Biomedical subjects

J T Thompson

Publications and source records attributed to J T Thompson.

At least 37 records · Page 2Linked to original sources

PubMed1996

Reoperation after failed macular hole surgery.

PURPOSE: The authors determined the anatomic and visual success rates of vitrectomy in patients who have failed previous macular hole surgery. METHODS: Standardized Early Treatment Diabetic Retinopathy Study (ETDRS)-style best-corrected visual acuity was measured in each patient pre- and postoperatively. Surgery was performed at two centers using a standardized protocol, as previously reported, using 1330 ng bovine-derived transforming growth factor-beta 2 (TGF-beta 2) and 16% perfluoropropane internal gas tamponade. Endpoint analyses were conducted for anatomic closure of the hole, visual improvement of three or more ETDRS lines, and final visual acuity of > or = 20/63 and > or = 20/40. RESULTS: Forty-eight failing macular hole surgery were reoperated. The anatomic results showed closure of the hole in 40 (83%) cases at the end of the mean follow-up interval of 7.4 months. The visual acuity improved in greater than or equal to three lines in 52%, was > or = 20/63 in 54%, and was > or = 20/40 in 25% of reoperated eyes. The only factor associated with a better final visual acuity was preoperative visual acuity better than 20/80. Nuclear sclerosis leading to cataract extraction was observed in 13 (30%) of 43 initially phakic eyes. CONCLUSIONS: Macular hole closure was induced in this subset of reoperated patients. Visual improvement occurred often, although in a lower percentage than has been reported for primary surgical eyes. Repeat vitrectomy should be considered in patients with persistent macular hole after failure of primary surgery.

Adolescent↗

PubMed1996

Intraocular tamponade duration and success of macular hole surgery.

PURPOSE: The authors compare the success of macular hole surgery with a short duration tamponade using 5% perfluoropropane (C3F8), intermediate duration tamponade using 10% C3F8, or a long duration tamponade using 16% C3F8 in a prospective consecutive clinical trial at two institutions. METHODS: Vitrectomy and fluid-gas exchange was performed in 29 eyes treated with 5% C3F8 and 1 week of prone positioning, 30 eyes treated with 10% C3F8 and 2 weeks of prone positioning, and 90 eyes treated with 16% C3F8 and 2 weeks of prone positioning 90% of time, followed by 2 weeks of prone positioning 50% of time. RESULTS: The macular hole was closed successfully in 19 of 29 eyes (65.6%) treated with 5% C3F8, 19 of 30 eyes (63.3%) treated with 10% C3F8, and 85 of 90 eyes (94.4%) treated with 16% C3F8 at 3 months (P = 0.00017 for 5% vs. 16% C3F8, P = 0.00006 for 10% vs. 16% C3F8). The visual acuity improvements measured by refraction using the Early Treatment Diabetic Retinopathy Study (ETDRS) acuity charts paralleled the success of macular hole closure. The acuity improved a mean improvement of + 9.6 ETDRS letters for eyes treated with 5% C3F8, + 6.4 ETDRS letters for eyes treated with 10% C3F8, and + 13.1 ETDRS letters in eyes treated in 16% C3F8. CONCLUSIONS: A long duration intraocular gas tamponade with 16% C3F8 gives a substantially higher success rate for macular hole surgery than a short (5% C3F8) or intermediate duration (10% C3F8) intraocular gas tamponade.

Adult↗

PubMed1995

Effect of size (mis)matching in clinical double-lung transplantation.

