Primary Open-Angle Glaucoma Workup

  • Author: Jerald A Bell, MD; Chief Editor: Hampton Roy Sr, MD   more...
 
Updated: Feb 14, 2012
 

Laboratory Studies

Patients suspected of having normal-tension glaucoma may need workup to rule out other causes for optic neuropathy, including, but not limited to, CBC, erythrocyte sedimentation rate (ESR), serology for syphilis (micro-hemagglutination-Treponema pallidum [MHA-TP], not Venereal Disease Research Laboratory [VDRL] test), and if suggested by the pattern of visual field loss, neuroimaging.

Progressive visual field loss in a patient with glaucoma is shown in the image below.

Example of progressive visual field loss over timeExample of progressive visual field loss over time (from top to bottom) in a patient with glaucoma. Notice the early appearance of an inferior nasal step and arcuate loss, with progressive enlargement and increasing density of the scotomata over time. Courtesy of M. Bruce Shields, MD.

Some researchers have suggested an autoimmune etiology for some glaucomatous optic neuropathies and have identified monoclonal gammopathies. Serum protein electrophoresis can identify these rare individuals.

Next

Imaging Studies

Fundus photography provides a permanent record of the appearance of the optic disc. Photographs taken over a period of time may be compared to track the progression of glaucoma.

The retinal nerve fiber layer sometimes can be imaged on high-contrast black and white film using red-free techniques. This can allow identification of nerve fiber layer defects that are characteristic of glaucomatous damage.

New techniques that use optical analysis of different physical properties of light can document the status of the optic nerve and the thickness of the nerve fiber layer, and they can be used to detect changes over time. The value of these technologies for diagnosing and following glaucoma over time continues to be an active topic of discussion and investigation. Modalities of the various technologies continue to be upgraded and enhanced, hopefully increasing the accuracy and likelihood of detecting glaucomatous damage.

Confocal scanning laser ophthalmoscopy (eg, HRT III) can examine the optic disc and peripapillary retina in 3 dimensions and provides quantitative information about the cup, neuroretinal rim, and contour of the nerve fiber layer. Increased resolution and software enhancements continue to improve this technology.

Scanning laser polarimetry (eg, GDX) measures the change in the polarization state of an incident laser light passing through the naturally birefringent nerve fiber layer to provide indirect estimates of peripapillary nerve fiber layer thickness. Improvements in neutralizing corneal light polarization (as opposed to that of the nerve fiber layer) have helped to decrease artifact in data obtained by this methodology.

Optical coherence tomography (eg, Stratus OCT) uses reflected light in a manner analogous to the use of sound waves in ultrasonography to create computerized cross-sectional images of the retina and optic disc, and it also gives quantitative information about the peripapillary retinal nerve fiber layer thickness. Newer increased resolution and three-dimensional spectral analysis hardware and software are also helping to propel this technology.

For these technologies, continuing studies show good reproducibility over time for the same instrument. However, significant variability and fluctuating correlation between instruments is still noted, especially when compared with visual field testing results and other clinical examination findings. Therefore, testing results for each modality should be clinically confirmed by examination findings and other testing and not just singly used for clinical decision-making.[8]

Fluorescein angiography, ocular blood flow analysis via laser Doppler flowmetry, color vision measurements, contrast sensitivity testing, and electrophysiological tests (eg, pattern electroretinograms) are used currently as research tools in the evaluation and management of patients with POAG. Routine clinical use is not advocated at this time.

Ultrasound biomicroscopy (UBM) may prove to be helpful in the future for obtaining a better view of the angle, iris, and ciliary body structures to rule out anatomical pathology and secondary causes of elevated IOP.

Previous
Next

Other Tests

Other tonometric methods

Goldmann applanation tonometry is considered the criterion standard. However, Goldmann applanation is dependent on corneal rigidity, curvature, thickness (measured by pachymetry), and other biomechanical properties, so there is much room for error in patients with atypical corneas or other eye conditions. Particularly, with the advent of refractive corneal procedures, and the subsequent exponential increase of postsurgical eyes, the issue of tonometric accuracy is becoming more and more paramount.

Studies now strongly suggest that applanation pressures vary significantly depending on corneal thickness.

  • Some patients diagnosed with OHT actually may be normotensive when corrected for increased corneal thickness.
  • Some supposed glaucoma suspects or patients with apparent low-tension glaucoma (with normal range IOPs on applanation) can have abnormally thin corneas on pachymetry (central corneal thickness measurements); therefore, their IOP measurements are underestimated by applanation.
  • Pachymetry may play a role in determining a fudge factor by which to adjust each patient's IOP measurement.
  • Pachymetry plays a role in the development of glaucoma in those with OHT (see Morbidity/Mortality and the image below).Ocular hypertension study (OHTS). Percentage of paOcular hypertension study (OHTS). Percentage of patients who developed glaucoma during this study, stratified by baseline intraocular pressure (IOP) and central corneal thickness (CCT).

Correction values according to corneal thickness are shown below.

Correction values according to corneal thickness. Correction values according to corneal thickness.

