Search PubMed⌕ Search

Biomedical subjects

H Lewis

Publications and source records attributed to H Lewis.

At least 91 records · Page 5Linked to original sources
PubMed1991

Scleral buckling for rhegmatogenous retinal detachment associated with severe myopia.

From Jan. 1, 1980, to Dec. 31, 1989, we performed scleral buckling surgery on 48 eyes of 46 patients for rhegmatogenous retinal detachments associated with severe myopia (greater than 5.00 diopters). Forty eyes of 38 patients were observed for at least six months, and the mean follow-up period was 46 months. Intraoperative complications occurred in four of 48 eyes (8%) and included retinal incarceration (two eyes), choroidal hemorrhage (one eye), and choroidal detachment (one eye). Three of the 40 eyes (7.5%) followed up for more than six months developed a recurrent retinal detachment and underwent a revision of the scleral buckle. At the last follow-up examination, the retinas of all 40 eyes were totally reattached. Final visual acuity of 20/40 or better was attained in 26 of 40 eyes (65%). Because of the low rate of intraoperative complications and the high rate of success, scleral buckling is recommended for most patients with rhegmatogenous retinal detachments associated with severe myopia.

Adolescent↗
PubMed1991

Tissue plasminogen activator treatment of experimental subretinal hemorrhage.

To determine if tissue plasminogen activator, a clot-specific fibrinolytic agent, could eventually be used to assist in the clearance or removal of subretinal hemorrhage, we studied the effect of subretinal injections of tissue plasminogen activator, autologous blood, balanced salt solution, and the combination of either tissue plasminogen activator or balanced salt solution after subretinal injection of autologous blood on retinal morphologic characteristics and clearance of subretinal hemorrhage in the albino rabbit. No morphologic evidence of tissue plasminogen activator toxicity was found in the rabbit retina at a dose of 25 to 50 micrograms/0.1 ml. Subretinal hemorrhage cleared faster after subretinal injection of tissue plasminogen activator when compared to balanced salt solution (P = .0005) but did not completely prevent overlying retinal degeneration. Both tissue plasminogen activator and balanced salt solution were found to decrease the toxic effects of subretinal blood on the morphologic characteristics of the rabbit retina, and this effect can be explained at least partly by dilution of the subretinal blood.

Animals↗
PubMed1991

Causes of failure after initial vitreoretinal surgery for severe proliferative vitreoretinopathy.

We performed initial vitreoretinal surgery on 81 eyes with rhegmatogenous retinal detachments complicated by severe proliferative vitreoretinopathy. Of 81 eyes, 68 (84%) had undergone previous scleral buckling. We performed vitreous base dissection on all 18 eyes (22%) that had anterior proliferative vitreoretinopathy. With one vitreoretinal operation, 66 of 81 eyes (81%) remained totally reattached. The main cause of initial anatomic failure and reoperation was either new or recurrent proliferation at the vitreous base. With additional vitreoretinal surgery and after a mean follow-up period of 19 months, 73 of 81 retinas (90%) were totally reattached. The final causes of anatomic failure were anterior proliferative vitreoretinopathy and proliferation from relaxing retinotomies. Of the 73 successfully reattached eyes, 62 (85%) had postoperative visual acuity of 5/200 or better.

Female↗
PubMed1991

Causes of failure after repeat vitreoretinal surgery for recurrent proliferative vitreoretinopathy.

During the last two years, we performed vitreoretinal surgery on 37 eyes with retinal detachments and recurrent severe proliferative vitreoretinopathy in 37 patients who had had previous failed scleral buckling and vitreous surgery for proliferative vitreoretinopathy. Anterior proliferative vitreoretinopathy was present in 32 of 37 eyes (86%); posterior proliferative vitreoretinopathy of fixed retinal folds in four quadrants of narrow or closed funnel shape occurred in 23 of 37 eyes (62%); and subretinal proliferation was noted in 16 of 37 eyes (43%). The retinas in 12 eyes (32%) redetached from new or recurrent anterior proliferative vitreoretinopathy in nine eyes, reopening of pre-existing retinal breaks in two eyes, or recurrent posterior periretinal proliferation in one eye. With additional vitreoretinal procedures in six eyes and after a mean follow-up period of 11 months, 27 of 37 retinas (73%) were totally reattached, and an additional five eyes (13%) had retinal reattachment posterior to the scleral buckle. Of the 32 patients with posterior retinal reattachment, final visual acuity of 5/200 or better was attained in 19 eyes (59%).

