Optometry最新文献

This is a review of the current literature describing the effect of atropine, bifocals, and/or contact lenses on slowing the progression of myopia. Cumulative data from a number of studies have demonstrated atropine instilled once a day in myopic eyes resulted in a 90% average reduction of myopia progression, as compared to untreated eyes, i.e., from 0.50 D/year to 0.05 D/year. Pirenzepine, a muscarinic pharmacological agent, has a minimal effect on pupil size and accommodation, and it has been shown to slow myopia by 44%. Bifocals and progressive lenses, which have been used for years to slow the progression of myopia, have recently been shown to produce, on average, only small, clinically insignificant treatment effects. However, their effectiveness is increased in children who are esophoric and have a large lag of accommodation, reducing myopia progression to between 0.25 and 0.40 D/year. Traditional correcting soft and gas permeable contact lenses, as well as novel spectacle lens designs, have not been shown to be effective in reducing myopic progression. Under-correction of the refractive error has been shown not only to be ineffective in slowing myopia, but has also been associated with an increased rate of myopia progression. Orthokeratology, using reverse geometry designed lenses, has been shown to be moderately effective in decreasing the progression of myopia by between 30 to 50% in a number of short-term, well-controlled studies, reducing myopia progression to between -0.25 and -0.35 D/year. Recently, there have been pilot studies using novel peripherally correcting soft contact lenses to slow the progression of myopia. Two of those lens designs have been shown to be moderately effective in slowing the progression of myopia, both of which had a 30% efficacy, reducing myopia progression to 0.35 D/year. In summary, myopia control is entering a new era with the use of contact lenses and pharmaceutical agents to effectively slow its progression with minimal side effects.

Background: Diabetic papillopathy is a benign optic neuropathy with a favorable predictable visual outcome, found in Type 1 and Type 2 patients with diabetes mellitus. The condition manifests with optic disc edema and minimal optic nerve dyfunction. Previous reports have described several similarities between diabetic papillopathy and non-arteritic anterior ischemic optic neuropathy; however, there are clinical differences that make them unique conditions;

Case report: A 62 year old Caucasian male with Type 2 diabetes manifested bilateral optic disc edema without visual dysfunction. The patient was diagnosed with diabetic papillopathy after an extensive systemic evaluation which did not reveal any contributory etiologies. The patient was followed with serial retinal nerve fiber layer scans using optical coherence tomography over the course of one year. The optical coherence tomography measurements demonstrate normalization of retinal nerve fiber layer following optic disc edema resolution;

Conclusions: Presented is a case report demonstrated the normalization of retinal nerve fiber layer following bilateral diabetic papillopathy. The use of optical coherence tomography is helpful in both documenting progression and differentiating from similar clinical entities.

Introduction: Central corneal thickness (CCT) imparts information about an individual's risk of conversion to glaucoma from ocular hypertension, progression of established glaucoma, and the likelihood of developing structural and functional abnormalities in patients with ocular hypertension. Most typically, CCT is measured through ultrasound (US) pachymetry. Currently, optical coherence tomography (OCT) has the ability to image the anterior segment, cornea, and anterior chamber angle. With this ability comes the option of determining CCT. The purpose of this study is to ascertain any significant difference in CCT measurement results as well as quantify the reproducibility of measurements of the two technologies. In addition, by measuring CCT both with traditional US pachymetry as well as spectral domain (SD) OCT technology, we sought to determine if CCT measurement by SD-OCT is an accurate, comparable and viable option;

Methods: Eighty eyes of forty healthy volunteers were used to determine CCT with both SD-OCT and US pachymetry. Three consecutive measurements were collected with each method on every eye.

Results: CCT measurements made by US pachymetry and SD-OCT were similar and consistent (r=0.99 for both methods). CCT measurements made by SD-OCT were consistently thinner by approximately 12 micrometers than measurements made by US pachymetry. Repeated measurements of CCT obtained by SD-OCT were more reproducible and had less variability than measurements obtained by US pachymetry. The mean within-subject standard deviation among SDOCT was significantly smaller than that in US pachymetry (1.92 in SD-OCT vs. 2.04 in US pachymetry, p=0.036);

Conclusions: Measurement of CCT by SD-OCT compares favorably with and is at least as accurate as measurements made by US pachymetry. Repeat measurements of CCT by SD-OCT have less variability than those obtained by US pachymetry, are more reproducible, possibly more reliable, and may better represent actual CCT.

