Development and validation of a computerized expert system for evaluation of automated visual fields from the Ischemic Optic Neuropathy Decompression Trial

BACKGROUND: The objective of this report is to describe the methods used to develop and validate a computerized system to analyze Humphrey visual fields obtained from patients with non-arteritic anterior ischemic optic neuropathy (NAION) and enrolled in the Ischemic Optic Neuropathy Decompression Trial (IONDT). The IONDT was a multicenter study that included randomized and non-randomized patients with newly diagnosed NAION in the study eye. At baseline, randomized eyes had visual acuity of 20/64 or worse and non-randomized eyes had visual acuity of better than 20/64 or were associated with patients refusing randomization. Visual fields were measured before treatment using the Humphrey Field Analyzer with the 24-2 program, foveal threshold, and size III stimulus. METHODS: We used visual fields from 189 non-IONDT eyes with NAION to develop the computerized classification system. Six neuro-ophthalmologists ("expert panel") described definitions for visual field patterns defects using 19 visual fields representing a range of pattern defect types. The expert panel then used 120 visual fields, classified using these definitions, to refine the rules, generating revised definitions for 13 visual field pattern defects and 3 levels of severity. These definitions were incorporated into a rule-based computerized classification system run on Excel(® )software. The computerized classification system was used to categorize visual field defects for an additional 95 NAION visual fields, and the expert panel was asked to independently classify the new fields and subsequently whether they agreed with the computer classification. To account for test variability over time, we derived an adjustment factor from the pooled short term fluctuation. We examined change in defects with and without adjustment in visual fields of study participants who demonstrated a visual acuity decrease within 30 days of NAION onset (progressive NAION). RESULTS: Despite an agreed upon set of rules, there was not good agreement among the expert panel when their independent visual classifications were compared. A majority did concur with the computer classification for 91 of 95 visual fields. Remaining classification discrepancies could not be resolved without modifying existing definitions. Without using the adjustment factor, visual fields of 63.6% (14/22) patients with progressive NAION and no central defect, and all (7/7) patients with a paracentral defect, worsened within 30 days of NAION onset. After applying the adjustment factor, the visual fields of the same patients with no initial central defect and 5/7 of the patients with a paracentral defect were seen to worsen. CONCLUSION: The IONDT developed a rule-based computerized system that consistently defines pattern and severity of visual fields of NAION patients for use in a research setting

A Tough Bone to Crack

Poor gait; Hearing loss; Visual lossA 5-year old male with worsening optic disc edema.VA: 20/30 OU at 5-years; 20/200 OU at 12-yearsOptic disc edema with proptosisSurgery; Steroid

Saccadic Error in Balint's Syndrome: A Quantitative Study

Balint's syndrome, which is characterized by optic ataxia, visual inattention, and "psychic paralysis of gaze" signifies bilateral parietooccipital lesions. "Psychic paralysis of gaze" or impairment of visually-guided saccades is a striking finding which can give the impression of cortical blindness

The Clinical Spectrum of Amiodarone Induced Optic Neuropathy

To describe the clinical spectrum of amiodarone-induced optic neuropathy.GVSamiodaron

Surgical Therapy of Neurogenic Motility Disorders

As Neuro-ophthalmologists, evaluation and management of cranial nerve palsies is a familiar event. This discussion will assume that each patient was fully evaluated in an appropriate fashion and that despite the tincture of time, he or she is still suffering from diplopia

Levodopa May Improve Vision Loss in Recent Onset Nonarteritic Anterior Ischemic Optic Neuropathy

Johnson and colleagues (Am J Ophthalmol 1996;121:77-83) had documented the efficacy of levodopa in promoting improvement of visual acuity in 30% of patients with visual loss from nonarteritic anterior ischemic optic neuropathy (NAION) of greater than 6 months duration. No improvement of visual field was identified when treatment with levodopa was initiated after 6 months of onset of NAION. It is possible that earlier treatment with levodopa could result in improved visual outcome

Visual Function in Optic Atrophy

Optic nerve pallor corresponds histologically to atrophy of the optic nerve fibers. Although ophthalmologists and other eye care specialists commonly evaluate patients with optic atrophy, we are unaware of published studies correlating the severity of optic atrophy with visual function

Sequential III and II Dysfunction with Pain and Vomiting

Supra-orbital pain; Nausea; VomitingA 56-year old male with supra-orbital pain and nasal polyps requiring surgery. Post-op developed horizontal diplopia.VA: 20/20 OU; Pupil sparring left III nerve palsyCTCystic pneumatization of left anterior clinoidSurgeryAttache

The Role of Weight Loss and Acetazolamide in Idiopathic Intracranial Hypertension

To determine the weight loss necessary for the resolution of papilledema associated with idiopathic intracranial hypertension (I3H)

A Routine Case of Acquired Hyperopia??

Diplopia; Visual loss; Headache; Facial painA 47-year-old male with a 3-month history of gradual loss of vision OS in primary gaze and monocular diplopia.AV: 20/20 OU (with the refraction OS 2.5 diopters more hyperopic than the previous spectacles obtained one year earlier); IOP: 9 OD, 16 OSCT; MRIIntraconal mass composed of oval and spindle cells, tumor giant cells with cell necrosis and hemorrhage.Surgery1. Rent AL, Mahoney EH, Gresik MV, et al.: Malignant rhabdoid tumor of the extremity. Cancer 60:1056-1059, 1987. 2. Tsuneyoshi M, Daimaru Y, Hashimoto H, et al.: Malignant soft tissue neoplasms with the histologic features of renal rhabdoid tumors. Hum Pathol 16:1235-1242, 1985. 3. Haas JE, Palmer NF, Weinberg AG, Beckwith JB: Ultrastructure of nalignant rhabdoid tumor of the kidney. Hum Pathol 12:646-657, 1981. 4. Bonnin JM, Rubenstein LJ, Palmer NF, Beckwith JB: The association of embryonal tumors originating in the kidney and the brain. Cancer 54:2137-2146, 1984. 5. Osborn M, Weber K: Tumor diagnosis by intermediate filament typing: A novel tool for surgical pathology. Laboratory Invest 48:372-394, 1983. 6. Miettinen M, Lehto VP, Badley RA, Virtanen I: Expression of intermediate filaments in soft-tissue sarcomas. Int J Cancer 30:541-546, 1982. 7. Erlandson RA: Diagnostic iaimunohistocheniistry of human tumors. Am J Surg Path 8:615-624, 1984