Biomedical subjects

William Feuer

Publications and source records attributed to William Feuer.

At least 19 recordsLinked to original sources

PubMed2015

Dry eye symptoms align more closely to non-ocular conditions than to tear film parameters.

OBJECTIVE: To evaluate the relationship between dry eye symptoms, non-ocular conditions and tear film parameters. DESIGN: Cross-sectional study. PARTICIPANTS/SETTING: The study population consisted of patients who were seen in the Miami Veterans Affairs eye clinic. Patients filled out standardised questionnaires assessing dry eye symptoms (dry eye questionnaire 5 (DEQ5) and ocular surface disease index (OSDI)), non-ocular pain, depression and post-traumatic stress disorder (PTSD), and also underwent measurement of tear film parameters. MAIN OUTCOME MEASURES: Correlations between dry eye symptoms and non-ocular conditions as compared with tear film parameters. RESULTS: 136 patients with a mean age of 65 (SD 11) years participated in the study. All correlations between the dry eye questionnaire scores (DEQ5 and OSDI) and (A) self-reported non-ocular pain measures (numerical rating scale and pain history), (B) depression and (C) PTSD were significant and moderate in strength (Pearson's coefficient 0.24 to 0.60, p<0.01 for all). All correlations between the dry eye questionnaires and tear film measures were weak (Pearson's coefficient -0.10 to 0.18) and most were not significant. Multivariable linear regression analyses revealed that PTSD and non-ocular pain more closely associated with dry eye symptoms than did tear film parameters. Specifically, non-ocular pain and PTSD accounted for approximately 36% of the variability in DEQ5 scores (R=0.60) and approximately 40% of variability in OSDI scores (R=0.64). Of note, none of the tear parameters remained significantly associated with dry eye symptoms in either model. CONCLUSIONS: Dry eye symptoms more closely align to non-ocular pain, depression and PTSD than to tear film parameters.

Aged↗

PubMed2006

Macular retinoblastoma: evaluation of tumor control, local complications, and visual outcomes for eyes treated with chemotherapy and repetitive foveal laser ablation.

OBJECTIVE: To determine tumor control rates, complication rates, and visual acuity (VA) for patients with macular retinoblastoma undergoing systemic chemotherapy and foveal diode laser ablation. DESIGN: Noncomparative retrospective case series. PARTICIPANTS: All patients with retinoblastoma in the macula at the Bascom Palmer Eye Institute between 1991 and 2004 were evaluated. Patients included in the study were managed by the same clinician with a planned therapeutic strategy. METHODS: Patients with Reese-Ellsworth groups I to IV disease underwent 4 to 9 cycles of systemic chemotherapy with vincristine, etoposide, and carboplatin, and patients with group V disease underwent 6 to 10 cycles with or without cyclosporine. All tumors underwent repetitive diode laser ablation (2-24 sessions) applied to the foveal and extrafoveal portions of tumors at each visit until tumors were deemed inactive for at least 6 months. MAIN OUTCOME MEASURES: Recurrence requiring external beam radiation therapy or enucleation; VA; and complications including iris atrophy, peripheral focal lens opacity, peripheral anterior synechiae, and foveal neovascular membrane. RESULTS: Forty-four eyes of 33 patients were treated. Eyes were classified as Reese-Ellsworth group I (1 [2%]), II (6 [12%]), III (3 [7%]), IV (5 [9%]), or V (29 [67%]). Thirty-eight eyes (86%) had successful tumor control and avoided enucleation at a median follow-up of 36 months. At 3 years, tumor control rates were 100% for Reese-Ellsworth groups I to IV and 83% for group V. All eyes requiring enucleation were in Reese-Ellsworth group V. No eyes required external beam radiation. The most common complications were iris atrophy (61%) and focal lens opacity (14%). Strabismus was noted in 16% of eyes. Snellen VA measured 20/40 or better in 36% of eyes, 20/80 or better in 57%, and 20/400 or better in 86%. An increasing number of laser applications and chemotherapy cycles was not associated with decreased VA, strabismus, or development of an afferent pupillary defect but was associated with development of local complications. CONCLUSIONS: A unique approach to the application of diode laser therapy characterized by repetitive foveal treatments and aggressive chemotherapy resulted in tumor control rates that exceed those previously published. Furthermore, despite laser application directly to the fovea, 57% of patients retained 20/80 or better vision.