Current United Network for Organ Sharing policy requires listing lung transplant recipients with an acceptable donor weight range, but lung size is a function of height, age, sex, and race. Frequently, lung transplant recipients are underweight, which results in a large discrepancy between donor and recipient weights. We reviewed our experience with size discrepancy between donors (D) and recipients (R) of 49 double-lung transplant (DLTX) procedures since July 1990. Pneumoreduction procedures were performed in 11 recipients of lungs judged to be too large at the time of DLTX (right middle lobectomy, 2; lingulectomy, 2; both, 6; right middle lobectomy and bilateral apical resections, 1). Predicted forced vital capacity (FVC) and total lung capacity (TLC) of donors and recipients were calculated. Donors were larger than recipients in general (D:R height = 1.02; D:R weight = 1.46), and, as a result, recipient-predicted lung volumes were smaller than donor-predicted lung volumes (D:R FVC = 1.1; D:R TLC = 1.1). Recipients undergoing pneumoreduction procedures had a significantly greater size discrepancy between donors and recipients; thus, both the ratio of D:R and the difference between D and R predicted FVC and TLC were significantly greater among recipients who underwent pneumoreduction, compared with nonreduced recipients. For recipients in the pneumoreduction group, predicted FVC and TLC were recalculated, with a proportionate amount subtracted based on the number of pulmonary segments removed. When the "corrected" FVC and TLC of the donors were compared with recipient-predicted FVC and TLC, there was no longer any significant difference between reduced and non-reduced groups, which implies that visual estimate of size mismatch at surgery is an accurate measure of size discrepancy. Post-DLTX spirometry showed identical improvement in FVC in patients who had pneumoreduction and those who did not, and survival at 6 months was identical in both groups. We conclude that pneumoreduction had no adverse effect on survival or post-DLTX spirometry, allowing safe use of larger donors in small recipients. Also, because lung size is more a function of height than weight, this study challenges the United Network for Organ Sharing practice of listing recipients with an acceptable donor weight range.

Adolescent↗

PubMed1995

Progression of nuclear sclerosis and long-term visual results of vitrectomy with transforming growth factor beta-2 for macular holes.

PURPOSE: We studied the progression of cataracts and visual acuity up to 36 months after vitrectomy and instillation of transforming growth factor beta-2 for treatment of full-thickness macular holes. METHODS: Sixty-four eyes with idiopathic and two with traumatic macular holes in this prospective consecutive series were divided into the following two groups: 56 phakic eyes were treated with 70, 330, or 1,330 ng of transforming growth factor beta-2 to study the progression of cataracts, and 31 phakic or pseudophakic eyes were treated with 1,330 ng of transforming growth factor beta-2 to study the long-term visual acuity after macular hole surgery. RESULTS: Eyes in the cataract progression study had a mean preoperative nuclear sclerosis grade of 0.4, which increased to 2.4 on final lens examination at a mean of 12.4 months postoperatively. The amount of nuclear sclerosis increased progressively with duration of follow-up, and 16 (76%) of 21 eyes followed up for 24 months or more required cataract extraction. The mean preoperative posterior subcapsular cataract grade was 0.0 and increased only slightly to 0.25 on final lens examination. All eyes had initial successful closure of the macular hole, but the macular hole reopened in two eyes (between six and 12 months and at 19 months) for an overall success rate of 29 (93.5%) of 31 eyes at a mean of 19.5 months. The visual acuity increased two or more Snellen lines in 29 (93.5%) of 31 eyes. The final visual acuity was 20/40 or better in 23 (74%) of 31 eyes and the visual improvement was stable in eyes followed up for three years. CONCLUSIONS: Nuclear sclerotic cataracts progress substantially after macular hole surgery with a long-acting intraocular gas tamponade. The visual acuity often decreases 12 or more months after vitrectomy because of cataract progression, but the visual results of vitrectomy and transforming growth factor beta-2 for macular holes are excellent when the cataracts are removed.

Adolescent↗

PubMed1995

Improved results of lung transplantation for patients with cystic fibrosis.

Patients with cystic fibrosis pose particular challenges for lung transplant surgeons. Earlier reports from North American centers suggested that patients with cystic fibrosis were at greater risk for heart-lung or isolated lung transplantation than other patients with end-stage pulmonary disease. During a 3 1/2 year period, 44 patients with end-stage lung disease resulting from cystic fibrosis underwent double lung transplantation at this institution. During the same interval, 18 patients with cystic fibrosis died while waiting for lung transplantation. The ages of the recipients ranged from 8 to 45 years, and mean forced expiratory volume in 1 second was 21% predicted. Seven patients had Pseudomonas cepacia bacteria before transplantation. Bilateral sequential implantation with omentopexy was used in all patients. There were no operative deaths, although two patients required urgent retransplantation because of graft failure. Cardiopulmonary bypass was necessary in six procedures in five patients and was associated with an increased blood transfusion requirement, longer postoperative ventilation, and longer hospital stay. Actuarial survival was 85% at 1 year and 67% at 2 years. Infection was the most common cause of death within 6 months of transplantation (Pseudomonas cepacia pneumonia was the cause of death in two patients), and bronchiolitis obliterans was the most common cause of death after 6 months. Actuarial freedom from development of clinically significant bronchiolitis obliterans was 59% at 2 years. Results of pulmonary function tests improved substantially in survivors, with forced expiratory volume in 1 second averaging 78% predicted 2 years after transplantation. Double lung transplantation can be accomplished with acceptable morbidity and mortality in patients with cystic fibrosis.