Other technology

Other technologies for measuring intraocular pressure continue to be studied to determine if they are more accurate than Goldmann tonometry. To date, none have been able to surpass it in accuracy for all patients; however, in the future, they may be useful for those who have abnormal pachymetry or other corneal properties. Their role is yet to be finalized.[9, 10, 11, 12] Two examples of new technology are described below.

The Ocular Response AnalyzerTM from Reichert[13] uses a rapid air impulse and an electro-optical system to record two applanation pressure measurements; one measurement is while the cornea is moving inward, and the other measurement is as the cornea returns. Because of its biomechanical properties, the cornea resists the dynamic air puff, thereby causing delays in the inward and outward applanation events and resulting in two different pressure values. See the image below.

Intraocular pressure measurements. Adapted from ReIntraocular pressure measurements. Adapted from Reichert Ophthalmic Instruments, Ocular Response Analyzer, How does it work Web page.

The average of these two pressure values provides a repeatable, Goldmann-correlated IOP measurement. The difference between these two values is referred to as corneal hysteresis, which is a measurement of the corneal tissue properties that is a result of viscous damping in the corneal tissue. Low corneal hysteresis demonstrates that the cornea is less capable of absorbing (damping) the energy of the air pulse. Clinical data from several studies show a universal reduction in post-LASIK corneal hysteresis.

Some experts hypothesize that this is not primarily a function of corneal thinning, but rather a result of weakening of the tissue structure related to creation of the flap. Decreased corneal hysteresis may also play a role in indicating the presence or onset of other corneal tissue disorders.

The PASCAL Dynamic Contour TonometerTM is a digital contact tonometer that directly measures IOP continuously based on a numeric output of IOP and ocular pulse amplitude (OPA). Unlike applanation tonometry, which is influenced by corneal thickness and other characteristics of the cornea, the PASCAL Dynamic Contour TonometerTM provides a direct measurement of IOP, independent of interindividual variations in corneal properties and biomechanics, and also measures pulsatile pressure fluctuations caused by the change in ocular blood flow during systole versus diastole.[1, 13]

In cases of increased corneal or scleral rigidity (ie, S/P keratoplasty, scleral buckle), the newer methods, as described above, as well as other alternatives, such as pneumotonometry or Tono-Pen, may also be more accurate than applanation methods.

Other tests

Other tests of historical and research interest include the following:

  • Tonography, which has been used to help determine trabecular outflow facility, is primarily a research tool used in testing pharmacologic agents.
  • Provocative testing (eg, water-drinking test) was used in the past to try to differentiate who would develop early open-angle glaucoma. This test was of no aid in distinguishing those patients who would develop visual field defects from those who would not develop them.

Patients whose visual field defects seem to progress in a manner uncharacteristic of glaucoma should have a workup for other causes of visual loss.

Previous
Next

Procedures

See Surgical Care.

Previous
Proceed to Treatment & Management
 
 
Contributor Information and Disclosures
Author

Jerald A Bell, MD  Staff Physician, Department of Ophthalmology, Billings Clinic

Jerald A Bell, MD is a member of the following medical societies: American Academy of Ophthalmology

Disclosure: Nothing to disclose.

Specialty Editor Board

Neil T Choplin, MD  Adjunct Clinical Professor, Department of Surgery, Section of Ophthalmology, Uniformed Services University of Health Sciences

Neil T Choplin, MD is a member of the following medical societies: American Academy of Ophthalmology, American Glaucoma Society, Association for Research in Vision and Ophthalmology, and California Medical Association

Disclosure: Nothing to disclose.

Francisco Talavera, PharmD, PhD  Adjunct Assistant Professor, University of Nebraska Medical Center College of Pharmacy; Editor-in-Chief, Medscape Drug Reference

Disclosure: Medscape Salary Employment

Martin B Wax, MD  Clinical Professor, Department of Ophthalmology, University of Texas Southwestern Medical School; Vice President, Ophthalmology Research and Development, Head, Ophthalmology Discovery Research, Alcon Labs, Inc

Martin B Wax, MD is a member of the following medical societies: American Academy of Ophthalmology, American Glaucoma Society, and Society for Neuroscience

Disclosure: Nothing to disclose.

Lance L Brown, OD, MD  Ophthalmologist, Affiliated With Freeman Hospital and St John's Hospital, Regional Eye Center, Joplin, Missouri

Disclosure: Nothing to disclose.

Chief Editor

Hampton Roy Sr, MD  Associate Clinical Professor, Department of Ophthalmology, University of Arkansas for Medical Sciences

Hampton Roy Sr, MD is a member of the following medical societies: American Academy of Ophthalmology, American College of Surgeons, and Pan-American Association of Ophthalmology

Disclosure: Nothing to disclose.

Additional Contributors

The authors and editors of eMedicine gratefully acknowledge the contributions of previous coauthors, Robert J Noecker, MD, and Emily Patterson, MD, to the development and writing of this article.

References

  1. Bathija R, Gupta N, Zangwill L, Weinreb RN. Changing definition of glaucoma. J Glaucoma. Jun 1998;7(3):165-9. [Medline].