Antineoplastic Combined Chemotherapy Protocols↗

PubMed2006

Management of retinal detachment when no break is found.

OBJECTIVE: To review the results of 2 different surgical approaches in the management of primary rhegmatogenous retinal detachments (RDs) with undetected retinal breaks. DESIGN: Retrospective, consecutive, interventional case series. PARTICIPANTS: Medical records of 44 patients with uncomplicated macula-involving primary rhegmatogenous-appearing RDs, but without retinal breaks detected preoperatively or intraoperatively, were reviewed. METHODS: All study patients were operated by the same surgeon between 1989 and 2004 using 2 approaches: 26 (59%) patients underwent a scleral buckling procedure (SBP) with or without subretinal fluid drainage, whereas 18 (41%) patients underwent scleral buckling combined with pars plana vitrectomy (PPV), fluid-gas exchange, and broad application of endolaser. MAIN OUTCOME MEASURES: Single operation and final postoperative anatomic success, and 2-month postoperative and final best-corrected visual acuity (VA) (negative logarithm of the minimum angle of resolution [logMAR]). RESULTS: Mean preoperative VAs were 1.73 logMAR units (median, 1.60; range, 0.48-2.60) in the combined surgery group and 1.52 logMAR units (median, 1.30; range, 0.30-2.60) in the scleral buckling group. Neither preoperative (P = 0.33), 2-month postoperative (P = 0.53), best-corrected (P = 0.98), nor final (P = 0.46) mean VA showed any statistically significant differences between the 2 treatment groups. A single operation reattachment rate of 72% (13/18 cases) was achieved in the combined surgery group, compared with 61.5% (16/26 cases) in the scleral buckling group (P = 0.17, log rank test). Immediate anatomic success rates were 89% after combined treatment and 38.5% after scleral buckling alone (P = 0.002). At the final visit, the retina was attached in 15 (83.3%) patients who received the combined treatment and in 22 (84.6%) patients who underwent scleral buckling (P = 0.900). Intraoperative subretinal hemorrhage occurred in 1 (5.6%) patient from the combined surgery group and in 2 (7.7%) patients from the scleral buckling group. Retinal incarceration in the drainage sclerotomy occurred in 1 (3.8%) case during the SBP. Proliferative vitreoretinopathy sufficient to require reoperation developed in 1 (5.6%) eye of the combined surgery group and in 3 (11.5%) eyes of the scleral buckling group. CONCLUSIONS: Scleral buckling is as effective in the management of uncomplicated rhegmatogenous RDs with undetected breaks as is surgery combining scleral buckling and PPV.

Adolescent↗

PubMed2006

Visual recovery after scleral buckling procedure for retinal detachment.

PURPOSE: To evaluate prognostic factors for visual and anatomic outcomes, including complications after scleral buckling procedure (SBP) for primary rhegmatogenous retinal detachments. DESIGN: Retrospective, consecutive, nonrandomized, comparative interventional case series. PARTICIPANTS: Patients undergoing SBP for primary rhegmatogenous retinal detachment performed by a single surgeon. METHODS: The patients' medical records were reviewed. Preoperative and intraoperative factors analyzed for their association with visual acuity and anatomic outcomes included macular detachment, duration of macular detachment, preoperative visual acuity, lens status, refractive error, extent of detachment, number of breaks, internal gas tamponade, and drainage of the subretinal fluid. Secondary outcomes included frequency of further surgery, complications, and fellow eye retinal detachment. The fellow eye of the patients was excluded from consideration of prognostic factors. MAIN OUTCOME MEASURES: Best-corrected visual acuity at 2 months and at final follow-up examination as well as anatomic factors including retinal reattachment at 1 day, 2 months, and last follow-up examination. RESULTS: There were 672 patients studied, including 457 (68%) with macular detachment. The use of gas, drainage of subretinal fluid, and lens status did not influence final anatomic or visual results. Macular detachment was the most important prognostic factor for anatomic (P = 0.031) and visual acuity success (P<0.001). Better preoperative visual acuity (P<0.001), fewer quadrants involved by the detachment (P<0.001), and lack of high myopia (P = 0.001) were important positive prognostic factors for visual acuity. The duration of macular detachment was not of prognostic value up to 30 days' duration. CONCLUSIONS: Visual recovery after retinal reattachment was most dependent on macular involvement. Duration of macular detachment had surprisingly little influence on postoperative visual acuity.

