Biomedical subjects

A R Bellows

Publications and source records attributed to A R Bellows.

At least 37 records · Page 2Linked to original sources

PubMed1987

Retreatment with argon laser trabeculoplasty.

Forty eyes in 37 patients that had previously successful 360 degrees argon laser trabeculoplasty were again found to have uncontrolled intraocular pressure (IOP) on maximally tolerated medical therapy and were retreated with argon laser trabeculoplasty to 180 degrees of the trabecular circumference. Successful retreatment was considered a decrease in IOP of 3 mmHg or more and sufficient to avoid further laser therapy or invasive glaucoma surgery. Laser trabeculoplasty retreatment was successful in 13 of the eyes treated (32%). Retreatment failed to control IOP in 27 of the retreated eyes (68%): either the IOP was not lowered by at least 3 mmHg (4 eyes) or the eyes required further laser therapy or surgery (23 eyes). The probability of successful IOP control 1 year after retreatment was 33% and only 14% after 1.75 years. No IOP elevations greater than 6 mmHg were recognized in the postlaser period. Although retreatment with argon laser trabeculoplasty can safely be used to control the IOP in some glaucomatous eyes, the likelihood of success is low.

Aged↗

PubMed1987

Chronic and recurrent choroidal detachment after glaucoma filtering surgery.

Chronic and recurrent choroidal (ciliochoroidal) detachments developed following glaucoma filtration surgery in 14 eyes of 13 patients during a 9-year period. Three specific subgroups were identified: recurrent, inflammatory, and chronic (present for more than 6 months). The factors that may be related to the development of chronic and recurrent choroidal detachments included patient age (mean, 68.8 years), systemic hypertension or atherosclerotic heart disease, hyperopia, aqueous suppressant therapy, ocular inflammation, and full-thickness filtration surgery. A total of 46 choroidal detachments in 14 eyes were recorded and required drainage of suprachoroidal fluid on 34 occasions. All eyes developed visually significant cataracts, and complete resolution of the recurrent or chronic choroidal detachment occurred following cataract extraction in six eyes. Treatment of chronic and recurrent choroidal detachments should include intense therapy of ocular inflammation, discontinuation of medications that can incite ocular inflammation, discontinuation of topical and systemic aqueous suppressant therapy, and when a visually significant cataract is present, cataract extraction combined with a choroidal tap should be performed.

Acetazolamide↗

PubMed1987

Failed laser trabeculoplasty requiring surgery in open-angle glaucoma.

Argon laser trabeculoplasty (ALT) has been successful in controlling open-angle glaucoma, but a significant number of patients still require filtration surgery. Concern that post-laser inflammatory changes or alterations of structural anatomy with damage to the trabecular meshwork may adversely affect the outcome of filtration surgery prompted a retrospective review of 87 consecutive eyes with open-angle glaucoma that required filtration surgery following failed ALT. The follow-up period was at least 6 months, with a mean of 18 months (6 to 38 months). Posterior lip sclerectomy was chosen for 69 eyes and trabeculectomy for 18 eyes. The overall success rate of filtration surgery during the follow-up period was 92%. There was no recognized difference in the response to filtration surgery following ALT.

Evaluation Studies as Topic↗

PubMed1986

Long-term evaluation of initial filtration surgery.

In a long-term study of 252 eyes that had initial glaucoma filtration surgery, there was an overall success rate of 85%. Rigid criteria for success included an intraocular pressure equal to or less than 19 mmHg, no further visual field loss or disc damage, and no glaucomatous etiology for a decrease in visual acuity. The success rate was evaluated over an extended postoperative period with a range of 2 to 14 years and a mean follow-up of five years (61 months). Full thickness procedures had a higher success rate for a greater length of time, 88% (6 years) than did trabeculectomy, 76% (4 years). If an eye was considered successful at two years, the probability of success at five years was 94.5% for full thickness procedures and only 82% for trabeculectomies. Choroidal effusion associated with hypotony and shallow anterior chamber was the most frequent postoperative complication. There was no difference in the incidence between full thickness procedures and trabeculectomies. Cataract extraction was indicated more often following full thickness procedures, 34%, than trabeculectomies, 21%. However, the performance of a choroidal tap or subsequent cataract extraction did not appear to influence the success of the filtration operation. Bleb leaks and bleb infection occurred only after full thickness operations and were associated with a high 5/8 (62%) rate of bleb failure and loss of glaucoma control. Full thickness filtering operations appeared to insure a lower pressure from a longer period of time than does trabeculectomy.

Adolescent↗

PubMed1985

Effect of cataract surgery on intraocular pressure reduction obtained with laser trabeculoplasty.