Adolescent↗
PubMed1991

Vitreous surgery for retinal detachment associated with choroidal coloboma.

We report the results of vitreous surgery in seven eyes with retinal detachments caused by retinal breaks at the margin of, or within, a choroidal coloboma. All seven eyes (100%) were reattached; visual acuities in five (71%) of the seven eyes improved from preoperative levels. Vitrectomy was combined with air-fluid exchange and endodrainage through preexisting retinal breaks or planned retinotomies in all but one of the cases. Part or all of the rim of the choroidal coloboma in six eyes underwent endophotocoagulation. The two eyes that did not experience postoperative visual improvement underwent intraoperative endolaser treatment 360 degrees around the optic nerve. If peripapillary endophotocoagulation is performed, especially through the papillomacular bundle, nerve fiber damage may occur and prevent visual recovery, despite retinal reattachment. For eyes with retinal detachment associated with choroidal colobomas involving the optic nerve, postoperative laser treatment through the papillomacular bundle may be preferable.

Adolescent↗
PubMed1991

A technique for facilitated visualization and dissection of the vitreous base, pars plana, and pars plicata.

We describe a technique to facilitate visualization of the vitreous base, pars plana, and pars plicata during vitreous surgery. This technique takes advantage of an externally applied fiberoptic light source coupled with scleral depression to enable direct viewing of the ciliary processes and anterior vitreous base. No special instrumentation or alteration in pars plana vitrectomy techniques is required. We have used this technique to enhance anterior dissection during vitrectomy surgery in the aphakic and pseudophakic eye associated with proliferative vitreoretinopathy, diabetic retinopathy, epithelial down-growth syndromes, and postvitrectomy fibrin formation.

Eye Diseases↗
PubMed1991

Otogenic Fusobacterium necrophorum meningitis.

A case of meningitis secondary to acute suppurative otitis media in a previously healthy child is reported. The only organism isolated from blood after aerobic and prolonged anaerobic culture was identified as Fusobacterium necrophorum. Complete recovery followed treatment with surgery and prolonged antibiotic therapy. The role of anaerobes in the development of meningitis, the isolation and identification of Fusobacterium necrophorum, the clinical presentations of F. necrophorum infection and the choice of antibiotics in the treatment of these infections are discussed.

Acute Disease↗
PubMed1991

Altered cell-mediated immunity to group A haemolytic streptococcal antigens in chronic plaque psoriasis.

The proliferative lymphocyte response to sonicated group A, beta-haemolytic streptococci (Strep-A) was measured by thymidine incorporation in 78 patients with psoriasis (guttate, chronic plaque or both). Lymphocytes from 72 of these patients were also cultured with streptokinase/streptodornase (SK/SD), and 20 of the patients with chronic plaque psoriasis were further tested with PPD, Candida albicans and sonicated Streptococcus mutans, a bacterial type not associated clinically with psoriasis. The median stimulation index (SI) of the psoriasis group to the Strep-A preparation was significantly higher than that of a group of 27 non-psoriatic individuals (P less than 0.05). Within this group, only the patients with chronic plaque psoriasis (n = 42) showed a significantly increased proliferative response compared to the non-psoriatic controls (median SI = 123.8 and 31.9, respectively, P less than 0.01). Although the lymphocyte response of the chronic plaque group to SK/SD was also markedly higher than that of the control group, this difference did not reach statistical significance. In addition, these patients did not show significantly increased responses to any of the other antigens tested, including S. mutans. No correlation was observed between the degree of proliferation to Strep-A and disease extent or activity. Similarly, ASO titres, which were raised in 11 out of 23 guttate and three out of nine chronic plaque psoriasis patients tested, did not correlate with the proliferative responses observed.