Adolescent↗

PubMed2006

Anecortave acetate as single and adjuvant therapy in the treatment of retinal tumors of LH(BETA)T(AG) mice.

PURPOSE: To evaluate the tumor control efficacy of the antiangiogenic agent anecortave acetate as single and combined therapy, in retinal tumor reduction using the LH(BETA)T(AG) mouse model of retinoblastoma. METHODS: Group A: Ten-week-old, LH(BETA)T(AG) mice received a single subconjunctival injection of anecortave acetate (1200, 600, 300, and 150 microg) delivered to right eyes only. Group B: Ten-week-old, LH(BETA)T(AG) mice received a single subconjunctival injection of anecortave acetate (600, 300, and 150 microg) delivered to right eyes only, either during a cycle of carboplatin (six subconjunctival deliveries) or after the completed cycle. Carboplatin was delivered at the subtherapeutic concentration of 62.5 microg. All animals were euthanatized at 16 weeks of age, and the eyes were examined histopathologically. RESULTS: A statistically significant reduction in tumor burden was detected after a single periocular injection of anecortave acetate. The reduction of tumor burden followed a U-shaped dose-response curve. Tumor burden was significantly decreased when anecortave acetate and carboplatin were combined. However, varying doses and delivery schedule of these agents had significant impact on the effectiveness of the combined treatment. The most effective scheme was delivering a low dose (150-300 microg) of anecortave acetate after a complete cycle of carboplatin. Histopathological evaluation showed no signs of retinal toxicity to anecortave acetate delivery alone or in combination with carboplatin. CONCLUSIONS: Anecortave acetate, as monotherapy or as adjuvant therapy, significantly controlled tumor burden in a murine model of retinoblastoma. Moreover, adjuvant therapy enabled the use of typically subtherapeutic carboplatin doses without decreasing efficacy of the therapy.

Animals↗

PubMed2006

Iontophoretic delivery of carboplatin in a murine model of retinoblastoma.

PURPOSE: To evaluate the efficacy and dose-response of transcorneoscleral Coulomb controlled iontophoresis (CCI) of carboplatin in the treatment of retinal tumors of a murine model of retinoblastoma. METHODS: Thirty 6-week-old LHBETATAG mice underwent a total of six, serial iontophoretic treatments administered two times per week using a current density of 2.57 mA/cm2 for 5 minutes. Fourteen animals received carboplatin treatments at concentrations of 1.4, 7.0, 10.0, or 14.0 mg/mL without current. Ten control mice underwent treatment with balanced saline solution. RESULTS: A dose-dependent inhibition of intraocular tumor was observed after repetitive iontophoretic treatment. At carboplatin concentrations of 7 mg/mL, 50% of the treated eyes (4/8) exhibited tumor control. No corneal toxicity was observed in eyes treated at carboplatin concentrations under 10 mg/mL. CONCLUSIONS: CCI delivery of carboplatin safely and effectively controls intraocular tumors in a dose-dependent manner in this murine model of retinoblastoma. CCI is a noninvasive, painless option for the focal delivery of carboplatin. However, further clinical and laboratory research is needed before this method of drug delivery is available for children with retinoblastoma.

Animals↗

PubMed2005

Visual field defects in deformational posterior plagiocephaly.

PURPOSE: We sought to determine whether visual field abnormalities occur in infants with deformational posterior plagiocephaly and to assess whether there is a relationship between the severity and laterality of visual field abnormalities with the severity and laterality of skull deformity. METHODS: A retrospective chart review was performed on 40 consecutive infants with deformational posterior plagiocephaly. Each was tested with standardized binocular arc perimetry in the horizontal plane. Sixteen patients also had 3-dimensional computed tomography of the skull. Hemifield asymmetry of >/=20 degrees and/or a decrease in hemifield values by >/=20 degrees from established normal patients was considered abnormal. Visual field data from study patients was plotted against previously published normative data. Graphs comparing visual field defects and laterality to cranial asymmetry also were generated. RESULTS: Thirty-five percent of infants with deformational posterior plagiocephaly had constriction of one or both hemifields by at least 20 degrees from established normal patients. Hemifield asymmetry of 20 degrees or more was found in 17.5% of infants tested. There was a significant difference in the worse hemifield values measured in each patient and the standard visual fields obtained from normative data ( P = 0.036). There was no correlation between the laterality of the visual fields to the laterality of the defects. A correlation between severity of hemifield constriction and % asymmetry on computed tomography was noted ( P = 0.209). CONCLUSIONS: Deformational posterior plagiocephaly may affect visual field development but neither the laterality nor the severity of skull deformity is predictive of the severity of visual field defects.

