Ophthalmologist (eyes)
21 years of experience
Accepting new patients

Education ?

Medical School Score
Texas Tech University (1989)
  • Currently 2 of 4 apples

Awards & Distinctions ?

Associations
American Board of Ophthalmology
American Academy of Ophthalmology

Affiliations ?

Dr. Freedman is affiliated with 4 hospitals.

Hospital Affilations

  • University Medical Center - Lubbock
  • Lincoln County Medical Center
  • TX Tech Physicians Associates
  • University Medical Center
  • Publications & Research

    Dr. Freedman has contributed to 17 publications.
    Title Doxycycline's Effect on Ocular Angiogenesis: an in Vivo Analysis.
    Date September 2010
    Journal Ophthalmology
    Excerpt

    To determine the in vivo effect of doxycycline on choroidal angiogenesis and pterygium growth by using a choroidal neovascular (CNV) murine model, a directed in vivo angiogenesis assay (DIVAA) and a pterygium murine model.

    Title The Effective Corneal Refractive Surface As a Function of a Point in Visual Space: a Three-dimensional Analysis.
    Date May 2009
    Journal Ophthalmic & Physiological Optics : the Journal of the British College of Ophthalmic Opticians (optometrists)
    Excerpt

    To develop a three-dimensional optical model of the anterior segment which will provide a basis for understanding the effects of corneal and adnexal problems on vision.

    Title Effective Corneal Refractive Diameter As a Function of the Object Tangent Angle in Visual Space.
    Date May 2006
    Journal Journal of Cataract and Refractive Surgery
    Excerpt

    PURPOSE: To determine whether the currently accepted method of selecting a minimum optical zone diameter for laser refractive surgery that is equal to or slightly greater than the dark-adapted pupil diameter provides a sufficient diameter of corneal surface to focus light arising from objects in the paracentral and peripheral visual field. SETTING: Department of Ophthalmology and Visual Sciences, Texas Tech University Health Sciences Center, Lubbock, Texas, USA. METHODS: An optical model of the anterior segment was developed to calculate the effective corneal refractive diameter (ECRD), which is the diameter of the area of cornea that refracts all incident light rays arising from an object through the physical pupil (PP). This model incorporates the patient variables of central anterior chamber depth (ACD), central corneal curvature (K(c)), and the diameter of the apparent entrance pupil (EP). The model was expanded to incorporate distant objects off the line of sight (LOS), described by their angular displacement from the fixation object in visual space (the object tangent angle delta(ob)). Results were calculated for the 360 meridian degree visual field (ie, for all objects in visual space perceptually displaced from the fixation object by angle delta(ob)). The effect of the prolate nature of the cornea was also investigated. RESULTS: The ECRD expanded rapidly as a function of PP and delta(ob) but was minimally influenced by K(c). Beyond a critical object tangent angle delta(c), light rays striking the corneal vertex were not refracted through the PP, and the ECRD became an annular surface centered on the corneal vertex. The delta(c) was not a function of K, but increased as the PP increased and decreased as the ACD increased. The prolate nature of the cornea had little influence on the ECRD, even for very peripheral light rays. CONCLUSIONS: The ECRD expands rapidly when considering distant objects only slightly displaced from the LOS. A patient treated with an optical zone equal to or slightly greater than the dark-adapted pupil diameter may experience vision quality loss for paracentral and midperipheral objects even under conditions of ambient indoor lighting.

    Title Microarray and Protein Analysis of Human Pterygium.
    Date March 2006
    Journal Molecular Vision
    Excerpt

