Pattern Of Field Loss Research Articles

Differences in visual field loss pattern when transitioning from SITA standard to SITA faster

Swedish Interactive Threshold Algorithm (SITA) Faster is the most recent and fastest testing algorithm for the evaluation of Humphrey visual fields (VF). However, existing evidence suggests that there are some differences in global measures of VF loss in eyes transitioning from SITA Standard to the newer SITA Faster. These differences may be relevant, especially in glaucoma, where VF changes over time influence clinical decisions around treatment. Furthermore, characterization of differences in localizable VF loss patterns between algorithms, rather than global summary measures, can be important for clinician interpretation when transitioning testing strategies. In this study, we determined the effect of transitioning from SITA Standard to SITA Faster on VF loss patterns in glaucomatous eyes undergoing longitudinal VF testing in a real-world clinical setting. Archetypal analysis was used to derive composition weights of 16 clinically relevant VF patterns (i.e., archetypes (AT)) from patient VFs. We found switching from SITA Standard to SITA Faster was associated with less preservation of VF loss (i.e., abnormal AT 2–4, 6–9, 11, 13, 14) relative to successive SITA Standard exams (P value < 0.01) and was associated with relatively greater preservation of AT 1, the normal VF (P value < 0.01). Eyes that transition from SITA Standard to SITA Faster in a real-world clinical setting have an increased likelihood of preserving patterns reflecting a normal VF and lower tendency to preserve patterns reflecting abnormal VF as compared to consecutive SITA Standard exams in the same eye.

Pointwise linear regression analysis of serial Humphrey visual fields and a correlation with electroretinography in birdshot chorioretinopathy

AimsTo investigate deterioration in serial Humphrey visual fields (HVFs) using pointwise linear regression (PLR) analysis in patients with birdshot chorioretinopathy (BCR) monitored with full field electroretinography (ERG).MethodsRetrospective review of the...

NATURAL COURSE OF VISUAL FIELD LOSS IN PATIENTS WITH TYPE 2 USHER SYNDROME

To evaluate the natural course of visual field loss in patients with Type 2 Usher syndrome and different patterns of visual field loss. Fifty-eight patients with Type 2 Usher syndrome who had at least three visual field measurements during a period of at least 3 years were studied. Kinetic visual fields measured on a standard calibrated Goldmann perimeter with II4e and V4e targets were analyzed. The visual field areas in both eyes were determined by planimetry with the use of a digitalizing tablet and computer software and expressed in square inches. The data for each visual field area measurement were transformed to a natural log unit. Using a mixed model regression analysis, values for the half-life of field loss (time during which half of the remaining field area is lost) were estimated. Three different patterns of visual field loss were identified, and the half-life time for each pattern of loss was calculated. Of the 58 patients, 11 were classified as having pattern type I, 12 with pattern type II, and 14 with pattern type III. Of 21 patients whose visual field loss was so advanced that they could not be classified, 15 showed only a small residual central field (Group A) and 6 showed a residual central field with a peripheral island (Group B). The average half-life times varied between 3.85 and 7.37 for the II4e test target and 4.59 to 6.42 for the V4e target. There was no statistically significant difference in the half-life times between the various patterns of field loss or for the test targets. The average half-life times for visual field loss in patients with Usher syndrome Type 2 were statistically similar among those patients with different patterns of visual field loss. These findings will be useful for counseling patients with Type 2 Usher syndrome as to their prognosis for anticipated visual field loss.

Acquired pits of the optic nerve in glaucoma: prevalence and associated visual field loss.

This study was performed to determine the prevalence of acquired pits of the optic nerve (APON) in glaucoma and the characteristics of associated visual field loss. Stereoscopic optic disc photos from 235 patients with a low-tension variety of primary open-angle glaucoma (LTG) and 251 primary open-angle glaucoma patients with intraocular pressures higher than 21 mmHg (HTG) were examined for the presence of typical APON as defined by a standard photograph (Fig 1). Associated visual field loss was evaluated with automated perimetry and patterns of field loss were identified. Out of a total of 486 patients, 63 APON were found in 51 eyes of 44 glaucoma patients. APONs were more prevalent in women. Acquired pits were more frequently (p<0.001) located inferiorly (70%) than superiorly (30%). There was a significantly higher prevalence (p<0.001) of APON in LTG patients (12.7%) than in HTG patients (5.6%). Dense visual field defects within five degrees of fixation occurred in 96% of patients with APON. Acquired pits of the optic nerve are more often located at the inferior optic disc than at the superior disc and are nearly always associated with visual field loss close to fixation. In a glaucoma referral center setting, APON are more prevalent in lower pressure glaucoma than in higher pressure glaucoma.

Rate of Visual Field Loss in Retinitis Pigmentosa

The authors quantitate the rate of visual field loss in patients with retinitis pigmentosa as it relates to different clinical field phenotypes. Goldmann visual fields were obtained with target V4e in 77 patients and with target II4e in 71 patients who had either isolated or various genetic types of retinitis pigmentosa and who met certain entrance criteria. The visual fields were categorized into five distinct clinical field phenotypes on the basis of their pattern of field loss. Mixed-model methods for the analysis of longitudinal data were used to model the natural logarithm of the visual field area as a function of patient age and clinical field phenotype. The average half-life (time over which half of the remaining field area would be lost) of the visual field area for each phenotype was computed from the results of this analysis. Visual field data were not analyzed for patients with a normal clinical field phenotype (type 1). Independent of the field phenotype, average half-life values were 7.3 years for target V4e and 6.8 years for target II4e, which were not statistically different (P = 0.16). Visual fields with partial or complete midperipheral ring scotomas (type 2) and those with only a residual central field (type 4) had a half-life of 9.5 and 9.4 years, respectively, for target V4e, and 8.9 and 8.0 years, respectively, for target II4e. Patients with partial peripheral restriction (type 5) lost visual fields with a half-life of 9.5 years for target V4e and 7.3 years for target II4e. None of these differences in the half-lives between the different phenotypes were statistically significant for either targets V4e or II4e. Fields with a residual central area and remaining temporal and/or nasal islands (type 3) had a half-life of 4.8 years for target V4e and 6.0 years for target II4e. The differences in half-lives between type 3 and each of the other field phenotypes were statistically significant for the V4e target, but not for the II4e target. The results of this study can be useful for counseling patients with retinitis pigmentosa and various visual field phenotypes as to their potential rate of visual field loss.

Visual Field Change in Low-tension Glaucoma over a Five-year Follow-up

There is some evidence that the nature and progression of disease in low-tension glaucoma may be distinct from other open-angle glaucomas. The authors assessed visual field change by retrospective case review of all patients treated for low-tension glaucoma by the Glaucoma Service, Wills Eye Hospital, for at least 5 years. Sixty-two glaucomatous eyes of 36 patients were identified. All eyes were treated medically and 40 (65%) underwent at least one surgical procedure. Twenty-eight eyes (47%) had initial field loss confined to a single hemi-field and in the remainder both hemi·fields were involved. Thirty of 57 eyes (53%) showed progression at 3 years and 38 (62%) of 57 had progressed by 5 years. A dense scotoma extending from the nasal periphery toward fixation was the most common visual field defect. The rate of field change in this population is significantly greater than in a cohort of primary open-angle glaucoma patients also seen at Wills Eye Hospital, but who had elevated intraocular pressures. Patterns of field loss and rate of progression in this lowtension glaucoma population suggest that the natural history of low-tension glaucoma differs from high-tension open-angle glaucoma.