Humans↗

PubMed2005

Combretastatin A-4 prodrug in the treatment of a murine model of retinoblastoma.

PURPOSE: To evaluate the effect of subconjunctival injections of combretastatin A-4 phosphate (CA-4P) prodrug treatment on tumor vasculature and growth in an animal model of hereditary retinoblastoma. METHODS: Twenty-four, 12-week-old simian virus-40 T-antigen-positive mice received six subconjunctival CA-4P injections at doses of 0.5, 1.0, 1.5, and 2.0 mg delivered at 72-hour intervals to the right eye only. Six control animals received placebo treatment. All animals underwent serial ophthalmic evaluations and were euthanatized at 16 weeks of age, and eyes were obtained for histopathologic examination. Eyes were graded for presence or absence of tumor, delay of tumor growth, and intratumoral vascularity. RESULTS: The use of subconjunctivally injected CA-4P prodrug induced an extensive, dose-dependent decrease in microvessel density and led to significant tumor reduction in treated eyes compared with the placebo control (P <0.001). No evidence of corneal, lenticular, choroidal, or retinal toxicity was observed by histopathologic evaluation. CONCLUSIONS: Subconjunctival delivery of CA-4P is associated with extensive dose-dependent reduction in blood vessel count in this murine model of retinoblastoma. A combination treatment of retinoblastoma incorporating CA-4P may allow enhanced tumor reduction enabling a decrease in standard treatment doses of both chemotherapy and external beam radiotherapy.

Animals↗

PubMed2004

External beam radiation "salvage" therapy in transgenic murine retinoblastoma.

OBJECTIVE: To determine the efficacy of low-dose "salvage" external beam radiation therapy (EBRT) following failed subconjunctival carboplatin chemotherapy in a murine model of heritable retinoblastoma. METHODS: Eighty-four eyes from 8-week-old, simian virus 40, T-antigen-positive mice were treated with 6 serial subconjunctival carboplatin injections (100 microg/25 microL). At 12 weeks of age, 64 eyes received EBRT for a total dose of 480 (4.8 Gy), 1200 (12.0 Gy), 1560 (15.6 Gy), or 3000 (30.0 Gy) rad. Twenty eyes received no additional therapy following subconjunctival carboplatin injections. Ten eyes received a total dose EBRT of only 3000 rad. Eight eyes received subconjuctival injections of only an isotonic sodium chloride solution. Ten eyes served as untreated controls. MAIN OUTCOME MEASURES: Eyes were enucleated at 20 weeks to assess the presence of tumor on histopathological examination. RESULTS: Salvage therapy using low-dose EBRT was able to reestablish tumor control in a dose-dependent manner. Increasing the EBRT dose to 3000 rad resulted in 100% tumor control. The dose-dependent curves were significantly different between the treatment groups-EBRT alone vs salvage EBRT after receiving subconjunctival carboplatin injections (P<.001). CONCLUSION: Low-dose hyperfractionated salvage EBRT following failed primary subconjunctival carboplatin chemotherapy is efficacious in the treatment of retinoblastoma in this animal model. Clinical Relevance Salvage EBRT using a reduced total radiation dose could be associated with a radiation-related treatment enhancement in pediatric retinoblastoma.

Animals↗

PubMed2004

Baerveldt glaucoma implant in the management of refractory childhood glaucomas.

