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Biomedical subjects

R V Keech

Publications and source records attributed to R V Keech.

At least 37 records · Page 2Linked to original sources
PubMed1990

The gradient filter test to assess amblyopia.

A new technique, the gradient filter test, was developed for evaluating changes in the visual acuity of preverbal children undergoing treatment for amblyopia. The gradient filter test consists of a series of calibrated photographic fog filter and prism lenses. The combined prism-filter lenses are placed in front of the normal fixing eye. The greatest density (fogging value) filter that causes a switch in fixation from the amblyopic to the normal eye is noted. In both normal eyes of 20 nonamblyopic patients and the fellow (non-amblyopic) eyes of 20 amblyopic patients, visual acuity decreased as the density of the prism-filter lens increased. The gradient filter test accurately detected an improvement in visual acuity when compared with optotype measurements in eight patients undergoing occlusion therapy. The gradient filter test is a useful clinical tool that can assess changes in visual acuity in preverbal children who are being treated for amblyopia.

Amblyopia↗
PubMed1990

Myopia induced by vitreous hemorrhage.

Six of 11 children developed myopia in one eye after vitreous hemorrhage. None had retinopathy of prematurity, glaucoma, aphakia, or scleral buckling. In seven children developing vitreous hemorrhage before 1 year of age, six exhibited a myopic anisometropia in the affected eye of 1.37 to 12.00 diopters (mean, -4.7 diopters; S.D., 4.0). The degree of myopia correlated with the age of onset and duration of media opacification. In the child without myopia, the hemorrhage did not obscure the posterior pole. None of the four children whose hemorrhage occurred after 2 1/2 years of age showed myopic anisometropia (mean, +0.16 diopters; S.D., 0.24). We conclude that vitreous hemorrhage occurring in infancy is strongly associated with the development of myopia in the affected eye.

Aging↗
PubMed1990

The medial rectus muscle insertion site in infantile esotropia.

The distance from the corneoscleral limbus to the insertion site of the medial rectus muscle was measured at several stages of medial rectus recession surgery in 20 patients (40 eyes) with infantile esotropia. Disinsertion of the medial rectus muscle resulted in a mean reduction in the distance from the muscle insertion site to the corneoscleral limbus of 0.903 mm (P less than .001), whereas the use of fixation forceps on the insertion to abduct the eye resulted in an additional mean reduction of 0.306 mm (P less than .01). The strabismus surgeon often uses the muscle insertion site as a reference point in determining the desired location for recessing a muscle. Our results suggest that this method of measurement is unreliable in infantile esotropia because the position of the medial rectus muscle insertion site varies considerably during surgery.

Child, Preschool↗
PubMed1989

Complications after surgery for congenital and infantile cataracts.

We reviewed the records of 78 patients who underwent 128 surgical procedures for congenital or infantile cataracts before age 30 months for the type and frequency of postoperative complications. The surgeries included 92 limbal lensectomies and anterior vitrectomies, 13 pars plicata lensectomies, 20 aspirations, and three additional procedures. Complications developed after 21 of the 105 lensectomy and anterior vitrectomy procedures. Ten eyes (10%) required additional surgery for a secondary membrane, 12 eyes (11%) developed glaucoma, and one (1%) developed a retinal detachment. Patients who underwent surgery by 8 weeks of age had a significantly greater number of complications (P less than .025). Patients undergoing cataract surgery early in life should be routinely examined for possible postoperative glaucoma. The best method for reducing secondary membrane formation and some types of glaucoma appears to be an extensive removal of the lens cortex, posterior capsule, and anterior vitreous.

Age Factors↗
PubMed1989

Management of monocular congenital cataracts.

From 1971 through 1985, a diagnosis of monocular congenital cataract was made in 14 consecutive patients. All patients had a visually significant cataract that was documented at birth or within 2 months of age. All patients were followed up long enough to report distance linear recognition acuity. Excellent visual acuity (V/A) correlated with earlier surgery, earlier contact lens fit, and excellent amblyopia therapy compliance. The oldest age for attainment of excellent or good V/A was 17 weeks. Patching therapy was based on the binocular fixation pattern. The patching program consisted of 50% occlusion until the age of 2 months and gradually increased to 100% occlusion after the age of 7 months. Six patients (43%) attained excellent V/A (greater than 20/50), with three patients (21%) attaining good V/A (20/60 to 20/100) and five patients attaining poor V/A (less than 20/100).

Cataract↗
PubMed1989

Management and visual acuity results of monocular congenital cataracts and persistent hyperplastic primary vitreous.

Sixty-two patients, 48 with a diagnosis of persistent hyperplastic primary vitreous (PHPV) and 14 with monocular congenital cataract (MCC) are reported. Nineteen patients with a diagnosis of PHPV and all patients with MCC received surgery with attempted visual rehabilitation. Early age of surgery, prompt optical correction with contact lens and aggressive patching therapy are required for successful visual rehabilitation. Glaucoma, retinal or optic nerve pathology, surgery later than three months of age or combinations of these factors were associated with poor prognosis. Isolated microphthalmos was not correlated with poor prognosis. Binocular fixation pattern was used to monitor patching therapy. Optokinetic nystagmus, visual evoked potentials or forced preferential looking were not employed. Of the 33 patients who underwent surgery, 10 (30%) achieved good (greater than or equal to 20/50) visual acuity, 8 (24%) achieved fair (20/60 to 20/100) and 15 (46%) achieved poor vision. In selected patients with the diagnosis of PHPV or MCC, visual rehabilitation can be achieved.

Age Factors↗
PubMed1989

Vertical offsets of horizontal recti muscles in the management of A and V pattern strabismus.

