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When the oculomotor nerve becomes paralyzed, the eye becomes fixed in a downward and outward position. This occurs when the opposite pull of the lateral rectus and superior oblique muscles is not balanced by the pull of the muscles enervated by the oculomotor nerve. The goal of treatment is to align the eye in the primary position, even if the mobility of the eye has to be limited. A report is presented of seven patients with oculomotor nerve palsy on one side who were treated surgically. The surgery involved transposition of the insertion of superior oblique muscle tendon of the eyeball to a point more forward and central to the insertion of the superior rectus muscle. Also, the lateral rectus muscle underwent large recession, and sometimes recession and resection of the horizontal recti muscles of the other eye was performed. Patients were followed for a minimum of one year; maximum follow-up was eight years. After one operation, four patients achieved orthophoria (straightened vision). One patient had minor residual exotropia (outward turning of the eye). The remaining two patients required surgery on the horizontal rectus muscles of the opposite eye to correct the eyelid position of the involved eye. (Consumer Summary produced by Reliance Medical Information, Inc.)

Manifest latent nystagmus is a jerk form of nystagmus (involuntary, rhythmic movements of the eyes) that is present at birth. This occurs when viewing an object with both eyes open, but fixating (directing the gaze so that the image falls at the central vision point) only with one eye. Strabismus (cross-eyes) is necessary for manifest latent nystagmus; patients with strabismus typically fixate with one eye but look with two eyes. Vision with both eyes is usually better (by one or more lines on the eye chart) than vision with just one eye. Methods of reducing nystagmus and improving binocular vision (vision with both eyes) were investigated in eight patients with manifest latent nystagmus. The age range of the patients was from 7 months to 12 years old. Seven of the eight patients had strabismus; five underwent surgery for correction of strabismus and the manifest latent nystagmus improved, to latent nystagmus. True latent nystagmus occurs when covering one eye, but does not occur when looking with both eyes. Binocular vision improved in four of the five patients treated surgically. The three patients who did not have surgery were treated with prescription glasses. One of these patients converted to latent nystagmus with improvement of vision and the other two had decreased manifest latent nystagmus with one having improved binocular vision. It is concluded that surgical correction of strabismus appears to convert manifest latent nystagmus to latent nystagmus. This may also improve binocular vision. (Consumer Summary produced by Reliance Medical Information, Inc.)

PURPOSE/METHODS: To investigate whether quantitative head and eye movement recordings can distinguish patients with spasmus nutans from patients with retinal diseases mimicking spasmus nutans. A patient with congenital stationary night blindness was followed up for seven years with electro-oculographic eye movement recordings. RESULTS/CONCLUSIONS: Rhythmic head movements and fine, intermittent, asymmetric, disconjugate, high-frequency, out-of-phase pendular nystagmus were recorded. Eye and head movement recordings of patients with congenital stationary night blindness can mimic spasmus nutans.

Groundwater is a crucial freshwater resource that supports half of the world's population and provides drinking water for countries like Denmark and Austria. However, we are pumping groundwater at a faster rate than it can naturally replenish, leading to declining levels in one-third of the world's largest groundwater basins. This poses a threat to thousands of underground species, such as blind eels and translucent crustaceans, that rely on groundwater. Groundwater ecosystems also play a vital role in supporting surface biodiversity across 52% of the Earth's land. Protecting groundwater and its associated species is essential for maintaining the sustainability of ecosystems and our societies. [Extracted from the article]