PURPOSE: To evaluate the effectiveness and safety of the Baerveldt glaucoma drainage implant (GDI) in the management of pediatric glaucomas. DESIGN: Retrospective noncomparative case series. PARTICIPANTS: Sixty-two children younger than 18 years who underwent Baerveldt GDI surgery. MAIN OUTCOME MEASURES: Intraocular pressure (IOP), intraoperative and postoperative complications, number of glaucoma medications, and VA. Success was defined as IOP of <22 mmHg and > or =5 mmHg with or without medications, no loss of light perception, and no further surgical intervention for glaucoma. Outcomes were compared for patients with primary and secondary glaucomas. RESULTS: Sixty-two eyes of 62 patients were identified. The mean patient age (+/- standard deviation) at time of Baerveldt glaucoma implant surgery was 6.5+/-5.6 years (range, 6 weeks-17 years). With an average follow-up of 23.4+/-21.7 months (range, 1-106), IOP was reduced from a mean of 35.0+/-8.7 mmHg (range, 17-54) preoperatively to 17.6+/-8.4 mmHg (range, 5-45) at last follow-up visit (P<0.001). Kaplan-Meier survival analysis showed a cumulative success of 85% at 6 months, 80% at 12 months, 67% at 24 months, and 60% in months 28 through 106. There was no difference between primary (N = 23) and secondary glaucoma (N = 39) patients in terms of length of follow-up, final IOP, number of medications, or cumulative success (P = 0.21). CONCLUSION: Baerveldt glaucoma implant surgery seems to be an effective treatment for primary and secondary refractory glaucomas in children. There is a risk of retinal detachment that may be related to the implant or other ocular conditions.

Adolescent↗

PubMed2004

Incidence of cataract extraction after diabetic vitrectomy.

PURPOSE: To determine the frequency of visually significant cataracts after vitrectomy for complications of diabetic retinopathy. METHODS: We studied 40 patients and 56 concurrent control patients in a retrospective, consecutive, comparative case series in an institutional setting. Entry criteria included phakic patients with a clear lens or mild lens opacity undergoing anatomically successful diabetic vitrectomy, without lens removal at the time of vitrectomy, without intraocular gas or silicone oil use, and with at least 1 year of postoperative follow-up examination information. Two comparative phakic control groups with the diagnosis of macular hole or epiretinal membrane were selected, also with follow-up examination information of at least 1 year postoperatively. The occurrence of cataract extraction was the principal outcome measure. Its validity as a measure of cataract formation was evaluated by ascertainment of improved visual acuity after cataract extraction. A secondary endpoint analysis included eyes that needed cataract extraction at the final follow-up examination. RESULTS: For the primary analyses (clear lens preoperatively), there were 26 patients in the study group, 38 in the macular hole control group, and 18 in the epiretinal membrane control group. The cumulative cataract extraction rates at 2 years were 15%, 66%, and 53% respectively. By using multivariate survival analysis, the patient age was an important factor, with a younger age associated with a lower rate of progression to nuclear sclerosis. After controlling for age, the difference in these three groups was still statistically significant. In the four patients with diabetes undergoing cataract surgery, the visual acuity improved at least two lines in only one of the eyes and did not change in three eyes. After expanding the outcome measures to include study patients with mild lens opacities at baseline or those judged to be in need of cataract surgery at the final follow-up examination, there was still a strongly statistically significant difference between the three groups. CONCLUSION: The rate of cataract extraction after vitrectomy in patients with diabetes is lower than in patients without diabetes undergoing vitrectomy and suggests a lower rate of cataract formation. This inference should be considered when attributing subnormal vision in a patient who has had a diabetic vitrectomy to a cataract. This is especially significant because the risk ratio in patients with diabetes in general and in patients with a previous vitrectomy is likely less favorable compared with the general population.

Adult↗

PubMed2004

Inter- and intrarater reliability in computed axial tomographic grading of splenic injury: why so many grading scales?

OBJECTIVE: After splenic trauma, critical decisions regarding operative intervention are often made with the aid of computed axial tomographic (CT) scan findings. No CT scan-based grading scale has been demonstrated to predict accurately which patients require operative or radiologic intervention for their splenic injuries. We hypothesized that use of the most common grading scale, the American Association for the Surgery of Trauma scale, would be associated with low intra- and interreliability scores. We assessed the ability of experienced trauma radiologists to differentiate grade III from grade IV splenic injuries. METHODS: The films of patients who had undergone abdominal CT scanning before splenectomy for grade III or IV injuries were serially evaluated by four trauma radiology faculty weekly for 3 weeks. We assessed intra- and interrater reliability for grading and for presence of contrast blush. RESULTS: Intrarater reproducibility yielded a weighted kappa score of 0.15 to 0.77. Interrater reliability weighted kappa scores ranged from 0 to 0.84, with a mean value of 0.23. CONCLUSION: CT imaging is not reliable for identifying grades III and IV splenic injury, as experienced radiologists often underestimate the magnitude of injury. Interrater reliability is poor. Factors other than the CT grade of splenic injury should determine whether patients require operative or angiographic therapy.

Humans↗

PubMed2003

Comparison of retinoblastoma reduction for chemotherapy vs external beam radiotherapy.