Actuarial Analysis↗

PubMed1995

Vitrectomy, fluid-gas exchange and transforming growth factor--beta-2 for the treatment of traumatic macular holes.

PURPOSE: To evaluate whether vitreous surgery is successful in closing full-thickness traumatic macular holes and whether there is subsequent improvement in visual acuity. METHODS: Twelve eyes from 12 consecutive patients with traumatic macular holes underwent vitrectomy, fluid-gas exchange and instillation of bovine or recombinant transforming growth factor (TGF)-beta-2. Three of four eyes underwent repeat vitrectomy with TGF-beta-2 after the initial procedure failed to close the macular hole. RESULTS: Eleven (92%) of 12 eyes had closure of the macular hole. Follow-up ranged from 3 to 33 months. Visual acuity improved by 2 or more lines in 8 (67%) of 12 eyes. Six (50%) of 12 eyes improved to 20/40 or better. All 3 eyes that underwent reoperation had successful closure of the macular hole and achieved 2 or more lines of visual improvement. CONCLUSION: Treatment of full-thickness traumatic macular holes with vitrectomy, fluid-gas exchange, and TGF-beta-2 may result in successful anatomic closure and visual improvement.

Adolescent↗

PubMed1995

Full-thickness macular hole formation in eyes with a pre-existing complete posterior vitreous detachment.

BACKGROUND: Tangential macular traction by the posterior vitreous cortex has been widely accepted as the major causative factor in the development of idiopathic macular holes. Separation of the posterior cortical vitreous should relieve this vitreoretinal traction. METHODS: The authors report five patients with idiopathic full-thickness macular hole formation that occurred in the presence of a well-documented pre-existing complete posterior vitreous detachment. RESULTS: Of five eyes, three underwent pars plana vitrectomy and instillation of transforming growth factor-beta. No residual prefoveal cortical vitreous was present at the retinal surface at the time of surgery. Additionally, clinically identifiable epiretinal membranes were present in three of five eyes, but these epiretinal membranes were extremely thin, transparent, induced minimal traction, and did not warrant surgical peeling. CONCLUSION: It is likely that, in these five patients, some mechanism other than tangential traction by prefoveal vitreous cortex is responsible for idiopathic full-thickness macular hole formation.

Aged↗

PubMed1995

Distribution of iatrogenic retinal breaks in macular hole surgery.

BACKGROUND: Intraoperative peripheral iatrogenic retinal breaks can be a serious complication of vitreous surgery. This study was undertaken to determine whether vitreous surgical techniques used for macular hole surgery were associated with a different incidence or distribution of retinal breaks. METHODS: The authors prospectively evaluated a series of 181 consecutive eyes undergoing macular hole surgery. Contemporaneous reporting of intraoperative and postoperative retinal breaks and postoperative retinal detachments was performed. Comparison was made to historic controls of two case series of patients undergoing vitreous surgery for other indications. RESULTS: Of 181 eyes, 10 (5.5%) had 15 intraoperative retinal breaks. Of the 15 breaks, 3 (20%) were in the quadrant near the surgeon's right-hand sclerotomy, 9 (60%) were in the two inferior quadrants, and 11 (73%) were in the two temporal quadrants. By comparison to previously reported case series, tears in our series were less likely to be near the right-hand sclerotomy (P = 0.00055) and more likely to occur in the two inferior retinal quadrants (P = 0.00015) and two temporal retinal quadrants (P = 0.0042). Two patients (1.1%) of 181 had postoperative retinal detachments. CONCLUSIONS: Patients undergoing vitreous surgery for macular hole have a similar incidence but different location of iatrogenic retinal breaks when compared with patients undergoing pars plana vitrectomy for other indications. These breaks are not distributed near sclerotomy sites and tend to be in the inferior and temporal retina. This establishes the need for greater intraoperative surveillance in these areas.

