PubMed Health⌕ Search

Biomedical subjects

D J Spalton

Publications and source records attributed to D J Spalton.

At least 19 recordsLinked to original sources
PubMed2005

Intravitreal triamcinalone acetonide for refractory uveitic cystoid macular oedema: longterm management and outcome.

PURPOSE: To establish the role of intravitreal triamcinalone acetonide (TA) in the long term management of refractory uveitic cystoid macular oedema (CMO) and to determine the long term visual outcome in these patients. METHOD: This is a retrospective observational case series. All patients had resistant CMO and active inflammation. The primary outcome measure was complete resolution of CMO on ocular coherence tomography. Visual acuity and intraocular pressure were also monitored. Twelve eyes of twelve patients received 2 (n = 10) to 4 (n = 2) mg of intravitreal TA. All had previously been unresponsive to orbital floor steroids. Fluorescein angiography was performed where indicated. RESULTS: There was complete resolution of CMO in all patients. Nine patients had improvement in acuity at there final follow up (mean follow up 40.5 months). Seven had improved by 2 lines (58%). In 3 patients there was no visual improvement. These 3 failed to respond to re-treatment. Five other patients were re-treated because of recurring CMO and deteriorating VA (median time to re-treatment 4 mths). The mean number of re-treatments for this group with orbital floor TA was three. 41.6% of patients developed ocular hypertension (33.8 mhg mean). One required a trabeculectomy. CONCLUSIONS: 2 mg of intravitreal TA is effective even in cases of resistant uveitic CMO. Although re-treatment is often required, the initial response to treatment can be maintained by subsequent orbital floor steroid injections.

Adult↗
PubMed2004

A mathematical model of factors that influence the performance of accommodative intraocular lenses.

In this work a mathematical model of capsule movement during pseudophakic accommodation is described to allow identification and evaluation of factors that may explain the variation in effect of accommodative intraocular lenses (IOLs) between patients. The model assumes that increasing vitreous pressure pushes the lens capsule forward as a circular diaphragm and that this movement is from a fixed fulcrum. With an IOL in situ, the capsule is taken to have a non-uniform thickness due to the presence of the anterior capsulorhexis. The model assumes a uniform capsular elasticity and ignores contributions from cellular elements such as posterior capsule opacification. Using our model and a regression formula to calculate capsular bag size, taking into account axial length and keratometry values, we are able to predict accommodative effect in individual patients. By simple geometry we have developed a mathematical model to identify variables that are important in pseudophakic accommodation. It provides the basis for the development of a more complex model that would address the movement of a lens taking into account the influence of the zonular system during accommodation.

Accommodation, Ocular↗
PubMed2004

Steroid prophylaxis in eyes with uveitis undergoing phacoemulsification.

AIM: To compare the efficacy of two preoperative steroid regimens for cataract surgery in patients with uveitis. METHODS: 40 uveitis patients with cataract underwent phacoemulsification and intraocular lens (IOL) implantation. Preoperatively they were randomised into two groups: group 1 (20 patients) received a single dose of intravenous methylprednisolone (15 mg/kg) half an hour before surgery, and group 2 (20 patients) received a 2 week course of oral prednisolone (0.5 mg/kg) which was tapered postoperatively. Preoperatively patients had aqueous flare and cells measured with the Kowa laser flare meter. On days 1, 7, 28, and 90 aqueous flare and cells were measured, and on days 7 and 90 fluorescein angiography was performed to determine the incidence of cystoid macular oedema (CMO). RESULTS: At all postoperative visits the mean increase in flare was greater for group 1 (intravenous steroid). Patients with posterior synechiae had greater blood-aqueous barrier damage (BAB) postoperatively. There were no statistically significant differences in logMAR visual acuity and incidences of CMO between the two groups at 7 and 90 days. CONCLUSION: A 2 week course of oral prednisolone, tapered postoperatively, produced a better recovery of the BAB than a single dose of intravenous methylprednisolone and is thus the recommended preoperative regimen.

