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Biomedical subjects

M W Preslan

Publications and source records attributed to M W Preslan.

13 recordsLinked to original sources

Baltimore Vision Screening Project. Phase 2.

BACKGROUND: Vision screening in preschool and school age children remains a valuable method of identifying potentially treatable visual abnormalities, as well as refractive errors in the school age population. A major difficulty in conducting these types of programs is the inconsistent follow-up encountered frequently in children identified by the screening program. The Baltimore Vision Screening Project was designed to address the issue of access to care for a group of inner city elementary school students by providing on-site evaluation and treatment. METHODS: A standard vision-screening protocol was administered to prekindergarten and kindergarten students attending an inner city elementary school and access to care provided at the school. Children identified by the screening were examined at the school, and appropriate treatment was prescribed. The second phase of the study details a return to the school 1 year after the initial screening. The purpose of this was to reassess the level of visual morbidity in this population and to evaluate the effects of providing treatment in the previous year. RESULTS: Two hundred eighty-five children were screened during the 1994-1995 school year. Visual morbidity statistics from the follow-up year were similar to those of the previous screening: 5.3% diagnosed with amblyopia, 3.2% with strabismus, and 7.4% with refractive errors. Forty of the 68 children identified, examined, and treated in the previous year still were attending the school during the follow-up investigation. Compliance with recommended treatment was 30% in this group, with only 20% of the students passing the vision screening the following year. CONCLUSIONS: The follow-up screening confirmed the presence of significant visual morbidity in this group of preschool and kindergarten students. Nearly two thirds of the students had not complied with the recommended treatment or spectacle wear or both, despite providing immediate access to this care through the vision-screening program.

Baltimore↗

Baltimore Vision Screening Project.

PURPOSE: This study estimates the prevalence of common visual disorders (amblyopia, strabismus, refractive errors) in a group of inner-city school children. In addition, the study addresses the issue of access to care for vision-screening programs, specifically for children with recognized difficulties in obtaining routine medical care. METHODS: School children from an inner-city elementary school were enrolled into a prospective vision-screening program combining the identification arm (screening) and diagnostic/treatment arm (ophthalmic examination). The screening consisted of Snellen E optotypes presented at a 10-foot test distance. Each child failing the vision screening was examined by an ophthalmologist at the school using standard protocol. This allowed the authors to examine all children identified through the vision-screening program. RESULTS: Six-hundred eighty children were screened during the 1993 to 1994 school year. Eleven percent (76) failed the vision screening and were examined, 68 of whom failed the ophthalmic examination. The estimated prevalence of visual morbidity was as follows: amblyopia, 3.9%; strabismus, 3.1%, and refractive errors, 8.2%. CONCLUSION: Amblyopia, strasbismus, and refractive errors were found in relatively high frequencies for this population sample of inner city children. These findings underscore the necessity of comprehensive vision-screening programs that integrate follow-up care. Children with limited access to specialized eye care must be provided with a mechanism for obtaining these services.

Amblyopia↗

Photorefraction screening in premature infants.

BACKGROUND: Photorefraction is a screening technique capable of detecting potentially amblyogenic ophthalmic abnormalities. This screening technique was included as part of a longitudinal outpatient follow-up program of premature infants. The purpose of this investigation is to test the applicability of this screening method in a population of infants at risk for visual compromise. METHODS: One-hundred eighty-two premature infants older than 3 months chronologic age were screened using a commercially available, off-axis photorefraction device. Ophthalmic examinations were performed concomitant with each photorefraction. In most cases, photorefractions were performed before and after administration of cycloplegic medications. All photorefractions were analyzed by an observer masked to the results of the ophthalmic examination. RESULTS: For the 182 patients, the mean birth weight and mean gestational age were 1034.5 g and 28.2 weeks, respectively. The prevalence of ophthalmic abnormalities in the study population was 18%. Sensitivity and specificity rates for the overall screening were 77% and 90%, respectively. Photorefractions were analyzable in 77% of patients studied, with the remaining 23% of our study population unsuccessfully screened. Very young infants (younger than 3 months corrected age) were particularly difficult to photograph, as evidenced by the preponderance of these patients (85%) in the nonanalyzable group. The readability of photorefractions in black infants was improved when cycloplegia was used for the photorefraction. CONCLUSION: Photorefraction screening was an acceptable method of screening for ophthalmic abnormalities in a group of premature infants. Future studies of photorefraction screening techniques in premature infants will need to improve the success rate in young infants, perhaps by improving the fixation device.