Humans↗

PubMed1995

Fundus photographic and fluorescein angiographic characteristics of pseudoholes of the macula in eyes with epiretinal membranes.

BACKGROUND: The fluorescein angiographic characteristics in eyes with pseudoholes of the macula associated with epiretinal membranes have not been studied extensively. METHODS: Stereo photographs and fluorescein angiograms from 83 consecutive eyes of 80 patients with pseudoholes of the macula were evaluated by two independent graders for epiretinal membrane opacity, fluorescence in the base of the pseudohole, and late perifoveal pooling of dye. RESULTS: Hyperfluorescence in synchrony with choroidal fluorescence appeared within the base of the pseudohole in 52 (63%) of the 83 eyes studied. The hyperfluorescence was smaller than the pseudohole in 37 (45%) eyes. Diffuse hyperfluorescence filled the pseudohole in 15 (18%) eyes. No fluorescence was seen in 20 (24%) eyes. Eleven (13%) eyes could not be graded due to coexistent macular disease or media opacity. Fluorescence within the area of pseudohole was less common in eyes with opaque epiretinal membranes than in eyes with visible or transparent epiretinal membranes (P = 0.002). Fluorescence within the area of the pseudohole was also less common in eyes with evidence of macular edema on fluorescein angiography (P < 0.001). The mean visual acuity was better for eyes with hyperfluorescence within the area of the pseudohole than for eyes without hyperfluorescence (P < 0.01). CONCLUSION: A common fluorescein angiographic characteristic associated with pseudoholes of the macula is early hyperfluorescence within the area of the pseudohole. This hyperfluorescence coincides with choroidal filling and appears to be a form of transmission defect rather than a blocking of surrounding choroidal fluorescence by the epiretinal membrane. This central hyperfluorescence may result in misdiagnosis of the macular pseudohole as a full-thickness macular hole.

Basement Membrane↗

PubMed1995

Effects of hyperbaric exposure on eyes with intraocular gas bubbles.

BACKGROUND: Air travel is known to be potentially hazardous for patients with intraocular gas bubbles, and the external pressure changes associated with hyperbaric oxygen therapy and scuba diving could be similarly dangerous. METHODS: Rabbits with a perfluoropropane/air gas mixture filling approximately 60% of the vitreous cavity of the right eye were exposed to 3 different hyperbaric pressure profiles to an equivalent depth of 33 feet. The first group were a control group and were not exposed to hyperbaric pressures. The second group remained at an equivalent depth of 33 feet for 30 minutes, and the third group remained at 33 feet for 1 minute. Both groups ascended to normal atmospheric pressure at a rate of 1 foot per minute. The fourth group remained at 33 feet for 1 minute and then ascended at a rate of 0.2 feet per minute. RESULTS: In all eyes with an intraocular gas bubble, intraocular pressure dropped to zero when the atmospheric pressure was increased, and rose to more than 50 mmHg when the atmospheric pressure was returned to normal. Pressures in excess of 50 mmHg were sustained for 10 minutes or longer in each rabbit exposed to one of the hyperbaric profiles. No significant intraocular pressure changes were observed in eyes without an intraocular gas bubble or eyes not exposed to hyperbaric pressure. CONCLUSION: Marked elevation in intraocular pressure occurs as a result of hyperbaric exposure in eyes with an intraocular gas bubble. Hyperbaric exposure is therefore not advisable for patients with intraocular gas bubbles.

Air↗

PubMed1995

Analysis of cystic fibrosis referrals for lung transplantation.

Patients with cystic fibrosis (CF) are being considered in increasing numbers as candidates for lung transplantation, despite earlier concerns that their nutritional status and the infective nature of their lung disease would contribute to increased morbidity and mortality. We undertook a retrospective analysis of patients with CF referred for consideration of lung transplant to identify factors that helped to select suitable transplant candidates and to identify characteristics that predicted death while on the waiting list. Analysis of 95 referred patients with CF demonstrated a high rate of suitability (78%) by our criteria. The mean weight of listed patients with CF was 77% predicted, and the mean FEV1 was 20% predicted. Sixteen percent of listed patients with CF died awaiting transplant. The FEV1 of these patients was significantly lower than that of patients who survived to transplant. This study implies that patients with CF are being referred for transplant late in the course of their disease. Earlier referral may lead to an increase in the number of patients with CF undergoing successful lung transplantation.