    PURPOSE: Pterygium is a sunlight-related, ocular-surface lesion that can obscure vision. In order to identify specific genes that may play a role in pterygium pathogenesis, we analyzed the global gene expression profile of pterygium in relation to autologous conjunctiva. METHODS: Oligonucleotide microarray hybridization was used to compare the gene expression profile between human whole pterygium and autologous conjunctiva. Selected genes were further characterized by RT-PCR, western blot, and immunohistochemistry, and comparisons were made with limbal and corneal tissues. RESULTS: Thirty-four genes exhibited a 2 fold or greater difference in expression between human whole pterygium and autologous conjunctiva. Twenty-nine transcripts were increased and five transcripts were decreased in pterygium. Fibronectin, macrophage-inflammatory protein-4 (MIP-4), and lipocalin 2 (oncogene 24p3; NGAL) were increased 9, 5, and 2.4 fold, respectively, while Per1 and Ephrin-A1 were decreased 2 fold in pterygium. Western blots showed that fibronectin and MIP-4 were increased in pterygium compared to limbus, cornea, and conjunctiva. Immunohistochemical analysis showed fibronectin in the stroma; lipocalin 2 in the basal epithelial cells, basement membrane, and extracellular stroma; and MIP-4 in all areas of the pterygium. CONCLUSIONS: These data show both novel and previously identified extracellular-matrix-related, proinflammatory, angiogenic, fibrogenic, and oncogenic genes expressed in human pterygium. Comparisons of selected genes with limbal and corneal tissues gave results similar to comparisons between pterygium and normal conjunctiva. The increased expression of lipocalin 2, which activates matrix metalloproteinases (MMP), is consistent with our previous findings that MMP-9 and other MMPs are highly expressed in pterygium basal epithelium.

    Title Topical Apraclonidine in the Diagnosis of Suspected Horner Syndrome.
    Date July 2005
    Journal Journal of Neuro-ophthalmology : the Official Journal of the North American Neuro-ophthalmology Society
    Excerpt

    Topical cocaine is used to confirm the clinical diagnosis of ocular sympathetic denervation, or Horner Syndrome (HS). Cocaine blocks re-uptake of norepinephrine (NE) by sympathetic nerve terminals in the iris dilator muscle, transiently increasing its concentration in the synaptic junction. Norepinephrine activates alpha1 receptors in the iris dilator to cause pupil dilation. In HS, cocaine fails to dilate the affected pupil as much as the unaffected pupil, but its indirect action makes it a weak dilator, and the test can give equivocal results. Cocaine is also a controlled substance and therefore difficult to obtain. A practical and reliable alternative to cocaine is apraclonidine, an ocular hypotensive agent that has a weak direct action on alpha1 receptors and therefore minimal to no clinical effect on the pupils of normal eyes. Patients with HS have denervation supersensitivity of the alpha1 receptors in the iris stroma of the affected eye, making the pupil dilator responsive to apraclonidine. In patients with HS, reversal of anisocoria occurs after bilateral instillation of apraclonidine 1% or 0.5%. Two cases that demonstrate this effect are reported. Apraclonidine should be considered a candidate to replace cocaine in the pharmacologic diagnosis of HS if a gold-standard comparison study confirms these results.

    Title Rapid, Painless Unilateral Vision Loss in a 37-year-old Healthy Woman.
    Date July 2004
    Journal Survey of Ophthalmology
    Excerpt

    A 37-year-old woman experienced painless, progressive vision loss to no light perception in the left eye over the course of 3 days. The right eye was unaffected. On examination, the only other abnormal finding was a +4 left afferent pupillary defect. She was initially diagnosed with retrobulbar optic neuritis and admitted for treatment with intravenous methylprednisolone. Neuro-imaging revealed a large right anterior cerebral artery aneurysm that crossed the midline to compress the left optic nerve. The aneurysm was treated with coil embolization, which was technically successful but which did not lead to significant improvement in vision.

    Title Transient Homonymous Hemianopia and Positive Visual Phenomena in Nonketotic Hyperglycemic Patients.
    Date June 2004
    Journal American Journal of Ophthalmology
    Excerpt

    PURPOSE: To report a case of a transient homonymous hemianopia in a patient with nonketotic hyperglycemia with negative magnetic resonance imaging (MRI) scans. DESIGN: Case report. METHOD: A 72-year-old woman with diabetes mellitus was referred to the neuro-ophthalmology service with hyperglycemia and multiple visual complaints. RESULTS: The patient was found to have a dense left homonymous hemianopia on examination. An MRI scan of the brain was negative for a lesion affecting the visual pathways. Resolution of the homonymous hemianopia and the patient's symptoms came with normalization of her blood glucose levels. CONCLUSION: Nonketotic hyperglycemia is an important diagnostic consideration in patients who present with homonymous visual field defects but have negative neuroimaging studies.