Administration, Oral↗
PubMed2001

Intravitreal triamcinolone for uveitic cystoid macular edema: an optical coherence tomography study.

PURPOSE: To investigate the use of intravitreal injection of triamcinolone acetonide (TA) for the treatment of refractory uveitic cystoid macular edema (CME). DESIGN: Prospective, nonrandomized, self-controlled comparative trial. PARTICIPANTS: Six patients with chronic CME resistant to treatment with systemic steroids, orbital floor steroids, and cyclosporine A. Three patients were followed for more than 1 year, and the other three for between 3 and 9 months. INTERVENTION: Injection of 2 mg of TA into the vitreous cavity. TESTING: Optical coherence tomography scanning of the fovea before and after injection and logarithmic minimal angle of resolution visual acuity. MAIN OUTCOME MEASURES: Visual acuity, retinal thickness, cystoid space height, and intraocular pressure. RESULTS: There was complete anatomic resolution of CME in five of the six cases within 1 week after injection. Cystoid spaces began to return between 6 weeks and 3 months after injection. Two patients with longer term follow-up responded to further orbital floor steroid injection and had no CME 1 year later. One patient had raised intraocular pressure develop, requiring a trabeculectomy. Mean improvement in visual acuity after 12 months was 0.27 (range, 0.14-0.42). CONCLUSIONS: Complete anatomic and, to some extent, functional recovery can be induced by intravitreal TA despite long-term refractory inflammatory CME. Optical coherence tomography aids in the management of these cases.

Adult↗
PubMed2001

Effect of optic size on posterior capsule opacification: 5.5 mm versus 6.0 mm AcrySof intraocular lenses.

PURPOSE: To determine the effect of intraocular lens (IOL) optic diameter on posterior capsule opacification (PCO) using digital retroillumination images. SETTING: Eye Department, St. Thomas' Hospital, London, United Kingdom. METHODS: In this prospective study, 60 patients with senile cataract had routine phacoemulsification by a single surgeon and received standardized medication. The patients were divided into 2 equal groups. The first group received a 5.5 mm 3-piece AcrySof IOL (MA30BM, Alcon) inserted in the bag. The second group received a 6.0 mm 3-piece AcrySof IOL (MA60BM, Alcon). Retroillumination images were obtained 1, 30, 90, 180, and 360 days postoperatively. The percentage area of PCO was calculated objectively by dedicated software at 90, 180, and 360 days. At 1 day, the degree of capsulorhexis-IOL contact was determined by inspecting the images. RESULTS: Throughout the follow-up, there was less PCO in the 6.0 mm optic group than in the 5.5 mm optic group, and the difference reached significance 1 year postoperatively (P =.0017). At 1 year, the median percentage of PCO was 1.5% (95% confidence interval [CI] 1.4-5.3) in the 6.0 mm group and 6.9% (95% CI 5.8-18.0) in the 5.5 mm group. CONCLUSIONS: A larger IOL optic diameter was associated with less PCO.

Acrylic Resins↗
PubMed2001

Effect of intraocular lens haptic compressibility on the posterior lens capsule after cataract surgery.

PURPOSE: To evaluate the effect of intraocular lens (IOL) haptic compressibility on the posterior capsule after cataract surgery. SETTING: Teaching hospital, London, United Kingdom. METHODS: In this randomized prospective study, 60 patients had standardized phacoemulsification with in-the-bag placement of a poly(methyl methacrylate) (PMMA) (Storz P497UV) or hydrogel (Storz Hydroview H60M) IOL. Both IOLs had PMMA haptics of identical configuration and length. The IOL haptic compressibility was measured in air and then during incubation in saline at 37 degrees C over 1 month. Digital retroillumination imaging was performed 1, 7, 28, 90, 180, 360, and 720 days postoperatively. The presence and duration of postoperative capsule folds were recorded and correlated with the haptic compressibility measurements, lens epithelial cell (LEC) growth patterns on the posterior capsule at 6 months, and the extent of posterior capsule opacification. RESULTS: On the first postoperative day, 21 patients (88%) in the Hydroview group had posterior capsule folds that persisted in 12 patients (50%) for 2 years. Nineteen patients (68%) in the PMMA group had folds at day 1 (P =.01), with 1 patient (3%) still having folds at 1 month (P =.0002) and no patient having folds at 3 months. At 6 months, 11 patients (46%) in the Hydroview group and no patient in the PMMA group had LEC growth in the direction of the folds. The PMMA IOLs showed a greater decrease in haptic compressibility during incubation. CONCLUSIONS: Haptic compressibility should be an important consideration in IOL design. The results suggest that to avoid posterior capsule folds, the compressibility should be less than 2.5 mN.

