Biomedical subjects

D K Heuer

Publications and source records attributed to D K Heuer.

At least 19 recordsLinked to original sources

PubMed1992

Incidence and management of glaucoma after intravitreal silicone oil injection for complicated retinal detachments.

BACKGROUND: Intravitreal silicone oil injection used for managing complicated retinal detachments can be associated with elevated intraocular pressure (IOP). This study was undertaken to determine the incidence of glaucoma in patients who underwent silicone oil injection, as well as to evaluate the effectiveness of medical and surgical therapy in patients in whom glaucoma developed. METHODS: The postoperative courses of 50 eyes of 47 consecutive patients who underwent pars plana vitrectomy and silicone oil injection for the management of complicated retinal detachments were reviewed retrospectively. The outcomes of patients who underwent silicone oil removal and/or glaucoma surgery also were evaluated. RESULTS: The mean overall postoperative IOP before any glaucoma surgery was 16.7 +/- 9.3 mmHg (range, 0 to 45 mmHg), with a mean follow-up of 16.6 +/- 12.1 months (range, 2 to 51 months). Twenty-four (48%) eyes had postoperative IOPs of at least 25 mmHg and IOP elevations of at least 10 mmHg above the preoperative levels. Twenty-one (42%) eyes underwent complete removal of silicone oil and/or glaucoma surgery to effect IOP control. The IOPs were controlled to 21 mmHg or less (but > 5 mmHg) in 8 of 14 eyes that underwent removal of silicone oil alone, in 3 of 5 eyes that underwent Molteno implantation, and in 1 eye that underwent Nd:YAG transscleral cyclophotocoagulation, but not in 1 eye that underwent a modified Schocket procedure (mean follow-up, 13.5 +/- 11.0 months; range, 0.2 to 33 months). CONCLUSION: Intraocular pressure elevation is a common occurrence after intravitreal silicone oil injection. The underlying mechanism may often be multifactorial in nature. Patients in whom uncontrolled IOP develops may benefit from aggressive medical and/or surgical treatment with silicone oil removal, glaucoma implants, or cyclodestructive procedures.

Adolescent↗

PubMed1992

Which is better? One or two? A randomized clinical trial of single-plate versus double-plate Molteno implantation for glaucomas in aphakia and pseudophakia.

PURPOSE: Previous studies have suggested that primary double-plate Molteno implantation may be beneficial. Therefore, the authors performed a randomized clinical trial to evaluate the relative effectiveness and safety of single- versus double-plate Molteno implantation. METHODS: From March 1988 to February 1990, 132 patients who underwent Molteno implantation for medically uncontrollable non-neovascular glaucomas in aphakia or pseudophakia were randomly assigned to receive either single- or double-plate implants. RESULTS: The 1- and 2-year life-table success rates (success [survival] defined as 6 mmHg < or = final intraocular pressure [IOP] < or = 21 mmHg without additional glaucoma surgery or devastating complication) were 55% and 46% with single-plate implantation and 86% and 71% with double-plate implantation, respectively. The final postoperative visual acuities were within one line of the preoperative visual acuities or had improved in 73% and 80% of patients, respectively. Choroidal hemorrhages and/or effusions, corneal decompensation, flat anterior chambers, and phthisis bulbi were more common in the patients who had undergone double-plate Molteno implantation; however, transient elevations of IOP during the first few postoperative months were more common in the patients who had undergone single-plate Molteno implantation. CONCLUSIONS: Double-plate Molteno implantation more frequently affords IOP control than single-plate Molteno implantation; however, double plates are associated with greater risks of choroidal hemorrhages and/or effusions, corneal decompensation, flat anterior chambers, and phthisis bulbi.

Adolescent↗

PubMed1992

Clinical experience with the single-plate Molteno implant in complicated glaucomas. Update of a pilot study.