Adolescent↗
PubMed1991

Surgical management of retinal detachment associated with the acute retinal necrosis syndrome.

We operated on nine eyes in eight patients with retinal detachment associated with acute retinal necrosis (ARN) syndrome. The patients were treated with scleral buckling, vitreoretinal surgery, or a combination of these treatments. Vitrectomised eyes underwent combinations of lensectomy, membrane dissection, scleral buckling, air-fluid exchange, endolaser photocoagulation, cryotherapy, and retinal tamponade with C3F8 gas or SF6 gas. Macular attachment was achieved in eight (89%) eyes. Vision improved in seven (78%) eyes, of which five (56%) achieved 20/200 or better vision. Three eyes that had received laser treatment posterior to areas of retinitis suffered retinal detachment despite this prophylactic treatment. Poor visual outcome resulted from viral infection of the optic nerve or macular involvement, macular hole formation, macular pucker, or hypotony.

Adolescent↗
PubMed1991

Abnormal blood pressure response to exercise in normoalbuminuric insulin dependent diabetic patients.

Eight male normoproteinuric Type I (insulin dependent) diabetic patients and eight age- and sex-matched non-diabetic control subjects were studied for their response to exercise. Systolic blood pressure showed an exaggerated response to exercise in the diabetic group (median 123, range 98-151 mmHg, pre-exercise vs. 187, 163-217 mmHg, immediately post exercise P less than 0.01) compared to the control group (median 112 (100-145) pre-exercise, 153 (138-178) post exercise). Resting noradrenaline levels were lower in the diabetic (D) compared with the control (C) group (D: 1.66, 0.55-3.92 nmol/l vs. C: 2.96, 2.04-4.49 nmol/l, P less than 0.02). Levels rose during exercise by 79% (25-307%) and 43% (4-90%) respectively (NS). Resting urinary sodium was raised in the diabetic group and fell during exercise (P less than 0.05) (D: 146, 74-244 mumol/min, C: 108.5 (83.4-151.0) pre-exercise vs. D: 73, 48-264 mumol/min, C: 81.7 (23.0-92.0) post exercise). Resting atrial natriuretic peptide levels were lower in the diabetic group (D: 10.1, 4.3-16.9 pmol/l vs. C: 16.0, 9.5-22.9 pmol/l, P less than 0.02) and levels rose significantly in both groups during exercise (D: 25.9, 5.2-38.9 pmol/l vs. C: 28.6, 17.3-47.2 pmol/l, P less than 0.05). We conclude that exercise provokes an exaggerated rise in systolic blood pressure and decrease in urinary sodium excretion in normoalbuminuric diabetic patients. These findings may reflect increased sensitivity to the renin-angiotensin-aldosterone system. Reduced atrial natriuretic peptide levels may stimulate sodium retention and increased blood pressure in early diabetes.(ABSTRACT TRUNCATED AT 250 WORDS)

Albuminuria↗
PubMed1990

Is metoprolol CR/ZOK more selective than conventional metoprolol and atenolol?

An alternative, simple method to assess beta 1-selectivity is to establish the impact of the beta blocker on beta 2-stimulated increases in plasma glucose and decreases in plasma potassium during an intravenous infusion of terbutaline. In the present study the effects of metoprolol CR/ZOK 100 mg, conventional metoprolol 100 mg, atenolol 100 mg, and placebo on these biochemical changes have been compared. In 12 healthy volunteers, terbutaline infusion of 6 micrograms/kg was administered intravenously over 1 hour. Three and a half hours before the infusion they were given a single dose of each of the four treatments in random order, single-blind. The maximum increase in plasma above baseline occurred at the end of a 60-minute terbutaline infusion. All three-beta blockers decreased the peak plasma glucose level achieved compared with placebo (P less than .01) but this reduction was significantly less with metoprolol CR/ZOK pretreatment than with atenolol (P less than .05). Similar results were seen for the AUC values for the curves obtained from the increments over the 60 minutes of the infusion and the subsequent 120 minutes after the infusion. In addition, both the AUC values and the maximum fall in potassium were significantly reduced by all treatments (P less than .05). The metoprolol CR/ZOK preparation produced significantly less effect than atenolol with respect to both AUC (P less than .05) and maximum fall (P less than .01) and significantly less effect than conventional metoprolol tablets in maximum fall (P less than .01). In conclusion, the metoprolol CR/ZOK formulation produces lower plasma concentrations and results in less effect on potassium and glucose compared to conventional metoprolol and atenolol.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

Choroidal neovascularization after laser photocoagulation for diabetic macular edema.