Thirty-nine eyes of 34 patients with open-angle glaucoma who had been treated successfully with argon laser trabeculoplasty underwent either extracapsular cataract extraction with posterior chamber intraocular lens implantation or intracapsular cataract extraction without lens implantation. Cataract surgery did not have a significant effect on the magnitude of intraocular pressure reduction obtained with laser trabeculoplasty. This study supports the view that eyes with coexisting cataract and glaucoma may benefit from laser trabeculoplasty before cataract surgery.

Aged↗

PubMed1984

Uveal melanoma: case report of extension through the optic nerve to the surgical margin in the orbital apex.

An unsuspected uveal melanoma arising in a phthisical eye extended through the optic nerve to the surgical margin in the orbital apex without involvement of other orbital structures. Step sections showed the continuous extension through the nerve. Factors likely to predispose to optic nerve extension include epithelioid cell type, large tumour size, peripapillary involvement, and glaucoma. Optic nerve extension carries the risks noted with orbital extension of intraocular tumour, but may in addition lead more directly to intracranial invasion, including a chiasmal syndrome. The role of exenteration and radiotherapy in these cases remains uncertain.

Humans↗

PubMed1983

Surgical management of chronic glaucoma in aphakia.

The surgical management of glaucoma in aphakia has been limited by poor success in the control of intraocular pressure and serious postoperative complications that threaten vision. A consecutive series of trabeculectomy filtering procedures in aphakic eyes with a mean preoperative intraocular pressure of 38 mmHg was followed for an average of 26 months and revealed a 62% control of intraocular pressure at 21 mmHg or less. Five additional patients (24%) had pressures lower than 21 mmHg following digital massage. The complication of decreased visual acuity following surgery was significant but not directly related to the surgical procedure. Another patient population with glaucoma and aphakia with a mean preoperative pressure of 25 mmHg was treated with laser trabeculoplasty. In 12 of 15 patients (80%) intraocular pressure was lower than 22 mmHg for an average of eight months and did not require glaucoma surgery. There were no significant complications following this therapy and all patients retained preoperative level of visual acuity. In aphakic patients who have uncontrolled glaucoma on maximal medical therapy, surgery is indicated. We recommend the following approach to surgical management: (1) Laser treatment to the trabecular meshwork if the angle is open; (2) if this fails, or the angle is extensively closed, a trabeculectomy filtering procedure is suggested; (3) cyclocryotherapy has been effective in controlling pressure but the unpredictable loss of vision has prompted caution in seeing eyes; (4) cyclodialysis; and (5) transpupillary or transscleral treatment of the ciliary processes are additional modes of therapy. Improved results of surgical treatment for glaucoma and aphakia have been encouraging and should be used when maximal medical therapy is ineffective.

Adult↗

PubMed1983

Argon laser trabeculoplasty for open angle glaucoma. A retrospective study of 380 eyes.

Three hundred and eighty eyes of 300 patients which were treated with argon laser trabeculoplasty for medically uncontrolled open angle glaucoma were studied retrospectively. Among the 334 eyes having at least six weeks follow up, the mean overall pressure drop was 8.1 mm Hg. In 19.2 per cent of eyes, pressure was inadequately controlled by laser treatment and subsequent glaucoma surgery was required. Phakic primary chronic open angle glaucoma (COAG), aphakic COAG, pseudoexfoliation, pigmentary, and low tension glaucoma eyes all had a significant drop in pressure. Eyes with juvenile glaucoma or inflammatory glaucoma had a much poorer response in terms of mean pressure drop and number requiring later operation. There was no statistically significant difference in response between aphakic and phakic coag eyes, between pseudoexfoliation and phakic COAG eyes, or between eyes treated over the full 360 degrees and eyes treated over half the angle with treatment over the second half later if needed. A higher initial pressure usually resulted in a greater lowering of pressure. Medication was reduced after treatment in 28.7 per cent of eyes. The data suggest that the effect of laser trabeculoplasty generally persists for at least one year. Complications were few, the most serious being elevated intraocular pressure, which rose 10 mm Hg or more in 2.1 per cent of all eyes.

Follow-Up Studies↗

PubMed1982

Filtration surgery in the treatment of neovascular glaucoma.

The disappointing visual acuity results following cyclocryotherapy for neovascular glaucoma have prompted us to consider filtration surgery as a reasonable alternative in the treatment of selected patients. All cases of surgically treated neovascular glaucoma were reviewed. There were 26 operations in 24 eyes with a follow-up ranging from six months to seven years and a mean of 22.8 months. Adequate pressure control was obtained in 16 of the 24 eyes (67%). In the eyes with successful control of intraocular pressure, vision was 20/400 or better in eight of the 16 eyes (50%). Four patients (17%) lost light perception. Approximately one half of the operations were trabeculectomies, and the others were posterior lip sclerectomies. There seemed to be no significant difference in the final intraocular pressure levels, number or degree of complications, or successes within the two subgroups. Panretinal photocoagulation, topical steroids, cycloplegics, and time for these measures to have their effect are important preoperative adjuncts to surgical treatment. We are encouraged by the long-term preservation of vision and control of intraocular pressure in many of these eyes.