Ninety-six patients who had undergone single-plate Molteno implantation for glaucomas with poor surgical prognoses were re-evaluated for long-term results. Control of intraocular pressure was achieved with one single-plate implant to a level less than 22 mmHg (but greater than 5 mmHg) without reoperation or devastating complications in 46% of the aphakic/pseudophakic eyes, 25% of eyes after failed filters, 25% of eyes with neovascular glaucomas, and 26% of eyes in patients younger than 13 years of age (life-table analysis at 5 years). Five-year success rates improved to 53%, 71%, 40%, and 56%, respectively, when data from second plates were included. Visual acuities improved or remained the same after one or two plates were implanted in 47% of aphakic/pseudophakic eyes, 17% of eyes after failed filters, 65% of eyes with neovascular glaucomas, and 63% of eyes in patients younger than 13 years of age on whom Snellen acuity was available. The most frequent overall complications after implantation of one or two plates included: corneal edema (19%), corneal graft decompensation (13%), and cornea-tube touch, retinal detachment, and cataract (8% each).

Adolescent↗

PubMed1991

Combined Molteno implantation and pars plana vitrectomy for neovascular glaucomas.

Ten patients underwent combined Molteno implantation and pars plana vitrectomy as the primary nonlaser surgical treatment of neovascular glaucoma associated with diabetic retinopathy (9 patients) or central retinal vein occlusion (1 patient). Combined surgery was performed most frequently because media opacities precluded adequate preoperative retinal ablation. Follow-up ranged from 3 to 43 (mean +/- standard deviation, 18.0 +/- 13.2) months. Six patients achieved final intraocular pressures less than 22 mmHg. Visual acuities remained the same or improved in four patients. Four patients had uncomplicated courses. Among the other patients, complications included: recurrent vitreous hemorrhage and retinal detachment (3 patients each); hyphema (2 patients); and tube block, extensive fibrin formation, epiretinal membrane, and total retinal necrosis (1 patient each).

Adult↗

PubMed1991

Molteno implantation for glaucoma in young patients.

Seventy patients younger than 21 years of age underwent Molteno implantation for nonneovascular glaucoma. Fifty-three (76%) patients had failed angle and/or conventional filtering surgery. Final intraocular pressure less than 22 mmHg (but over 5 mmHg) was achieved in 40 (62%) of the 65 patients with at least 6-month follow-up (range, 6 to 59 months; mean +/- standard deviation, 22.7 +/- 14.1 months); however, only 22 (34%) were controlled after the initial Molteno implantation procedure, and 54 (83%) patients underwent further glaucoma and/or nonglaucoma surgical procedures. The visual acuities remained within one line of their preoperative levels or improved in 25 (68%) of the 37 patients on whom Snellen acuities were available. The most frequent complications included: tube-cornea touch (20%, transient in 3%), corneal edema (17%), retinal detachment (16%), tube block (10%), cataract (9%), chronic hypotony or phthisis (9%), pupillary or cyclitic membrane (9%), hyphema (7%), flat anterior chamber (6%), and large postoperative choroidal effusion (6%). Despite the high rates of subsequent surgical interventions and complications, Molteno implantation has been a useful approach for achieving intraocular pressure reduction in young patients with glucoma.

Adolescent↗

PubMed1991

Apraclonidine prophylaxis for postcycloplegic intraocular pressure spikes.

A randomized, prospective, double-masked study was undertaken to determine the risk of postcycloplegic intraocular pressure spikes in patients with open-angle glaucoma and to evaluate apraclonidine prophylaxis in minimizing these spikes. Patients were stratified as miotic treated or untreated and each group was randomized to receive either placebo (artificial tears) or apraclonidine in both eyes before instillation of tropicamide. In both the miotic treated and untreated groups that received placebo, there was a high incidence, (37% and 38%, respectively) of clinically significant (greater than or equal to 6 mmHg) intraocular pressure spikes after instillation of tropicamide. In both the miotic treated and untreated groups, there was a statistically significant difference in postcycloplegic intraocular pressure between the subgroup that received placebo and the group that received apraclonidine prophylaxis (P = 0.003 and P = 0.006, respectively). Additionally, four eyes that received placebo had a spike of over 10 mmHg (range, 12 to 27 mmHg), while only one eye had an increase of greater than 10 mmHg (12 mmHg) in the apraclonidine group. Thus, apraclonidine appears to be a useful agent for minimizing precipitous increases in intraocular pressure after cycloplegia in eyes of open-angle glaucoma patients prone to this complication of cycloplegia.