  2. Van Buskirk EM, Cioffi GA. Glaucomatous optic neuropathy. Am J Ophthalmol. Apr 15 1992;113(4):447-52. [Medline].

  3. Costa VP, Jimenez-Roman J, Carrasco FG, Lupinacci A, Harris A. Twenty-four-hour ocular perfusion pressure in primary open-angle glaucoma. Br J Ophthalmol. Oct 2010;94(10):1291-4. [Medline].

  4. Czudowska MA, Ramdas WD, Wolfs RC, Hofman A, De Jong PT, Vingerling JR, et al. Incidence of Glaucomatous Visual Field Loss: A Ten-Year Follow-up from the Rotterdam Study. Ophthalmology. Sep 2010;117(9):1705-12. [Medline].

  5. De Moraes CG, Juthani VJ, Liebmann JM, Teng CC, Tello C, Susanna R Jr, et al. Risk factors for visual field progression in treated glaucoma. Arch Ophthalmol. May 2011;129(5):562-8. [Medline].

  6. Rao HL, Kumar AU, Babu JG, Senthil S, Garudadri CS. Relationship between Severity of Visual Field Loss at Presentation and Rate of Visual Field Progression in Glaucoma. Ophthalmology. Feb 2011;118(2):249-53. [Medline].

  7. Nouri-Mahdavi K, Zarei R, Caprioli J. Influence of visual field testing frequency on detection of glaucoma progression with trend analyses. Arch Ophthalmol. Dec 2011;129(12):1521-7. [Medline].

  8. Leung CK, Liu S, Weinreb RN, et al. Evaluation of retinal nerve fiber layer progression in glaucoma a prospective analysis with neuroretinal rim and visual field progression. Ophthalmology. Aug 2011;118(8):1551-7. [Medline].

  9. Chihara E. Assessment of true intraocular pressure: the gap between theory and practical data. Surv Ophthalmol. May-Jun 2008;53(3):203-18. [Medline].

  10. ElMallah MK, Asrani SG. New ways to measure intraocular pressure. Curr Opin Ophthalmol. Mar 2008;19(2):122-6. [Medline].

  11. Annette H, Kristina L, Bernd S, Mark-Oliver F, Wolfgang W. Effect of central corneal thickness and corneal hysteresis on tonometry as measured by dynamic contour tonometry, ocular response analyzer, and Goldmann tonometry in glaucomatous eyes. J Glaucoma. Aug 2008;17(5):361-5. [Medline].

  12. Kaufmann C, Bachmann LM, Thiel MA. Comparison of dynamic contour tonometry with goldmann applanation tonometry. Invest Ophthalmol Vis Sci. Sep 2004;45(9):3118-21. [Medline].

  13. Reichert, Inc. The Ocular Response Analyzer. Available at http://www.ocularresponseanalyzer.com/. Accessed 2008.

  14. Heijl A, Peters D, Leske MC, Bengtsson B. Effects of argon laser trabeculoplasty in the early manifest glaucoma trial. Am J Ophthalmol. Nov 2011;152(5):842-8. [Medline].

  15. Francis BA, Hong B, Winarko J, et al. Vision loss and recovery after trabeculectomy: risk and associated risk factors. Arch Ophthalmol. Aug 2011;129(8):1011-7. [Medline].

  16. Allen RC, Netland PA, eds. Glaucoma Medical Therapy: Principles and Management. American Academy of Ophthalmology; 1999.

  17. Alward WL. The genetics of open-angle glaucoma: the story of GLC1A and myocilin. Eye. Jun 2000;14 (Pt 3B):429-36. [Medline].

  18. American Academy of Ophthalmology. Preferred Practice Patterns: Primary Open Angle Glaucoma Suspect and POAG. 1995-1996.

  19. Ang GS, Bochmann F, Townend J, et al. Corneal biomechanical properties in primary open angle glaucoma and normal tension glaucoma. J Glaucoma. Jun-Jul 2008;17(4):259-62. [Medline].

  20. Ashaye AO, Adeoye AO. Characteristics of patients who dropout from a glaucoma clinic. J Glaucoma. Apr-May 2008;17(3):227-32. [Medline].

  21. Aung T, Chew PT, Yip CC, et al. A randomized double-masked crossover study comparing latanoprost 0.005% with unoprostone 0.12% in patients with primary open-angle glaucoma and ocular hypertension. Am J Ophthalmol. May 2001;131(5):636-42. [Medline].

  22. Azuara-Blanco A, Burr JM. Assessment of glaucoma imaging technology. Ophthalmology. Jul 2008;115(7):1266-7; author reply 1267-8. [Medline].

  23. Bakri SJ, McCannel CA, Edwards AO, et al. Persisent ocular hypertension following intravitreal ranibizumab. Graefes Arch Clin Exp Ophthalmol. Jul 2008;246(7):955-8. [Medline].

  24. Beckers HJ, Schouten JS, Webers CA, et al. Side effects of commonly used glaucoma medications: comparison of tolerability, chance of discontinuation, and patient satisfaction. Graefes Arch Clin Exp Ophthalmol. Oct 2008;246(10):1485-90. [Medline].

  25. Bengtsson B. A new rapid threshold algorithm for short-wavelength automated perimetry. Invest Ophthalmol Vis Sci. Mar 2003;44(3):1388-94. [Medline].

