Diagnostic and therapeutic challenges.
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Carotid Artery Diseases↗
Biomedical subjects
Tom S Chang
Publications and source records attributed to Tom S Chang.
Outcomes of 140 consecutive cases of 25-gauge transconjunctival surgery for posterior segment disease.
PURPOSE: To evaluate the safety and efficacy of 25-gauge instrumentation for a variety of vitreoretinal conditions on previously nonvitrectomized eyes. DESIGN: Single-center, retrospective, interventional case series. PARTICIPANTS: One-hundred forty eyes of 140 patients were evaluated at the Doheny Retina Institute from July 2002 to July 2003. INTERVENTION: All patients underwent surgical procedures using the Millennium 25-gauge Transconjunctival Standard Vitrectomy system. Twenty eyes (14.3%) underwent procedures without vitrectomy. MAIN OUTCOME MEASURES: Postoperative visual acuity (VA), intraocular pressure, surgical time, postoperative inflammation, complications, and number of sutured sites. RESULTS: No intraoperative complications were noted. No cases required conversion to 20-gauge machines. Ten cases (7.1%) involved single-site sclerotomy suture placement due to bleb formation at the conclusion of the procedure, but 5 of these entry sites were enlarged to facilitate larger instrumentation for tissue manipulation. Median VA improved from 20/250 (logarithm of the minimum angle of resolution, 1.08+/-0.47) preoperatively to 20/60 (0.47+/-0.30) (P<0.0001) at final visit. Mean follow-up was 33.8+/-9.7 weeks, and all eyes were observed for a minimum of 12 weeks. Mean total surgical time was 17.4+/-6.9 minutes. Intraocular pressures remained stable throughout the postoperative course. Five eyes (3.8%) presented on day 1 with shallow choroidal detachments, but all resolved by day 7, and none required volume infusion during the postoperative period. All but one of these cases was within the first 50 procedures performed. No detectable inflammation was noted in any eyes by 4 weeks postoperatively. No case of retinal detachment or endophthalmitis was recorded. CONCLUSIONS: Transconjunctival surgery using 25-gauge instrumentation may hasten postoperative recovery by decreasing overall surgical time and postoperative inflammation. Procedures requiring minimal intraocular manipulation did not require sutures and, thus, may be better suited for this surgical modality.
Aged↗
The white dot syndromes.
PURPOSE: To review the distinctive and shared features of the white dot syndromes, highlighting the clinical findings, diagnostic test results, proposed etiologies, treatments, and prognosis. DESIGN: Review. METHODS: Review of the literature. RESULTS: Common white dot syndromes are reviewed, including acute posterior multifocal placoid pigment epitheliopathy, birdshot chorioretinopathy, diffuse unilateral subacute neuroretinitis, multiple evanescent white dot syndrome, multifocal choroiditis with panuveitis, serpiginous choroiditis, and acute zonal occult outer retinopathy. CONCLUSIONS: The white dot syndromes are a group of disorders characterized by multiple whitish-yellow inflammatory lesions located at the level of the outer retina, retinal pigment epithelium, and choroid. For clinicians and researchers alike, they present significant diagnostic and therapeutic challenges.
Choroid Diseases↗
Anterior segment complications associated with scleral buckling.
This article discusses the early and late postoperative complications of scleral buckling involving the anterior segment of the eye. Emphasis is placed on the incidence, pathogenesis, clinical presentation, and treatment of each complication. Preventive measures are also discussed.
Anterior Eye Segment↗
Limited macular translocation for the management of subfoveal choroidal neovascularization after photodynamic therapy.