Adrenergic alpha-Agonists↗

PubMed1990

Primate trabeculectomies with 5-fluorouracil collagen implants.

Bilateral trabeculectomies were performed on four normal cynomolgus monkeys. Highly purified bovine skin collagen implants with either 1 mg of 5-fluorouracil or physiologic saline (one each per monkey by randomized, masked assignment) were sutured under the scleral flaps. The randomization code was not broken until all clinical and histopathologic observations had been completed. Six weeks postoperatively, the 5-fluorouracil-treated eyes had more deeply open internal trabeculectomy ostia than the control eyes; however, the intraocular pressures were indistinguishable, the filtering blebs were only minimally different, and half of each group had trace or mild anterior subcapsular lenticular changes. Histologically, a multinucleated foreign body giant cell reaction was evident in all of the collagen implants, but the 5-fluorouracil-treated eyes had less vigorous or delayed reactions compared to the control eyes. The collagen implant appears to be a poor drug delivery system in this model of glaucoma filtering surgery, because it incites a granulomatous inflammatory reaction.

Animals↗

PubMed1990

Molteno implantation for secondary glaucomas associated with advanced epithelial ingrowth.

Nine patients with advanced epithelial ingrowth underwent Molteno implantation for medically uncontrollable secondary glaucomas. Substantial reductions in intraocular pressures (IOPs) were observed in most patients (preoperative IOPs ranged from 5 to 48 mmHg [mean +/- standard deviation, 33.6 +/- 14.6 mmHg]; postoperative IOPs ranged from 10 to 30 mmHg [mean +/- standard deviation, 16.0 +/- 6.5 mmHg]); follow-up ranged from 9 to 47 months (mean +/- standard deviation, 18.8 +/- 12.1 months). Seven (78%) patients had final postoperative IOPs of less than 22 mmHg, five (56%) retained formed vision (visual acuity of at least 1/200), and six (67%) remained comfortable. Postoperative complications related to Molteno implantation included one case each of: conjunctival wound leak, vitreous-tube block, tube-cornea touch, and iris-tube block (or tube retraction). Complications attributed to epithelial ingrowth included five cases of corneal decompensation with band keratopathy. Molteno implantation is an effective technique for palliative treatment of secondary glaucomas associated with advanced epithelial ingrowth, frequently maintaining modest vision and comfort in eyes in which the intraocular epithelialization is too extensive for surgical removal and/or destruction.

Adult↗

PubMed1989

The influence of decreased retinal illumination on automated perimetric threshold measurements.

Decreased retinal illumination (such as can be caused by pupillary constriction or light absorption by ocular media opacities) was simulated with a randomly ordered series of neutral density filters in front of the right eyes of five subjects with dilated pupils. Threshold measurements were performed on Humphrey and Octopus perimeters at 0, 5, 10, 15, 20, and 25 degrees nasally along the 180-degree meridian. A 0.6-log unit neutral density filter, which reduces retinal illumination the equivalent of halving the pupillary diameter, decreased the mean Humphrey thresholds by 1.1 +/- 0.8 decibels (dB) (mean +/- standard deviation) and the mean Octopus thresholds by 1.7 +/- 1.4 dB. Statistically significant (P less than or equal to .05, Dunnett's test) threshold depressions were observed at all eccentricities with a 1.5-log unit neutral density filter on the Humphrey perimeter (-4.5 +/- 0.7 dB) and with a 1.0-log unit neutral density filter on the Octopus perimeter (-3.5 +/- 1.0 dB).

Adult↗

PubMed1988

The influence of simulated light scattering on automated perimetric threshold measurements.

The effect of light scattering by ocular media opacities on OCTOPUS and Humphrey perimeter threshold measurements was simulated with randomly ordered sequences of six ground-glass diffusers in the right eyes of five subjects. Threshold measurements were performed at 0 degrees, 5 degrees, 10 degrees, 15 degrees, 20 degrees, and 25 degrees nasally along the 180 degrees meridian with the F4 program on an OCTOPUS perimeter, and with twice-repeated profiles on a Humphrey perimeter. The reduction in differential light sensitivity correlated well with the 2.7-dB to 16.7-dB reduction in stimulus intensity caused by the 46% to 98% scattering of incident light by the diffusers. Contrast sensitivity in the presence of a glare source (Miller-Nadler glare test) was also affected by the diffusers, such that a 75% contrast target was not visible through the strongest diffuser whereas a 5% contrast target was visible without a diffuser. Conversely, the diffusers had very little effect on visual acuity measurements that were performed with projected high-contrast targets in a darkened room. Our data suggest that even minimal light scattering, such as might be caused by a cataract that has a relatively insignificant effect on visual acuity, may influence threshold measurements.

