Prevalence and laterality of lattice retinal degeneration within a primary eye care population.

PURPOSE: The purpose of this study was to determine the prevalence of lattice retinal degeneration (LRD) in a primary eye care population and to compare this prevalence to that of other studies reported from selected populations. In addition, the percentage of unilateral and bilateral cases was to be determined. METHODS: A prospective study design was conceived to examine 600 consecutive patients presenting to the UABSO Primary Care Clinics. Each patient had been appointed for general eye examination. The following data were collected contemporaneously over six months from September 1993 to March 1994: demographics, medical and ocular history; refractive correction (calculated and recorded as spherical equivalent, SE); best-corrected visual acuity; and the presence and features of all ocular fundus findings, as evaluated through a dilated pupil. RESULTS: Of the 600 patients examined, 31 (5.2%) had LRD. Subjects ranged in age from 14 to 78 years (mean, 37.4 +/- 17.9 yrs.). Seventeen (55%) of the patients were white and 14 (45%) were black; 21 patients (68%) were female and 14 (32%) were male. The mean refractive correction (SE) was -1.77 D (range, +2.25 to -8.00 D). The lesions were bilateral in 19 (61.3%) of the patients; unilateral in 12 (38.7%). LRD lesions were observed in the vertical meridian (within 30 degrees of 6 or 12 o'clock) in all patients. CONCLUSIONS: The prevalence of LRD in a primary eye care population is comparable to that reported from other, selected populations. The proportion of bilateral cases in our material was greater than that from some other studies. Another item of note from the present data was exclusively vertical geographic location. We attribute the greater prevalence of bilateral cases in this material to the nature of the eye care delivery system.

Iridodialysis in a rhesus macaque: a case report.

During routine physical examination, a five-year-old male rhesus macaque (Macaca mulatta) was observed to have gaps in the right iris. Ophthalmic examination revealed inferior and superior iridodialysis with an anterior cortical cataract. The optic nerve head and fundus were normal. Uninvolved areas of the iris and anterior-chamber angle were normal on the basis of results of gonioscopy. Tonometry revealed normal intraocular pressure. The cause of the iridodialysis in this monkey's eye was not known. The animal had been housed individually since arrival due to requirements of the research protocol. Although the concomitant cataract supports a traumatic cause, there was no history of cranial or other ocular injuries. Trauma from fighting through the cage walls, self-trauma or falling inside the cage while under sedation cannot be ruled out. Multiple hematologic evaluations disclosed no abnormalities. This animal did not manifest behavioral abnormalities or any indication of pain. Therefore, treatment was not initiated. Intraocular pressure continues to be monitored at least semiannually.

Association between visual reaction time and batting, fielding, and earned run averages among players of the Southern Baseball League.

BACKGROUND: This study was performed to investigate the relationship between vision reaction time (VRT) and batting, fielding, and pitching skill in baseball. METHODS: A vision screening of 213 professional baseball players in the Southern Baseball League was performed, and the visual reaction times of these players were determined. Official Southern Baseball League statistics were consulted to obtain the players' batting average, fielding average, and earned run average. RESULTS: The mean visual reaction time for all players was 239 msec. There was no significant association between mean VRT and age or race. The mean VRT for dominant eyes was not significantly different from the mean VRT for nondominant eyes. For the 92 players who batted at least 100 times, an association was found between mean VRT and batting average (p = 0.017). For the 168 fielders in the league playing at least 20 games, no statistically significant association was found between mean VRT and fielding average. Similarly, no association was found between mean VRT and earned run average for the B8 pitchers who had participated in more than 20 games. CONCLUSIONS: An association was found between visual reaction time and batting skill in baseball. No association was found between visual reaction time and fielding or pitching skill.

Association between eye and hand dominance and hitting, fielding and pitching skill among players of the Southern Baseball League.

