Biomedical subjects
Publications and source records attributed to R H Osher.
We describe a simple, rapid technique for creating a filtering bleb in the early postoperative period using the argon or Nd:YAG laser. After cutting a suture, an immediate reduction of the intraocular pressure will result as filtration occurs, thereby safely eliminating the need for and the risk of traditional surgery.
A prospective clinical investigation of radial keratotomy employing the Fyodorov method and instrumentation was initiated in March, 1980. The results of the first 147 eyes undergoing this surgical procedure for the reduction or elimination of myopia were analyzed one year following surgery. The mean preoperative, uncorrected visual acuity was finger counting vision and the mean preoperative myopic spherical equivalent was 5.33 diopters. The preoperative myopic refractive error ranged from 1.75 to 11.75 diopters. Radial keratotomy resulted in a mean uncorrected visual acuity of 20/35 with a mean reduction on myopia of 4.66 diopters. Eighty percent of the 147 eyes experienced 20/40 or better uncorrected vision. Sixty-eight percent of high myopia eyes (6.00 to 11.75 D) attained this level of uncorrected vision with a mean reduction of myopia of 6.23 diopters. Glare and variation of vision were the most frequently reported complications. A non-progressive endothelial cell loss of 5.2 percent was observed. The degree of preexisting myopia, patient age, fellow eye experience and surgeon learning curve significantly influenced the surgical result and facilitated the predictability of the procedure. Incision depth was directly related to surgical result. The low myopia group achieved stabilization of effect by six months while stabilization occurred later in patients with high degrees of initial myopia. Patient satisfaction was high and 78 per cent of the patients elected to undergo radial keratotomy in their fellow eye.
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With the increased popularity of extracapsular cataract surgery, the need for a peripheral iridectomy has been questioned. Some surgeons feel that the risks involved in performing the iridectomy are greater than when leaving the iris untouched. The indications and risks of iridectomy with cataract surgery are discussed. Four case reports are presented. In three cases, iridectomy was not performed with cataract surgery, and a pupillary block developed. In one of these three, a congenital cataract, secondary angle closure, developed requiring filtering surgery. In the fourth case, an iridectomy prevented serious complications from an unusual degree of postoperative inflammation with complete posterior synechia following uneventful cataract surgery.
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Vitritis is a relatively common clinical finding, and a significant number of patients present with vitritis as the major or only finding. The records of 199 patients coded "vitritis" at the Bascom Palmer Eye Institute were reviewed. Forty-seven patients fit in the category of "idiopathic vitritis" and formed a relatively distinct group of predominantly elderly woman who complained of floaters or blurred vision. The visual acuities were usually good and the anterior segments were generally normal. They had diffuse bilateral vitreous inflammation and either a normal fundus or reactive changes such as cystoid macular edema or preretinal "cellophane" membranes. Extensive medical evaluations were usually unremarkable. This study helps identify a group of patients with a typical presentation and rather characteristic eye findings. Additional work will be necessary to establish the pathogenesis, the natural course, and the efficacy of treatment.
A 62-year-old man had progressive visual loss from neurosyphilis while his optic disks appeared atrophic. At no time was there evidence of inflammation of the globe or of either optic disk. The presence of an extremely high IgG index and five oligoclonal bands in the cerebrospinal fluid indicated that the central nervous system was synthesizing antibody specific to Treponema pallidum. Recent investigations indicate that much larger doses of penicillin are necessary for adequate treatment of neurosyphilis than have been recommended previously.
The Morning Glory syndrome (MGS) is a congenital optic nerve anomaly that has received scant attention since first described by Handmann in 1929. We studied ten eyes and eight patients displaying variations of the syndrome. We found that the syndrome may be bilateral, hereditary, and associated with other congenital anomalies. When bilateral, visual function was only moderately disturbed. The anomaly is usually limited to the eye, and the retrobulbar nerve and brain appear normal, as documented by ultrasound and computed tomography. Surprisingly, increasing fibrovascular tissue produces traction on the disc substance and vasculature, vitreous, macula, and peripapillary retina. These findings may place these patients within a spectrum of congenital optic nerve anomalies ranging from staphylomata to posterior persistent hyperplastic primary vitreous.
Twenty-seven consecutive patients whose diagnoses were previously unestablished and who demonstrated baring of the circumlinear vessel underwent thorough ophthalmologic examinations. Evidence supporting optic nerve damage was found in 24 of these 27 patients. The majority of patients had either primary or secondary glaucoma, although neurologic, ischemic, and retinal causes of optic atrophy were also found. In the three patients in whom no cause was established, either unusual asymmetry or size of cupping was noted. Baring of the circumlinear vessel should alert the examiner to look for causes of optic nerve damage.