In‐depth understanding of the potential implications of climate change is required to guide decision‐ and policy‐makers when developing adaptation strategies and designing infrastructure suitable for future conditions. Impact models that translate potential future climate conditions into variables of interest are needed to create the causal connection between a changing climate and its impact for different sectors. Recent surveys suggest that the primary strategy for validating such models (and hence for justifying their use) heavily relies on assessing the accuracy of model simulations by comparing them against historical observations. We argue that such a comparison is necessary and valuable, but not sufficient to achieve a comprehensive evaluation of climate change impact models. We believe that a complementary, largely observation‐independent, step of model evaluation is needed to ensure more transparency of model behavior and greater robustness of scenario‐based analyses. This step should address the following four questions: (1) Do modeled dominant process controls match our system perception? (2) Is my model's sensitivity to changing forcing as expected? (3) Do modeled decision levers show adequate influence? (4) Can we attribute uncertainty sources throughout the projection horizon? We believe that global sensitivity analysis, with its ability to investigate a model's response to joint variations of multiple inputs in a structured way, offers a coherent approach to address all four questions comprehensively. Such additional model evaluation would strengthen stakeholder confidence in model projections and, therefore, into the adaptation strategies derived with the help of impact models. This article is categorized under:Climate Models and Modeling > Knowledge Generation with ModelsAssessing Impacts of Climate Change > Evaluating Future Impacts of Climate Change Comprehensive evaluation of climate change impact models combining both observation‐based and response‐based strategies.

The diagnosis of patients with rod monochromatism (RM) and blue-cone monochromatism (BCM) may be difficult. The relative direction and symmetry of nystagmus of the two eyes, as well as the existence or nature of rhythmic head movements, are not known. We analyzed simultaneous eye and head movement recordings of 16 patients with RM and three patients with BCM. Longitudinal examinations were performed in seven patients. Younger patients had pendular, intermittent or continuous oblique nystagmus with both eyes oscillating in phase or out of phase with equal amplitudes. Older patients had continuous symmetrical oblique jerk nystamus with decreasing velocities in the slow phase. In two children, we demonstrated evolution from pendular to predominantly jerk nystagmus. Rhythmic head movements were detected in all children. Patients with RM and BCM exhibit a distinct entity of nystagmus and can be differentiated from patients with congenital or latent nystagmus. However, eye and head movements can mimic spasmus nutans.

• Background: Early childhood nystagmus may herald blindness, brain tumors, benign idiopathic motor nystagmus or spasmus nutans. Nystagmus unique to low vision was sought.

Background: Previous studies have shown that both a single dose of levodopa and a 1-week administration of levodopa improve visual functions in adult amblyopic patients. In the present study, we investigated the effect of increased dosage and duration of levodopa on amblyopes' visual functions. • Methods: Visual acuity and visual fields were examined before and after 3 weeks of daily administration of levodopa/carbidopa as well as 1 month and 2 months after completion of drug therapy in a double masked-design. • Results: A significant increase in visual acuities and a decrease in fixation point scotomas were found. Changes were of comparable dimension to those found after 1 week of levodopa administration. Improvement of visual functions persisted 2 months after the levodopa/carbidopa administration was completed. • Conclusion: The present study confirms previous findings of improvement in visual function in amblyopia after levodopa/carbidopa administration. However, increasing the dosage and the duration of levodopa did not enhance the effect in adults.

The author offers a logical procedure and philosophy for the pediatrician to use for the examination of infants and children, giving guidelines for proper time periods for examinations and for the extent of the examination.

Purpose:The purpose of the study is to investigate diagnostic criteria and treatment methods for patients with congenital periodic alternating nystagmus (PAN).

• A 4-year-old boy had been noted from birth to have bilateral masses obscuring the entire outer portion of the eyes. Systemic findings included mild growth retardation, multiple cortical lesions of the distal metaphyseal ends of the lower extremities, and diffuse skin pigmentation of the right side of the body. The epibulbar lesions were excised; on the right side, there was a thin cornea that necessitated corneal transplantation. The diagnosis of composite epibulbar choristomas associated with linear epidermal nevus was established by pathologic examination. This case report as well as a literature review establish the association of epibulbar choristomas with cutaneous linear nevi of the epidermal and sebaceous types.

