Effect of Pilocarpineon Visual Acuity and On

Total Page:16

File Type:pdf, Size:1020Kb

Effect of Pilocarpineon Visual Acuity and On Br J Ophthalmol: first published as 10.1136/bjo.60.10.676 on 1 October 1976. Downloaded from Brit. 7. Ophthal. (1976) 6o, 676 Effect of pilocarpine on visual acuity and on the dimensions of the cornea and anterior chamber D. POINOOSAWMY, S. NAGASUBRAMANIAN, AND N. A. P. BROWN From the Department of Experimental Ophthalmology, Institute of Ophthalmology, London There are many data on the effect of pilocarpine on the reduction in intraocular pressure resulting from the anterior chamber, particularly in respect to pilocarpine, but this has not previously been reduction in intraocular pressure and in anterior measured. The present study investigates the chamber depth and miosis, but the effect of pilo- effect of pilocarpine on the cornea with pachometry carpine on the anterior chamber volume and corneal and keratometry. curvature has not previously been studied. Pilo- carpine commonly causes reduced visual acuity Materials and methods which may be partly due to miosis, but in this study reduced visual acuity is shown to be mainly due to a SELECTION OF SUBJECTS of myopic change. The mechanism the myopic Altogether 105 patients of both sexes were selected. change has not previously been established and it They ranged in age from 35 to 70 years and included is now shown to be caused by changes in radius of normal subjects as well as patients with confirmed curvature of the lens, similar to changes occurring narrow-angle and chronic simple glaucomas. In all I8o in accommodation; changes in radius of curvature eyes were studied. of the cornea are relatively unimportant. Pilocarpine reduces the anterior chamber depth Methods (Heim, I94I; Rosengren, I950; T6rnqvist, 1956; Bleeker, 1960; Romano, I968; Wilkie, Drance, In those patients already receiving pilocarpine, the drug and Schulzer, I969; Poinoosawmy and Roth, I974). was withdrawn for at least 24 hours before beginning http://bjo.bmj.com/ This effect is probably related to an increase in the the study. The following parameters were studied sagittal width of the lens as demonstrated by before and after the administration of pilocarpine and, in some subjects, again after its withdrawal. ultrasound (Abramson, 1972; Abramson, Coleman, Visual acuity. Standard Snellen chart at 6 m (with Forbes, and Franzen, I972) and is not connected distance correction if required). with the reduction in intraocular pressure. In this Anterior chamber depth (Haag-Streit pachometer and study the reduction in anterior chamber depth is slit-image photography). correlated with the reduction in anterior chamber Anterior chamber cross-section area (slit-image photo- on October 4, 2021 by guest. Protected copyright. volume and in the radius of curvature of the lens; graphy, from which anterior chamber volume was these have not hitherto been reported. calculated). Miosis may result in better visual acuity in some Comeal thickness (Haag-Streit pachometer). patients who are initially ametropic, but reduced Applanation tension (Goldmann). is Pupil diameter (pupillometer). visual acuity the more usual effect of pilocarpine. Lens anterior radius (slit-image photography). Visual acuity has been shown to improve if the The photographic method described by Jones and pupil diameter is reduced to 2-5 mm (Hallden, Maurice (I963) for measuring the volume of the anterior I973a and b) and to deteriorate with further chamber by means of attachments to the Haag-Streit reduction below this figure; this deterioration is goo slit-lamp was later modified (Brown, 1973a) to believed to be due to diffraction. The current study produce an improved image of the anterior chamber; shows that changes in visual acuity result from measurements were then made from the photographs factors unrelated to miosis. using a Perspex grid (Figs i and 2). The modified An increased radius of curvature of the cornea technique was used in the present study for measuring has been shown to occur with a rise in intraocular the depth and for calculating the volume of the anterior chamber. pressure (Poinoosawmy and Roth, 1974). Reduction The radius of curvature of the anterior surface of the in corneal radius is therefore to be anticipated with lens was measured in only i0 eyes in which the lens was well recorded in the photographs when Address for reprints: D. Poinoosawmy, Department of Experimental sufficiently Ophthalmology, Institute of Ophthalmology, Judd Street, London the pupil was miosed. The radii were measured from WCiH 9QS the projected images using the mirror technique as Br J Ophthalmol: first published as 10.1136/bjo.60.10.676 on 1 October 1976. Downloaded from Effect of pilocarpine on visual acuity 677 (I) http://bjo.bmj.com/ (2) FIGS I and 2 Anterior segment photographs