S Robert Witherspoon

Texas Retina Associates, Dallas, Texas, United States

Are you S Robert Witherspoon?

Claim your profile

Publications (7)18.43 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: The prevalence of primary open-angle glaucoma (POAG) in patients with corneal endothelial dystrophy has not been previously studied. Prevalence of POAG in patients with endothelial dystrophy was compared with that in the general population to determine the presence of a relationship between the diseases. Retrospective case-control study. A study of the prevalence of POAG in 430 eyes of 215 patients with endothelial dystrophy was conducted. Patients followed for less than 6 months were excluded. Relative risk of POAG was calculated using age- and race-matched control data from the Baltimore Eye Survey and the Los Angeles Latino Eye Survey for comparison. Ocular hypertension (OHT) and secondary glaucoma (SG) rates after penetrating keratoplasty (PK) and Descemet stripping endothelial keratoplasty (DSEK) were separately analyzed. Relative risk of POAG in white, African American, and Hispanic patients with endothelial dystrophy was 0.94, 2.59, and 3.7, respectively (P = 0.89, 95% confidence interval [CI], -0.028 to 0.0289; P = 0.13; 95% CI, 0.011-0.274; P = 0.055; 95% CI, 0.0423-0.356). Relative risk of SG and combined OHT/SG in PK versus DSEK was 4.15 and 1.95 (P < 0.001; 95% CI, 0.0654-0.322; P = 0.005; 95% CI, 0.116-0.332), respectively. No differences in OHT/SG rates were found comparing PK-triple with PK, DSEK-triple with DSEK, and repeat with primary PK or DSEK (P = 0.98; P = 0.62; P = 0.95; P = 0.87), respectively. No increased risk of POAG was found in patients with endothelial dystrophy. Increased prevalence of OHT/SG was shown with PK versus DSEK; possible mechanisms include mechanical closure of Schlemm's canal by running suture and prolonged steroid use.
    Eye & contact lens 09/2011; 37(6):332-6. DOI:10.1097/ICL.0b013e31822d0fa6 · 1.47 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Transplant chorioretinopathy is a rare complication following solid organ or bone marrow transplantation and can result in severe vision loss. This series presents electroretinogram (ERG) results in patients with this condition. Patients who presented with bilateral vision loss following bone marrow or solid organ transplantation were identified. A complete ophthalmologic examination, fundus photography, and fluorescein angiography (FA) were performed. Full-field ERG was obtained in all patients and a multifocal ERG (mfERG) was obtained in two patients. Four patients were identified. All patients had bilateral vision loss and displayed a characteristic pattern of mottled hyperfluorescence on FA. Three patients developed progressive vision loss ranging from 20/60 to hand motions whereas one retained 20/40 vision. All patients exhibited moderate to severe cone dysfunction, while the degree of rod abnormalities was varied. Two patients with severe cone dysfunction showed mild clinical changes initially, but later developed progressive vision loss and chorioretinal atrophy. Transplant chorioretinopathy patients undergoing ERG testing show cone dysfunction with a variable degree of rod dysfunction. ERG abnormalities preceded the visual acuity and clinical changes in two patients, suggesting that ERG may be a helpful predictor of the clinical course in this rare disease.
    Clinical Ophthalmology 07/2010; 4:777-83. · 0.76 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Three patients with chronic, noninfectious uveitis requiring immunosuppressive therapy underwent fluocinolone acetonide (FA) implant exchange complicated by dissociation of the medication reservoir from its anchoring strut. In 2 patients, the medication reservoir descended into the vitreous cavity and required pars plana vitrectomy with intraocular foreign body removal techniques for its retrieval. The use of viscoelastic or perfluorocarbon to elevate the device was helpful in the safe removal of the FA implant device. Surgeons performing FA implant exchange should be aware of this potential complication and anticipate the possible need for vitreoretinal instrumentation and personnel. Patients undergoing FA explantation or exchange should be counseled regarding this potential complication prior to surgery.
    Archives of ophthalmology 09/2009; 127(9):1218-21. DOI:10.1001/archophthalmol.2009.203 · 4.40 Impact Factor
  • S. Robert Witherspoon · Andreas K. Lauer · Jonathan L. Marinaro
    [Show abstract] [Hide abstract]
    ABSTRACT: Ocular injuries caused by CEWs are rare occurrences. Some 30 years after its introduction, two case reports have documented the sight threatening potential of these weapons [1,2]. In discussing the impact of ocular injuries by CEWs, understanding pertinent ocular and adnexal anatomy as well as the terminology of ocular injuries is useful in effectively managing individuals requiring extrication of an embedded probe.
