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Biomedical subjects

A R Bellows

Publications and source records attributed to A R Bellows.

At least 19 recordsLinked to original sources

Ciliary body neurilemoma. Unusual clinical findings intimating the diagnosis.

BACKGROUND: Neurilemomas (schwannomas) rarely occur intraocularly. When present, they pose a diagnostic dilemma for the physician and often are mistaken as a malignant lesion, resulting in enucleation. METHODS: The authors report the clinical findings of a 46-year-old man with a slowly progressive growing mass of the anterior chamber, associated with glaucoma and the development of cataract. To further delineate the tumor's features, ancillary techniques, including ultrasonography, computed tomography, and magnetic resonance imaging, were conducted. A definitive anterior chamber biopsy of the tumor was performed with histologic examination and electron microscopy. RESULTS: Ultrasonography, high-resolution computed tomography and magnetic resonance imaging showed a well-delineated mass of the inferior ciliary body involving nearly 5 clock hours of the angle. Two clinical features that suggested a longstanding tumor were brilliant transillumination of the mass (leading to the impression of a "cystic mass," not corroborated by ultrasonography) and retrodisplacement of the involved iris root. The histology, and particularly the electron microscopic features, confirmed the diagnosis of a neurilemoma, a benign tumor of the anterior segment. CONCLUSION: Intraocular neurilemomas are extremely rare tumors. Few are well documented with modern ancillary techniques. Clinical findings in conjunction with radiographic and ultrasonic features may support the diagnosis of a benign tumor. For this patient, confirmation via biopsy permitted combined cataract and glaucoma surgery to rehabilitate the eye, which retains 20/20 visual acuity 3 years after the procedure.

Anterior Chamber

Iris retraction syndrome after intraocular surgery.

BACKGROUND: The authors report the postoperative development of iris retraction syndrome in two individuals. This is a rare syndrome that can present with pupillary block after an unrepaired rhegmatogenous retinal detachment. PATIENTS: The authors report two patients who had the iris retraction syndrome shortly after intraocular surgery. One patient had pupillary block that developed 6 months after cataract extraction and posterior chamber intraocular lens implantation. A second patient had uveitis, hypotony, and pupillary seclusion 4 weeks after pars plana vitrectomy. RESULTS: Both patients were treated successfully with a scleral buckling procedure and peripheral iridectomy. CONCLUSION: Postoperative uveitis that occurs with iris retraction and pupillary seclusion should alert the physician of an occult retinal detachment and warrant a thorough dilated funduscopic examination. Features unique to this report include the development of iris retraction syndrome in the presence of a pseudophakos, the rapidity of onset of this disorder after retinal detachment, and its masquerade as a persistent postoperative uveitis.

Aged

Long-term efficacy of argon laser trabeculoplasty. A 10-year follow-up study.

PURPOSE: Argon laser trabeculoplasty (ALT) is commonly used in the treatment of open-angle glaucoma. Varying success rates in lowering intraocular pressure (IOP) and controlling glaucoma are reported in studies with follow-up periods from 1 to 5 years, and few reports are available with follow-up to 10 years. The authors retrospectively reviewed the efficacy of ALT in patients followed up to 10 years. METHODS: Ninety-three patients with open-angle glaucoma underwent 360 degrees ALT. Mean follow-up was 52 +/- 43 months (mean +/- standard deviation; range, 1-132 months). Successful treatment at the time of final follow-up was defined as a decrease in IOP of 3 mmHg or greater from pretreatment level, IOP of 19 mmHg or less, stable visual field, stable optic nerve, and no further laser or surgical intervention. RESULTS: The decrease in IOP was 8.9 +/- 5.4 mmHg at 1 year, 10.0 +/- 4.2 mmHg at 5 years, and 8.9 +/- 5.2 mmHg at 10 years. The probability of success at 1 year was 77%, at 5 years 49%, and at 10 years 32%. Failure was most common in the first year after treatment (23%), and thereafter failure occurred at a rate of 5% to 9% per year. The mean decrease in IOP for all 93 eyes at time of maximum follow-up was 6.1 +/- 7.1 mmHg. CONCLUSION: Argon laser trabeculoplasty is an effective means for reducing IOP in many patients followed for an extended time. However, up to one half of eyes within 5 years of ALT and two thirds of eyes within 10 years may require additional laser or surgical intervention for glaucoma control.

Aged

Holmium laser sclerectomy. Success and complications.