BACKGROUND: The relationship between eye dominance and batting skill in baseball has been investigated, but conflicting results have been obtained. In addition, little attention has been given to the relationship, if any, between eye dominance and fielding and pitching skill. METHODS: A vision screening of 215 professional baseball players in the Southern Baseball League was performed and the eye dominance of these players was determined by a sighting test. Handedness for batting, fielding, and pitching was determined by history. RESULTS: The screening revealed that 66 percent of players were right-eye dominant and that, of 92 players who met the criteria established to qualify for the league batting championship, 60 percent had matched dominance of eye and hand. When official league batting averages were obtained for these 92 players, it was found that there was no statistically significant difference between batters with matched dominance (.278 mean batting average). For the 149 fielders in the league, no statistically significant differences based on eye dominance were found for fielding average (.893 matched dominance, .864 crossed dominance); for the 89 pitchers, a similar result was obtained. Pitchers were also evaluated with respect to eye dominance and earned run average, but no significant difference was found (3.91 matched dominance, 4.03 crossed dominance). CONCLUSIONS: Results indicate that there is no association between eye dominance, and hitting, fielding, or pitching skill in baseball.

The photic sneeze response: a descriptive report of a clinic population.

BACKGROUND: The prevalence of the photic sneeze response (PSR) as well as other characteristics have been studied in selected populations. However, the PSR has not been investigated in a general eye care patient population. This study was performed in an attempt to characterize the epidemiologic, descriptive, and demographic aspects of the photic sneeze response among patients attending for primary eye care. METHODS: A questionnaire on demographics, risk factors, and triggering stimuli was distributed to 500 consecutive patients presenting for a general eye examination at an academic health center optometry clinic. RESULTS: Three hundred and sixty-seven of 500 questionnaires were returned (73.4%). Among this sample 33% were self-recognized photic sneezers with the majority being females (67%) and Caucasian (94.3%). Statistically significant correlations were found between the presence of photic sneezing and the presence of a deviated nasal septum and a non-significant association was found with tobacco use. Uniform frequency of sneezing does not occur in response to light stimulus; only 12.3% of sneezers responded consistently to sunlight exposure. The majority of sneezers (90.7%) responded with three or fewer sneezes. The interval between successive sneezes was fewer than 19 seconds in 85% of respondents. Fewer than 27% of respondents were able to recall a parent who exhibited a sneeze response. CONCLUSIONS: The PSR is not an uncommon phenomenon. Systemic associations with the PSR are as diverse as deviated nasal septum and tobacco use. Results suggest that there may be a threshold level of light or frequency of light exposure which produces the response and that more patients may acquire the response than inherit it.

The OSHA bloodborne pathogens standard. Implications for optometric practice.

The Occupational Safety and Health Act empowers the Occupational Safety and Health Administration (OSHA) to establish a standard when it determines that a significant risk to employees exists. Leading to the OSHA bloodborne pathogen Standard were the following events: recognition of Hepatitis B virus as an occupational hazard where blood and body fluids are handled. Similarly, the human immunodeficiency virus (HIV) had been shown to infect those exposed to blood and body fluids, and OSHA was petitioned by two unions to require employers to require Hepatitis B vaccine free of charge and to mandate general infection control practices as recommended by the Centers for Disease Control (CDC) as early as 1983. OSHA determined that the risk of contracting Hepatitis B virus and HIV was significant and that the final bloodborne pathogens Standard would substantially reduce that risk.

Diagnosis and primary care management of tear film deficiencies.

The tear film is a complex physical and biochemical structure. It functions to lubricate and protect the ocular surface from a variety of insults. Disorders of the tear film can lead to patient complaints as well as observable clinical signs. Combining clinical observations with a knowledge of the dynamic interaction of the tear film and the ocular surface should allow the practitioner to develop a management plan for symptomatic patients. This article details the many tests available for assessing tear film and ocular surface integrity, and discusses means of managing complications.

Enhanced non-contact examination of the vitreous and retina.