Adult↗

PubMed1981

Endophthalmitis in aphakic patients with unplanned filtering blebs wearing contact lenses.

Four female patients with known unplanned filtering blebs following cataract surgery developed endophthalmitis, two weeks to 30 months after being fit with corneal contact lenses. Three patients were wearing hard contact lenses and one wore a soft lens. Significant blepharoconjunctivitis was present and treated in two patients, but intraocular infection was not averted. When endophthalmitis was diagnosed, all patients had clinical evidence of a bleb infection as well as hypopyon. Despite aggressive medical therapy, two eyes required enucleation while two eyes survived with good vision. We recommend that eyes that have unplanned filtering blebs following cataract surgery should not have a contact lens inserted until the blebs have been closed.

Aged↗

PubMed1981

Cyclocryotherapy for glaucoma.

CCT is a simple, noninvasive, short, ablative surgical procedure that has been effectively used to treat advanced uncontrolled glaucoma. A specific protocol is recommended and the rationale for strict adherence is presented. The long-term benefits of CCT in patients with open-angle glaucoma following cataract extraction have been well established. However, although patients with neovascular glaucoma may have adequate pressure control following CCT, the serious complications of progression to no light perception and phthisis bulbi have discouraged its use. CCT can be effective for neovascular glaucoma when other methods of surgical management prove unsuccessful and visual prognosis is very poor. The loss of functional vision occurred in fewer than 10 percent of eyes treated with CCT, and it is important to emphasize that only eyes with greatest risk and poorest prognosis were treated with this modality. CCT has become an important addition to the surgical armamentarium for the treatment of some specific types of glaucoma.

Ciliary Body↗

PubMed1981

Exogenous Nocardia asteroides endophthalmitis associated with malignant glaucoma.

A 42-year-old man sustained a penetrating corneal wound with a soil-contaminated wire and developed Nocardia asteroides endophthalmitis. A month delay in diagnosis occurred while topical and systemic steroids were prescribed for persistent anterior uveitis, but the diagnosis was finally established by separate aqueous and vitreous aspirates. The patient's course was complicated by a form of malignant glaucoma that was relieved by vitreous aspiration and reformation of the anterior chamber. Surgical intervention, followed by intensive topical and systemic sulfonamide therapy, has resulted in potential visual improvement.

Adult↗

PubMed1981

Choroidal detachment. Clinical manifestation, therapy and mechanism of formation.

One hundred and twelve eyes of 103 patients were analyzed during a 9 1/2-year period after surgical drainage of a choroidal (ciliochoroidal) detachment (CD). Choroidal detachment in five groups of postoperative patients was studied. CD after surgery for cataract, for cataract and glaucoma, and for glaucoma alone had different time courses, but in all of these, there were similar amounts of protein (67% of plasma protein concentration) in the suprachoroidal fluid (SCF). In marked contrast was a group of patients with intraoperative choroidal effusions and very little protein (18% of plasma concentration) in the SCF. Identified also was a chronic recurrent form of CD that usually persisted for more than three months. Three distinct mechanisms by which choroidal effusion is formed were recognized, (1) one with evidence for the effusion occurring through an intact isoporous membrane (groups 1-3); (2) a second in which hemorrhagic SCF appeared acutely or subacutely (groups 1 and 2) through a disrupted isoporous membrane; and (3) a third form, an intraoperative choroidal effusion in patients with elevated episcleral venous pressure. Increased filtration rate of serum through an intact choriocapillary membrane caused molecular sieving of serum proteins. Inflammation, infection, cataract formation, and corneal edema were uncommonly encountered. Indications for surgery and recommended surgical technique are outlined in detail.

Biological Transport↗

PubMed1979

Choroidal effusion during glaucoma surgery in patients with prominent episcleral vessels.

Rapid intraoperative choroidal effusion and flattening of the anterior chamber occurred during glaucoma filtering surgery in four young patients with prominent episcleral vessels, elevated episcleral venous pressure, and advanced open-angle glaucoma. Two of these four patients had Sturge-Weber syndrome. Intraoperative release of suprachoroidal fluid (SCF) through a posterior sclerotomy facilitated reformation of the anterior chamber and repositioning of the iris and ciliary body. Posterior sclerostomy performed prior to opening the anterior chamber minimized the above-mentioned untoward series of events. Analysis of SCF and serum demonstrated considerable differences in total protein and individual immunoglobulin levels; this appears to be a manifestation of molecular sieving at the level of the choriocapillaris. Choroidal detachment and postoperative serous retinal detachment are manifestation of this phenomenon.