Aged↗
PubMed2000

Posterior capsular opacification with hydrogel, polymethylmethacrylate, and silicone intraocular lenses: two-year results of a randomized prospective trial.

PURPOSE: To compare the visual outcome, percentage of posterior capsular opacification, and laser capsulotomy rates with polymethylmethacrylate, silicone, and hydrogel intraocular lens implants at 1 and 2 years postoperatively. METHODS: Ninety-three eyes of 93 patients were randomized to receive a polymethylmethacrylate, silicone, or hydrogel intraocular lens implant. A standardized surgical protocol was followed by a single surgeon using phacoemulsification with capsulorhexis; any patients with surgical complications were excluded, and all patients received standardized medication and follow-up. Patients were examined at days 1 and 7, months 1, 3, and 6, and years 1 and 2 after surgery. At each assessment, best-corrected logMAR visual acuity and Pelli-Robson contrast sensitivity were measured. Posterior capsular opacification was objectively assessed by digital retroillumination imaging with the use of a dedicated software program and calculated as the percentage area of opacified capsule. Laser capsulotomy was performed if the eye had lost 2 lines of visual acuity with a clinically opaque capsule. RESULTS: At 2 years postoperatively, the mean percentage area of posterior capsular opacification for hydrogel lenses was 63%; for polymethylmethacrylate, 46%; and for silicone, 17%. Hydrogel intraocular lenses were associated with 17% more posterior capsule opacification than were polymethylmethacrylate lenses (95% confidence interval, 1-33; P =. 037) and 45% more than were silicone lenses (95% confidence interval, 33-58; P <.0001) at 2 years. Polymethylmethacrylate lenses had 28% more posterior capsule opacification than silicone lenses (95% confidence interval, 13-43; P <.0001) at 2 years. Twenty-eight percent of patients with hydrogel intraocular lenses required an Nd:YAG laser posterior capsulotomy at 2 years, compared with 14% with polymethylmethacrylate, whereas no patients with silicone lenses needed a capsulotomy (P =.014). Visual acuity was not significantly different among the three groups, but patients with silicone intraocular lenses had significantly better contrast sensitivity than those with hydrogel lenses (P =.046). CONCLUSIONS: Intraocular lenses made of this specific hydrogel were associated with a significantly higher degree of posterior capsular opacification and more laser capsulotomies than polymethylmethacrylate and silicone intraocular lenses.

Aged↗
PubMed2000

Comparison between optical coherence tomography and fundus fluorescein angiography for the detection of cystoid macular edema in patients with uveitis.

PURPOSE: To compare optical coherence tomography (OCT) with fundus fluorescein angiography (FFA) for the detection of cystoid macular edema (CME) in patients with uveitis. DESIGN: Prospective comparative observational series. PARTICIPANTS: One hundred twenty-one eyes of 58 patients with uveitis of varied causes (seven patients were studied twice). TESTING: Patients with suspected CME underwent OCT scanning followed by FFA at the same visit. MAIN OUTCOME MEASURES: Detection and distribution of macular edema. RESULTS: One hundred eight eyes had similar results on both OCT and FFA in that 67 eyes had CME and 41 eyes had no CME. In 10 eyes subretinal fluid was detected on OCT but not FFA. Five of these eyes had CME on FFA but not OCT. Three other eyes had CME that was detected by FFA but not by OCT. Compared with FFA, the OCT sensitivity for detecting CME was 96% (including the eyes with subretinal fluid), and the OCT specificity was 100%. CONCLUSIONS: OCT is as effective at detecting CME as is FFA but is superior in demonstrating axial distribution of fluid.