OBJECTIVE: To determine the time course and extent of tumor reduction associated with systemic chemotherapy or external beam radiotherapy (EBRT) in the treatment of advanced intraocular retinoblastoma. METHODS: Retrospective review of children with Reese-Ellsworth stages IV and V retinoblastoma undergoing primary globe-conserving therapy with either systemic chemoreduction or EBRT. Study variables were recorded at baseline, at monthly intervals for the first 6 months, and at 12 months after the initiation of treatment. Tumor volumes were calculated using basal area and height values determined by ultrasonography, physical examination, and fundus photographic review. MAIN OUTCOME MEASURES: Outcome measures included tumor volume, tumor reduction, regression pattern, treatment-related complications, metastases, and survival. RESULTS: Twenty-six eyes of 26 patients were evaluated for tumor response; 18 patients were treated with systemic chemotherapy and 8 patients were treated with EBRT. Median follow-up was 36 months. A mean 68% reduction in tumor volume occurred after 1 cycle of chemotherapy compared with a 12% reduction at a similar time point (1 month) after initiation of EBRT (P<.004). There was no statistically significant difference in tumor volume reduction between treatment modalities at the 12-month follow-up visit. Both systemic chemoreduction and EBRT achieved 100% globe conservation and 100% patient survival in this series. CONCLUSIONS: Retinoblastoma reduction exhibits a differential time course based on the applied primary treatment. Systemic chemotherapy is associated with earlier tumor reduction than EBRT.

Antineoplastic Combined Chemotherapy Protocols↗

PubMed2003

Retinal detachment rate after vitrectomy for retained lens material after phacoemulsification.

PURPOSE: To report the rate of retinal detachment after vitrectomy for retained intravitreal lens material after phacoemulsification using specific vitrectomy techniques designed to minimize retinal detachment. DESIGN: Consecutive, interventional case series. METHODS: Retrospective chart review of 100 consecutive eyes (one surgeon) of 100 patients undergoing vitrectomy for retained lens material after phacoemulsification and followed up for 3 months or longer unless an outcome event had occurred. Vitrectomy techniques employed to minimize the frequency of retinal detachment included inducing posterior vitreous detachment with maximal vitreous removal before phacofragmentation to avoid vitreous trauma, lens fragment debulking before fragmentation, use of low energy with high aspiration during removal of retained lens material, and intraoperative indirect ophthalmoscopic evaluation of the retinal periphery with scleral indentation to diagnose and treat intraoperative retinal breaks. The main outcome measures included prevalence of coexisting retinal detachment in eyes with retained lens material, incidence of retinal detachment or retinal breaks after vitrectomy for removal of retained lens material, and final visual acuity. RESULTS: The prevalence of previtrectomy retinal detachment was 4%; the incidence of postvitrectomy retinal detachment was 4%; the final visual acuity was 20/40 or better in 53%. One patient had a retinal break recognized during vitrectomy and was treated with retinocryopexy, but postoperative retinal detachment developed from a separate break. Three others were treated during vitrectomy for retinal breaks (including two with known preexisting breaks) and did not have any retinal detachment. Poor previtrectomy visual acuity (hand motions) was a risk factor for postvitrectomy retinal detachment. CONCLUSIONS: The rate of retinal detachment reported after vitrectomy for retained lens material after phacoemulsification can be minimized to approximately the rate expected with cataract extraction complicated by vitreous loss by employing standard surgical techniques. Higher risk eyes may benefit from more frequent postvitrectomy examinations.

Aged↗

PubMed2003

Scanning laser polarimetry with variable corneal compensation and optical coherence tomography in normal and glaucomatous eyes.