BACKGROUND: Fundus biomicroscopy is the clinical standard for comprehensive stereoscopic examination of the posterior segment of the eye. METHODS: Double aspheric hand-held condensing lenses provide excellent stereopsis and a uniformly illuminated wide-field image of the vitreous, retina and choroid. Although there is adequate visualization of vitreous structure, reflectance, and optical lens aberrations, including pupil aberrations, impose limitations on the resolving capabilities of the observation system. RESULTS: Fundus biomicroscopy using the Volk Superfield NC lens provides a superior view of the vitreous structure and a stereoscopic, wide field of view of the structures of the retina and choroid, including a detailed view of the optic disc and macula. CONCLUSIONS: This paper describes the new Volk Superfield NC lens and presents an overview of the high quality imaging capabilities and clinical application of the lens especially with respect to vitreous examination.

Intraocular pressure response to scleral indentation.

PURPOSE: Intraocular pressure (IOP) is influenced by many factors. Our purpose was to determine the immediate response of the IOP to scleral indentation (SI). METHODS: Twenty-five subjects had IOP measured using Goldmann applanation tonometry before and after SI. The total indentation time was 40 s. IOP was remeasured in a masked fashion. RESULTS: Average IOP for the control eyes was 15.32 mm Hg (range: 10 to 22 mm Hg) before SI and 14.80 mm Hg (range: 9 to 24 mm Hg) after SI. The average IOP for the subject eyes was 15.08 mm Hg (range: 8 to 22 mm Hg) before SI and 13.14 mm Hg (range: 6 to 22 mm Hg) after SI. CONCLUSIONS: These results indicate an average decrease of 1.94 mm Hg for the subject eyes vs. 0.52 mm Hg for the control eyes in response to SI. This represents a statistically significant drop in IOP among the subject eyes in response to SI (p < 0.001).

Angioid streaks and AC hemoglobinopathy--a newly discovered association.

It is estimated that approximately 2 percent of African-Americans possess one gene for C hemoglobin. This is usually demonstrated on hemoglobin electrophoresis. Hemoglobin C trait (AC hemoglobinopathy) is considered a clinically benign condition; there are no characteristic physical abnormalities. Angioid streaks in the ocular fundus represent a progressive, bilateral, degenerative disorder characterized by breaks in Bruch's membrane. The pathogenesis of angioid streaks in the hemoglobinopathies is thought to be linked to iron deposition in Bruch's membrane. This report describes what is believed to be the first reported case of angioid streaks associated with hemoglobin C trait.

The initial assessment of ocular contusion injury.

The initial assessment of blunt ocular trauma requires taking a thorough history, measuring visual acuity, evaluating pupils, extraocular muscles, intraocular pressure, and anterior adnexa, and examining the interior of the eye by means of biomicroscopy and ophthalmoscopy. More sophisticated means of examination may be necessary before treatment strategies can be determined. The most common types of injuries are contusions, abrasions, lacerations, and penetrating wounds of the eye. The most serious injuries requiring treatment are penetrating wounds, hyphemas, and retinal detachments. The initial goal of management is to provide timely recognition and treatment of the injury, and to stabilize the condition and promptly refer the patient if specialized care is necessary.

Rotary Diamond Chart--a new visual field screening device.

The Rotary Diamond Chart (RDC) is presented as a new clinical method suitable for screening general optometry patients for visual field defects. A pilot study was conducted using both the rotary diamond chart and a central 76-point threshold-related screening test (Allergan-Humphrey) on 21 consecutive clinical patients. Full-threshold field testing was then completed on those subjects failing either screening test. The RDC detected five of six visual field defects including one very subtle defect which was not detected by the automated screening test. The sensitivity of the RDC visual field screening assessment was 83.33 percent with a specificity of 100 percent. These results suggest that the RDC is an effective clinical visual field screening test. It is easy for the clinician to use and for the patient to understand.

Lattice degeneration of the retina and retinal detachment.