Adolescent↗

PubMed1995

Efficacy of fluid-air exchange during pars plana vitrectomy.

PURPOSE: Vitreous fluid that remains trapped in the peripheral vitreous cavity after vitrectomy with fluid-air exchange can result in a smaller than desired intravitreal gas bubble size. To evaluate the effectiveness of a single fluid-air exchange in dehydrating the vitreous cavity, we measured the rate and volume of posterior vitreous fluid migration after an initial fluid-air exchange. METHODS: Thirty-eight eyes undergoing vitrectomy for macular hole closure had measurements of posterior vitreous fluid accumulation at either 5, 10, 15, or 20 minutes after fluid-air exchange. RESULTS: An average of 0.38 ml of fluid accumulated posteriorly within 10 minutes after the initial fluid-air exchange compared to 0.22 ml that accumulated after 5 minutes (P = 0.0003). A mean of 0.04 ml accumulated during each 5-minute interval between 10 and 20 minutes after the initial fluid-air exchange. CONCLUSION: Fluid composing 10% of the vitreous volume may migrate and accumulate posteriorly within 10 minutes of an apparently complete fluid-air exchange. Fluid aspiration after a 10-minute wait after the initial fluid-air exchange helps maximize vitreous cavity dehydration and should be employed when a large gas bubble is required after vitrectomy.

Adolescent↗

PubMed1994

Fluorescein angiographic characteristics of macular holes before and after vitrectomy with transforming growth factor beta-2.

We evaluated the fluorescein angiographic features of full-thickness macular holes before and after vitrectomy, fluid-gas exchange, and instillation of transforming growth factor beta-2 in 43 eyes in a masked fashion to evaluate the angiographic characteristics of macular holes preoperatively and the changes that occur with successful and unsuccessful closure of the macular hole. Hyperfluorescence was present in the base of the macular hole preoperatively in 34 of 43 eyes (79.1%), was questionable in eight of 43 eyes (18.6%), and was definitely absent in only one of 43 eyes (2.3%). The hyperfluorescence in the base of the macular hole disappeared in 19 of 20 eyes (95%) with successful closure of the macular hole (P < .00001) and appeared to be caused by blocked fluorescence at the site of the macular hole. The photographic features of eyes with unsuccessful closure of the macular hole changed little, except that the size of the cuff of neurosensory detachment around the hole increased and was associated with decreased postoperative visual acuity. These angiographic changes support the presence of a glial tissue plug bridging a small defect in the fovea of eyes with successful closure of a macular hole.

Combined Modality Therapy↗

PubMed1994

Indocyanine green angiography in multiple evanescent white-dot syndrome.

Using indocyanine green angiography we examined two patients with multiple evanescent white-dot syndrome. Both patients had unilateral loss of vision and a fundus appearance typical of multiple evanescent white-dot syndrome. Fluorescein angiography in both patients disclosed a patchy hyperfluorescent pattern at the level of the retinal pigment epithelium. Using indocyanine green angiography, we observed multiple deep, small, round hypofluorescent lesions that appeared early and persisted into the late phases. The spots appeared to block the underlying choroidal pattern. These hypofluorescent spots were clearly visible and present throughout the posterior pole. Many more spots were seen on indocyanine green angiography than were visible by clinical examination or angiography. After follow-up examinations, there was a rapid resolution of the spots over four to six weeks with return of vision. Our findings show that indocyanine green angiography can be a valuable tool in the recognition and further understanding of multiple evanescent white-dot syndrome.

Adult↗

PubMed1994

Effects of intraocular bubble duration in the treatment of macular holes by vitrectomy and transforming growth factor-beta 2.