Choroidal neovascular membranes (CNVMs) developed in eight patients after photocoagulation for clinically significant diabetic macular edema (DME). The CNVMs developed in areas where Bruch's membrane was ruptured and were diagnosed 2 weeks to 5 months after treatment. Only six patients had symptoms. The CNVMs were treated in four patients; final visual acuity was poor in all eight patients. This serious complication that follows laser treatment for DME may be related to the use of repeated small-size, short-duration laser or intense laser burns, or both.

Aged↗
PubMed1989

Choroidal neovascular membrane and other chorioretinal complications of acquired syphilis.

We reviewed ten patients who had posterior segment complications of acquired syphilis. Five of these patients had a neovascular membrane of the choroid associated with secondary or tertiary syphilis. Vision was stabilized after laser photocoagulation in one patient who had a choroidal neovascular membrane. Five additional patients had ocular manifestations including uveitis, optic neuritis, neuroretinitis, chorioretinitis, retinal hemorrhages, arterial and venous occlusion, vasculitis, and retinitis. Treatment of chorioretinal complications of syphilis with intravenous penicillin, if initiated early in the course of the disease, may result in excellent visual recovery.

Adult↗
PubMed1989

Treatment of postvitrectomy fibrin pupillary block with tissue plasminogen activator.

We injected 25 micrograms of recombinant tissue plasminogen activator into the anterior chamber or the vitreous cavity in seven aphakic patients for pupillary block caused by a complete fibrin pupillary membrane that formed after vitrectomy with fluid-gas exchange. Progressive fibrin deposition resulted in pupillary block by three days after vitrectomy surgery in six patients, and seven days after vitrectomy in one patient. The pupillary block was associated with increased intraocular pressure in six patients. Tissue plasminogen activator was injected via the corneoscleral limbus in five patients and via the pars plana in two patients. In all patients, injection of tissue plasminogen activator resulted in complete fibrinolysis of the fibrin pupillary membrane within four hours, associated with a deepening of the anterior chamber. In the six patients with increased intraocular pressure at the time of tissue plasminogen activator injection, dissolution of the fibrin membrane was associated with a decrease in pressure. In all patients, intraocular pressure had returned to normal by three days after the injection. No complications were associated with the injection.

Adult↗
PubMed1989

Lithium carbonate intoxication. A case report and review of the literature.

Lithium carbonate is a widely used and invaluable drug in the treatment and prevention of manic-depressive illness. However, this medication has a low therapeutic index and, therefore, many attendant side effects. Acute lithium carbonate intoxication affects predominantly the central nervous system and the renal system and is potentially lethal. We studied a case of acute lithium carbonate intoxication characterized by a prolonged comatose state, severe nephrogenic diabetes insipidus, and glucose intolerance. Of interest, the patient's symptoms and signs of toxic reaction developed after normalization of the plasma lithium ion levels. We reviewed the multisystemic toxic effects of lithium carbonate as well as its teratogenic potential and guidelines for its use during pregnancy. The management of acute lithium carbonate intoxication should include hydration with normal saline, intensive care monitoring, and dialysis if indicated.

Humans↗
PubMed1989

Relationship between ANP, cyclic GMP and tissue kallikrein following saline infusion in healthy volunteers.

Infusion of saline in healthy volunteers produced a significant rise in plasma atrial natriuretic peptide, which was accompanied by the urinary excretion of cyclic GMP and sodium. Although the time-course of cyclic GMP excretion almost mirrored that of plasma ANP, that of sodium showed sustained phase, indicating involvement of additional humoral regulators. ANP did not stimulate the excretion of enzymic or immunoreactive tissue kallikrein.

Adult↗