Exudates and Transudates↗
PubMed2000

Double-masked prospective ocular safety study of a lens epithelial cell antibody to prevent posterior capsule opacification.

PURPOSE: To evaluate the intraocular safety of an immunoconjugate (MDX-RA) developed to prevent posterior capsule opacification (PCO) in human eyes. SETTING: St. Thomas's Hospital Eye Department, London, United Kingdom. METHODS: Twenty-six patients had phacoemulsification and implantation of an intraocular lens (IOL). All were randomly allocated at the end of surgery to receive a 0.1 mL placebo or 0.1 mL of the immunotoxin MDX-RA intracamerally. Two doses of the drug were tested: 8 patients with a low dose (50 units), 9 patients with a high dose (100 units), and 9 with placebo. Follow-up at days 1, 14, 30, 60, 90, and 180 consisted of visual acuity measured by the Early Treatment of Diabetic Retinopathy Study test, contrast sensitivity, aqueous flare, specular microscopy of the IOL's anterior surface, and corneal endothelial counts. The percentage area of PCO was measured from retroillumination images of the posterior capsule. RESULTS: There was no decrease in corneal endothelial cell count in toxin-treated patients. Early postoperative flare, anterior chamber cell count, and corneal pachymetry were higher in toxin-treated patients. The median percentage area of PCO at 1 year was 32.0 in the placebo group, 3.8 in the low-dose group, and 7.4 in the high-dose group (P = .06). CONCLUSION: This prospective, randomized, placebo-controlled trial confirmed that MDX-RA is safe for intraocular use and is of potential value for further clinical trials of the prevention of PCO.

Aged↗
PubMed2000

Quantitative volume replacement in the correction of post-traumatic enophthalmos.

We describe a technique to correct enophthalmos that involves measurement of the volume of the injured orbit followed by an accurate replacement of this volume with an autogenous bone graft. Twelve consecutive patients were treated with this technique and all but one showed an improvement in enophthalmos. Four of the seven with diplopia improved after the operation.

Bone Transplantation↗
PubMed2000

Quantification of posterior capsular opacification in digital images after cataract surgery.

PURPOSE: To describe a software program developed to provide an objective assessment of the amount of posterior capsular opacification (PCO) in high-resolution digital images of the posterior capsule after cataract surgery. METHODS: Images are analyzed by a set protocol of defining the area of the posterior capsule, removing the Purkinje light reflexes by intensity segmentation, contrast enhancement, filtering to enhance low-density PCO, and variance analysis using a co-occurrence matrix to assess texture. The accuracy of the system was tested for validity and repeatability. RESULTS: The software developed has been demonstrated to be an objective method of quantifying PCO. In validation tests, the image analysis-derived measure of PCO showed good agreement with clinically derived measures of PCO. Clinicians assessed PCO on a computer screen image and also under slit lamp examination (Pearson correlation coefficient for both methods >0.92). The entire acquisition and analysis system was demonstrated to have a confidence limit for 2 SDs of 9.8% for group data. CONCLUSIONS: This system is capable of producing an accurate and reproducible measure of PCO that is relevant to assessing techniques of PCO prevention.

Aged↗
PubMed1999

Surface cytologic features on intraocular lenses: can increased biocompatibility have disadvantages?