Lattice retinal degeneration is considered the most significant peripheral retinal disorder potentially predisposing to retinal breaks and retinal detachment. Lattice degeneration affects the vitreous and inner retinal layers with secondary changes as deep as the retinal pigment epithelium and perhaps the choriocapillaris. Variations in clinical appearance are the rule; geographically, lattice lesions favor the vertical meridians between the equator and the ora serrata. Lattice degeneration begins early in life and has been reported in sequential generations of the same family. Along with its customary bilateral occurrence, lattice shares other characteristics of a dystrophy. The association between the vitreous and retina in lattice lesions may be responsible for the majority of lattice-induced retinal detachments. The tumultuous event of posterior vitreous separation in the presence of abnormally strong vitreoretinal adherence is the trigger for a retinal tear that, in turn, may lead to retinal detachment. Although retinal holes in young patients with lattice degeneration may play a role in the evolution of retinal detachment, the clinical course of lattice degeneration seems to be one of dormancy rather than of progressive change. This discussion outlines the pathophysiology of lattice retinal degeneration and the relationship of pathophysiology to clinical presentation. The epidemiology of lattice degeneration is summarized, as are the possible precursors to retinal detachment. A clinical characterization of the natural history of lattice degeneration is offered, and interventions for complications are described. To conclude, management strategies from a primary-care standpoint are reviewed.

UV-A absorbing characteristics of commercial sunglasses intended for recreational and general use.

Ultraviolet radiation (UVR) is known to cause photokeratitis with acute symptoms. It also has been demonstrated that UVR has the potential to accelerate human cataractogenesis. For certain recreational pursuits, protection from specific UVR wavebands is important to the prescriber, the dispenser, and the patient or consumer of sunglasses. By knowing the ultraviolet absorbance characteristics of lens materials, practitioners would be able to advise their patients. In this study, the UV-A spectra of pairs of sunglasses purchased anonymously were measured. The results indicate that manufacturers' claims of UVR protection, or absorbance, are valid with respect to the UV-A waveband. No association between UV-A absorbance and lens material or cost was established.

Something new under the sun.

Ultraviolet radiation can exert adverse acute and chronic effects on many ocular tissues, including the lens. Chronic exposure to ultraviolet B wavelengths has been linked to cortical cataracts, and posterior subcapsular cataracts have likewise been associated with the chronic effects of ultraviolet radiation. Aphakic patients require protection from the injurious effects of ultraviolet radiation, and clinicians must be familiar with the transmittance guidelines for ultraviolet-protective eyewear and prescribe lenses that absorb injurious wavelengths.

An alternative gonioscopy and fundus contact lens protocol.

The clinical procedures for gonioscopy and fundus contact lens examination traditionally have required the use of a topical anesthetic and an interface solution. I have replaced the topical anesthetic and interface solution with a disposable contact lens. The alternative protocol was performed on 18 volunteers, none of whom showed any significant adverse effects of the procedure. The pre- and post-slit lamp microscopic results are discussed in addition to the advantages and potential pitfalls of the new protocol.

Portable tonometers: a clinical comparison of applanation and indentation devices.

Optometric services to outpatient clinics, nursing homes and hospitals require portable equipment for ocular assessment. Of the various tonometric methods available, Goldmann applanation tonometry remains the standard. We present a clinical comparison of the hand-held version of Goldmann's instrument (Perkins tonometer) and the less expensive Schiotz tonometer. In a clinical comparison, we measured the intraocular pressure (IOP) of 51 inpatient and outpatient veterans (100 eyes) during routine examination. In each case the Perkins applanation tonometer was used first. This measurement was followed by IOP measurements using the Schiotz indentation tonometer with the 7.5 g and 5.5 g plunger loads. Plunger loads were alternated so that each was used, initially, 50% of the time. Good correlations, ranging from +.85 to +.68, were achieved between the applanation and indentation modes. Compact portability, lower cost and comparable reliability make the Schiotz tonometer a viable option for IOP screening.