taken before (Fig. i) and after (Fig. 2) pilocarpine. Note distance between posterior surface of cornea and anterior surface of lens (3-1 mm before and 2-7 mm after administration) on October 4, 2021 by guest. Protected copyright. described by Fisher (I97i) and modified by Brown Table I Changes in cornea, intraocular pressure, (I973a) to allow for corneal refraction. and anterior chamber depth with pilocarpine Results Mean values from 55 eyes with glaucoma CHANGES IN CORNEA, INTRAOCULAR PRESSURE, AND ANTERIOR CHAMBER DEPTH WITH PILOCARPINE Without With (TABLE I) pilo- pilo- There was no change in comeal thickness, but there was carpine carpine Difference a significant reduction in the radii of curvature of both the horizontal and vertical meridia of the comeae with Corneal thickness (mm) 0-56 o-56 o pilocarpine, which correlated well with the reduction in Horizontal meridia intraocular pressure (r=o-64). There was also a signifi- (mm) 7-86 7-78 -o.o8* cant shallowing of the anterior chamber. Vertical meridia (mm) 7-90 7-8 I -o009* Intraocular pressure (mmHg) 3o07 I9-6 -II*I CHANGES IN VISUAL ACUITY WITH PILOCARPINE AC depth (mm) 2.72 2v6i -o-II* The visual acuity with pilocarpine in 102 glaucomatous eyes deteriorated in 78 eyes, improved in six, and was *Significant P = > o o5 Br J Ophthalmol: first published as 10.1136/bjo.60.10.676 on 1 October 1976. Downloaded from 678 British 3ournal of Ophthalmology unchanged in the remainder. In those eyes in which the visual acuity deteriorated it fell from one to five lines 210' on the Snellen chart. In all these eyes the visual acuity * . ;* could be corrected to the previous value with the 190. * * * * addition of minus spheres to the distance refraction. :.T_ @ - s * - . s The correction needed varied from ** -o-25D to -I175D . s. with a mean value of o-95D. Miosis occurred in all 170- * ^ * eyes * . * but was evidently not the cause of the reduced visual . 4.. * * @ b- *: acuity since this could be corrected with minus lenses. 150' * * -t * **,, .t > * * t*:0 CHANGES IN ANTERIOR CHAMBER DIMENSIONS * * * - 130- .s. s WITH PILOCARPINE (Table II) : *@2. 2 . ._c There was a highly significant reduction in anterior * dd: *1 * .. *- chamber depth, area, and calculated volume within 15 ... * . :X: * minutes (P= <ooI); this increased up to 30 minutes, s : but it did not increase after 6o minutes. The anterior 90 #;5 ..S: - chamber volume was found to be well correlated with + :: *- the anterior chamber depth as shown in Fig. 3. * *2.t . " 70- * * tA sZ tE. CHANGES IN LENS RADIUS OF CURVATURE (Table III) S .* * 50 :.w* In all the lenses measured, the radius of curvature of 5. *- the anterior surface became shorter with pilocarpine. The change in radius was highly significantly correlated 30 (r=o 84) with the degree of myopic change in refraction. * * w *B * w * W * W * * - The change in radius was also highly significantly 0 10 I5 2-0 2-5 3.0 3.5 4'0 correlated (r=o-84) with the change in anterior chamber Anterior chamber depth in mm depth and inversely r= o 84 with the age of the subject. FIG. 3 Correlation between volume and depth of anterior chamber Table II Changes in anterior chamber dimensions with pilocarpine Discussion Mean values for 125 eyes http://bjo.bmj.com/ This decrease in the depth of the anterior chamber Without After pilocarpine as a result of pilocarpine confirms earlier reports pilo- (Heim, I941; Rosengren, I950; T6rnqvist, 1956; carpine 15 min 30 min 6o min Bleeker, I960; Abramson and others, 1972). The change in visual acuity for distance appears AC depth (mm) 2z82 2-38 2-27 2.25 to be accounted for by a myopic shift since the Area (mm") 21vO i6.5 i5.8 I5.7 visual acuity could be corrected to pretreatment on October 4, 2021 by guest. Protected copyright. Volume (1±1) 155 117 112 III levels, in all patients in whom it was reduced, by the addition of minus lenses. The small reduction in radius of curvature of Table III Radius of curvature of the anterior the cornea after pilocarpine had been instilled is lens surface before and after pilocarpine likely to be related directly to the fall in intraocular pressure. The reduction in radius alone would Age Before After (years) pilocarpine pilocarpine produce a myopic shift, but it is likely to be out- weighed by an accompanying reduction in axial (mm) (mm) length of the globe. It has previously been shown I 73 I2-5 9'3 (Poinoosawmy and Roth, 1974) that raised intra- 2 39 14'8 9'3 ocular pressure is associated with an increase in 3 68 13'5 Io'9 the radius of curvature of the cornea and with a 4 74 112 Io'6 myopic shift which appears to be due to increased 5 45 I2 7 9,7 axial length of the globe. Thus the small changes 6 73 IO-I 8-I in external dimensions of the eye resulting from 7 77 I2.8 9'4 reduced intraocular pressure 8 75 i i8 would probably IIO0 result in a net hypermetropic shift.