In five patients, extreme gaze resulted in the appearance and expansion of a lesion located at the site of a venous vortex ampulla. The dimensions and color of the lesion varied depending upon the direction and duration of gaze. The lesion expanded when the head was positioned below the level of the heart and when a Valsalva maneuver was performed, even when the primary position of gaze was maintained. The lesion rapidly detumesced and disappeared when the head was elevated, digital pressure was exerted on the globe, or gaze was directed elsewhere. Fluorescein angiography confirmed that this tumefaction originated from the venous vortex ampulla. These dynamic features observed ophthalmoscopically and demonstrated by ultrasonography are characteristic of the vortex ampulla varix; the lesion should not be confused with a malignancy.
Progressive loss of vision, optic disc pallor, and optociliary shunt vessels (the Hoyt-Spencer sign) constitute the clinical triad of optic nerve sheath meningiomas. However, optociliary shunt vessels may also follow central vein occlusions, and less commonly occur with a few other conditions. This report presents a comparative study of fluorescein angiograms performed on eight patients with optociliary shunt vessels. Four patients had optic nerve sheath meningiomas, and four patients had central retinal vein occlusions. The following differences in the fluorescein angiograms were noted in the two groups. In the optic nerve sheath meningioma group, the shunt vessels fill earlier (in the arteriovenous phase), the flow drains to central venous tributaries, and the late staining is hyperfluorescent to other veins. However, in the central vein occlusion group, the shunts fill later (in the venous phase), show a flow draining to the outer disc margin, and late staining is eufluorescent with other veins. Although optic nerve sheath meningiomas and old vein occlusions are usually rather easily differentiated by a complete examination, the fluorescein angiographic patterns are not only pertinent with regards to the pathogenesis of optociliary vessels, but in certain cases may be clinically helpful in making an important clinical differentiation.
Baring of the circumlinear vessel is reported as an early sign of optic nerve damage. Evidence is presented to show that this finding is not present in the normal population and, unlike previously described signs of glaucomatous cupping, can be observed at a stage of glaucoma prior to the development of visual field loss. Analysis of a series of stereoscopic photographs from selected high-risk ocular hypertensive patients disclosed a 54% incidence of baring of the circumlinear vessel. Although initially thought to be pathognomonic for glaucomatous cupping, baring of the circumlinear vessel is seen rarely in acquired cupping from optic atrophy secondary to other causes.
Four patients with infiltrative orbital disease involving an extraocular muscle demonstrated a characteristic retraction-motility pattern. The cardinal feature was retraction of the globe on attempted gaze opposite the field of action of the involved muscle. Variable eye movement limitation was present in the field of action and opposite to the field of action of the involved muscle. When motility was restricted, the force-duction test was positive. Modest proptosis and episcleal vascular congestion over the extraocular muscle insertion were associted physical findings. Dysthyroid eye disease, inflammatory myositis, and neoplasms are among the infiltrative myopathies that may produce an acquired orbital retraction symdrome.
Sustained gaze fatigue was found in two patients whose diplopia was the first manifestation of myasthenia gravis. Although ocular excursions initially appeared full, a slow drift toward the primary position occurred during sustained extreme gaze. This motility pattern signifies pathologic extraocular muscle fatigue and strongly implicates myoneural junction disease. When myasthenia gravis is suspected, the presence of sustained gaze fatigue provides a tentative clinical diagnosis to be confirmed by pharmacologic testing.
A computed tomography scan obtained in two patients with monocular visual loss showed diffuse enlargement and enhancement of the intraorbital portion of the involved optic nerve. Although these tomographic features were initially interpreted as an optic nerve glioma by the neuroradiologist, the ensuing clinical course established the diagnosis of optic neuritis.
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Three patients with myasthenia gravis demonstrated a distinctive sign of orbicularis fatigue. After momentary opposition on gentle sustained lid closure, the lid margins separated, resulting in widening of the palpebral fissure and scleral exposure. The patient thus appeared to "peek" at the examiner. The "peek" sign was not observed in 200 control patients and in 49 of 50 patients with facial weakness secondary to a spectrum of neuromuscular disorders. Three of 25 patients with myasthenia gravis displayed this sign, and in one patient it was the major diagnostic finding. The presence of the "peek" sign suggests the diagnosis of myasthenia gravis.