PubMed · 1813506
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G R Bell. 1991. Unrelaxed accommodation.. https://pubmed.ncbi.nlm.nih.gov/1813506/
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OBJECTIVE: To determine the 15-year outcome of patients with partly accommodative esotropia with a high accommodative convergence to accommodation (AC/A) ratio who underwent surgery based on the angle of esotropia at one-third meter while wearing full hyperopic correction. METHODS: A retrospective chart review to determine the 15-year outcome of 25 patients whose 6-month outcome had been previously reported as part of a prospective, randomized, masked clinical trial. All patients had partly accommodative esotropia with a high AC/A ratio and underwent surgery based on their esotropia at one-third meter while wearing full-distance optical correction. RESULTS: Fifteen years after surgery, 19 of the 22 patients for whom follow-up data are available had between 0 and less than 10 prism diopters of esotropia. Only 6 of the 19 needed to continue to wear optical correction to maintain satisfactory alignment; however, 8 more needed spectacles for visual purposes. Only 1 patient needed to use a bifocal add to have satisfactory alignment at one-third meter. All patients showed some degree of sensory fusion, with 4 obtaining 40 seconds of stereopsis and another 8 obtaining between 60 and 200 seconds of stereopsis. CONCLUSION: Surgery for the near angle obtained with patients wearing their full hyperopic distance correction provides excellent motor and sensory results in patients with partly accommodative esotropia with a high AC/A ratio.
The microscopic anatomy of the eye of the Weddell seal was studied with various light and electron microscopic methods with a view to correlating morphological findings with the biology of this seal which is adapted to the extremes of the Antarctic environment and to extreme diving excursions into the lightless depths of the sea. In the retina an area centralis was found but no fovea centralis. The densely packed photoreceptors consist exclusively of highly differentiated rods, which in primates detect light at low intensity but have rather poor image discrimination. The ganglion cells are relatively scarce, suggesting a high degree of convergence of the light-sensitive cells on the ganglion cells. The pigment epithelium is almost devoid of pigment granules. The extensive tapetum lucidum is about 400-500 microm thick and is composed of about 30 layers of specialized cells. The cornea is 650 (center) to 800-900 (periphery) microm thick. Its structure and glycosaminoglycan histochemistry correspond to that of other mammals. The iridocorneal angle is unusually deep and pervaded by an elaborate trabecular meshwork, which together with a complex canal of Schlemm can be correlated with the ability to absorb large amounts of fluid. The ciliary muscle and its antagonist, the membrane of Bruch, are poorly developed, suggesting relatively poor abilities of accommodation. The combination of a well-developed tapetum lucidum, an unpigmented pigment epithelium, well-developed rods, and a high number of rods converging on only few ganglion cells is obviously an adaptation to an extreme light sensitivity, enabling the animals to make use of the little light available in the deep sea.
BACKGROUND: Dyslexia is defined as a reading and/or writing disability persisting after exclusion of organic causes. Studies show that ocular disorders, especially small refraction errors, hypoaccommodation and symptomatic heterophoria, are often not detected or treated in cases of reading and/or writing problems which were otherwise diagnosed as dyslexia. METHODS: We evaluated the data of patients referred to our department from December 1997 to March 2000 with the diagnosis of dyslexia. RESULTS: We found ocular disturbances in 28 (84.8%) out of 33 children, 26 (78.8%) showed improved reading after therapy. They had mostly accommodative problems: uncorrected hyperopia, hypoaccommodation and/or exophoria compensated by accommodative convergence (pathophoria). CONCLUSIONS: Our results underline the importance of the correction of even small refraction and/or motility errors in the presence of reading and writing difficulties.