Those patients who have reduced vision in one eye and a variable esotropia should be suspected of having the nystagmus blockage syndrome. Typically such patients will have a head turn in the direction of the good eye with a prefered medial fixation point. Careful examination will reveal a nystagmus with the preferred position as the null point. Also, any patient who repeatedly has a recurrent esotropia after surgery should be suspected of having the nystagmus blockage syndrome. It is important to perform a posterior fixation suture with a recession on the medial recti of both eyes and to alter the null point by recessing the medial rectus more than 3 mm and resecting the lateral rectus appropriately for the head turn at the same surgical procedure. The eye with poor vision also should have the lateral rectus resected.

• Horizontal prism placement in normal subjects results in an apparent change in phoria by an amount equal in power and opposite in direction to the prisms used. However, the measured phoria gradually returns toward the value preceding the placement of prisms. This is termed phoria adaptation. This response was measured in five normal subjects and five patients with cerebellar deficit. The magnitude of the response was significantly reduced in the patient group. Visual acuities and fusional reserves were comparable in the two groups. The mean age was greater, and the stereoscopic acuity decreased, in the patient group. These factors were unlikely to account for the reduced response in patients. The results suggest that the phoria adaptation response in normal subjects depend on the integrity of the cerebellum.

OBJECTIVE: Acquired nystagmus may cause oscillopsia and in some cases decreased visual acuity. Such symptoms may be debilitating. We evaluated the efficacy of retrobulbar botulinum neurotoxin A in the visual rehabilitation of patients with acquired symptomatic nystagmus. PATIENTS: Adults with acquired nystagmus from multiple sclerosis or brain-stem hemorrhage were recruited for this treatment study. Eligible patients were unable to perform visual tasks that they had performed prior to the onset of the nystagmus. DESIGN AND INTERVENTION: A prospective study evaluated the results of the retrobulbar injection of 25 to 30 U of botulinum neurotoxin A. Patients underwent testing of visual function, including eye movement recordings before and after initial injections. Patients were followed up for changes in their visual function for at least 6 months following the last injection. RESULTS: Six patients (nine eyes) with acquired nystagmus were treated with a series of 17 injections of retrobulbar botulinum neurotoxin A. Each patient had subjective and objective improvement in distance visual acuity following the injection. A reduction in the amplitude of the nystagmus was seen following each of the injections, but the frequency of the nystagmus was generally unchanged. Visual improvement usually lasted no more than 8 weeks. However, improvement persisted for 6 months after injection in two patients with oculopalatal myoclonus. CONCLUSION: Botulinum neurotoxin A transiently improves the visual function of patients with acquired nystagmus. For patients with oculopalatal myoclonus the improvement seems to last longer, about 6 months in two patients.

Dissociated vertical deviation (DVD), a vertical strabismus, is often associated with infantile esotropia, latent nystagmus and excyclo-torsion. DVD usually becomes apparent at about three years of age. The authors wished to determine whether DVD is a manifestation of an abnormal motor vergence system or is part of a visual system disorder. Vertical eye movements of six subjects with DVD, on cover-uncover and alternate cover tests, were studied using the magnetic search eye coil system. Asymmetry between the eyes' saccades were quantified during the DVD upward movement and during a trial of pure vertical saccades. In three subjects the vertical deviation increased to its full amount through a smooth vertical divergence movement, and in the other three patients through a combination of smooth and asymmetrical saccade-like movements. The latencies of the DVD, the peak velocity of the deviation movements, its time constant and the asymmetries in the saccades suggest that DVD represents an abnormal vertical vergence system.

The ultrastructure of normal and diseased temporal arteries is studied. Degeneration of the smooth muscle cells in the media appeared to be the initial pathological change. Fragmentation of the elastic fibers and giant cell reaction may be secondary to the destructive changes.

Meridional refractometry is a process whereby the meridional power of the corrective lens is measured in three predetermined meridians of the eye and the final prescription calculated from these data. The calculation is based on equations derived from Laurance's approximation of the meridional power of a cylindrical lens. The derivation of these equations, beginning with Laurance's approximation, is given. Prior knowledge of the position of the principal axes is not required, but the method is only applicable to the correction of regular ametropias.