    Title Neurofibroma Involving the Caruncle.
    Date February 2004
    Journal Archives of Ophthalmology
    Title Pupil Size and the Ablation Zone in Laser Refractive Surgery: Considerations Based on Geometric Optics.
    Date December 2003
    Journal Journal of Cataract and Refractive Surgery
    Excerpt

    PURPOSE: To determine whether the currently accepted method of selecting a minimum ablation zone size for refractive surgery based on dark-adapted pupil diameter is substantiated by geometric optical analysis. SETTING: Department of Ophthalmology and Visual Sciences, Texas Tech University Health Sciences Center, Lubbock, Texas, USA. METHODS: An optical model of the anterior segment was developed to calculate the effective corneal refractive diameter (ECRD), which is the diameter of the area of cornea that refracts all incident light rays arising from objects along the line of sight though the physical pupil (PP). The concept of the entrance pupil (EP) was reexamined and developed, and the ECRD was calculated over a range of corneal curvatures (K), anterior chamber depths (ACDs), and EP sizes. The model was generalized to include oblique light rays. Calculations were performed using MatLab Optimization Toolbox software (The MathWorks). RESULTS: For a given EP size, the ECRD was significantly influenced by K and slightly influenced by ACD. CONCLUSIONS: For objects on the line of sight, the ECRD was smaller than the EP in all cases. Regarding rays from objects in the periphery, the ECRD expanded rapidly as the angle of oblique incidence increased.For objects on the line of sight, the ECRD is always smaller than the clinically measured pupil (EP) because the EP is substantially magnified relative to the PP. Ablation zones larger than the EP should, in theory, prevent scattered or defocused light rays from contributing to the foveal image. When considering objects in the periphery, the increase in ECRD is sufficiently rapid that current refractive procedures cannot stop scattered light from these objects from contributing to the retinal image.

    Title The Weight of the Basic and Clinical Science Course.
    Date September 2003
    Journal Ophthalmology
    Title The Utility of 0.5% Apraclonidine in the Diagnosis of Horner Syndrome.
    Date August 2003
    Journal Archives of Ophthalmology
    Title Beta-cyclodextrins Enhance Bioavailability of Pilocarpine.
    Date December 1993
    Journal Current Eye Research
    Excerpt

    Cyclodextrins have been used to improve drug solubility, stability and absorption for oral and parenteral administration. However, their potential for improving ocular drug delivery has received little attention. To evaluate the ability of hydroxypropyl-beta-cyclodextrins to improve ophthalmic drug bioavailability following topical administration, the miotic effect of topical solutions of pilocarpine was studied in New Zealand White rabbits. Pilocarpine varying in dose from 5 to 500 micrograms in the presence or absence of 5% cyclodextrin was administered (50 microliters) topically and the change in pupil diameter determined. These results demonstrated that pilocarpine alone or in the presence of cyclodextrin produces a dose-related reduction in pupil diameter. The addition of cyclodextrins produced a significant left-shift in the dose response curve, with an ED50 of 64 micrograms and 19 micrograms for pilocarpine and pilocarpine/5% cyclodextrin solutions, respectively. Studies in which the concentration of cyclodextrin was varied revealed that a one-to-one molar ratio of pilocarpine to cyclodextrin was sufficient to provide maximum increase in pilocarpine bioavailability. Electrophysiology and scanning electron microscopic studies demonstrated that cyclodextrin does not disrupt the normal ion transport currents, barrier properties or surface features of the corneal epithelium. Viscosity measurements indicated that difference in the viscosity of pilocarpine and pilocarpine/cyclodextrin solutions cannot account for increased bioavailability of pilocarpine. These data support the idea that the addition of cyclodextrin significantly improves the ocular bioavailability of pilocarpine. This enhanced bioavailability of pilocarpine does not appear to be due to a mechanism destructive to the epithelium or to an increase in vehicle viscosity.

    Title How to Inform the Elderly About Quality Preventive Oral Care.
    Date February 1987
    Journal Illinois Dental Journal
    Title Care Delivery in a University Geriatric Dental Program.
    Date October 1985
    Journal General Dentistry
    Title Geriatric Dentistry in the Predoctoral Curriculum.
    Date July 1985
    Journal Journal of Dental Education
    Excerpt

    The elderly component of the general population has been increasing in the past decades and will continue to increase well into the future. This group of people presents to the dentist with a unique set of characteristics, both dental and physical. To treat the elderly more competently and to provide clinical training to undergraduates simultaneously, a geriatric dental program was initiated in 1976 at the University of Illinois College of Dentistry. The program's current status and operation are described.

    Title Preventive Dentistry.
    Date January 1981
    Journal Quintessence International, Dental Digest
    Title The Elderly Need Your Care, Too.
    Date October 1980
    Journal Dental Student

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