Adult↗

PubMed1988

Clinical experience with the single-plate Molteno implant in complicated glaucomas.

Ninety patients with medically uncontrollable glaucomas and poor surgical prognoses received single-plate Molteno implants (Optomat Supplies, Dunedin, New Zealand) without postoperative adjunctive systemic antifibrosis therapy. Eleven patients had insufficient follow-up for assessment of intraocular pressure (IOP) or visual acuity outcome. The initial Molteno implant procedures in the remaining 79 patients were successful (IOP less than or equal to 21 mmHg with at least 6 months' follow-up) in 26 (63%) of the 41 patients older than 12 years of age with non-neovascular glaucomas in aphakia/pseudophakia; 7 (70%) of the 10 patients older than 12 years of age with non-neovascular glaucomas in phakic eyes after failed filtering surgery; 7 (47%) of the 15 patients with neovascular glaucomas; and 7 (54%) of the 13 patients younger than 13 years of age with non-neovascular glaucomas. The visual acuities remained within one line of their preoperative levels or improved in 31 (76%) of the 41 aphakic or pseudophakic eyes with non-neovascular glaucomas; 3 (30%) of the 10 phakic eyes with non-neovascular glaucomas after failed filtering surgery; 10 (67%) of the 15 eyes with neovascular glaucomas; and 9 (100%) of the 9 eyes with non-neovascular glaucomas in patients younger than 13 years of age on whom Snellen acuity was available.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed1988

Glaucoma update.

Explore the source record for details and available documents.

Glaucoma↗

PubMed1987

Clinical evaluation of the Oculab Tono-Pen.

We performed a clinical evaluation on a prototype version of the Tono-Pen hand-held tonometer. A masked, randomized design was used to compare the instrument with the Goldmann tonometer. We tested 270 eyes. For pressures of 6 to 24 mm Hg, the Tono-Pen tonometer measured, on average, 1.7 mm Hg higher than the Goldmann tonometer. This difference was statistically significant (P less than .0001). In the range above 24 mm Hg, no statistically significant difference was found in the pressures measured with the two instruments. Measurements made with the Tono-Pen were sufficiently close to those made with the Goldmann tonometer to be considered clinically accurate.

Evaluation Studies as Topic↗

PubMed1987

Serious corneal complications of glaucoma filtering surgery with postoperative 5-fluorouracil.

We studied four patients who, having received postoperative 5-fluorouracil after glaucoma filtering operations, developed serious corneal complications. All four patients had preexisting corneal abnormalities including keratoconjunctivitis sicca, exposure keratopathy, and bullous keratopathy. All of the patients developed epithelial defects in the postoperative period. The complications included bacterial corneal ulceration (two patients), sterile corneal ulceration and corneal perforation (one patient), and a keratinized corneal plaque with underlying sterile stromal infiltrate (one patient). The use of 5-fluorouracil, which is an antimetabolite with considerable corneal epithelial toxicity, after glaucoma filtering surgery frequently causes corneal epithelial defects that may lead to secondary complications. Patients receiving this drug should have their corneal status closely monitored. In patients with corneal epithelial disease, 5-fluorouracil should be used with caution.

Aged↗

PubMed1987

The influence of refraction accuracy on automated perimetric threshold measurements.