    TASER® Conducted Electrical Weapons: Physiology, Pathology, and Law, 02/2009: pages 201-209;
  • [Show abstract] [Hide abstract]
    ABSTRACT: Long-term antiretroviral therapy (ART) is associated with lipodystrophy, peripheral neuropathy, lactic acidosis, and myopathy. Blepharoptosis, without prior ART association, is usually caused by age-associated involutional ptosis, but it is also seen in mitochondrial myopathies with external ophthalmoplegia, cardiac conduction disturbances, and neurological impairments. Patients presented over a 2-year period. Four patients underwent surgical blepharoptosis repair. Five human immunodeficiency virus type 1-infected patients (median age, 50 years; range, 46-53 years) who were receiving ART presented with severe blepharoptosis; 2 of these 5 also presented with external ophthalmoplegia. Findings included decreased palpebral fissure height (median, 6.5 mm; normal height, 9 mm), mildly impaired levator function (median, 10 mm; normal, >13 mm), and markedly decreased marginal reflex distance (median, 0.5 mm; normal, 4 mm). A greater advancement of the levator aponeurosis was required during surgical repair, a finding consistent more with myogenic than with involutional blepharoptosis. All patients had severe lipodystrophy, which preceded blepharoptosis by a median interval of 4.7 years (range, 2.8-5.7 years). Four patients also presented with peripheral neuropathy and metabolic abnormalities before the onset of blepharoptosis, and 3 had cardiac conduction disturbances. Patients received ART for a median of 7.8 years (range, 4.9-11.2 years), thymidine analogue-containing ART for a median of 7.1 years (range, 1.2-7.9 years), and protease inhibitor-containing ART for a median of 7.1 years (range, 4.9-8.9 years). We report the novel findings of blepharoptosis and external ophthalmoplegia in patients who are receiving ART. Ptosis was preceded by lipodystrophy with long-term use of both thymidine-analogue- and protease inhibitor-containing ART. The findings are most consistent with myogenic ptosis in a generalized mitochondrial myopathy syndrome. Clinicians should also be watchful for other potential myopathic ptosis-associated complications, including proximal weakness, dysphagia, deafness, and cardiac conduction disturbances.
    Clinical Infectious Diseases 09/2008; 47(6):845-52. DOI:10.1086/591202 · 8.89 Impact Factor
  • Justin Charton · S Robert Witherspoon · Kamel Itani · F Ray Jones · Bradly Marple · Brian Morse
    [Show abstract] [Hide abstract]
    ABSTRACT: We describe 3 cases of natural killer/T-cell lymphoma that presented by masquerading as orbital cellulitis. All of the patients were examined for pain, fever, proptosis, and motility restriction. Computed tomography of the orbits and sinuses revealed orbital soft-tissue swelling without focal abscess in all 3 cases. Bacterial and fungal cultures were negative in each case and all of the patients had initial improvement on systemic antibiotics, only to relapse several days later. Diagnosis of natural killer/T-cell lymphoma was then made based on biopsy of the orbit or sinus. Natural killer/T-cell lymphoma should be considered in cases of orbital cellulitis or sinusitis that fail to respond to traditional management. Biopsy of the affected region should be performed expeditiously to diagnose this condition. Repeat biopsy may be needed.
    Ophthalmic Plastic and Reconstructive Surgery 03/2008; 24(2):143-5. DOI:10.1097/IOP.0b013e3181659867 · 0.88 Impact Factor
  • Source
    S Robert Witherspoon · R Nick Hogan · W Matthew Petroll · V Vinod Mootha
    [Show abstract] [Hide abstract]
    ABSTRACT: To report the clinical, histopathologic, and confocal findings of corneal siderosis. A 35-year-old man presented after a car battery explosion with diffuse left corneal anterior stromal pigment deposition and an intraocular metallic foreign body of the left iris. The corneal pigment was analyzed by confocal microscopy and a lamellar corneal biopsy. Confocal microscopy showed the pigment to be highly reflective material in the corneal stroma with greatest density anteriorly. Histologic examination revealed the pigment to be iron with a diagnosis consistent with corneal siderosis. Corneal biopsy with Prussian blue established siderosis as the etiology of corneal pigmentation. A short delay in the removal of the foreign body contributed to the development of siderosis. The location of the foreign body on the iris may account for the predominant corneal involvement and relative sparing of the retina. Confocal microscopy may be useful in the evaluation of corneal siderosis.
    Cornea 01/2008; 26(10):1270-2. DOI:10.1097/ICO.0b013e318145330b · 2.04 Impact Factor