Optokinetic nystagmus is a physiological reflex, initiated by objects moving in a constant direction in the visual field in such a manner as to cause the appearance of a jerking type of nystagmus. The nystagmus consists of a slow or following phase and a rapid recovery phase.This review covers the period from 1954 to the present. For detailed bibliographies prior to 1954, the reader is referred to the usual texts,15,35,77 plus a review of the optokinetic literature from 1946 to 1954 by Kestenbaum.36 Tichy72 reviewed the literature prior to 1956, but Tichy's work is available only in Czech. THE PHYSIOLOGY OF THE OPTOKINETIC REFLEX Electronic instrumentation has provided investigators with recording systems, some of them ingenious, for studying eye movements. The photoelectric cell has been used to measure light reflected from retinal vessels19 and thereby extremely fine eye movements; or for more gross measurement the

This is a report of dysjunctive eye movements, both spatial and temporal, that were noted while recording eye movements by means of electro-oculography.1,2 It has recently been stated that "... the nonfixing eye follows the movements of the fixating eye quite faithfully."3 It is the purpose of this report to demonstrate, with electrooculographic records, the independent nature of each eye, as well as the dysjunctive eye movement patterns.Electro-oculography is based upon the cornea-retinal potential, which was first demonstrated by du Bois-Reymond4 in 1849. The eye acts as a small dipole, so that, if electrodes are placed about the eye, a change in the electrode potential will occur when the cornea becomes closer to one electrode and farther from the diametrically opposite electrode. A record of the eye movements is obtained when the electrodes are placed in the principle meridians, vertical and horizontal, of each eye and recorded

Consecutive biopsies were studied electron microscopically on three temporal arteritis patients. All biopsies showed a combination of pathological changes of various stages of the disease with confirmation of the smooth muscle cell involvement. Biopsies obtained in the clinically acute periods showed inflammatory elements predominantly. Later biopsies of the same patient showed granulomatous reactions and muscular regeneration.

Three methods for simplifying the solution of the equations used in meridional refractometry are outlined: solution by time-sharing, multiple-access digital computers; solution by special-purpose analogue computer; and solution by nomogram. The advantages and the disadvantages of each method are discussed. It is suggested that a special-purpose analogue computer is the most feasible data reduction device for meridional refractometry.

Parts I through IV1-4 of this series describe normal and pathologic retinal vascular patterns of human eyes. The technique employed allows study of the retinal vascular tree as a whole mount. Many of these mounts from diseased eyes showed capillary acellularity. While it was inferred that this acellularity was caused by ischemia, no proof could be given. The present experiment was designed to study the sequential changes following temporary and unrelieved ischemia of the eye. If the acellularity was found in such an experiment, then a more secure interpretation of changes in diseased eyes would be justified. PROCEDURE Cats were used because the retinal vascular pattern closely resembles that of the human retina, and the fundus could be continuously visualized with the ophthalmoscope throughout the course of the experiment.Three methods of inducing retinal ischemia were employed: elevation of the intraocular pressure above the arterial pressure of the eyes;

The opticokinetic reflex has been used by a number of investigators1,2 to estimate visual acuity objectively and, more recently, has been utilized by Gorman3 in this laboratory to estimate the visual acuity of newborn infants. The present investigation is an attempt to correlate Gorman's objective results with known subjective visual acuities.The opticokinetic reflex is dependent upon a reflex arc composed of the retina, optic nerve, optic tract, optic cortical areas, association fibers to the ocular motor centers and finally with the cranial nerves 3, 4, and 6. The fact that cortical areas are necessary for this reflex was early established by Cords4 and subsequently verified by many others. As a result of this, it can be stated confidently that when the reflex is present the subject is capable of vision.5Opticokinetic nystagmus (train nystagmus) is present when a visible field is moved in front of