Background: Blunt force trauma can affect all structures in the eye, frequently causing complications such as hyphema or microhyphema. A hyphema is defined as bleeding in the anterior chamber that layers and forms a visible clot. A microhyphema occurs when the red blood cells are suspended in the anterior chamber, and do not form a layered clot. Microhyphema is a rarely reported, visually significant complication. Ocular trauma is the second most common cause of visual impairment, and appropriate management must be executed swiftly and efficiently to maximize a patient's visual potential;

Case report: A 21-year-old Indian male presented after ocular contusion to the right eye. His visual acuity was reduced at initial presentation. Pertinent clinical findings included red blood cells in the anterior chamber and ecchymosis of the orbital adnexa, with associated conjunctival injection. Subsequently, the patient developed commotio retinae;

Conclusion: It is important for clinicians to take a detailed case history of the event, perform a thorough ocular exam, select proper treatment/therapy, monitor the patient closely, and make appropriate referrals as needed. This case report discusses the clinical findings, treatment, and management of 1 patient with an ocular contusion resulting in microhyphema and commotio retinae.

Background: Toxic retinopathy is an uncommon sequella in the treatment of certain autoimmune diseases with hydroxychloroquine (HCQ). We present two cases of HCQ toxic retinopathy, as well as a discussion on how to diagnose and manage early toxicity findings;

Case reports: Two cases are presented of patients who experienced toxic effects of HCQ therapy. The first patient had bull's eye maculopathy confirmed with visual field testing and optical coherence tomography (OCT). The second patient had early signs of toxic maculopathy validated by repeat visual field and OCT testing;

Conclusions: Management of toxic maculopathy includes the cessation of hydroxychloroquine, continued monitoring of the toxic effects and optimizing the remaining vision. The irreversible and potential devastating effect of HCQ toxic maculopathy underscores the importance of early diagnosis and working with the patient's rheumatologist.

Background: The purpose of this study was to assess monocular and binocular distance perception, and stereoacuity, in individuals with mild traumatic brain injury (mTBI) who reported the symptom of "poor depth perception";

Methods: Ten patients with mTBI were tested and compared with ten visually-normal asymptomatic individuals in the following areas: perceived distance, stereoacuity at distance (3 meters) and near (40 cm), and a 9-item 5-point rating-scale questionnaire related to distance perception. Distance perception was assessed under monocular and binocular viewing conditions in both clustered and isolated static environments. Magnitude estimation was used to obtain the distance perception response function of physical versus perceived distance using common objects positioned at distances of 0.77 to 12.84 meters.

Results: The mean distance perception response function slopes were not significantly different in the two groups for any of the test conditions. Stereoacuity (sec arc) was slightly reduced at both near and distance in the individuals with mTBI (36 ± 24.58 and 84 ± 68.34, respectively) as compared with the normal subjects (20 ± 0 and 51 ± 9.93, respectively). The mTBI group mean symptom score was 3.24 ± 0.26 indicating a moderate problematic level;

Conclusions: Similarity of the mean distance response functions in the mTBI group under monocular and binocular viewing conditions suggested that their misperception of distance was not due to a "binocular vergence" problem. Similarly, the slightly reduced stereoacuity in the mTBI group was not sufficient to explain their symptom of "poor depth perception." Thus, it is speculated that this problem reflects a higher-level cortical perceptual phenomenon related to diffuse brain damage in areas dealing with visuo-spatial mapping.

Convergence insufficiency is a common binocular vision disorder affecting approximately 5% of the population in the United States. It is often associated with a host of symptoms that occur when doing near work, such as reading and computer viewing. This article reviews the existing literature on convergence insufficiency including etiology, diagnosis, sensorimotor findings, and management.