PURPOSE: To compare the effect of a long-acting (16% perfluoropropane [C3F8]) versus a short-acting (air) intraocular gas tamponade on visual outcome and macular hole closure rate after vitrectomy and intravitreal instillation of transforming growth factor-beta 2 (TGF-beta 2) on the macula. METHODS: Vitrectomy with removal of the posterior hyaloid fluid-gas exchange with instillation of TGF-beta 2 was performed in 15 eyes treated with air and 37 eyes treated with 16% C3F8 using identical surgical techniques (mean follow-up, 5.6 months). RESULTS: The macular hole was closed successfully in 36 (97%) of 37 eyes treated with 16% C3F8 and in 8 (53.3%) of 15 eyes treated with air (P = 0.00007). The visual acuity improved by a mean of 3.1 lines on the Early Treatment of Diabetic Retinopathy Study chart for eyes treated with 16% C3F8 and 1.3 lines for eyes treated with air (P = 0.003). CONCLUSIONS: A longer duration intraocular gas tamponade from 16% C3F8 gives a much higher rate of successful closure of macular holes and improved visual acuity using vitrectomy and TGF-beta 2 than does air.

Aged↗

PubMed1994

The use of perfluoro-octane in the management of giant retinal tears without proliferative vitreoretinopathy.

PURPOSE: A technique for managing giant retinal tears without proliferative vitreoretinopathy (PVR) is presented, and visual outcome, anatomic reattachment, and postoperative complications are discussed. METHODS: A total of 25 consecutive cases of retinal detachment from giant retinal tears in eyes without PVR that had not previously undergone surgery were reviewed. A surgical technique combining pars plana vitrectomy, perfluoro-octane, and fluid-gas exchange was used. Scleral buckling was performed in 23 (92%) of 25 eyes, and pars plana lensectomy was performed in 11 (69%) of the 16 phakic eyes. A minimum follow-up period of 6 months was documented in each case. RESULTS: Of the 25 eyes, redetachment occurred in 3 (12%) after the initial procedure, and further surgery was necessary to successfully reattach the retina. A total of 9 secondary procedures were performed in 7 (28%) of the 25 eyes. Final retinal reattachment was achieved in all 25 eyes. Final Snellen visual acuity was 20/80 or better in 18 (72%) patients and 20/200 or better in 21 (84%) patients. CONCLUSION: The anatomic and visual results of this method of surgical treatment of giant retinal tears without PVR compare favorably to those achieved with techniques that use a nonbuckling approach, but with reduced ocular morbidity.

Adolescent↗

PubMed1994

Infectious complications of lung transplantation. Impact of cystic fibrosis.

It has been suggested that the presence of airway pathogens prior to lung transplantation (LT) in patients with cystic fibrosis (CF) may place these patients at a higher risk for infectious complications after LT. There is particular concern regarding patients colonized with multiresistant Pseudomonas, including P. cepacia, and fungi, including Aspergillus. We report our experience with LT for patients with CF and compare the results with those of patients with LT for other indications. Between January 1990 and March 1993, we performed LT for 27 patients with CF and 32 without CF. Nearly all (89%) of the patients with CF were colonized with P. aeruginosa; many were cultured with P. cepacia (19%) and Aspergillus (63%). The non-CF group rarely had organisms identified pre-LT. No patients with CF underwent pre-LT sinus drainage or received pre-LT treatment for Aspergillus. All of the patients received perioperative antibiotics and a standard regimen of immunosuppression and prophylactic antibiotics. The incidence of infectious complications was the same in the two groups; however, there was an association between obliterative bronchiolitis and pulmonary infections. One of the patients with CF with P. cepacia died as a result of this organism. None of the patients with CF required treatment for Aspergillus post-transplant. We conclude that patients with CF, despite the presence of airway pathogens, are at no greater risk of infectious complications after LT than are other patients.

Adult↗

PubMed1993

Resolution of an absolute scotoma and improvement of relative scotomata after successful macular hole surgery.

Visual loss in eyes with full-thickness macular holes is thought to be caused by the absence of retinal function in the area of the neurosensory defect as well as reduction in retinal function in the surrounding area of neurosensory retinal detachment. To improve characterization of the visual function of eyes after successful macular hole surgery, we studied six eyes preoperatively and postoperatively with macular microperimetry using the scanning laser ophthalmoscope. Best-corrected visual acuity was improved postoperatively in all eyes. Microperimetry performed preoperatively demonstrated an absolute scotoma that corresponded to the neurosensory defect in all eyes, with surrounding concentric isopters of relative scotomata. No detectable absolute scotoma was found in any eye postoperatively. All eyes showed partial or complete resolution of the surrounding relative scotomata. Improvements in visual acuity after successful macular hole surgery may be related to disappearance of a detectable absolute scotoma as well as improvement in the surrounding retinal function.

Aged↗