• A new chart determines resultant prism power and angle when correction of combined horizontal and vertical deviation with a single prism, set at an angle intermediate between horizontal and vertical, is desired. The chart is based on a derivation so weighted as never to permit a vertical error greater than one tenth as large as the associated horizontal error, with use of commercially available sizes of plastic Fresnel-type prisms. This weighting takes into account differences in horizontal and vertical fusional reserves. A compass rose facilitates proper alignment of the prisms.(Arch Ophthalmol 95:1255-1257, 1977)

Black conjunctival deposits have been attributed to epinephrine since Löwenstein's report in 1930.1 Such conjunctival deposits are not unusual with prolonged topical application of epinephrine; yet no corneal deposits due to chronic use of epinephrine have previously been reported. The purpose of this paper is to document two patients with deposits in their corneas associated with prolonged topical epinephrine application. The corneal deposits in case 1 grossly resembled a melanoma. REPORT OF CASES CASE 1. —A 75-year-old Italian male returned to the eye clinic for a routine visit. One and one-half years previously the patient had been admitted to the Massachusetts Eye and Ear Infirmary with absolute glaucoma OS and open-angle glaucoma OD. The left eye had corneal edema, complete peripheral anterior synechiae, rubeosis iridis, tension of 80 mm Hg, cataract, and no light perception. The patient stated that this eye had been blind for over six months. A

Cerebral aneurysms and vascular accidents are frequently associated with migraine headaches.1-3 While cerebral aneurysms are usually the cause of cranial nerve palsies occurring in patients with a migraine history,2 other vascular anomalies in the cranium may also be responsible for the migrainous aura. It is the purpose of this paper to further document a vascular abnormality associated with migraine. The present case has several noteworthy features. First, the pattern of the headaches was limited to the distribution of the second division of the left trigeminal nerve. Second, a parieto-occipital arteriovenous abnormality was demonstrated, which would account for the visual symptoms. Third, 2 intracranial aneurysms were demonstrated, and last, a third intracranial aneurysm was postulated to explain the cephalalgia and third cranial nerve palsy. REPORT OF CASE A 43-year-old white unmarried woman was admitted to the hospital with a chief complaint of double vision for one week.The patient

The problem of proprioception in the extraocular movements has been examined previously. Cooper, Daniel, and Whitteridge demonstrated on histological grounds that proprioceptors exist in the extrinsic eye muscles of man. By electrophysiological methods, they showed that the nerves from the eye muscles carry afferent impulses from stretch receptors to the brain stem. We were interested in finding out if these afferent impulses from the eye muscles had a cortical or conscious component similar to that present in other musculature, or whether vision (retinoception) or touch (of cornea and conjunctiva on conjunctiva) is a major factor. If these eye movements are knowledgeable when vision and touch are obtunded, then the term "proprioception"—("appreciation of position, balance, and changes in equilibrium on the part of the muscular system, especially during locomotion"), according to Blakiston's New Gould Medical Dictionary—may be properly used with reference to the extraocular muscles. If this is not the

There appear to be no reports to date indicating any relationship between the use of alternate-day steroid therapy and thromboembolic phenomena, let alone the relationship of these factors to temporal arteritis. We report two cases of thromboembolic complications occurring during prednisone treatment of temporal arteritis. Demonstration of a causal link awaits further study, for the association reported here may be due to chance. Our intent is only to alert other physicians to the possibility of such a link.

In response to the information needs of scientists and physicians who work in the field of vision, we have developed a direct-access, on-line specialized information retrieval system which combines computer-assisted instruction and bibliographic retrieval. An essential feature of the system is its accessibility via remote computer terminal. The key to the data base is a thesaurus which contains specific terminology arranged in a hierarchical structure. The thesaurus is used both for indexing the literature and for retrieving the information stored in the computer. Courses of instruction on selected subjects in ophthalmology have been programmed and form part of the data base. A search of the literature retrieval system by single subject, or by a combination of several subjects chosen from the thesaurus, retrieves the appropriate bibliographic citations. The response to the service offered by the Vision Information Center indicates that the center should expand its facilities to satisfy the needs of its clients.