PURPOSE: To report our initial experience of limited macular translocation in patients with subfoveal choroidal neovascularization secondary to age-related macular degeneration following photodynamic therapy with verteporfin. DESIGN: Interventional case series. METHODS: Retrospective review of four eyes of four consecutive patients with subfoveal choroidal neovascularization secondary to age-related macular degeneration who underwent effective limited macular translocation following photodynamic therapy. The mean logarithm of minimal angle of resolution preoperative best-corrected visual acuity was 20/190 (range, 20/150 to 20/200), and in all eyes the visual acuity was 20/150 or worse. The major outcome measures were postoperative visual acuity and complications related to the surgery. RESULTS: The mean postoperative follow-up was 6.75 months (range, 6-8 months). Postoperative best-corrected visual acuity improved by 2 or more Snellen lines of visual acuity in three of four eyes (75%) and remained within 1 line in one of four eyes (25%). The mean postoperative best-corrected visual acuity was 20/100 (range, 20/40 to 20/150), and in two of the four eyes (50%) the visual acuity achieved was 20/100 or better. No complication was observed. CONCLUSIONS: Limited macular translocation may be a viable option in patients who have previously undergone photodynamic therapy.
Aged↗
Characteristics of visual loss by scanning laser ophthalmoscope microperimetry in eyes with subfoveal choroidal neovascularization secondary to age-related macular degeneration.
PURPOSE: To evaluate the effects of subfoveal choroidal neovascularization secondary to age-related macular degeneration on functional parameters obtained by scanning laser ophthalmoscope microperimetry. DESIGN: Retrospective observational case series and cross-sectional study. METHODS: At the Doheny Retina Institute and Wilmer Eye Institute a consecutive series of 179 eyes of 175 patients with subfoveal choroidal neovascularization secondary to age-related macular degeneration was studied. The onset of visual symptoms, best-corrected visual acuity, fluorescein angiography, evaluation of fundus microperimetry and fixation pattern using the Rodenstock scanning laser ophthalmoscope were obtained for each patient. The main outcome measures were central retinal sensitivity and fixation pattern (fixation location and fixation stability) in eyes with subfoveal choroidal neovascularization and their relationship to the length of disease, type and characteristics of choroidal neovascularization, and visual acuity. RESULTS: Of 179 eyes, 135 (75%) had central fixation, 27 (15%) had poor central fixation, and 17 (9%) had predominantly eccentric fixation. Seventy-six eyes (42%) had stable fixation, 70 eyes (39%) had relatively unstable fixation, and 33 eyes (18%) had unstable fixation. In 50 eyes (28%) a dense central scotoma was noted. Eighty-nine of 100 eyes (89%) with length of symptoms of less than 3 months had predominantly central fixation and 58 (58%) had stable fixation; 14 of 34 eyes (41%) with length of symptoms of more than 6 months had predominantly central fixation, and 5 eyes (15%) had stable fixation. In 15 eyes of patients who elected not to receive treatment, successive scanning laser ophthalmoscope microperimetry were obtained over time (follow-up of 18 months after onset of symptoms). Three months or less after the onset of symptoms, 13 eyes (87.7%) had predominantly central fixation and 9 eyes (60%) had stable fixation. More than 3 months and 6 months or less after the onset of symptoms, 10 eyes (66.7%) had predominantly central fixation and 7 eyes (46.7%) had stable fixation. This trend was further demonstrated in eyes more than 6 months after the onset of symptoms. CONCLUSIONS: We conclude that the sequence of events leading to visual function deterioration appears to involve an initial mild decrease in central retinal sensitivity and visual acuity followed by progressive fixation instability and, ultimately, development of an absolute central scotoma with totally eccentric fixation. Increased length of disease is associated with worse fixation pattern and retinal sensitivity deterioration as assessed by scanning laser ophthalmoscope microperimetry. A better understanding of the characteristics of visual loss assessed by fixation pattern evaluation and microperimetry in age-related macular degeneration may help optimize timing, patient selection, and treatment options in eyes with this condition.
Aged↗
Inverted pneumatic retinopexy: a method of treating retinal detachments associated with inferior retinal breaks.