Amblyopia↗

Transient subcapsular cataract formation in a child with diabetes.

Transient cataracts in patients with insulin-dependent diabetes mellitus (IDDM) are rare and have been reported only in association with severe ketoacidosis or hyperosmolarity. We present an adolescent with transient bilateral posterior subcapsular cataracts, which developed after the recent onset of IDDM without ketoacidosis or severe hyperosmolarity.

Acute Disease↗

Septo-optic dysplasia in two siblings.

We treated two siblings, a sister and brother, who had features of septo-optic dysplasia, including bilateral optic nerve hypoplasia, absent septum pellucidum, and partial pituitary insufficiency. Additionally, midline central nervous system abnormalities of the corpus callosum and cerebellum were shown. The familial occurrence of this disorder raises the possibility of autosomal-recessive inheritance.

Abnormalities, Multiple↗

Oculocardiac reflex during manipulation of adjustable sutures after strabismus surgery.

We studied 44 patients who underwent strabismus surgery with the use of adjustable sutures to determine the occurrence of the oculocardiac reflex during the postoperative adjustment process. We defined the reflex as at least a 10% decrease in the baseline heart rate. Only two patients (4.5%) displayed an oculocardiac reflex during the adjustment. We did not identify any preadjustment factors that would increase the susceptibility to develop the reflex.

Adolescent↗

Treatment of partly accommodative esotropia with a high accommodative convergence-accommodation ratio.

We conducted a prospective, randomized, masked comparison of two treatments for the nonaccommodative element in esotropic patients with a high accommodative convergence-accommodation ratio. One group received symmetric medial rectus recessions with posterior fixation sutures; the other received symmetric medial rectus recessions without posterior fixation sutures but augmented according to formula taking into account the near deviation. Previous experience had suggested that our surgical formula based solely on the distance deviation would lead to excessive undercorrections. A higher percentage of the augmented recession group achieved satisfactory alignment and were able to discontinue wearing bifocals postoperatively than the posterior fixation group. The data also showed a trend (though not statistically significant) suggesting that more members of the augmented recession group were able to discontinue wearing spectacles entirely. We concluded that the posterior fixation suture technique is not as effective as the augmented recession technique for the treatment of partly accommodative esotropia with a high accommodative convergence-accommodation ratio.

Accommodation, Ocular↗

Accommodative esotropia: review of current practices and controversies.

The treatment of accommodative esotropia requires a thorough evaluation at first presentation to elucidate all factors involved. The degree of hypermetropia, character of the esodeviation (i.e., intermittent or constant), presence or absence of amblyopia, and the AC/A ratio are all important in the initial management of these patients. In addition, the binocular status can be of prognostic value. Close follow-up is needed to ensure maintenance of binocularity and appropriate early intervention to modify the course before bifixation is lost.

Accommodation, Ocular↗

Congenital glaucoma and retinal dysplasia.