Recommended publications
  • Visual Acuity Assessment
    VISUAL ACUITY ASSESSMENT J. R. WEATHERILL Bradford Tests of visual function in cataract patients are performed recognised that patients with macular dysfunction have in order to answer two questions: (I) To what extent is the difficulty in reading out of proportion to their Snellen cataract responsible for the patient's symptoms? (2) Will acuity. This difficultyis probably due to parafoveal scoto­ removal of the cataract improve the patient's sight? To mas which prevent the whole word being seen at the same answer the firstquestion the optical qualities of the eye are time. If a patient reports that the main problem is with assessed, and to answer the second tests are employed reading, it is helpful to observe whether the patient holds which assess retinal and neural function and which are the page steadily or keeps moving it to avoid scotomas. relatively unaffected by the optical degradation caused by With current reading tests patients with poor macular opacities in the media. At Bradford we employ the tests function can read small print for brief periods, particularly listed in Table I. if they are used to reading and recognise the overall shape of the words. A Logmar equivalent for near vision com­ Snellen Acuity prising random words of equal length and composed of Although the Snellen acuity test measures the function of letters without either ascenders or descenders, read under only the central 1_20 in monochrome at 100% contrast, it controlled conditions of illumination and at a standard dis­ is nonetheless the 'gold standard' by which ophthal­ tance, would provide a more accurate measure of macular mologists judge and are judged.
    [Show full text]
  • GUIDE for the Evaluation of VISUAL Impairment
    International Society for Low vision Research and Rehabilitation GUIDE for the Evaluation of VISUAL Impairment Published through the Pacific Vision Foundation, San Francisco for presentation at the International Low Vision Conference VISION-99. TABLE of CONTENTS INTRODUCTION 1 PART 1 – OVERVIEW 3 Aspects of Vision Loss 3 Visual Functions 4 Functional Vision 4 Use of Scales 5 Ability Profiles 5 PART 2 – ASSESSMENT OF VISUAL FUNCTIONS 6 Visual Acuity Assessment 6 In the Normal and Near-normal range 6 In the Low Vision range 8 Reading Acuity vs. Letter Chart Acuity 10 Visual Field Assessment 11 Monocular vs. Binocular Fields 12 PART 3 – ESTIMATING FUNCTIONAL VISION 13 A General Ability Scale 13 Visual Acuity Scores, Visual Field Scores 15 Calculation Rules 18 Functional Vision Score, Adjustments 20 Examples 22 PART 4 – DIRECT ASSESSMENT OF FUNCTIONAL VISION 24 Vision-related Activities 24 Creating an Activity Profile 25 Participation 27 PART 5 – DISCUSSION AND BACKGROUND 28 Comparison to AMA scales 28 Statistical Use of the Visual Acuity Score 30 Comparison to ICIDH-2 31 Bibliography 31 © Copyright 1999 by August Colenbrander, M.D. All rights reserved. GUIDE for the Evaluation of VISUAL Impairment Summer 1999 INTRODUCTION OBJECTIVE Measurement Guidelines for Collaborative Studies of the National Eye Institute (NEI), This GUIDE presents a coordinated system for the Bethesda, MD evaluation of the functional aspects of vision. It has been prepared on behalf of the International WORK GROUP Society for Low Vision Research and Rehabilitation (ISLRR) for presentation at The GUIDE was approved by a Work Group VISION-99, the fifth International Low Vision including the following members: conference.