OBJECTIVE: To compare the anterior surface cytologic features and effect on blood-aqueous barrier of polymethyl methacrylate, silicone, and hydrogel intraocular lens (IOL) implants to give an indication of their biocompatibility. METHODS: This prospective study was performed at an English-teaching hospital. Ninety eyes were randomized to receive a polymethyl methacrylate, silicone, or hydrogel implant. A standardized surgical protocol was performed by a single surgeon using phacoemulsification. Patients were seen at intervals for 1 year. Measurements of visual acuity, contrast sensitivity, and anterior chamber laser flare and cells were obtained; and an assessment of lens cytologic features using specular microscopy of the anterior IOL surface was performed. RESULTS: Visual acuity and contrast sensitivity were not significantly different among the 3 groups. Hydrogel IOLs were associated with fewer inflammatory cells on their surface than polymethyl methacrylate and silicone IOLs (P<.001), but with significantly more lens epithelial cells (LECs) (P<.001). Patients with hydrogel implants without LECs had greater blood-aqueous barrier breakdown than those with LECs. CONCLUSIONS: The hydrogel IOLs were associated with a reduced inflammatory cell reaction but had many more LECs on their anterior surface. Those IOLs associated with increased blood-aqueous barrier damage did not develop LECs. If an IOL is too biocompatible, then it may incite the growth of LECs over its surface, which could have disadvantages.

Aged↗
PubMed1999

The effect of capsulorhexis size on posterior capsular opacification: one-year results of a randomized prospective trial.

PURPOSE: Posterior capsular opacification is the most common surgically related cause of reduced vision after cataract surgery. We studied the effect of capsulorhexis size on the pattern and severity of posterior capsular opacification. METHODS: In this prospective study 75 patients underwent standardized phacoemulsification with capsulorhexis and in-the-bag placement of a 5.5-mm polymethylmethacrylate intraocular lens implant. The patients were randomly assigned to receive either a small capsulorhexis of 4.5 to 5 mm to lie completely on the intraocular lens optic or a large capsulorhexis of 6 to 7 mm to lie completely off the lens optic. Patients were examined at days 1, 14, 30, 90, and 180 and at year 1 with logMAR visual acuity assessment, Pelli-Robson contrast sensitivity testing, anterior chamber flare and cell measurement, and high-resolution digital retroillumination imaging of the posterior capsule. The pattern of posterior capsular opacification was determined, and the percentage area of posterior capsular opacification was calculated for each image with dedicated image analysis software. RESULTS: Large capsulorhexes were associated with significantly more wrinkling of the posterior capsule and worse posterior capsular opacification than small capsulorhexes. At 1 year the average percentage area of posterior capsular opacification was 32.7% for small capsulorhexes (95% confidence interval, 19.8 to 45.6) and 66.2% for large capsulorhexes (95% confidence interval, 57.7 to 74.6) (P = .0001). The patients with large capsulorhexes had significantly poorer visual acuities and a trend toward worse contrast sensitivities. CONCLUSION: This study demonstrated significantly greater wrinkling and opacification of the posterior capsule and worse visual acuity with large capsulorhexes than with small capsulorhexes. In cataract surgery with a polymethylmethacrylate intraocular lens, a small capsulorhexis with the edge completely on the surface of the implant is preferable to a large capsulorhexis in reducing posterior capsular opacification.

Aged↗
PubMed1999

Are optic disc drusen inherited?

OBJECTIVE: To conduct family studies of the incidence of optic disc drusen and related optic disc anomalies among relatives of those affected. DESIGN: Retrospective case series with prospective examination of patients and their relatives using B-scan ultrasonography and color photography. PARTICIPANTS: A total of 27 relatives of 7 probands with bilateral optic disc drusen were examined. MAIN OUTCOME MEASURES: Presence of optic disc drusen on clinical examination or B-scan ultrasonography and presence of related anomalies, including absence of optic disc cup and presence of anomalous vasculature. RESULTS: Only 1 of 27 relatives had optic disc drusen (3.7%). Thirty of 53 eyes had anomalous vessels (57%), and 26 eyes had no optic cup (49%). CONCLUSION: The primary pathology of optic disc drusen is likely to be an inherited dysplasia of the optic disc and its blood supply, which predisposes to the formation of optic disc drusen.

Adolescent↗
PubMed1999

Dominant optic atrophy. Refining the clinical diagnostic criteria in light of genetic linkage studies.