PURPOSE: To introduce the new approach of inverted pneumatic retinopexy for the management of rhegmatogenous retinal detachments with inferior retinal breaks. DESIGN: Retrospective, noncomparative case series. PARTICIPANTS: Eleven patients presenting with rhegmatogenous retinal detachments with causative inferior retinal breaks. INTERVENTION: Sterile gas/air injection, cryopexy/laser retinopexy, with inverted positioning. MAIN OUTCOME MEASURES: Postoperative primary and final anatomical outcome, visual acuity, and complications. RESULTS: Patients were followed for a minimum of 3 months (mean, 5.1 months). Primary retinal reattachment was obtained in 10 of 11(91%) patients. One patient sustained a redetachment secondary to proliferative vitreoretinopathy, resulting in a single operation reattachment rate of 82%. Final reattachment was obtained in 11 of 11 (100%) patients. Mean visual acuity improved about 3 lines from 20/60 to 20/30, with 11 of 11 patients experiencing improvement in their visual acuity. Two patients required an additional surgical procedure to achieve final anatomic success. No new breaks were identified in the postoperative period, and no complications resulted from the pneumatical procedure. CONCLUSIONS: Inverted pneumatic retinopexy can successfully repair retinal detachments with inferior retinal breaks under appropriate conditions.
Adult↗
Induction of proliferative vitreoretinopathy by a unique line of human retinal pigment epithelial cells.
BACKGROUND: The most widely used models of proliferative vitreoretinopathy (PVR) rely on injection of cells into the vitreous of animals. Using retinal pigment epithelial (RPE) cells from human PVR membranes may produce a more accurate model of human PVR. We performed a study to determine whether human RPE cells derived from a single epiretinal membrane (ERM) are capable of inducing the same disease in the rabbit eye, and whether the induced ERMs had cellular components similar to those of human PVR membranes. METHODS: Cells were harvested from a human ERM obtained at surgery for PVR. RPE cells were cultured from the membrane and injected into the right eye of 24 New Zealand albino rabbits. The left eyes served as controls. The eyes were examined by indirect ophthalmoscopy over 4 weeks. The enucleated eyes were then examined by means of microscopy and histochemical analysis. RESULTS: By day 7, PVR had developed in all but 1 of the 24 experimental eyes, with 8 progressing to localized tractional retinal detachment. By day 21, localized tractional retinal detachment had developed in 17 eyes; 1 eye progressed to extensive tractional retinal detachment by day 28. Immunostaining showed that mostly RPE cells, but also myofibroblasts, glial cells and collagen, were present in the newly formed rabbit PVR membranes. INTERPRETATION: Human RPE cells cultured from a PVR membrane appear to be capable of inducing PVR in rabbits. The resultant ERMs are similar to those formed in human PVR and consist mainly of RPE cells.
Animals↗
Assessment of vision-related function in patients with age-related macular degeneration.
OBJECTIVE: To investigate the validity of the visual function index (VF-14) in assessing visual function in patients with age-related macular degeneration (AMD). DESIGN: Prospective noncomparative observational case series. PARTICIPANTS: One hundred fifty-nine consecutive patients attending a sole practitioner's academic retina-only clinic from May 1998 through August 1998 and from May 1999 through August 1999. MAIN OUTCOME MEASURES: Correlations were calculated between the VF-14 scores and the medical outcomes study 36-item short form (SF-36), weighted comorbidity scale, visual acuity and clinical AMD severity (stage), and vision self-assessment scales. Documentation of the severity of macular degeneration was performed by a sole examiner. RESULTS: There was a moderately strong correlation between visual acuity and trouble with vision (r = 0.51), satisfaction with vision (r = -0.50), and overall quality of vision (r = -0.56). A strong correlation was noted between VF-14 score and patients' self-rating of amount of trouble with vision (r = -0.67), satisfaction with vision (r = 0.62), and overall quality of vision (r = 0.67). In comparison, correlations between SF-36 score and patients' self-rating of amount of trouble with vision, satisfaction with vision, and overall quality of vision ranged from r = 0.37 to r = -0.40. Linear regression analysis for the overall study population indicated that AMD severity was not an independently significant predictor of VF-14 score after adjusting for visual acuity. However, among patients with 20/20 vision in the better eye, AMD severity was an independently significant predictor of VF-14 score after adjusting for visual acuity in the worse eye. CONCLUSIONS: The VF-14 exhibits a considerable degree of validity as a measure of functional impairment in patients with AMD. Age-related macular degeneration severity was an independently significant predictor of VF-14 score in the group of patients with 20/20 vision in the better eye, but this did not hold true for the overall study population. Age-related macular degeneration is associated with substantial impairment in reported visual function.