    [Show full text]
  • Visual Performance of Scleral Lenses and Their Impact on Quality of Life In
    A RQUIVOS B RASILEIROS DE ORIGINAL ARTICLE Visual performance of scleral lenses and their impact on quality of life in patients with irregular corneas Desempenho visual das lentes esclerais e seu impacto na qualidade de vida de pacientes com córneas irregulares Dilay Ozek1, Ozlem Evren Kemer1, Pinar Altiaylik2 1. Department of Ophthalmology, Ankara Numune Education and Research Hospital, Ankara, Turkey. 2. Department of Ophthalmology, Ufuk University Faculty of Medicine, Ankara, Turkey. ABSTRACT | Purpose: We aimed to evaluate the visual quality CCS with scleral contact lenses were 0.97 ± 0.12 (0.30-1.65), 1.16 performance of scleral contact lenses in patients with kerato- ± 0.51 (0.30-1.80), and 1.51 ± 0.25 (0.90-1.80), respectively. conus, pellucid marginal degeneration, and post-keratoplasty Significantly higher contrast sensitivity levels were recorded astigmatism, and their impact on quality of life. Methods: with scleral contact lenses compared with those recorded with We included 40 patients (58 eyes) with keratoconus, pellucid uncorrected contrast sensitivity and spectacle-corrected contrast marginal degeneration, and post-keratoplasty astigmatism who sensitivity (p<0.05). We found the National Eye Institute Visual were examined between October 2014 and June 2017 and Functioning Questionnaire overall score for patients with scleral fitted with scleral contact lenses in this study. Before fitting contact lens treatment to be significantly higher compared with scleral contact lenses, we noted refraction, uncorrected dis- that for patients with uncorrected sight (p<0.05). Conclusion: tance visual acuity, spectacle-corrected distance visual acuity, Scleral contact lenses are an effective alternative visual correction uncorrected contrast sensitivity, and spectacle-corrected contrast method for keratoconus, pellucid marginal degeneration, and sensitivity.
    [Show full text]
  • Taking the Mystery out of Abnormal Pupils
    Taking the mystery out of abnormal pupils No financial disclosures Course Title: Taking the mystery out [email protected] of abnormal pupils Lecturer: Brad Sutton, OD, FAAO Clinical Professor IU School of Optometry . •Review of Anatomy Iris anatomy Iris sphincter Iris dilator Parasympathetic pathway Sympathetic pathway Parasympathetic Pathway Parasympathetic Pathway Light stimulates the retina then impulse Four neuron arc travels with the ganglion cells through the Retina to the pretectal nucleus in the chiasm into the optic tracts. 80% go to the midbrain (1) LGN , 20% to the pretectal nuclei.They Pretectal nucleus to the EW nucleus (2) then hemidecussate and terminate at the EW nucleus EW nucleus to the ciliary ganglion (3) Ciliary ganglion to the iris sphincter with short ciliary nerves (4) 1 Points of Interest Sympathetic Pathway Within the second order neuron there are Three neuron arc 30 near response fibers for every light Posterior hypothalamus to ciliospinal response fiber. This allows for light - near center of Budge ( C8 - T2 ). (1) dissociation. Center of Budge to the superior cervical The third order neuron runs with cranial ganglion in the neck (2) nerve III from the brain stem to the ciliary Superior cervical ganglion to the dilator ganglion. Superficially located prior to the muscle (3) cavernous sinus. Points of Interest Second order neuron runs along the surface of the lung, can be affected by a Pancoast tumor Third order neuron runs with the carotid artery then with the ophthalmic division of cranial nerve V 2 APD Testing testing……………….AKA……… … APD / reverse APD Direct and consensual response Which is the abnormal pupil ? Very simple rule.