  26. Bengtsson B, Heijl A. Normal intersubject threshold variability and normal limits of the SITA SWAP and full threshold SWAP perimetric programs. Invest Ophthalmol Vis Sci. Nov 2003;44(11):5029-34. [Medline].

  27. Berdahl JP, Allingham RR, Johnson DH. Cerebrospinal fluid pressure is decreased in primary open-angle glaucoma. Ophthalmology. May 2008;115(5):763-8. [Medline].

  28. Berisha F, Feke GT, Hirose T, et al. Retinal blood flow and nerve fiber layer measurements in early-stage open-angle glaucoma. Am J Ophthalmol. Sep 2008;146(3):466-472. [Medline].

  29. Bramley T, Peeples P, Walt JG, et al. Impact of vision loss on costs and outcomes in medicare beneficiaries with glaucoma. Arch Ophthalmol. Jun 2008;126(6):849-56. [Medline].

  30. Brandt JD. Corneal thickness in glaucoma screening, diagnosis, and management. Curr Opin Ophthalmol. Apr 2004;15(2):85-9. [Medline].

  31. Brandt JD, Beiser JA, Gordon MO, et al. Central corneal thickness and measured IOP response to topical ocular hypotensive medication in the Ocular Hypertension Treatment Study. Am J Ophthalmol. Nov 2004;138(5):717-22. [Medline].

  32. Brandt JD, Beiser JA, Kass MA, et al. Central corneal thickness in the Ocular Hypertension Treatment Study (OHTS). Ophthalmology. Oct 2001;108(10):1779-88. [Medline].

  33. Brubaker RF. Mechanism of action of bimatoprost (Lumigan). Surv Ophthalmol. May 2001;45 Suppl 4:S347-51. [Medline].

  34. Bruhn RL, Stamer WD, Herrygers LA, et al. Relationship between Glaucoma and Selenium Levels in Plasma and Aqueous Humor. Br J Ophthalmol. Jun 12 2008;[Medline].

  35. Brusini P, Salvetat ML, Zeppieri M, et al. Comparison of ICare tonometer with Goldmann applanation tonometer in glaucoma patients. J Glaucoma. Jun 2006;15(3):213-7. [Medline].

  36. Cantor L. Section 10: Glaucoma. In: Basic and Clinical Science Course. American Academy of Ophthalmology; 1996-1997.

  37. Chaudhry I, Wong S. Recognizing glaucoma. A guide for the primary care physician. Postgrad Med. May 1996;99(5):247-8, 251-2, 257-9, Pass;M. [Medline].

  38. Chauhan BC. Endothelin and its potential role in glaucoma. Can J Ophthalmol. Jun 2008;43(3):356-60. [Medline].

  39. Chen TC, Ahn Yuen SJ, Sangalang MA, Fernando RE, Leuenberger EU. Retrobulbar chlorpromazine injections for the management of blind and seeing painful eyes. J Glaucoma. Jun 2002;11(3):209-13. [Medline].

  40. Cheung W, Guo L, Cordeiro MF. Neuroprotection in glaucoma: drug-based approaches. Optom Vis Sci. Jun 2008;85(6):406-16. [Medline].

  41. Chihara E. Assessment of true intraocular pressure: the gap between theory and practical data. Surv Ophthalmol. May-Jun 2008;53(3):203-18. [Medline].

  42. Cioffi GA, Latina MA, Schwartz GF. Argon versus selective laser trabeculoplasty. J Glaucoma. Apr 2004;13(2):174-7. [Medline].

  43. Colton T, Ederer F. The distribution of intraocular pressures in the general population. Surv Ophthalmol. Nov-Dec 1980;25(3):123-9. [Medline].

  44. Cox JA, Mollan SP, Bankart J, et al. Efficacy of antiglaucoma fixed combination therapy versus unfixed components in reducing intraocular pressure: a systematic review. Br J Ophthalmol. Jun 2008;92(6):729-34. [Medline].

  45. Craven ER, Walters TR, Williams R, et al. Brimonidine and timolol fixed-combination therapy versus monotherapy: a 3-month randomized trial in patients with glaucoma or ocular hypertension. J Ocul Pharmacol Ther. Aug 2005;21(4):337-48. [Medline].

  46. Deokule S, Weinreb RN. Relationships among systemic blood pressure, intraocular pressure, and open-angle glaucoma. Can J Ophthalmol. Jun 2008;43(3):302-7. [Medline].

  47. Dhaliwal JS, Mason BF, Kaufman SC. Long-term use of topical tacrolimus (FK506) in high-risk penetrating keratoplasty. Cornea. May 2008;27(4):488-93. [Medline].

  48. Doughty MJ, Zaman ML. Human corneal thickness and its impact on intraocular pressure measures: a review and meta-analysis approach. Surv Ophthalmol. Mar-Apr 2000;44(5):367-408. [Medline].

  49. ElMallah MK, Asrani SG. New ways to measure intraocular pressure. Curr Opin Ophthalmol. Mar 2008;19(2):122-6. [Medline].

