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Biomedical subjects

G F Hilton

Publications and source records attributed to G F Hilton.

At least 19 recordsLinked to original sources
PubMed1995

Pneumatic retinopexy failures. Cause, prevention, timing, and management.

BACKGROUND: Pneumatic retinopexy is a procedure for reattaching the retina by injecting an expanding gas bubble and using either laser or cryopexy. The procedure is controversial because there may be a lower initial success rate, and intraocular gas may increase the risk of proliferative vitreoretinopathy. METHODS: The authors performed a retrospective review of 107 unpublished consecutive cases of pneumatic retinopexy together with a literature review of 25 statistical series with primary attention to failures. Univariate and multivariate analyses were carried out on the data set, and adjusted odds ratios for risk factors associated with failure were calculated using logistic regression. RESULTS: Initially, 74 (69%) of 107 patients had successful results, and with re-operations the success rate increased to 98%. Failure of the procedure to achieve retinal reattachment occurred soon after the initial procedure, with 86% of recorded failures occurring within the first month. The initial cause of failure was new or missed breaks in 14.9%, reopened initial breaks in 11.2%, and breaks never closed in 4.6%. Risk factors that showed a correlation with failure were patients being male (adjusted odds ratio = 2.65), eyes with preoperative visual acuity worse than 20/50 (adjusted odds ratio = 1.21), eyes with four quadrants of retinal detachment or total detachment (adjusted odds ratio = 2.03), aphakic or pseudophakic eyes (adjusted odds ratio = 1.91), and eyes with additional pathologic findings (adjusted odds ratio = 3.14). Poor visual outcome was associated with initial visual acuity less than 20/50 (adjusted odds ratio = 15.7) and eyes with four quadrants of retinal detachment or total detachment (adjusted odds ratio = 5.01). CONCLUSIONS: Failures of pneumatic retinopexy occur early in the postoperative course. Factors known to be associated with failure of retinal reattachment using scleral buckling also were associated with failure in pneumatic retinopexy. A higher success rate in females was noted, suggesting that educational efforts may need to be greater in males. Poorer visual results occurred in patients with poor initial vision and in eyes with four quadrants of retinal detachment or total detachments.

Cryosurgery↗
PubMed1995

A new classification of the retinoschises.

BACKGROUND: Two classifications of retinoschisis were published in the 1960s. A marked expansion of our knowledge of the diseases that give rise to retinoschisis indicates the need for an updated classification. METHODS: The new classification is based on the authors' clinical experience, an extensive review of the literature, and a survey of 20 vitreoretinal specialists. RESULTS: There are three types of retinoschisis: degenerative, hereditary, and secondary. Degenerative retinoschisis is very common and has been published extensively. In addition to the well known X-linked hereditary retinoschisis, there are less common pedigrees with autosomal recessive or autosomal dominant patterns. There are at least 18 ocular diseases that may show varying degrees of secondary retinoschisis. CONCLUSION: The many types of retinoschisis are divided into these major categories. The multiplicity of types is emphasized by the plural form of the term: "the retinoschises."

Data Collection↗
PubMed1994

A multivariate analysis of anatomic success of retinal detachments treated with scleral buckling.

One hundred and twenty-three preoperative, intraoperative, and postoperative variables were evaluated to assess their effect on anatomic success of scleral buckling for retinal detachment. The relative importance of each variable was tested in a logistic regression equation. This equation identified ten significant variables for predicting the outcome of retinal detachment surgery. The significant variables were: preoperative proliferative vitreoretinopathy (adjusted odds ratio, AOR, 13.60), previous buckle by G.F. Hilton (AOR = 8.03), total detachment (AOR = 5.72), preoperative vitreous hemorrhage (AOR = 3.08), tension less than 10 mm Hg (AOR = 2.40), hemorrhagic complications (AOR = 2.62), previous buckles by others (AOR = 2.10), injection into the vitreous at surgery with either saline or balanced salt solution (AOR = 2.32) or air/sulfahexafluoride (AOR = 7.06), and preoperative vision less than 0.3 (20/60 or worse) (AOR = 2.14). The number of cryopexy applications was specifically tested in the equation, but while significant in a univariate analysis, it was not found to be significant in the multivariate analysis.

Cryosurgery↗
PubMed1991

Pneumatic retinopexy. A two-year follow-up study of the multicenter clinical trial comparing pneumatic retinopexy with scleral buckling.

The authors report 2-year follow-up information on 179 of 198 eyes (90%) enrolled in a previously published multicenter, randomized, controlled clinical trial comparing pneumatic retinopexy (PR) with scleral buckling (SB) for the management of selected retinal detachments. Scleral buckling was compared with PR with regard to redetachment after the initial 6-month follow-up period (1% versus 1%), overall attachment (98% versus 99%), subsequent cataract surgery (18% versus 4%; P less than 0.05), preoperative visual acuity (no significant difference), and final visual acuity of 20/50 or better in eyes with macular detachment for a period of 14 days or less (67% versus 89%; P less than or equal to 0.05). Reoperations after a failed PR attempt did not adversely affect visual outcome. After 2 years, PR continues to compare favorably with SB.

