after surgery were (0.724 +/- 0.587) (Delta)/D, (2.754 +/- 1.565) (Delta)/D, (1.618 +/- 1.027) (Delta)/D in turn. There were significant difference among those groups (P < 0.001). That also appeared in different degree of myopia naked before surgery (P < 0.01). We found no significant difference between the groups wearing glasses before surgery and naked after surgery (P > 0.05). A positive correlation was built up between postoperative AC/A ratio and AC/A ratio of wearing glasses or refractive diopter before surgery (r = 0.550, P < 0.001; r = 0.185, P < 0.005). And the postoperative AC/A ratios had a negative correlation to age or length of ocular axis (r = -0.340, P < 0.001; r = -0.192, P < 0.002). The regression equation for postoperative AC/A ratios was figured out as Y((Delta)/D) = 4.080 0 - 0.031 8X(1) - 0.097 1X(2) + 0.325 0X(3) (P < 0.001). X(1) = age (year), X(2) = length of ocular axis (mm), X(3) = preoperative AC/A ratio with weaning glasses ((Delta)/D). CONCLUSION: The naked AC/A ratios are higher than the preoperative's after LASIK, but lower than the wearing glasses's before surgery. It is influenced by the factors, such as: the preoperative AC/A ratio of wearing glasses, the length of ocular axis and the age.
Whiplash or indirect injuries to the neck as a consequence of motor vehicle collisions are a common occurrence in which the frequency of ocular complications is largely unknown. Ophthalmic and oculomotor function was investigated in a longitudinal study of 39 cases who had their initial ophthalmological assessment within one week of the whiplash injury. Ten of 39 cases had ocular symptoms and signs which developed shortly after the accident. The principal abnormality in 6 of these was decreased convergence and accommodation, superior oblique muscle paresis in 2, decreased stereoacuity in 1 and bilateral vitreous detachments in 1 patient. All but 2 had complete resolution of their symptoms within 9 months. Four other patients were asymptomatic but had ophthalmic signs which resolved within 3 months. Oculomotor abnormalities following whiplash injuries are generally mild, have a good prognosis, and would appear from this study to be commoner than hitherto expected.