  50. Eskridge JB. Ocular hypertension or early undetected glaucoma?. J Am Optom Assoc. Sep 1987;58(9):747-69. [Medline].

  51. Filippopoulos T, Rhee DJ. Novel surgical procedures in glaucoma: advances in penetrating glaucoma surgery. Curr Opin Ophthalmol. Mar 2008;19(2):149-54. [Medline].

  52. Gedde SJ, Schiffman JC, Feuer WJ, Herndon LW, Brandt JD, Budenz DL. Treatment outcomes in the tube versus trabeculectomy study after one year of follow-up. Am J Ophthalmol. Jan 2007;143(1):9-22. [Medline].

  53. George MK, Emerson JW, Cheema SA, et al. Evaluation of a modified protocol for selective laser trabeculoplasty. J Glaucoma. Apr-May 2008;17(3):197-202. [Medline].

  54. Gordon MO, Beiser JA, Brandt JD, et al. The Ocular Hypertension Treatment Study: baseline factors that predict the onset of primary open-angle glaucoma. Arch Ophthalmol. Jun 2002;120(6):714-20; discussion 829-30. [Medline].

  55. Gordon MO, Kass MA. The Ocular Hypertension Treatment Study: design and baseline description of the participants. Arch Ophthalmol. May 1999;117(5):573-83. [Medline].

  56. Greenfield DS, Girkin C, Kwon YH. Memantine and progressive glaucoma. J Glaucoma. Feb 2005;14(1):84-6. [Medline].

  57. Greenfield DS, Weinreb RN. Role of optic nerve imaging in glaucoma clinical practice and clinical trials. Am J Ophthalmol. Apr 2008;145(4):598-603. [Medline].

  58. Grus F, Sun D. Immunological mechanisms in glaucoma. Semin Immunopathol. Apr 2008;30(2):121-6. [Medline].

  59. Grus FH, Joachim SC, Wuenschig D, et al. Autoimmunity and glaucoma. J Glaucoma. Jan-Feb 2008;17(1):79-84. [Medline].

  60. Gupta N, Weinreb RN. New definitions of glaucoma. Curr Opin Ophthalmol. Apr 1997;8(2):38-41. [Medline].

  61. Halkiadakis I, Kipioti A, Emfietzoglou I, et al. Comparison of optical coherence tomography and scanning laser polarimetry in glaucoma, ocular hypertension, and suspected glaucoma. Ophthalmic Surg Lasers Imaging. Mar-Apr 2008;39(2):125-32. [Medline].

  62. Hernandez R, Rabindranath K, Fraser C, et al. Screening for open angle glaucoma: systematic review of cost-effectiveness studies. J Glaucoma. Apr-May 2008;17(3):159-68. [Medline].

  63. Hitchings RA. Glaucoma: current thinking. Br J Hosp Med. Mar 20-Apr 2 1996;55(6):312-4. [Medline].

  64. Hodapp EA, Anderson DR. Treatment of early glaucoma. In: Focal Points. Vol 4. 1986.

  65. Holz HA, Lim MC. Glaucoma lasers: a review of the newer techniques. Curr Opin Ophthalmol. Apr 2005;16(2):89-93. [Medline].

  66. Hoskins HD Jr. The management of elevated intraocular pressure with normal optic discs and visual fields. II. An approach to early therapy. Surv Ophthalmol. May-Jun 1977;21(6):479, 489-93. [Medline].

  67. Inatani M, Iwao K, Inoue T, et al. Long-term relationship between intraocular pressure and visual field loss in primary open-angle glaucoma. J Glaucoma. Jun-Jul 2008;17(4):275-9. [Medline].

  68. Jacobi S, Dubielzig RR. Feline primary open angle glaucoma. Vet Ophthalmol. May-Jun 2008;11(3):162-5. [Medline].

  69. Jamil AL, Mills RP. Glaucoma tube or trabeculectomy? That is the question. Am J Ophthalmol. Jan 2007;143(1):141-2. [Medline].

  70. Johnson TD, Zimmerman TJ. Ocular hypertension, glaucoma suspect, preglaucoma, or glaucoma? Synopsis of views. Ann Ophthalmol. Nov 1986;18(11):313-4. [Medline].

  71. Juzych MS, Chopra V, Banitt MR, et al. Comparison of long-term outcomes of selective laser trabeculoplasty versus argon laser trabeculoplasty in open-angle glaucoma. Ophthalmology. Oct 2004;111(10):1853-9. [Medline].

  72. Kahook MY, Noecker RJ. Comparison of corneal and conjunctival changes after dosing of travoprost preserved with sofZia, latanoprost with 0.02% benzalkonium chloride, and preservative-free artificial tears. Cornea. Apr 2008;27(3):339-43. [Medline].

  73. Kass MA. When to treat ocular hypertension (with discussion). Surv Ophthalmol. 1980;28(Supp.):229-234.

  74. Kass MA, Hart WM Jr, Gordon M, et al. Risk factors favoring the development of glaucomatous visual field loss in ocular hypertension. Surv Ophthalmol. Nov-Dec 1980;25(3):155-62. [Medline].

  75. Kiekens S, Veva De Groot, Coeckelbergh T, et al. Continuous positive airway pressure therapy is associated with an increase in intraocular pressure in obstructive sleep apnea. Invest Ophthalmol Vis Sci. Mar 2008;49(3):934-40. [Medline].