The effect of refraction accuracy on the differential light threshold of a Goldmann size III (0.43 degrees diameter) stimulus was evaluated in the right eyes of five normal subjects with randomly ordered sequence of plano, +1.00-, +2.00-, +3.00-, +4.00-, +5.00-, and +6.00-diopter (D) spherical overcorrections. Threshold measurements were performed at 0 degree, 5 degrees, 10 degrees, 15 degrees, 20 degrees, and 25 degrees eccentricity nasally along the 180 degrees meridian with the F4 program on the Octopus 201 perimeter. The +1.00- through +6.00-D overcorrections decreased the threshold values by an average of 1.4, 2.9, 4.2, 5.6, 6.7, and 7.6 dB, respectively, compared with the plano overcorrection. The depression of the differential light threshold was of similar magnitude at all eccentricities within the central 25 degrees.

Adult↗

PubMed1987

Glaucoma filtering surgery with 5-fluorouracil.

A life-table analysis of surgical outcomes was performed on the first eye of 155 patients who were enrolled in a pilot study of glaucoma filtering surgery with postoperative subconjunctival 5-fluorouracil (5-FU) injections. The success rates at 1-, 2-, and 3-year intervals were 68, 63, and 63%, respectively, for 88 patients with non-neovascular glaucoma in aphakia; 82, 75, and 75% for 39 patients with non-neovascular glaucoma after unsuccessful filtering surgery; and 68% at each yearly interval for 28 patients with neovascular glaucoma. Complications which resulted from filtering surgery and the 5-FU injections included corneal epithelial defects (55.5%), conjunctival wound leaks (36.8%), suprachoroidal hemorrhage (5.8%), rhegmatogenous retinal detachment (2.6%), endophthalmitis and phthisis (1.9% each), and corneal scarring, late bleb leak, malignant glaucoma, and traction retinal detachment (1.3% each). A Cox Model regression analysis failed to demonstrate a correlation between surgical success and age, race, type of filtering procedure, or total dose of 5-FU received. Postoperative subconjunctival 5-FU may increase the operative success rate for selected patients with a high risk for failure after glaucoma filtering surgery.

Actuarial Analysis↗

PubMed1987

The effect of beta irradiation on monkey Tenon's capsule fibroblasts in tissue culture.

Fibroblast proliferation with subsequent bleb scarring is a major cause of filtering surgery failure. To investigate possible antiproliferative effects of beta radiation, owl monkey Tenon's capsule fibroblasts in tissue culture were irradiated to doses of 30, 100, 300, 1,000, and 3,000 rads with a linear accelerator and to doses of 95,285, and 950 rads with a Strontium-90 applicator. The irradiated cell proliferation expressed as the percentage of the non-irradiated control growth on the third and seventh days, respectively, after beta irradiation was: 97% and 96% after 30 rads; 72% and 90% after 100 rads; 48% and 44% after 300 rads; 39% and 14% after 1,000 rads; and 39% and 14% after 3,000 rads. Similar effects on cell proliferation were observed with the Strontium-90 applicator. The inhibitory effect of beta irradiation on fibroblast proliferation in tissue culture suggests that beta irradiation after filtering surgery may reduce postoperative bleb scarring.

Animals↗

PubMed1987

Subconjunctival 5-fluorouracil mechanisms of ocular penetration.

Aqueous, corneal, and tear film 14C 5-fluorouracil (5-FU) levels were measured in rabbit eyes to better understand the mechanisms of intraocular penetration after subconjunctival injection. Significantly higher aqueous and tear 5-FU levels were achieved one hour after administration when the subconjunctival injection was given transconjunctivally rather than percutaneously through the upper lid [aqueous = 65.7 +/- 9.1 micrograms/ml vs 21.3 +/- 5.1 micrograms/ml (mean +/- SE; p = 0.02, 2-tailed t-test); and tears = 5408.8 +/- 357.3 micrograms/ml vs 228.0 +/- 46.4 micrograms/ml (mean +/- SE; p = 0.004, 2-tailed t-test)]. The aqueous 5-FU levels four hours after transconjunctival injection were significantly greater in anesthetized rabbits without blink reflexes than in those with intact reflexes [32.0 +/- 3.2 micrograms/ml vs 13.4 +/- 0.5 micrograms/ml (mean +/- SE; p = 0.026, 2-tailed t-test)]. The corneal 5-FU levels four hours after transconjunctival injection were greatest nearest the injection site. Direct corneal penetration appears to account for the majority of the aqueous 5-FU concentration after subconjunctival injection; however, there may also be diffusion through the limbus.

Animals↗