Aged↗
Initial experience using the transconjunctival sutureless vitrectomy system for vitreoretinal surgery.
OBJECTIVE: To describe the initial experience and to evaluate the safety and feasibility of using the 25-gauge Transconjunctival Sutureless Vitrectomy System (TSV) for a variety of vitreoretinal procedures. DESIGN: Retrospective review of a consecutive interventional case series. PARTICIPANTS: Thirty-five eyes of 33 patients, including cases of idiopathic epiretinal membrane (12 cases), retinal detachment (6 cases), macular hole (5 cases), branch retinal vein occlusion (4 cases), retinopathy of prematurity (4 cases), persistent diabetic macular edema (1 case), diabetic vitreous hemorrhage (1 case), retained lens material after cataract extraction (1 case), and Norrie disease (1 case). INTERVENTION: All patients underwent surgery using the 25-gauge TSV. MAIN OUTCOME MEASURES: Intraocular pressure, visual acuity, and postoperative complications. RESULTS: The median preoperative intraocular pressure was 16 mmHg (range, 10-21 mmHg), whereas the median intraocular pressure on the first postoperative day was 12 mmHg (range, 6-28 mmHg). The median intraocular pressure at 1 week and 1 month were both 16 mmHg (range, 10-30 mmHg). Overall, the median preoperative visual acuity was 20/100 (range, 20/30 to hand motions), and the median postoperative visual acuity after a mean follow-up of 14 weeks (range, 1-60 weeks) was 20/60 (range, 20/20-20/150). One eye developed a postoperative retinal detachment. CONCLUSIONS: The 25-gauge TSV seems to be practical and safe for a variety of vitreoretinal procedures. The concept of transconjunctival surgery has the potential to increase the efficiency of a variety of vitreoretinal surgeries and possibly hasten the postoperative recovery and outcomes in several conditions by simplifying the surgical procedure; minimizing surgically induced trauma; and decreasing the convalescence period, the operating time, and the postoperative inflammatory response.
Adult↗
Patient selection for macular translocation surgery using the scanning laser ophthalmoscope.
OBJECTIVES: To evaluate the use of the scanning laser ophthalmoscope (SLO) as a predictor for potential visual improvement in eyes with subfoveal choroidal neovascularization (CNV) secondary to age-related macular degeneration (AMD) undergoing limited macular translocation. DESIGN: Retrospective noncomparative case series. PARTICIPANTS: Consecutive series of 71 eyes of 70 patients with subfoveal CNV secondary to AMD that underwent effective and uncomplicated limited macular translocation at the Wilmer Ophthalmological Institute. METHODS: Evaluation of the fundus microperimetry and fixation pattern was conducted on all patients using the Rodenstock scanning laser ophthalmoscope (G. Rodenstock Instrument GmbH, Munich, Germany) within 72 hours before surgery. MAIN OUTCOME MEASURES: Sensitivity and specificity in addition to positive and negative predictive values of SLO findings for visual outcome after macular translocation. RESULTS: Stable fixation presented the highest positive predictive value for visual acuity equal to or better than 20/100 (30 of 33 = 0.91), and predominantly eccentric fixation had the highest negative predictive value for visual acuity worse than 20/100 (7 of 9 = 0.78). Sensitivity was higher for the presence of predominantly central fixation (42 of 48 = 0.87), and specificity was higher for relatively unstable/unstable fixation (20 of 23 = 0.87). CONCLUSIONS: Eyes with stable and central fixation (without dense central scotoma) good preoperative visual acuity, and short length of symptoms are those with the greatest chance to achieve good vision after macular translocation. The knowledge of the fixation and microperimetry pattern enables better understanding of the macular function in eyes with AMD and may be useful for evaluation of baseline retinal cell viability. Incorporation of these testing modalities may help to optimize patient selection for macular translocation or other future techniques aimed at rescuing photoreceptors.