  76. Krupin T, Liebmann JM, Greenfield DS, et al. The Low-pressure Glaucoma Treatment Study (LoGTS) study design and baseline characteristics of enrolled patients. Ophthalmology. Mar 2005;112(3):376-85. [Medline].

  77. Ku JY, Danesh-Meyer HV, Craig JP, et al. Comparison of intraocular pressure measured by Pascal dynamic contour tonometry and Goldmann applanation tonometry. Eye. Feb 2006;20(2):191-8. [Medline].

  78. Lacey J, Cate H, Broadway DC. Barriers to adherence with glaucoma medications: a qualitative research study. Eye. Apr 25 2008;[Medline].

  79. Landers JA, Goldberg I, Graham SL. Detection of early visual field loss in glaucoma using frequency-doubling perimetry and short-wavelength automated perimetry. Arch Ophthalmol. Dec 2003;121(12):1705-10. [Medline].

  80. Lasseck J, Jehle T, Feltgen N, et al. Comparison of intraocular tonometry using three different non-invasive tonometers in children. Graefes Arch Clin Exp Ophthalmol. Oct 2008;246(10):1463-6. [Medline].

  81. Latina MA, Gulati V. Selective laser trabeculoplasty: stimulating the meshwork to mend its ways. Int Ophthalmol Clin. 2004;44(1):93-103. [Medline].

  82. Latina MA, Tumbocon JA. Selective laser trabeculoplasty: a new treatment option for open angle glaucoma. Curr Opin Ophthalmol. Apr 2002;13(2):94-6. [Medline].

  83. Lebrun-Julien F, Di Polo A. Molecular and cell-based approaches for neuroprotection in glaucoma. Optom Vis Sci. Jun 2008;85(6):417-24. [Medline].

  84. Lee PP, Walt JW, Rosenblatt LC, et al. Association between intraocular pressure variation and glaucoma progression: data from a United States chart review. Am J Ophthalmol. Dec 2007;144(6):901-907. [Medline].

  85. Leske MC, Connell AM, Wu SY, et al. Distribution of intraocular pressure. The Barbados Eye Study. Arch Ophthalmol. Aug 1997;115(8):1051-7. [Medline].

  86. Levin LA, Peeples P. History of neuroprotection and rationale as a therapy for glaucoma. Am J Manag Care. Feb 2008;14(1 Suppl):S11-4. [Medline].

  87. Li HK, Tang RA, Oschner K, et al. Telemedicine screening of glaucoma. Telemed J. Fall 1999;5(3):283-90. [Medline].

  88. Liesegang TJ. Glaucoma: changing concepts and future directions. Mayo Clin Proc. Jul 1996;71(7):689-94. [Medline].

  89. Lin SC. Endoscopic and transscleral cyclophotocoagulation for the treatment of refractory glaucoma. J Glaucoma. Apr-May 2008;17(3):238-47. [Medline].

  90. Lin SC. Endoscopic and transscleral cyclophotocoagulation for the treatment of refractory glaucoma. J Glaucoma. Apr-May 2008;17(3):238-47. [Medline].

  91. Lin SC, Singh K, Jampel HD, Hodapp EA, Smith SD, Francis BA, et al. Optic nerve head and retinal nerve fiber layer analysis: a report by the American Academy of Ophthalmology. Ophthalmology. Oct 2007;114(10):1937-49. [Medline].

  92. Linner E. The natural course of ocular pressure in ocular hypertension. Surv Ophthalmol. Nov-Dec 1980;25(3):136-8. [Medline].

  93. Lipton SA. Possible role for memantine in protecting retinal ganglion cells from glaucomatous damage. Surv Ophthalmol. Apr 2003;48 Suppl 1:S38-46. [Medline].

  94. Liu J, Roberts CJ. Influence of corneal biomechanical properties on intraocular pressure measurement: quantitative analysis. J Cataract Refract Surg. Jan 2005;31(1):146-55. [Medline].

  95. Madadi P, Koren G, Freeman DJ, et al. Timolol concentrations in breast milk of a woman treated for glaucoma: calculation of neonatal exposure. J Glaucoma. Jun-Jul 2008;17(4):329-31. [Medline].

  96. Medeiros FA, Zangwill LM, Bowd C, et al. Comparison of the GDx VCC scanning laser polarimeter, HRT II confocal scanning laser ophthalmoscope, and stratus OCT optical coherence tomograph for the detection of glaucoma. Arch Ophthalmol. Jun 2004;122(6):827-37. [Medline].

  97. Memarzadeh F, Ying-Lai M, Azen SP, et al. Associations with intraocular pressure in Latinos: the Los Angeles Latino Eye Study. Am J Ophthalmol. Jul 2008;146(1):69-76. [Medline].

  98. Migdal C. Glaucoma medical treatment: philosophy, principles and practice. Eye. Jun 2000;14 (Pt 3B):515-8. [Medline].

  99. Miglior S, Casula M, Guareschi M, et al. Clinical ability of Heidelberg retinal tomograph examination to detect glaucomatous visual field changes. Ophthalmology. Sep 2001;108(9):1621-7. [Medline].