OBJECTIVE: To describe the clinical findings and refine the clinical diagnostic criteria for dominant optic atrophy based on eight British families in which the diagnosis was confirmed by linkage analysis. DESIGN AND PARTICIPANTS: Case series; 92 subjects in 8 pedigrees had both eyes examined. INTERVENTION: Family members received a domiciliary examination based on best-corrected visual acuity, color vision using Ishihara and Hardy Richter Rand (HRR) plates, confrontation field testing using a red target, and optic disc evaluation using a direct ophthalmoscope. Genomic DNA was extracted from leukocytes or buccal mucosal cells and genotyped using 12 fluorescently labeled microsatellite markers from the region 3q27-q29. MAIN OUTCOME MEASURES: Subjects were classified clinically as definitely or possibly affected on the basis of the domiciliary examination before genetic analysis, and these results were compared with the haplotype analysis. RESULTS: Clinically, 43 subjects were identified as definitely affected, 4 as possibly affected, and 45 as unaffected. Visual acuity in affected subjects ranged from 6/6 to count fingers and declined with age. On genetic analysis, a haplotype was identified in each family, which was found in all definitely affected members but not in those regarded as unaffected. The four possibly affected individuals also bore the haplotype that segregated with the disease. CONCLUSIONS: Simple clinical tests are highly efficacious in diagnosing dominant optic atrophy. Contrary to accepted criteria, symptoms begin before the age of 10 years in only 58% of affected individuals. Visual acuity in affected subjects is highly variable. A mild degree of temporal or diffuse pallor of the optic disc and minimal color vision defects, in the context of a family with dominant optic atrophy, are highly suggestive of an individual being affected, even if the visual acuity is normal. This widens the generally accepted diagnostic criteria for this disease.

Adolescent↗
PubMed1999

The effect of polymethylmethacrylate, silicone, and polyacrylic intraocular lenses on posterior capsular opacification 3 years after cataract surgery.

OBJECTIVE: To compare the visual outcome, neodymium:YAG (Nd:YAG) capsulotomy rates, and percentage of posterior capsular opacification (PCO) seen with polymethylmethacrylate (PMMA), silicone, and polyacrylic intraocular lens implants 3 years after surgery. DESIGN: Randomized, prospective trial. PARTICIPANTS: Ninety eyes of 81 patients were examined at a British teaching hospital. INTERVENTION: Ninety eyes were prospectively randomized to receive a PMMA, silicone, or polyacrylic (AcrySof, Alcon, Fort Worth, TX) implant. All lenses had 6-mm disc optics with PMMA haptics. A standardized surgical protocol was performed by a single surgeon using an extracapsular technique with capsulorhexis; any surgical complications were excluded and all patients had standardized postoperative medication and follow-up. MAIN OUTCOME MEASURES: Patients were seen at 6 months and 1, 2, and 3 years after surgery. At 3 years, logarithm of the minimum angle of resolution (LogMAR) visual acuity and Pelli-Robson contrast sensitivity were measured and YAG capsulotomy rates determined. Posterior capsular opacification was assessed objectively by digital retroillumination imaging using dedicated software and calculated as the percentage area of opacified capsule. RESULTS: At 3 years, the overall follow-up rate was 71%: 19 patients were available for examination with polyacrylic lens implants, 22 with silicone, and 23 with PMMA. There was a significant difference in percentage PCO at 3 years among the lens types (P = 0.0001). Polyacrylic lenses were associated with less PCO (10%) than silicone (40%) and PMMA lenses (56%). The YAG capsulotomy rate was 0% for polyacrylic, 14% for silicone, and 26% for PMMA (P = 0.05). The visual acuity and contrast sensitivity were not significantly different among the three groups if patients with age-related macular degeneration and those requiring YAG capsulotomies are excluded. CONCLUSIONS: Intraocular lenses made from polyacrylic are associated with a significantly reduced degree of PCO and lower YAG rates.

Acrylates↗