The differential diagnosis of leukocoria (pseudoglioma) in the neonate includes multiple conditions, including malformations with retinal dysplasia as a component. Typically bilateral, retinal dysplasia is characteristically seen in microphthalmic eyes. Certain chromosomal defects have been described. The case reported herein presented in the first month of life with an enlarged eye, elevated intraocular pressure, prominent iris vasculature, and leukocoria. Family history was positive in one respect: this is the second child of a Viet Nam veteran exposed to Agent Orange. The first child, from a different mother, also had birth defects. Other than his left eye, the child is completely normal. Ultrasonography showed posterior vitreous opacities of indeterminate configuration. CT scan suggested a posterior intraocular mass. Histologically, the principal features were an anomalous, largely unformed corneoscleral angle, intraocular hemorrhage, and retinal dysplasia. Light microscopic studies were performed. The corneoscleral angle revealed an anteriorly inserted iris with an absence of trabecular meshwork and Schlemm's canal. This case is considered unique on the basis of the association of retinal dysplasia with congenital glaucoma and larger-than-normal eye. The significance of reported paternal exposure to Agent Orange in this instance is unknown.

2,4,5-Trichlorophenoxyacetic Acid↗

Artifacts of measuring during strabismus surgery.

Several different artifacts can induce errors in measurements obtained during strabismus surgery. Fixating the severed rectus muscle stump with forceps during strabismus surgery can result in a temporary anterior displacement of the insertion. This may result in inaccuracies in determining the site to which the muscle is to be recessed. This displacement was quantified in a prospective masked manner and was found in some patients to result in as much as 1 mm of error. It can be prevented by measuring the recession prior to fixating the insertion stump with forceps; however, it cannot always be prevented by measuring from the limbus, which also introduces other artifacts due to geometric principles. An "advancement effect" occurs during a rectus muscle recession due to the mechanics of suture placement in the muscle. It was quantified in a masked manner and found to be approximately .5 mm in most cases. A "V" shaped deformity of the insertion stump may occur immediately adjacent to the forceps. This deformity frequently distorts the insertion by as much as several millimeters.

Humans↗

Refractive error changes following strabismus surgery.

Several uncontrolled, retrospective studies have suggested that permanent changes in refractive error can be seen following strabismus surgery. We prospectively enrolled 68 patients undergoing strabismus surgery for evaluation of pre- and postoperative cycloplegic refraction. In addition, the adult patients had computerized corneal topography recorded using the Corneal Modeling System, (Computed Anatomy, Inc, New York, NY). Pre- and postoperative refractions were compared using spherical equivalent and meridional equivalent (90- and 180-degree meridian). We found no significant change in the spherical equivalent between the pre- and postoperative measurements. However, a significant increase in the astigmatic power at 180 degrees (meridional equivalent at 180 degrees) was detected in both pediatric and adult patients. We did not observe any qualitative change in the corneal topography pre- and postoperatively. The change in astigmatic power at 180 degrees is equivalent to additional plus-cylinder correction at 90 degrees and was persistent throughout the 4-month postoperative period.

Adolescent↗

Laser therapy for retinopathy of prematurity.

Nine patients were treated with indirect ophthalmoscope argon laser photocoagulation for threshold retinopathy of prematurity (ROP). A total of 16 eyes were treated at an average postconceptional age of 36.31 weeks. All eyes demonstrated regression of threshold ROP. Follow up was between 1 and 14 months postoperatively. Laser photocoagulation for ROP may be an effective alternative in treating high risk levels of ROP.

Female↗

Regression pattern in retinopathy of prematurity.

We characterized the regression pattern of retinopathy of prematurity (ROP) for 266 infants examined over a 22-month period. Infants were included in the evaluation with a birth weight of less than or equal to 1500 g. Regression of retinopathy was observed in all but 11 infants, who were treated for threshold ROP. ROP limited to the peripheral retina resolved around term (40 weeks postconceptional age). Posterior ROP and/or stage 3 ROP underwent a protracted course of resolution, often not reaching zone 3 until 42 to 45 weeks after conception. Permanent retinal/vascular sequelae of ROP were observed in 10% of infants with ROP. The most common abnormality was failure to completely vascularize the temporal retinal periphery. Overall, retinal morbidity from ROP was an infrequent occurrence (18 of 266 premature infants--6.8%).

Female↗