  100. Milla E, Duch S, Buchacra O, et al. Poor agreement between Goldmann and Pascal tonometry in eyes with extreme pachymetry. Eye. Mar 28 2008;[Medline].

  101. Minckler DS. Histology of optic nerve damage in ocular hypertension and early glaucoma. Surv Ophthalmol. Apr 1989;33 Suppl:401-2; discussion 409-11. [Medline].

  102. Naskar R, Dreyer EB. New horizons in neuroprotection. Surv Ophthalmol. May 2001;45 Suppl 3:S250-5; discussion S273-6. [Medline].

  103. Nouri-Mahdavi K, Nikkhou K, Hoffman DC, et al. Detection of early glaucoma with optical coherence tomography (StratusOCT). J Glaucoma. Apr-May 2008;17(3):183-8. [Medline].

  104. Phelps CD. The no treatment approach to ocular hypertension. Surv Ophthalmol. Nov-Dec 1980;25(3):175-82. [Medline].

  105. Poli A, Strouthidis NG, Ho TA, et al. Analysis of HRT images: comparison of reference planes. Invest Ophthalmol Vis Sci. Sep 2008;49(9):3970-5. [Medline].

  106. Quigley HA, Enger C, Katz J, et al. Risk factors for the development of glaucomatous visual field loss in ocular hypertension. Arch Ophthalmol. May 1994;112(5):644-9. [Medline].

  107. Qureshi IA. Effects of mild, moderate and severe exercise on intraocular pressure of sedentary subjects. Ann Hum Biol. Nov-Dec 1995;22(6):545-53. [Medline].

  108. Racette L, Sample PA. Short-wavelength automated perimetry. Ophthalmol Clin North Am. Jun 2003;16(2):227-36, vi-vii. [Medline].

  109. Reeder CE, Franklin M, Bramley TJ. Managed care and the impact of glaucoma. Am J Manag Care. Feb 2008;14(1 Suppl):S5-S10. [Medline].

  110. Reus NJ, Colen TP, Lemij HG. The prevalence of glaucomatous defects with short-wavelength automated perimetry in patients with elevated intraocular pressures. J Glaucoma. Feb 2005;14(1):26-9. [Medline].

  111. Ritch, Shields, Krupin, eds. The Glaucomas. 2nd ed. 1992.

  112. Rivera JL, Bell NP, Feldman RM. Risk factors for primary open angle glaucoma progression: what we know and what we need to know. Curr Opin Ophthalmol. Mar 2008;19(2):102-6. [Medline].

  113. Roizen A, Ela-Dalman N, Velez FG, et al. Surgical treatment of strabismus secondary to glaucoma drainage device. Arch Ophthalmol. Apr 2008;126(4):480-6. [Medline].

  114. Sahin A, Niyaz L, Yildirim N. Comparison of the rebound tonometer with the Goldmann applanation tonometer in glaucoma patients. Clin Experiment Ophthalmol. May-Jun 2007;35(4):335-9. [Medline].

  115. Schuman JS. Clinical experience with brimonidine 0.2% and timolol 0.5% in glaucoma and ocular hypertension. Surv Ophthalmol. Nov 1996;41 Suppl 1:S27-37. [Medline].

  116. Serle JB. A comparison of the safety and efficacy of twice daily brimonidine 0.2% versus betaxolol 0.25% in subjects with elevated intraocular pressure. The Brimonidine Study Group III. Surv Ophthalmol. Nov 1996;41 Suppl 1:S39-47. [Medline].

  117. Shields MB. Textbook of Glaucoma. 4th ed. Lippincott Williams & Wilkins; 1998.

  118. Shih CY, Graff Zivin JS, Trokel SL, et al. Clinical significance of central corneal thickness in the management of glaucoma. Arch Ophthalmol. Sep 2004;122(9):1270-5. [Medline].

  119. Siam GA, Gheith ME, de Barros DS, et al. Limitations of the Heidelberg Retina Tomograph. Ophthalmic Surg Lasers Imaging. May-Jun 2008;39(3):262-4. [Medline].

  120. Spaeth GL. Early primary open-angle glaucoma: diagnosis and management. Preface. Int Ophthalmol Clin. Spring 1979;19(1):vii-ix. [Medline].

  121. Stamper RL, Lieberman MF, Drake MV. Becker-Shaffers Diagnosis and Therapy of the Glaucomas. 7th ed. Mosby-Year Book; 1999.

  122. Sunaric-Megevand G, Leuenberger PM. Results of viscocanalostomy for primary open-angle glaucoma. Am J Ophthalmol. Aug 2001;132(2):221-8. [Medline].

  123. Svizenska I, Dubovy P, Sulcova A. Cannabinoid receptors 1 and 2 (CB1 and CB2), their distribution, ligands and functional involvement in nervous system structures - A short review. Pharmacol Biochem Behav. May 25 2008;[Medline].

  124. Tezel G, Kolker AE, Kass MA, et al. Parapapillary chorioretinal atrophy in patients with ocular hypertension. I. An evaluation as a predictive factor for the development of glaucomatous damage. Arch Ophthalmol. Dec 1997;115(12):1503-8. [Medline].