    [Show full text]
  • Bass – Glaucomatous-Type Field Loss Not Due to Glaucoma
    Glaucoma on the Brain! Glaucomatous-Type Yes, we see lots of glaucoma Field Loss Not Due to Not every field that looks like glaucoma is due to glaucoma! Glaucoma If you misdiagnose glaucoma, you could miss other sight-threatening and life-threatening Sherry J. Bass, OD, FAAO disorders SUNY College of Optometry New York, NY Types of Glaucomatous Visual Field Defects Paracentral Defects Nasal Step Defects Arcuate and Bjerrum Defects Altitudinal Defects Peripheral Field Constriction to Tunnel Fields 1 Visual Field Defects in Very Early Glaucoma Paracentral loss Early superior/inferior temporal RNFL and rim loss: short axons Arcuate defects above or below the papillomacular bundle Arcuate field loss in the nasal field close to fixation Superotemporal notch Visual Field Defects in Early Glaucoma Nasal step More widespread RNFL loss and rim loss in the inferior or superior temporal rim tissue : longer axons Loss stops abruptly at the horizontal raphae “Step” pattern 2 Visual Field Defects in Moderate Glaucoma Arcuate scotoma- Bjerrum scotoma Focal notches in the inferior and/or superior rim tissue that reach the edge of the disc Denser field defects Follow an arcuate pattern connected to the blind spot 3 Visual Field Defects in Advanced Glaucoma End-Stage Glaucoma Dense Altitudinal Loss Progressive loss of superior or inferior rim tissue Non-Glaucomatous Etiology of End-Stage Glaucoma Paracentral Field Loss Peripheral constriction Hereditary macular Loss of temporal rim tissue diseases Temporal “islands” Stargardt’s macular due
    [Show full text]
  • Ophthalmology Abbreviations Alphabetical
    COMMON OPHTHALMOLOGY ABBREVIATIONS Listed as one of America’s Illinois Eye and Ear Infi rmary Best Hospitals for Ophthalmology UIC Department of Ophthalmology & Visual Sciences by U.S.News & World Report Commonly Used Ophthalmology Abbreviations Alphabetical A POCKET GUIDE FOR RESIDENTS Compiled by: Bryan Kim, MD COMMON OPHTHALMOLOGY ABBREVIATIONS A/C or AC anterior chamber Anterior chamber Dilators (red top); A1% atropine 1% education The Department of Ophthalmology accepts six residents Drops/Meds to its program each year, making it one of nation’s largest programs. We are anterior cortical changes/ ACC Lens: Diagnoses/findings also one of the most competitive with well over 600 applicants annually, of cataract whom 84 are granted interviews. Our selection standards are among the Glaucoma: Diagnoses/ highest. Our incoming residents graduated from prestigious medical schools ACG angle closure glaucoma including Brown, Northwestern, MIT, Cornell, University of Michigan, and findings University of Southern California. GPA’s are typically 4.0 and board scores anterior chamber intraocular ACIOL Lens are rarely lower than the 95th percentile. Most applicants have research lens experience. In recent years our residents have gone on to prestigious fellowships at UC Davis, University of Chicago, Northwestern, University amount of plus reading of Iowa, Oregon Health Sciences University, Bascom Palmer, Duke, UCSF, Add power (for bifocal/progres- Refraction Emory, Wilmer Eye Institute, and UCLA. Our tradition of excellence in sives) ophthalmologic education is reflected in the leadership positions held by anterior ischemic optic Nerve/Neuro: Diagno- AION our alumni, who serve as chairs of ophthalmology departments, the dean neuropathy ses/findings of a leading medical school, and the director of the National Eye Institute.