Adult↗

PubMed1979

Scanning electron microscopy of trabeculectomy specimens in open-angle glaucoma.

We examined trabeculectomy specimens obtained at the time of surgery for inadequately controlled open-angle glaucoma by scanning electron microscopy. Of the 50 specimens ten included a broad area of the trabecular meshwork. In these ten specimens the meshwork was obscured by material. We believe the degree of occlusion was significant in these specimens, which would lead to obstruction of aqueous outflow. No similar material was found in control specimens from persons of similar age.

Aged↗

PubMed1979

Angiogenesis capacity as a diagnostic marker for human eye tumors.

Solid tumors have the capacity to continuously stimulate the proliferation of new capillaries. Aliquots (0.1 cc) of aqueous humor were aspirated from the anterior chamber of the eye of 38 patients undergoing elective ophthalmologic surgery. The material was lyophilized and then inplanted on the chorioallantoic membrane (CAM) of 10-day-old chick embryos for bioassay. The angiogenesis capacity of each sample was graded as negative or positive. Nine of 10 patients with histologically proven retinoblastoma had positive vascular responses. Seven of 11 patients with choroidal malignant melanoma had a positive response to their aqueous humor on the CAM. Aqueous samples from eyes with an iris and ciliary body malignant melanoma and a metastatic breast carcinoma to the iris had a positive angiogenic response. By contrast, only one of 15 patients undergoing operation for cataracts, glaucoma, or other nonmalignant ocular disease showed an angiogenesis response. The one patient who a positive assay later developed lymphocytic leukemia. These studies show that certain intraocular tumors display angiogenesis capacity before clinically evident neovascular changes of floating tumor cells are seen. Patients without tumors showed no angiogenesis response.

Angiogenesis Inducing Agents↗

PubMed1978

Cyclocryotherapy of chronic open-angle glaucoma in aphakic eyes.

Twenty-six eyes of 25 patients with chronic open-angle glaucoma and surgical aphakia with inadequate control of intraocular pressure (IOP) despite maximal medical treatment were treated with cyclocryotherapy, according to a prospective protocol and specific technique. (Neovascular and synechial glaucoma were excluded from this series.) In most cases topical medications were resumed after cyclocryotherapy. During follow-up of seven to 95 months (average, 46 months), IOP was reduced to 19 mm Hg or lower in 24 out of 26 eyes (92%). In two eyes, persistent decrease in visual acuity, unrelated to reduction of IOP, occurred after cyclocryotherapy. On the basis of the long-term benefits obtained by this procedure, we concluded that cyclocryotherapy should be considered the procedure of choice in the treatment of primary open-angle glaucoma in surgically aphakic eyes when pressure cannot be adequately reduced by maximally tolerated medical treatment.

Aged↗

PubMed1978

Molecular sieving in suprachoroidal fluid formation in man.

Suproachoroidal fluid (SCF) obtained at the time of the surgical evacuation of a clinically significant choroidal detachment (CD) was analyzed for its chemical and cellular components in four distinct subgroups: (1) CD following cataract surgery, (2) CD (nonhemorrhagic) following glaucoma surgery, (3) CD (hemorrhagic) following glaucoma surgery, and (4) intraoperative CD during glaucoma surgery in patients with elevated episcleral venous pressure. The fluid obtained in groups 1, 2, and 4 was clear and slightly xanthochromic and contained low-molecular-weight substances in concentrations essentially equal to serum. Proteins and other high-molecular-weight substances were present in lesser amounts than in serum. Albumin, alpha1-antitrypsin, and transferrin were present in amounts approximately equal to those in serum, whereas alpha2-macroglobulin, IgM and IgG were decreased. beta-Lipoprotein and beta-complement were absent. It is postulated that this distribution of serum proteins is a manifestation of molecular sieving and is consistent with the existence of an isoporous membrane between the intravascular and suprachoroidal space with a pore diameter of 144 A. In the intraoperative choroidal effusions, there was evidence for exclusion of more of the lower, as well as all of the higher, molecular weight proteins. This suggested that the degree of molecular sieving increased with increasing filtration rate. In the hemorrhagic SCF, the distinctive character of the fluid and the protein concentrations indicated that the integrity of the capillary membrane was mardkedly disrupted, thereby allowing higher-molecular-weight proteins and cellular elements to enter the space.

Ascorbic Acid↗