PURPOSE: To evaluate the relationship between visual function and retinal nerve fiber layer (RNFL) measurements obtained with scanning laser polarimetry with variable corneal compensation (SLP-VCC) and optical coherence tomography (OCT). DESIGN: Cross-sectional analysis of normal and glaucomatous eyes in a tertiary care academic referral practice. METHODS: A commercial GDx nerve fiber analyzer was modified to enable the measurement of corneal polarization axis and magnitude so that compensation for corneal birefringence was eye specific. Complete examination, SLP with fixed corneal compensation (FCC) and variable corneal compensation (VCC), optical coherence tomography (OCT) imaging of the peripapillary RNFL, and automated achromatic perimetry were performed in all subjects. Exclusion criteria were visual acuity less than 20/40, diseases other than glaucoma, and unreliable perimetry. RESULTS: Fifty-nine patients (59 eyes; 29 normal, 30 glaucomatous) were enrolled (mean age, 56.7 +/- 20.3 years, range, 20-91). All eyes with glaucoma had associated visual field loss (average mean defect, -8.4 +/- 5.8 dB). Using SLP-FCC, nine of 12 retardation parameters (75%) were significantly less in glaucomatous eyes. Using SLP-VCC, 11of 12 retardation parameters (92%) were significantly less in glaucomatous eyes. Multiple regression models constructed for each retardation parameter with visual field demonstrated that the following VCC parameters were statistically significant whereas FCC parameters were not: ellipse average (FCC, P =.28, VCC, P =.001), superior average (FCC, P =.38, VCC, P <.001), inferior average (FCC, P =.10, VCC, P =.008), average thickness (FCC, P =.30, VCC, P =.031), and superior integral (FCC, P =.43, VCC, P =.001). Similar results were obtained for multiple regression models constructed with OCT-derived RNFL thickness: ellipse average (FCC, P =.99, VCC, P =.002), superior average (FCC, P =.90, VCC, P <.001), inferior average (FCC, P =.61, VCC, P =.007), and superior integral (FCC, P =.92, VCC, P <.001). CONCLUSIONS: Compared with fixed compensation, mean-based SLP parameters generated with SLP-VCC have greater correlation with visual function and RNFL thickness assessments obtained with OCT.

Adult↗

PubMed2002

Hyperfractionated external beam radiation therapy in the treatment of murine transgenic retinoblastoma.

OBJECTIVE: To determine the in vivo efficacy of hyperfractionated external beam radiation therapy (EBRT) in comparison with standard daily EBRT in a murine model of heritable retinoblastoma. METHODS: Two hundred twenty eyes from 6-week-old simian virus-40 large T-antigen--positive mice were treated with a total dose of EBRT ranging from 10-76 Gy (1000 to 7600 rad). One hundred ten eyes underwent EBRT administered in 2.0-Gy (200-rad) fractions once per day. Forty-two eyes received hyperfractionated EBRT administered in 1.2-Gy (120-rad) fractions twice per day, while 48 eyes received EBRT twice daily in fractions of 5.0 Gy (500 rad). Twenty eyes served as untreated controls. All eyes were obtained for histopathologic examination and graded positive if any tumor was present. RESULTS: A dose-dependent inhibition of ocular tumor was observed for EBRT in these transgenic retinoblastoma mice. The tumor control dose for 50% of eyes (TCD(50)) treated with 2.0 Gy fractions of EBRT was 45 Gy (4500 rad) when treatments were administered once daily. A significant increase in tumor control was observed when treatments were administered twice per day at fractions of 1.2 Gy, resulting in a TCD(50) of 33 Gy (3300 rad) (P =.003). A further increase in tumor control was observed when twice-daily EBRT was administered in 5.0 Gy fractions resulting in a TCD(50) of 28 Gy (2800 rad). CONCLUSIONS: Hyperfractionated EBRT safely and effectively controls intraocular retinoblastoma in this transgenic animal model. Use of hyperfractionation allows for a reduction in total radiation delivered dose, while shortening the total treatment time. CLINICAL RELEVANCE: This treatment approach may be applicable in the management of pediatric retinoblastoma by maintaining excellent tumor control, while reducing treatment-associated complications.

Animals↗

PubMed2002

Corneal thickness indices discriminate between keratoconus and contact lens-induced corneal thinning.