    [Show full text]
  • Miotics in Closed-Angle Glaucoma
    Brit. J. Ophthal. (I975) 59, 205 Br J Ophthalmol: first published as 10.1136/bjo.59.4.205 on 1 April 1975. Downloaded from Miotics in closed-angle glaucoma F. GANIAS AND R. MAPSTONE St. Paul's Eye Hospital, Liverpool The initial treatment of acute primary closed-angle Table i Dosage in Groups I, 2, and 3 glaucoma (CAG) is directed towards lowering intraocular pressure (IOP) to normal levels as Group Case no. Duration IOP Time rapidly as possible. To this end, aqueous inflow is (days) (mm. Hg) (hrs) reduced by a drug such as acetazolamide (Diamox), and aqueous outflow is increased via the trabecular I I 2 8 5 meshwork by opening the closed angle with miotics. 3 7 21 3 The use of miotics is of respectable lineage and hal- 5 '4 48 7 lowed by usage, but regimes vary from "intensive" 7 8 I4 5 9 I0 I8 6 (i.e. frequent) to "occasional" (i.e. infrequent) instilla- I I 2 12 6 tions. Finally, osmotic agents are used after a variable '3 5 20 6 interval of time if the IOP remains raised. Tlle pur- I5 '4 I8 6 pose of this paper is to investigate the value of '7 '4 i6 6 miotics in the initial treatment of CAG. I9 6 02 2 2 2 8 2I 5 Material and methods 4 20t 20 6 Twenty patients with acute primary closed-angle glau- 6 I i8 5 http://bjo.bmj.com/ coma were treated, alternately, in one of two ways 8 4 i8 5 detailed below: I0 6 I8 6 I2 I0 20 6 (I) Intravenous Diamox 500 mg.
    [Show full text]
  • Visual Optics
    Visual Optics Jim Schwiegerling, PhD Ophthalmology & Optical Sciences University of Arizona Visual Optics - Introduction • In this course, the optical principals behind the workings of the eye and visual system will be explained. • Furthermore, descriptions of different devices used to measure the properties and functioning of the eye will be described. • Goals are a general understanding of how the visual system works and exposure to an array of different optical instrumentation. 1 What is Vision? • Three pieces are needed for a visual system – Eye needs to form an “Image”. Image is loosely defined because it can be severely degraded and still provide information. – Image needs to be converted to a neural signal and sent to the brain. – Brain needs to interpret and process the image. Analogous Vision System Feedback Video Computer Camera Analysis Display Conversion & Image To Signal Interpretation Formation 2 Engineering Analysis • Optics – Aberrations and raytracing are used to determine the optical properties of the eye. Note that the eye is non- rotationally symmetric, so analysis is more complex than systems normally discussed in lens design. Fourier theory can also be used to determine retinal image with the point spread function and optical transfer function. •Neural– Sampling occurs by the photoreceptors (both spatial and quantification), noise reduction, edge filtering, color separation and image compression all occur in this stage. •Brain– Motion analysis, pattern recognition, object recognition and other processing occur in the brain. Anatomy of the Eye Anterior Chamber –front portion of the eye Cornea –Clear membrane on the front of the eye. Aqueous – water-like fluid behind cornea. Iris – colored diaphragm that acts as the aperture stop of the eye.
    [Show full text]
  • Scleral Lenses in the Management of Keratoconus
    ARTICLE Scleral Lenses in the Management of Keratoconus Muriel M. Schornack, O.D., and Sanjay V. Patel, M.D. Management of patients with keratoconus consists primarily of Purpose: To describe the use of Jupiter scleral lenses (Medlens Innova- providing optical correction to maximize visual function. In very tions, Front Royal, VA; and Essilor Contact Lenses, Inc., Dallas, TX) in the management of keratoconus. mild or early disease, spectacle correction or standard hydrogel or Methods: We performed a single-center retrospective chart review of our silicone hydrogel lenses may provide adequate vision. However, initial 32 patients with keratoconus evaluated for scleral lens wear. All disease progression results in increasing ectasia, which gives rise patients were referred for scleral lens evaluation after exhausting other to complex optical aberrations. Rigid gas-permeable contact lenses nonsurgical options for visual correction. Diagnostic lenses were used in mask these aberrations by allowing a tear lens to form between the the initial fitting process. If adequate fit could not be achieved with contact lens and the irregular corneal surface. Zadnik et al. found standard lenses, custom lenses were designed in consultation with the that 65% of patients who enrolled in the Collaborative Longitudi- manufacturers’ specialists. The following measures were evaluated for nal Evaluation of Keratoconus study were wearing rigid gas- each patient: ability to tolerate and handle lenses, visual acuity with scleral permeable lenses in one or both eyes at the time of enrollment.4 lenses, number of lenses, and visits needed to complete the fitting process. Despite their optical benefit, corneal rigid gas-permeable lenses Results: Fifty-two eyes of 32 patients were evaluated for scleral lens may not be appropriate for all patients with keratoconus.