  125. Tezel G, Kolker AE, Wax MB, et al. Parapapillary chorioretinal atrophy in patients with ocular hypertension. II. An evaluation of progressive changes. Arch Ophthalmol. Dec 1997;115(12):1509-14. [Medline].

  126. Van Buskirk EM. Medicolegal aspects of glaucoma care. Surv Ophthalmol. Jul-Aug 1998;43(1):83-6. [Medline].

  127. Woodward DF, Krauss AH, Chen J, et al. The pharmacology of bimatoprost (Lumigan). Surv Ophthalmol. May 2001;45 Suppl 4:S337-45. [Medline].

  128. Yu DY, Su EN, Cringle SJ, et al. Comparison of the vasoactive effects of the docosanoid unoprostone and selected prostanoids on isolated perfused retinal arterioles. Invest Ophthalmol Vis Sci. Jun 2001;42(7):1499-504. [Medline].

  129. Yu JY, Kahook MY, Lathrop KL, et al. The effect of probe placement and type of viscoelastic material on endoscopic cyclophotocoagulation laser energy transmission. Ophthalmic Surg Lasers Imaging. Mar-Apr 2008;39(2):133-6. [Medline].

  130. Yucel YH, Gupta N. Paying attention to the cerebrovascular system in glaucoma. Can J Ophthalmol. Jun 2008;43(3):342-6. [Medline].

  131. Zangwill LM, Jain S, Racette L, et al. The effect of disc size and severity of disease on the diagnostic accuracy of the Heidelberg Retina Tomograph Glaucoma Probability Score. Invest Ophthalmol Vis Sci. Jun 2007;48(6):2653-60. [Medline].

  132. Ziemer Ophthalmology. The Pascal Dynamic Contour Tonometer. Available at http://www.ziemergroup.ch/home/products/pascal.html. Accessed 2008.

 
Previous
Next
 
Advanced glaucomatous damage with increased cupping and substantial pallor of the optic nerve head. Courtesy of M. Bruce Shields, MD.
Flowchart for evaluation of a patient with suspected glaucoma. Used by permission of the American Academy of Ophthalmology.
Diagram of intraocular pressure distribution, with a visible skew to the right (somewhat exaggerated compared to the actual distribution). Note that, while uncommon, field loss among individuals with pressures in the upper teens can occur. Also, note that the average pressure among those with glaucomas is in the low 20s, even though most individuals with pressures in the low 20s do not have glaucoma. Used by permission from Survey of Ophthalmology.
Diagram showing the relative proportion of people in the general population who have elevated pressure (horizontally shaded lines) and/or damage from glaucoma (vertically shaded lines). Notice that most have elevated pressure but no sign of damage (ie, ocular hypertensives), but there are also those with normal pressures who still have damage from glaucoma (ie, normal tension glaucoma). Courtesy of M. Bruce Shields, MD.OHT = horizontal lines only NTG = vertical lines only POAG and other glaucomas with both elevated intraocular pressure and damage = overlapping horizontal and vertical lines
Humphrey visual field, right eye, showing patient with advanced glaucomatous field loss. Notice both the arcuate extension from the blind spot (Bjerrum scotoma) and the loss nasally (nasal step), which often occurs early in the disease process. Courtesy of M. Bruce Shields, MD.
Illustration of progressive optic nerve damage. Notice the deepening (saucerization) along the neural rim, along with notching and increased excavation/sloping of the optic nerve and circumlinear vessel inferiorly. Courtesy of M. Bruce Shields, MD.
Example of progressive visual field loss over time (from top to bottom) in a patient with glaucoma. Notice the early appearance of an inferior nasal step and arcuate loss, with progressive enlargement and increasing density of the scotomata over time. Courtesy of M. Bruce Shields, MD.
Optic nerve asymmetry in a patient with glaucomatous damage, left eye, showing optic nerve excavation inferiorly (similar to Image 5). Courtesy of M. Bruce Shields, MD.
Glaucomatous optic nerve damage, with sloping and nerve fiber layer rim hemorrhage at the 7-o'clock position. Hemorrhage is indicative of progressive damage, usually due to inadequate pressure control. Further notching and pallor corresponding to the area of hemorrhage usually is seen several weeks after resorption of the blood. Courtesy of M. Bruce Shields, MD.
Correction values according to corneal thickness.
Ocular hypertension study (OHTS). Percentage of patients who developed glaucoma during this study, stratified by baseline intraocular pressure (IOP) and central corneal thickness (CCT).
Intraocular pressure measurements. Adapted from Reichert Ophthalmic Instruments, Ocular Response Analyzer, How does it work Web page.
 
 
 
All material on this website is protected by copyright, Copyright © 1994-2012 by WebMD LLC.
This website also contains material copyrighted by 3rd parties.

DISCLAIMER: The content of this Website is not influenced by sponsors. The site is designed primarily for use by qualified physicians and other medical professionals. The information contained herein should NOT be used as a substitute for the advice of an appropriately qualified and licensed physician or other health care provider. The information provided here is for educational and informational purposes only. In no way should it be considered as offering medical advice. Please check with a physician if you suspect you are ill.