PURPOSE: To evaluate two indices generated from measurements obtained from the Orbscan Corneal Topography System (CTS; Orbscan, Inc., Salt Lake City, UT) to distinguish contact lens-induced corneal thinning from keratoconus. The corneal thickness index (CTI) was used to compare central and peripheral corneal thicknesses. The discriminant function 1 (DF1) was used to evaluate corneal thickness and central keratometry measurements. DESIGN: Case-control study. PARTICIPANTS: Fifty-four patients with keratoconus or suspected keratoconus, 75 contact lens wearers, and 67 normal controls. METHODS: In the initial model-building study, the central and peripheral corneal thickness and central keratometry (K) readings were evaluated retrospectively in 1 eye each of 23 patients with clinically defined keratoconus, 31 contact lens wearers, and 43 normal patients with the Orbscan CTS. Two methods (corneal thickness index [CTI] and discriminant function 1 [DF1]) were evaluated for their efficacy in classifying these conditions. The CTI was designed as the ratio between mean peripheral corneal thickness and the central corneal thickness, and the formula for the DF1 was as follows: DF1 = 0.044 x central thickness - 0.030 x nasal thickness + 9.210 x CTI - 0.157 x Max K - 8.9. In the subsequent validation study, the results were verified in a separate group of keratoconus patients (n = 23), keratoconus suspects (n = 8), contact lens wearers (n = 44), and normal patients (n = 24). MAIN OUTCOME MEASURES: Corneal thickness index (CTI) and discriminant function 1 (DF1). RESULTS: The corneal thickness in patients with keratoconus and contact lens wearers was significantly thinner than that of normal eyes in the central and eight peripheral measured sites (P < 0.001). The corneal thickness in contact lens wearers was significantly greater than in keratoconus patients in the inferotemporal (P = 0.013), inferior (P = 0.003), and central (P < 0.001) sites and was borderline different in the superior site (P = 0.07). In the model-building study, the CTI in keratoconus patients (1.28 +/- 0.15) was significantly greater than in contact lens-wearing (1.10 +/- 0.03; P < 0.001) and normal eyes (1.09 +/- 0.04; P < 0.001). The CTI was not significantly different between normal and contact lens-wearing eyes (P = 0.68). A CTI value of 1.16 or more showed a sensitivity of 91% and specificity of 99% in differentiating keratoconus from contact lens-wearing and normal eyes. The DF1 value was significantly lower in keratoconic eyes than in contact lens-wearing and normal eyes. A DF1 value of -0.6 showed a 96% sensitivity and 99% specificity in differentiating keratoconus from contact lens-wearing and normal eyes. Similar results were obtained in the validation study. CONCLUSIONS: Corneal thickness indices generated from the Orbscan CTS appear to be sensitive and specific for diagnosing keratoconus. These indices may prove to be clinically useful parameters for distinguishing keratoconus from contact lens-induced corneal thinning.

Adult↗

PubMed2002

Combined Baerveldt glaucoma drainage implant and trabeculectomy with mitomycin C for refractory glaucoma.

PURPOSE: To describe the surgical technique and clinical outcomes of a procedure for refractory glaucoma, concurrent Baerveldt glaucoma implant (BGI) and trabeculectomy with mitomycin C. MATERIALS AND METHODS: Medical records of all patients who underwent combined Prolene-ligated BGI and trabeculectomy with mitomycin C were retrospectively reviewed. Main outcome measures were intraocular pressure (IOP), number of glaucoma medications, visual acuity, and complications. Kaplan-Meier survival analysis was used to determine success, defined as IOP < 22 mm Hg, no reoperation for glaucoma, and no loss of light perception vision. RESULTS: The mean +/- SD follow-up period for 38 eyes of 36 patients was 34 +/- 36 months (range, 3-121 months), during which 18 of 38 eyes (47%) required laser suture lysis of the Prolene suture. Intraocular pressure was reduced from a mean (+/- SD) preoperative value of 35.7 +/- 12.8 to 12.7 +/- 4.7 mm Hg at 1-year follow-up and 11.9 +/- 5.5 mm Hg at the last follow-up visit ( < 0.001). Number of medicines used for glaucoma was reduced from a mean +/- SD preoperative value of 2.5 +/- 0.9 to 0.5 +/- 0.6 at 1-year follow-up and 0.6 +/- 0.8 at the last follow-up visit ( < 0.001). LogMar visual acuity remained stable at mean of 1.15 +/- 0.85 preoperatively, compared with 1.14 +/- 1.05 at 1-year follow-up, but declined to 1.61 +/- 1.01 at the last follow-up visit, a loss of an average of four lines of vision ( = 0.004). Cumulative success was 91% at year 1, 86% at year 2, and 81% at year 3. Three eyes (8%) had suprachoroidal hemorrhages, one eye (3%) needed reoperation for an extruded implant, one (3%) eye had poor vision due to chronic hypotony, three eyes (8%) required additional glaucoma surgery during the postoperative period, and one eye (3%) needed revision of the implant for pressure control. CONCLUSIONS: Combined BGI and mitomycin C trabeculectomy provides excellent postoperative IOP control in patients with refractory glaucoma.

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