    [Show full text]
  • Contrast Sensitivity and Acuity Relationship in Strabismic and Anisometropic Amblyopia
    Br J Ophthalmol: first published as 10.1136/bjo.72.1.44 on 1 January 1988. Downloaded from British Journal of Ophthalmology, 1988, 72, 44-49 Contrast sensitivity and acuity relationship in strabismic and anisometropic amblyopia M ABRAHAMSSON AND J SJOSTRAND From the Department of Ophthalmology, University of Goteborg, Sahlgren's Hospital S-413 45 Goteborg, Sweden SUMMARY The contrast sensitivity function (CSF) and visual acuity were determined in children and adults with unilateral amblyopia due to strabismus or anisometropia with central fixation. The preschool children were examined repeatedly during occlusion treatment. All amblyopes had CSF deficits. The CSF was characterised by its peak value (the maximal sensitivity, Smax, and the spatial frequency at which Smax occurs, Frmax) calculated by a single peak least-square regression method. The two amblyopic groups showed discrepancies in relationship of both Smax and Frmax versus visual acuity both initially and during treatment. The strabismic cases had a more marked visual acuity deficit in relation to the contrast sensitivity losses, whereas these parameters are affected similarly in anisometropic amblyopes. The relationship between recovery of visual acuity and CSF during the initial month of occlusion treatment was of prognostic significance for the outcome of visual acuity improvement. copyright. Amblyopia is defined as an optically uncorrectable receives an input with deprived form and contour. loss of vision, usually monocular, without demon- There is no evidence that a strabismic eye receives a strable pathology in the posterior pole of the eye. blurred image, whereas several studies indicate that This condition develops in early childhood and it abnormal binocular interaction is present in http://bjo.bmj.com/ affects up to 5% of the population.
    [Show full text]
  • Drug Class Review Ophthalmic Cholinergic Agonists
    Drug Class Review Ophthalmic Cholinergic Agonists 52:40.20 Miotics Acetylcholine (Miochol-E) Carbachol (Isopto Carbachol; Miostat) Pilocarpine (Isopto Carpine; Pilopine HS) Final Report November 2015 Review prepared by: Melissa Archer, PharmD, Clinical Pharmacist Carin Steinvoort, PharmD, Clinical Pharmacist Gary Oderda, PharmD, MPH, Professor University of Utah College of Pharmacy Copyright © 2015 by University of Utah College of Pharmacy Salt Lake City, Utah. All rights reserved. Table of Contents Executive Summary ......................................................................................................................... 3 Introduction .................................................................................................................................... 4 Table 1. Glaucoma Therapies ................................................................................................. 5 Table 2. Summary of Agents .................................................................................................. 6 Disease Overview ........................................................................................................................ 8 Table 3. Summary of Current Glaucoma Clinical Practice Guidelines ................................... 9 Pharmacology ............................................................................................................................... 10 Methods .......................................................................................................................................
    [Show full text]
  • Home Visual Acuity Testing
    Home Visual Acuity Testing Vision testing is an important component of the eye evaluation. While office-based testing is most accurate, in-home testing can still provide helpful information for your doctor. The vision charts in this document may either be printed or viewed on a computer or tablet. We recommend printing the chart, if possible, instead of using a screen. Tape it to a wall in a well- lit space. Instructions 1. To test distance vision, adults should use the standard ETDRS eye chart (page 2). Children should use the HOTV chart and matching page (pages 3 and 4). 2. Please be sure that the chart is displayed at the correct size prior to testing. The circle on the chart should measure 1 inch, the size of a US quarter dollar coin. The orange lines at the bottom of the charts should each measure 86 mm, the size of the long edge of a standard credit card. If viewing on a digital screen, adjust the document zoom until the document is displayed in the correct dimensions. 3. If you wear glasses to see far away, wear them for the distance vision test. Stand exactly 5 feet from the eye chart when checking distance vision. 4. If you wear reading glasses or bifocals, wear them for the near vision test. Hold the near vision chart 14 inches from your face when checking near vision. 5. Test vision using one eye at a time. Cover the opposite eye using a Kleenex, large spoon, or palm of a hand. Watch carefully to avoid accidental peeking, especially in between fingers.
    [Show full text]