Cataract Extraction↗
PubMed1991

Pneumatic retinopexy. An analysis of intraoperative and postoperative complications. The Retinal Detachment Study Group.

There have been 26 series (1,274 eyes) published on the use of pneumatic retinopexy for selected retinal detachments. Eighty percent were reattached with a single procedure and 98% with reoperations. New retinal breaks occurred in 13% and proliferative vitreoretinopathy in 4%. The three complications reported with pneumatic retinopexy but not with scleral buckling are subretinal gas, gas entrapment at the pars plana, and subconjunctival gas. Twenty-six complications of pneumatic retinopexy, most of which may also occur with scleral buckling, are discussed as to incidence, cause, prevention, and management.

Combined Modality Therapy↗
PubMed1990

The complication of pneumatic retinopexy.

There have been 26 published series with a total of 1274 detachments operated with pneumatic retinopexy. Eighty percent were reattached with a single procedure and 98% with reoperations. New breaks occurred in 13% and PVR in 4%. The complications published in 101 papers on pneumatic retinopexy in the last 5 years are analyzed as to frequency, prevention, management, and results.

Cryosurgery↗
PubMed1989

Pneumatic retinopexy. A multicenter randomized controlled clinical trial comparing pneumatic retinopexy with scleral buckling. The Retinal Detachment Study Group.

Pneumatic retinopexy was compared with scleral buckling in a multicenter (7 centers), randomized, controlled, clinical trial with 198 patients. Admission criteria included detachments with retinal break(s) no greater than 1 clock hour in size, within the superior two thirds of the fundus, without significant proliferative vitreoretinopathy (PVR). All patients were followed for at least 6 months. Scleral buckling was compared with pneumatic retinopexy with regard to single-operation reattachment (82 versus 73%), reattachment with one operation and postoperative laser/cryotherapy (84 versus 81%), overall reattachment with reoperations (98 versus 99%), final visual acuity of 20/50 or better in eye with preoperative detachment of the macula for 2 weeks or less (56 versus 80%), PVR (5 versus 3%), and new retinal breaks (13 versus 23%). Complications, including reoperations, as measured by the "score" system, were similar. The anatomic results of the two operations were not significantly different (P greater than 0.05), but pneumatic retinopexy had less morbidity and better postoperative visual acuity (P = 0.01). Pneumatic retinopexy is recommended for cases meeting the admission criteria.

Cataract Extraction↗
PubMed1988

Testing a mechanism of control in human cholesterol metabolism: relation of arginine and glycine to insulin and glucagon.

Eight men were given 2 casein meals, one with and one without a supplement of arginine and glycine, to measure the effect on plasma amino acids, insulin and glucagon. Supplementation resulted in increased levels of plasma glucagon, glycine and arginine, a tendency to decreased insulin and significantly lower insulin/glucagon ratio, tryptophan and tyrosine. The data suggest that insulin and glucagon, which control cholesterol metabolism, respond to dietary and postprandial plasma amino acid levels of arginine and glycine.

Amino Acids↗
PubMed1988

Expanded indications for pneumatic retinopexy.

The Collaborative Pneumatic Retinopexy Study evaluated retinal detachments (RDs) secondary to one break or group of breaks no larger than 1 clock hour located within the superior 8 clock hours of the fundus. Eyes with prominent proliferative vitreoretinopathy (PVR) were excluded. Forty eyes which exceed these criteria and were treated with pneumatic retinopexy have been retrospectively evaluated to determine what preoperative conditions limit the application of pneumatic retinopexy. Multiple breaks in multiple quadrants, large tears up to 2.5 clock hours in size, and RDs associated with a moderate degree of PVR were successfully managed with pneumatic retinopexy. The greatest number of failures were due to inferior breaks. The overall success rate for pneumatic retinopexy was 75%. New breaks occurred in 12.5% of eyes, but all of these were successfully managed.

Humans↗
PubMed1987

Pneumatic retinopexy. A collaborative report of the first 100 cases.

The preliminary experience of one surgeon, using pneumatic retinopexy for 20 consecutive cases of rhegmatogenous retinal detachment, was previously reported. The collaborative experience of six surgeons using pneumatic retinopexy for 100 cases is now reported. This series includes cases with pseudophakia, aphakia, macular detachment, macular breaks, vitreous hemorrhage, trauma, and old detachments. Initially, 91% were reattached, but seven recurrences yielded a 6-month follow-up cure rate of 84% with pneumatic retinopexy. With subsequent scleral buckling, 98% were reattached. Postoperative complications included proliferative vitreoretinopathy (3%), macular pucker (3%), and new/missed retinal breaks (7%). A review of the literature disclosed postoperative new/missed retinal breaks in nine series: 21, 3, 8, 4, 9, 7, 5, 4, and 13%. There were no cases of glaucoma, cataract, subretinal gas, endophthalmitis, or extension of the detachment into a previously attached macula. Pneumatic retinopexy offers the advantages of reduced tissue trauma, fewer complications, no hospitalization, and less expense. The major disadvantage is the need for postoperative positioning.

Cryosurgery↗