PURPOSE: To investigate the safety and efficacy of holmium YAG laser sclerectomy, a new laser filtration procedure. METHODS: The authors performed holmium YAG laser sclerectomy on 49 eyes of 46 patients (mean follow-up, 12.3 +/- 1.1 months). RESULTS: Mean preoperative intraocular pressure (IOP) was 26.9 +/- 1.3 mmHg; postoperative mean IOP on last follow-up visit was 19.7 +/- 1.6 mmHg. Thirty (61%) of 49 eyes achieved a final IOP of 5 to 22 mmHg, 29 (59%) of 49 had a final IOP of 5 to 19 mmHg, and 21 (43%) of 49 had a final IOP of 5 to 15 mmHg. Sixteen (73%) of 22 eyes treated postoperatively with 5-fluorouracil (5-FU) had a final IOP of 21 mmHg or less. Twenty-seven percent of eyes lost one or more lines of vision, and 36% of eyes gained one or more lines of vision; there was no median change in visual acuity. Complications included suprachoroidal hemorrhage in 7 (14%) of 49 eyes and intraoperative vitreous hemorrhage in 2. Seventeen (35%) of 49 eyes required a second IOP-lowering procedure. CONCLUSION: Holmium YAG laser sclerectomy is an effective means to perform glaucoma filtration surgery. This is a full-thickness filtering procedure, with all of the risks attendant.

Aged

Argon laser gonioplasty in the treatment of angle-closure glaucoma.

We used argon laser gonioplasty to treat angle-closure glaucoma unrelieved by patent iridectomy. Laser energy (mean; 30 spots, 723 mW, and 0.2 second) was applied to the peripheral iris stroma to open the anterior chamber angle. Twenty of 32 eyes were successfully treated. After a median follow-up period of 18 months, 17 of these 20 successfully treated eyes (85%) had an intraocular pressure less than or equal to 19 mm Hg, and 19 of these 20 successfully treated eyes (95%) had an intraocular pressure less than or equal to 21 mm Hg. The 20 successfully treated eyes had a median duration of angle closure of 12 days. Twelve unsuccessfully treated eyes had a median duration of angle closure of 90 days. All successfully treated eyes had more than 50% of the treated angle opened by argon laser gonioplasty and all but three successfully treated eyes had more than three clock hours opened by argon laser gonioplasty. Argon laser gonioplasty may be successful in treating angle-closure glaucoma unrelieved by iridectomy, especially in cases that are recognized and treated soon after onset.

Acute Disease

Contact transscleral Nd:YAG laser cyclophotocoagulation. Midterm results.

BACKGROUND: Early reports of both contact and noncontact transscleral Nd:YAG laser cyclophotocoagulation have been encouraging; however, recent evidence indicates a significant incidence of hypotony, visual loss, and phthisis with the noncontact technique with more than 6 months of follow-up. The authors sought to determine the intermediate term effects of contact transscleral Nd:YAG laser cyclophotocoagulation (CYC). METHODS: The authors followed 116 eyes of 114 patients for a minimum of 1 year after treatment of advanced glaucoma with CYC. RESULTS: The mean preoperative intraocular pressure (IOP) of 35.0 +/- 1.0 mmHg decreased to 18.6 +/- 1.1 mmHg (P less than 0.0001) during the average follow-up of 19.0 +/- 0.6 months (range, 12 to 36 months). Intraocular pressure control of 3 to 25 mmHg was achieved in 72%, 3 to 22 mmHg in 65%, and 3 to 19 mmHg in 56% of eyes. Retreatment was required in 31 of the 116 eyes (27%). Intraocular pressure decreased to less than 3 mmHg in 9 eyes and to 0 mmHg in 6 of these 9 eyes. Nineteen eyes, all with initial visual acuity of counting fingers or worse, progressed to no light perception; 17 of 36 eyes (47%) with visual acuity of 20/200 or better lost 2 or more Snellen lines. CONCLUSION: Midterm results of CYC continue to be encouraging but are tempered by a nearly 10% incidence of hypotony or phthisis and the progression of visual loss.

Adolescent

Probe placement and power levels in contact transscleral neodymium:YAG cyclophotocoagulation.

Transscleral cyclophotocoagulation using a free-running, thermal-mode neodymium:YAG laser with a 2.2-mm-diameter sapphire-tipped contact probe was performed on 27 enucleated human eyes to investigate the effect of probe placement and power levels. We concluded from gross, light, and scanning electron microscopic examinations that a tissue destructive effect on ciliary body and epithelium was produced by positioning the anterior edge of the probe tip 0.5 to 1.0 mm from the visible limbus using a 5- to 9-W power setting for 0.7 second. An 11-W power setting resulted in extensive loss of anatomic integrity of the ciliary body. Limbal probe placement produced significant iris and lens damage while positioning the probe 1.5 mm posterior to the limbus affected primarily pars plana. Damage to the sclera was not observed using this method of cyclophotocoagulation.

