Amblyopia and visual acuity in children with Down's syndrome.

BACKGROUND/AIMS: Amblyopia in people with Down's syndrome has not been well investigated. This study was designed to determine the prevalence and associated conditions of amblyopia in a group of home reared children with Down's syndrome. METHODS: All children in the study group underwent an evaluation of visual acuity. In addition, previous ophthalmological records were reviewed, and a subgroup of children was examined. For the purposes of this study, amblyopia was defined quantitatively as a difference of two Snellen acuity lines between eyes or if unilateral central steady maintained (CSM) vision and a clear fixation preference was observed. A high refractive error was defined as a spherical equivalent more than 3 dioptres and astigmatism more than 1.75 dioptres. Anisometropia was defined as a difference of at least 1.5 dioptres of sphere and/or 1.0 dioptre of cylinder between eyes. 68 children with Down's syndrome between the ages of 5 and 19 years were enrolled in the final study group. RESULTS: Amblyopia was observed in 15 (22%) of 68 patients. An additional 16 (24%) patients had bilateral vision less than 20/50. Strabismus, high refractive errors, and anisometropia were the conditions most commonly associated with decreased vision and amblyopia CONCLUSION: This study suggests that the prevalence of amblyopia is higher than previously reported. Fully 46% of these children with Down's syndrome had evidence of substantial visual deficits. These patients may be at higher risk for visual impairment and should be carefully examined for ophthalmological problems.

Relative efficacy of the argon green, argon blue-green, and krypton red lasers for 10-0 nylon subconjunctival laser suture lysis.

BACKGROUND AND OBJECTIVE: To determine the optimal wavelength for subconjunctival laser suture lysis. MATERIALS AND METHODS: 130 black monofilament 10-0 nylon sutures were sewn subconjunctivally into the bare sclera of enucleated rabbit globes. The lowest energy levels facilitating laser suture lysis were determined for the argon green (514.5 NM), argon blue-green (488.0 NM, 514.5 NM), and krypton red (647.1 NM) wavelengths. In addition, absorption spectroscopy was performed on the suture material and conjunctiva using the Perkin Elmer W/VIS Lambda 2 spectrometer. RESULTS: Krypton red produced the fewest buttonhole defects, and it was also the most efficient energy source for suture lysis (P = 0.0001) under nontenectomized conjunctiva. Absorbance spectra studies revealed peak absorbance at 628 NM for the 10-0 nylon suture material. CONCLUSIONS: Based on animal and absorption spectroscopy studies, krypton red may be a safer and more efficient wavelength for subconjunctival laser suture lysis.

Prognostic importance of ophthalmic manifestations in childhood leukaemia.

In order to assess the systemic prognosis of children with leukaemic ocular involvement, 63 of 131 patients admitted to hospital with acute leukaemia were evaluated ophthalmically. A total of 28 of 63 showed ophthalmic involvement and were followed up for up to 84 months. Twenty seven of 28 patients (96.4%) died within 28 months after the onset of ocular involvement and within 83 months after the onset of leukaemia. The 5 year survival rate of patients with ophthalmic manifestations was 21.4% (6/28). This survival rate was significantly lower than that of those who lacked ophthalmic manifestations (16/35: 45.7%, p < 0.05). All of the patients with ophthalmic manifestations had either bone marrow relapse or central nervous system leukaemia. The prognosis was related to risk factors such as central nervous system leukaemia or bone marrow relapse in most cases.

Diagnosis of diabetic eye disease.

The correct diagnosis of proliferation diabetic retinopathy is essential, because it is a treatable disease and missing the diagnosis can lead to the patient becoming blind. We examined the ability of internists and ophthalmologists to diagnose proliferative retinopathy under optimal conditions. Twenty-three physicians performed retinal examinations on ten diabetic patients and one normal patient with dilated pupils. Physician examiners were members of a university medical center and included 10 internists, 2 diabetologists, 4 senior medical residents, 4 general ophthalmologists, and 3 ophthalmologists who were subspecialists in retinal disease. Correct diagnosis was determined separately by the consensus of three ophthalmologists specializing in retinal disease, who reviewed seven-view stereo fundus photographs and medical charts. Of a possible 483 individual eye a examinations, 438 were completed. The overall error rate was 61%. The error rate for missing the diagnosis of proliferative retinopathy varied from 0% for retinal specialists to 49% for internists, diabetologists, and medical residents. We conclude that potentially serious mistakes in diagnosis are currently made by the physicians who care for most diabetic patients. Experience and specialized knowledge lessen that the error rate. Further education or greater use of referrals may be necessary to provide optimal patient care.

Effect of lateral cervical cord lesions on the respiratory rhythm of anaesthetized, decerebrate cats after vagotomy.

1. The lateral cervical cord of vagotomized, anaesthetized cats was superficially lesioned at the C3 or the C7 level before or after midcollicular decerebration.2. These cord lesions eliminated the inhibition of diaphragmatic discharge caused by chest compression. Previous work (Remmers, 1973) indicates that this change can be attributed to loss of reflex inhibition of inspiratory activity by intercostal afferents, probably as a result of interruption of tracts ascending in the lateral columns.3. Decerebrate cats with bilateral cervical cord lesions displayed abnormal respiratory patterns, ranging from apnoea to apneusis.4. The results are consistent with the hypothesis that the lateral columns carry proprioceptive feed-back from intercostal mechanoreceptors which promotes rhythmic breathing in the anaesthetized decerebrate cat.