Aged↗
Validity of the SF-12 quality of life instrument in patients with retinal diseases.
OBJECTIVE: To investigate the construct validity and reliability of the SF-12 with the SF-36 composite scores in patients with retinal diseases. DESIGN: Cross-sectional study. PARTICIPANTS: One thousand eighty-one patients with retinal disease presenting for care at a tertiary referral university-based retina practice. METHODS: Each patient completed the SF-36 before his or her initial ocular examination. The SF-12 is based on a subset of 12 items from the SF-36. MAIN OUTCOME MEASURES: Physical Composite Score (PCS) and Mental Composite Score (MCS) as determined by the SF-36 and SF-12. RESULTS: Eight hundred thirty-nine (78%) of the participants had scorable PCS and MCS scores on the SF-12. No significant differences were found between the SF-36 and SF-12 for the PCS and MCS overall and stratified by the four most frequently occurring disease categories (all P > 0.20). There were statistically significant differences across the disease categories in the mean PCS scores (P < 0.001) on the SF-36 and SF-12 and the MCS score on the SF-36 (P = 0.04). The SF-12 PCS and MCS scores were highly correlated with similar indicators (composite scores and subscales) on the SF-36. CONCLUSIONS: The SF-12 is a valid measure of general health status for ophthalmic research, as long as differences in mental composite scores do not need to be demonstrated between different ocular disease groups. The benefit of reduced administration time makes the SF-12 a recommended general quality-of-life outcomes tool.
Adult↗
A new 25-gauge instrument system for transconjunctival sutureless vitrectomy surgery.
OBJECTIVES: To introduce and evaluate the infusion and aspiration rates and operative times of the 25-gauge transconjunctival sutureless vitrectomy system (TSV) DESIGN: In vitro experimental and comparative interventional study. PARTICIPANTS AND CONTROLS: Twenty eyes of 20 patients underwent a variety of vitreoretinal procedures using the 25-gauge TSV, including idiopathic epiretinal membrane (n = 10), macular hole (n = 4), rhegmatogenous retinal detachment (n = 3), branch retinal vein occlusion (n = 2), diabetic vitreous hemorrhage (n = 1), and 20 cases similar in diagnosis and severity were matched to provide comparison between duration of individual portions of the surgical procedures with the existing 20-gauge vitrectomy system. METHODS: Description of the 25-gauge TSV is provided; infusion and aspiration rates of the 25-gauge and standard 20-gauge vitrectomy system were measured in vitro using balanced saline solution and porcine vitreous for several levels of aspirating power and bottle height, and operating times of individual portions of surgical procedures were measured for the 25-gauge and 20-gauge vitrectomy system. MAIN OUTCOME MEASURES: Infusion, aspiration rates, and operative times of the 20-gauge and 25-gauge vitrectomy system. RESULTS: Infusion and aspiration rates of the 25-gauge TSV system were reduced by an average of 6.9 and 6.6 times, respectively, compared with the 20-gauge system when balanced saline solution was used. The average flow rate of the Storz 25-gauge cutter (at 500 mmHg, 1500 cuts per minute [cpm]) was 40% greater than that of the 20-gauge pneumatic cutter (at 250 mmHg, 750 cpm) but about 2.3 times less than the 20-gauge high-speed cutter (at 250 mmHg, 1500 cpm). Mean total operative time was significantly greater for the 20-gauge high-speed cutter (26 minutes, 7 seconds) than for the 25-gauge vitrectomy system (17 minutes, 17 seconds) (P = 0.011). CONCLUSIONS: Although the infusion and aspiration rates of the 25-gauge instruments are lower than those for the 20-gauge high-speed vitrectomy system, the use of 25-gauge TVS may effectively reduce operative times of select cases that do not require the full capability of conventional vitrectomy.
Diabetes Complications↗
Posterior retinal vasculitis associated with multiple sclerosis.
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Adult↗