Aged

Surgical goniosynechialysis for angle-closure glaucoma.

Fifteen patients with synechial angle-closure glaucoma uncontrolled by medical and laser therapy were treated with surgical goniosynechialysis. Five patients were treated with goniosynechialysis alone, and ten were treated with goniosynechialysis in combination with other surgical procedures. The procedure was successful, in terms of reducing synechiae, in 14 eyes (93%). The extent of angle closure was reduced from 340 degrees +/- 45 degrees (mean +/- standard deviation) preoperatively to 80 degrees +/- 70 degrees postoperatively; the mean reduction was 260 degrees +/- 95 degrees (P less than 0.0001) for the group overall and 280 degrees +/- 80 degrees (P less than 0.0007) for the subgroup treated with goniosynechialysis alone. The mean preoperative intraocular pressure (IOP) was 40 +/- 4 mmHg. The mean postoperative IOP was 14 +/- 4 mmHg. The mean reduction in IOP was 26 +/- 15 mmHg (P less than 0.0001) for the group overall and 27 +/- 18 mmHg (P less than 0.015) for the subgroup treated with goniosynechialysis alone. Glaucoma medications were reduced from a mean of 2.6 +/- 1.0 preoperatively to 1.1 +/- 1.2 postoperatively for the group overall and to 1.4 +/- 1.5 for the subgroup treated with goniosynechialysis alone. Complications consisted of two eyes with intraoperative bleeding. One of these required intraoperative conversion to surgical trabeculectomy. The other was associated with a transient postoperative IOP elevation to 40 mmHg. Surgical goniosynechialysis may be an effective means of reducing synechiae and lowering IOP, either alone or in conjunction with other surgical procedures, in patients with angle closures of less than 6 months' duration.

Adult

Contact transscleral continuous wave neodymium:YAG laser cyclophotocoagulation.

Advanced glaucoma in 140 eyes of 136 patients was treated with contact transscleral continuous wave neodymium:YAG (Nd:YAG) laser cyclophotocoagulation (CYC) with a sapphire-tipped probe. The anterior edge of the probe was placed 0.5 to 1.5 mm posterior to the limbus, using 7 to 9 W of power for 0.7 seconds with 32 to 40 applications, sparing the 3 and 9 o'clock meridians. Patients were studied prospectively. The mean preoperative intraocular pressure (IOP) of 36.7 +/- 0.97 mmHg decreased to 21.2 +/- 0.99 mmHg (P = 0.004) after treatment (mean follow-up, 3.2 +/- 0.35 months) for a mean decrease in IOP of 15.5 +/- 1.21 mmHg and a mean percent decrease of 39%. Forty-one eyes were followed 6 or more months (mean, 6.7 +/- 0.25 months). The CYC reduced IOP to 25 mmHg or less in 71% of eyes, to 22 mmHg or less in 62% of eyes, and to 19 mmHg or less in 49% of eyes. Maximum lowering of IOP occurred 1 week to 1 month after treatment and remained at that level through 6 months of follow-up. Retreatment was required in 11% of patients; only one patient was retreated more than once. Four patients treated with 9 W of power developed IOPs below 5 mmHg; two of these patients had an IOP of 0 mmHg. Other complications of therapy were minimal, and patients had little pain. There was no significant change in visual acuity. Early results of this newly available therapy are encouraging.

Adolescent

Management of encapsulated filtration blebs.

Increased intraocular pressure (IOP) in encapsulated filtration blebs was evaluated in 49 eyes of 49 patients followed for 6 to 48 months (mean +/- standard deviation, 19.7 +/- 12.6 months). Intraocular pressure increased from 10.2 +/- 7.5 mmHg at 1 week postfiltration surgery to a peak of 26.1 +/- 10.7 mmHg at 3 weeks postoperatively and then decreased to 16.2 +/- 5.0 mmHg at 16 weeks and remained stable through the follow-up period. Thirty-nine eyes had a final IOP of 19 mmHg or less; 35 eyes required medical therapy alone (antiglaucoma drops, oral carbonic anhydrase inhibitors, and/or digital massage) with a final IOP of 14.1 +/- 3.8 mmHg; and 14 eyes required surgical reintervention for medically uncontrolled IOP elevation, and five of these eyes required two or more surgical reoperative procedures. Vigorous medical therapy, including glaucoma medications, topical steroids, and digital massage, is particularly important for encapsulated blebs during the first 2 months after surgery. After this period, IOP decreases and often remains sufficiently reduced to avoid further surgical intervention.

Cysts

The dural shunt syndrome. I. Management of glaucoma.