Vertical transposition of the horizontal rectus muscles is the preferred operation in cases of A and V pattern strabismus in which oblique muscle dysfunction is inadequate to merit oblique surgery. Fifty-nine patients undergoing standard horizontal surgery with half tendon width vertical offsets and eight patients undergoing two-thirds to full tendon width offsets were retrospectively studied. Technique for pattern measurement and surgery are discussed. Postoperative data were analysed on a short-term (less than six weeks) and long-term (greater than 12 months) basis. Standard horizontal surgery combined with half-tendon width vertical transposition is shown to be an effective operation for collapsing all subgroups of A and V pattern strabismus when indications are appropriate. The initial correction to within +/- 10 D of pattern was 96% over all with 78% remaining collapsed to within +/- 10 D over an average 36-month follow-up. Recess-resect, bimedial and bilateral rectus recession operations with offsets are all approximately equally effective in pattern collapse. A graded pattern collapse response was found with greater collapse being related to greater initial pattern. The risk of conversion, from a more desirable pattern (AET, VXT) to a less desirable pattern (AXT, VET) is low (7.3%). For patterns greater than 30 D, three quarters to full-tendon width offsets were effective in collapsing pattern. For A and V patterns with significant oblique muscle dysfunction, oblique surgery is advocated.

Follow-Up Studies↗
PubMed1989

Absent and anomalous superior oblique and superior rectus muscles.

Anomalous or absent superior oblique or superior rectus muscles have usually been reported in the context of craniofacial disorders. We report a case of absent superior oblique and superior rectus muscles in the right eye and anomalous superior oblique and superior rectus muscles in the left eye in an otherwise healthy 4-year-old boy. The possibility of anomalous or absent extraocular muscles should be considered in unusual and complex presentations of strabismus, and alternative surgical strategies should be considered preoperatively. The clinical triad of levator palpebrae superioris, superior rectus and superior oblique dysfunction should suggest embryologic abnormalities of these muscles.

Child, Preschool↗
PubMed1988

Xanthoma disseminatum. An unusual histiocytosis syndrome.

The histiocytoses are a diverse group of illnesses that present a variety of diagnostic and therapeutic dilemmas. In this article, we describe the case of an 8-year-old boy with xanthoma disseminatum, a histiocytic disorder involving the skin, eyes, and brain. In our discussion, we have emphasized the clinical, pathologic, and radiographic features that distinguish this entity from clinically similar juvenile xanthogranuloma and Langerhans' cell histiocytoses (histiocytosis X) such as the Hand-Schuller-Christian syndrome. The importance of differentiating the various histiocytoses, in view of their varying natural histories and therapeutic responsiveness, is reviewed in relation to the new classification system for these disorders proposed by the Histiocyte Society.

Brain Diseases↗
PubMedDate not supplied

Adjustable suture strabismus surgery.

We examined 333 patients between the ages of 11 and 70 years who underwent strabismus surgery with adjustable sutures over a ten-year period. The type of strabismus, the number and amount of adjustments, the postoperative drift, and complications were evaluated. A large percentage of patients required adjustment to obtain the desired postoperative position. The postoperative drift patterns were characteristic for each type of preoperative deviation and were similar to that reported for nonadjustable procedures. Adjustable suture techniques were especially helpful in selected horizontal deviations, vertical deviations, and the more complex strabismus problems. The complications from adjustable suture operations in this series were minimal.

Adolescent↗
PubMedDate not supplied

The polarized three-dot test.

A new binocular sensory test was designed using polarizing filters. The polarized three-dot test (P3D) subtends the same visual angle as the Worth four-dot test (W4D). Sensory testing was performed at distance and near in 100 patients using the W4D and P3D tests. Every patient reliably completing the W4D test also completed the P3D test. Twelve patients failed to complete both tests. Fifteen patients could not reliably complete the W4D test but were able to perform the P3D, thus increasing the interpretable response rate from 73% for the W4D test to 88% for the P3D (chi square, p less than .0001). In every case but one, fusion by W4D testing was also found by the P3D test. In addition, the P3D identified 19 cases of fusion not found by W4D testing. The results suggest that the P3D test is superior to the W4D test in the clinical assessment of central and peripheral fusion.

Adolescent↗
PubMedDate not supplied

Adjustable suture strabismus surgery for acquired vertical deviations.

Forty-seven patients undergoing 51 adjustable suture strabismus procedures for acquired vertical deviations were evaluated for preoperative and adjustment factors which might influence the postoperative alignment. The type of deviation, surgical procedure, previous surgery, immediate postadjustment alignment, and immediate postadjustment versions were assessed. Oblique muscle surgery in addition to an adjustable vertical rectus muscle significantly decreased the success rate (p = .0303). Other less important factors were a previous history of strabismus surgery and a moderate limitation of versions following the adjustment. A slight over- or undercorrection after adjustment did not affect the success.

Adolescent↗
PubMedDate not supplied

The surgical overcorrection of intermittent exotropia.

Many strabismus surgeons recommend an initial surgical overcorrection for intermittent exotropia. Others caution against overcorrection because of possible nasal suppression and amblyopia in children, or because of possible diplopia in adults. We reviewed the records of 69 patients who were initially overcorrected following surgery for an intermittent exotropia. The mean postoperative follow-up was 3.1 years. Eight patients (11.6%) had a persistent overcorrection of 3 prism diopters or more and three patients (4.3%) had persistent diplopia. Patients with a persistent overcorrection had a greater mean age (P less than .02) and a greater mean initial overcorrection (P less than .005) compared with the patients who were not overcorrected 3 delta or more. No child lost stereoacuity or developed amblyopia due to the overcorrection.

Adolescent↗