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VF in glaucoma.pptx
- 1. CHARACTERISTIC VISUAL FIELD DEFECTSIN GLAUCOMA Dr ALSHYMAA MOUSTAFA OPTHALMOLOGIST
- 2. CONTENTS •Introduction •What about theVF ? •Anatomical distrubution of NF. •Field Changes in glaucoma.
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- 4. • Glaucoma isthe most common indication for performing a visual field test. • Glaucoma is defined as an optic neuropathy characterized by progressive loss of retinal ganglion cells and Nerve Fiber Layer (NFL) with topographic changes of the optic nerve head (neuroretinal changes) and associated typical visual field loss. • Several studies have suggested that the retinal NFL defects precede the optic disc changes and visual field loss.
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- 6. • “Island ofvision surrounded by the sea of darkness” • There is a gradual rise in altitude of the island from the periphery to the center where it peaks, representing the increase in sensitivity to light from the retinal peripheryto the fovea.... Why....?!
- 9. What is ... •Blindspot? •Fixation point? •Scotoma? •Field defect? •Bjerrum area?
- 10. Blind Spot • Normallythe optic disc correlates to the physiological blind spot due to absence of photoreceptors and is represented as a deep well in the hill of vision. • physiological blind spot is vertically oval; approximately 7.5 × 5.5 degrees in extent and represent the temporal visual field projection of the optic nerve. • Its usual location being 12° to 17° horizontal from the fovea and 2°above and 5°below the horizontal divide passing through the fixation
- 13. Fixation Point • Themaximum retinal senstivity, which is localized in the center of the VF and Corresponding to fovea. Temporal Nasal
- 14. Scotoma • It isan area of abnormal retinal sensitivity surrounded by areas of normal retinal sensitivity. • The scotoma is considered absolute if the retinal sensitivity is nearly absent and relative when the sensitivity is reduced as compared to the normal. • +Ve ,if the patient aware for it and -ve,if not aware.
- 16. Field defect • Absoluteor relative decrease in retinal senstivity extending to the peripheral field.
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- 23. • Typically thefirst nerve fiber bundles affected in glaucoma are those entering the upper and the lower poles of the optic disc. • When bundles of nerve fibers get damaged at the optic disc, the region of visual field supplied by these fibers looses its visual sensitivity resulting in a localized depression or scotoma.
- 24. Visual field defects •Lesions affecting the papillomacular bundle produce a central sscotoma. • If this central scotoma is connected with the physiological blind spot it is described as cecocentral scotoma. • Damage to some of the fibers of the papillomacular bundle not involving the fixation produces a paracentral scotoma. • Damage to the temporal arcuate retinal nerve fibers givesrise to characteristic arcuate scotomas, which finish abruptly at the horizontal meridian in the nasalfield. • Damage to the vascular supply of the inner retina, resulting from vascular occlusion, will typically give rise to large scotomas, corresponding to the retinal areasinvolved. • Lesions affecting nasal retinal fibers produce temporal wedge defdect.
- 26. Field Changes in glaucoma NONSPECIFIC • Generalized depression • Baring of the blind spot • Enlarged blind spot SPEIFIC • Early: 1. Paracentral scotoms 2. Seidel scotoma 3. Nasal step • Late: 1. Arcuate scotoma 2. Ring scotoma 3. Ronne Nasal step • Advanced: 1. Tunnel vision 2. Blind
- 34. GLAUCOMA OR NOT? Anderson criteria
- 35. ANDERSON CRITERIA Minimum criteriato label a field defect as glaucomatous as defined by Anderson are: 1. A cluster of 3 or more non edge points in a location typical for glaucoma, that are depressed to an extent < 5 percent of the population with one of these points depressed to an extent found in < 1 percent of the population on consecutive fields. 2. The CPSD or the PSD depressed to a level found in < 5 percent of the population on consecutive fields 3. Lastly the GHT outside normal limits on atleast 2 fields.
- 36. Note: • In thepresence of all these criteria the field can be labeled glaucomatous, as it is highly suggestive of glaucoma. • Even in the presence of one positive criterion clinical correlation should be made.
- 37. Schematic illustration of differenttypes of glaucoma defect patterns (a) Nasal step, (b) Temporal wedge, (c) Superior arcuate defect (d) early superior paracentral defect at 10°. (e) Superior fixation-threatening paracentral defect. (f) Superior arcuate with peripheral breakthrough and early inferior defect.
- 39. GRADING OF GLAUCOMA Hodappclassification
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- 42. CASE 1 • Clinicalhistory—> 61 years old male patient with complains of decreased vision right eye. • On examination the Right eye BCVA was 6/60 and IOP was 26 mm Hg. • There was significant cataract and shallow anterior chamber and gonioscopy revealed closed angles in the right eye. • ONH showed -> 0.9:1 CD ratio with notching.
- 46. • Interpretation offields—24-2 SITA standard of the right eye showed advanced field loss impinging the macula with a temporal island of vision. • Note the dense nature of the defect with 0 dB retinal sensitivities at most of the test locations. • Total deviation plot shows generalized depression due to cataract with superimposed glaucomatous field defect and pattern deviation plot highlights the advanced glaucomatous field defect.
- 47. • The 10-2threshold test revealed similar defect. • Macular test was also done to evaluate for macula. • Note the macular threshold program printout has only gray scale, threshold values and the depth of the defect.
- 48. CASE 2 • Clinicalhistory—> 88 year old male patient with known primary open angle glaucoma well controlled on antiglaucoma medication and cataract in both eyes. • BCVA 6/36 OU. • IOP was 14 mm Hg on antiglaucoma medication in both eyes. • Optic nerve head in the Right eye showed 0.6:1 CDR with a large inferior rim notch. Left eye showed 0.3:1 CDR with healthy NRR.
- 50. • Interpretation offields—> 24-2 SITA standard test showing RIGHT EYE dense superior arcuate scotoma corresponding to the inferior rim notch. • Note the foveal threshold of 23 dB corresponding to a visual acuity of 6/36. • Total deviation shows generalized depression due to cataract • which corresponds to a negative MD of –15.6 dB with a significant p value. • Pattern Deviation highlights the hidden scotoma in the superior arcuate area corresponding to a significant PSD of 10.94 dB.
- 51. CASE 3 •Clinical history—>32 years old male patient with juvenile open angle glaucoma well controlled on topical medication. •ONH evaluation of the right eye revealed 0.7:1 CD ratio with marked superior rim thinning.
- 53. •Interpretation of fields—> •Righteye 30-2 SITA standard test showing classical inferior arcuate scotoma corresponding to the ONH findings.
- 54. CASE 4 •Clinical history—>62 years old female patient with POAG well controlled on topical medication. •ONH examination of Rt eye showed 0.65 CD ratio with marked inferior rim thinning.
- 56. •Interpretation of fields—>Rt eye 24-2 SITA standard showing superolior arcuatet scotoma with nasal stept corresponding to the ONH findings.
- 57. •Clinical history—60 yearsold male patient with POAG well controlled •on topical medication. ONH evaluation showed 0.65:1 CD ratio with •marked inferior rim thinning in right eye. • CASE 5
- 59. • Interpretation offields—Right eye 24-2 SITA standard test showing • Seidel’s scotoma in the superior hemifield corresponding to the ONH • findings.
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