The authors present four cases of the dural shunt syndrome in which shallowing of the anterior chamber or rubeosis developed. All patients were female, ranging in age from 66 to 79 years, exhibiting elevated intraocular pressure (IOP), decreased extraocular movements, injected tortuous episcleral vessels, and proptosis. The authors managed these four cases with laser iridotomy, gonioplasty, panretinal photocoagulation, or medical treatment. It is important to recognize associated findings in patients with shallow anterior chambers and elevated IOPs so that a diagnosis of a dural shunt is considered and appropriately treated. Theories on the mechanisms of increased IOP in the dural shunt syndrome and the management of various types of glaucoma in four different cases are reviewed.

Aged

The effect of anterior chamber depth on endothelial cell count after filtration surgery.

Eighteen patients undergoing glaucoma filtration surgery underwent specular microscopic examination 1 day prior to surgery and 4 to 6 months after surgery. Patients were evaluated postoperatively for the presence of iridocorneal or lenticular-corneal touch, anterior chamber depth, and inflammation. Ten eyes that maintained their anterior chamber following glaucoma filtration surgery did not have a significant decrease in corneal endothelial cell density. However, eight eyes that developed a shallow anterior chamber with iridocorneal touch had a mean (+/- SD) decrease of 265 +/- 185 cells (12.4%) peripherally and 250 +/- 243 cells (11.6%) centrally in corneal endothelial cell count. None of the patients with iridocorneal touch developed corneal edema after a mean follow-up of 44.4 +/- 18.0 months. Iridocorneal touch after glaucoma filtration surgery is associated with loss of endothelial cells yet appears to be well tolerated by the cornea.

Aged

The development of encapsulated filtering blebs.

The development of an encapsulated filtering bleb (Tenon's cyst) complicated 56 of 409 consecutive filtering operations (13.7%) performed during a 40-month period after January 1983. Fifteen eyes (27.8% of encapsulated blebs) required surgical revision. The recognition of bleb encapsulation occurred 20.4 +/- 12.7 days (mean +/- standard deviation) postoperatively. Prolonged duration of beta-adrenergic antagonist therapy was associated with an increased frequency of bleb encapsulation (180.6 +/- 128.5 weeks without encapsulation, 229.0 +/- 129.3 weeks with encapsulation, P less than 0.009). Bleb encapsulation occurred in 42 of 272 eyes with previous argon laser trabeculoplasty, but in only 4 of 85 eyes without any previous anterior segment laser (P less than 0.01). Encapsulated filtering blebs developed in 4 of 12 (33.3%) eyes with congenital glaucoma and 4 of 9 (44.4%) eyes with juvenile glaucoma (P less than 0.0002). The intraocular pressures (IOPs) in the eyes with encapsulated filtering blebs were significantly elevated at 1, 2, and 3 postoperative weeks, and at final follow-up compared with eyes without bleb encapsulation.

Adolescent

Pupillary block with posterior chamber intraocular lenses.

We present 12 cases of pupillary block associated with extracapsular cataract extraction and posterior chamber intraocular lenses. In one case, pupillary block occurred despite the presence of a surgical iridectomy. The other 11 patients did not have a surgical iridectomy performed. We recommend that a surgical iridectomy or laser iridotomy be performed in all patients who undergo extracapsular cataract extraction with the implantation of posterior chamber intraocular lenses. Ophthalmologists need to be vigilant in watching for the development of pupillary block in these patients, since pupillary block is not a benign event and serious visual loss or disability may occur.

Aged

Long-term efficacy of argon laser trabeculoplasty.

Long-term efficacy of 360 degrees argon laser trabeculoplasty was studied in 118 eyes of 93 patients with uncontrolled chronic open-angle glaucoma. The mean intraocular pressure (IOP) decrease was 8.9 +/- 5.4 mmHg (mean +/- standard deviation [SD] in 71 eyes at 1 year, 9.3 +/- 4.3 mmHg (mean +/- SD) in 51 eyes at 3 years, and 10.3 +/- 3.9 mmHg (mean +/- SD) in 28 eyes at 5 years. The probability of success at 4 years (decrease in IOP greater than or equal to 3 mmHg, IOP less than or equal to 19 mmHg, stable visual field, stable optic nerve, and no further laser or surgical intervention) was 52%. Pretreatment IOP, diagnosis, previous operations, age, and sex were not significant determinants for success or failure. Eyes receiving argon laser trabeculoplasty before cataract surgery maintained control of IOP after surgery. Failure was most common in the first year after treatment (23%), and thereafter failure occurred at a rate of 7 to 10% per year.

Aged

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

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

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