Long-term studies of visual field changes by means of computerized perimetry (Octopus 201) in eyes with glaucomatous field defects after normalization of the intra-ocular pressure

Lack of Visual Field Improvement After Initiation of Intraocular Pressure Reducing Treatment in the Early Manifest Glaucoma Trial

Purpose

We evaluate how visual fields are affected by the initiation of IOP-reducing therapy in previously untreated glaucoma individuals.

Methods

Qualifying individuals with newly diagnosed glaucoma having normal to moderately elevated IOP were prospectively randomized either to IOP-reducing therapy or to no treatment. Before randomization, individuals underwent repeatedly Standard Automated Perimetry (SAP) testing and Goldmann tonometry. Three months after randomization, patients again underwent SAP and tonometry. Changes between baseline and the 3-month follow-up visit in the perimetric summary index, mean deviation (MD), and total deviation values at significantly depressed test points were compared between the treated and untreated groups.

Results

Of 255 individuals studied, 129 were randomized to treatment and 126 to no treatment. Intraocular pressure decreased by an average of 24% among treated and by 0.6% in the untreated patients. Mean deviation deteriorated slightly in both groups; mean change was −0.15 and −0.44 dB in the treated and untreated groups, respectively; the difference was not statistically significant, (P = 0.16). No association was seen between IOP reduction and change in MD. Sensitivities decreased slightly in significantly depressed test points, mean change was −0.45 dB in the untreated and −0.38 dB in the treated groups (P = 0.88).

Conclusions

Observed visual field changes among glaucoma patients receiving initial IOP-reducing therapy were not significantly different to changes seen in patients who received no treatment. Thus, our results did not support the idea that visual field status improves after initiation of IOP- reducing therapy in glaucoma individuals, at least not in individuals with initially normal to moderately elevated IOPs.

Rate and amount of visual loss in 102 patients with open-angle glaucoma followed up for at least 15 years

PURPOSE

To determine the probability of worsening of glaucoma and the rate of change in patients having open-angle glaucoma for approximately 20 years.

DESIGN

Retrospective, noncomparative case series.

PARTICIPANTS

One hundred and two patients diagnosed and treated for open-angle glaucoma before 1982. TESTING/INTERVENTION: The optic disc and visual field of one eye of each patient were graded independently at diagnosis and periodically throughout the follow-up period for a minimum of 15 years (mean, 19 +/- 3 years), using a scale ranging from 0 = no damage to 5 = far-advanced damage. Therapy was contemperaneous and stepped through medical laser, and surgery.

MAIN OUTCOME MEASURES

The probability of worsening by one or more stages was plotted against the length of follow-up (Kaplan-Meier survival curves).

RESULTS

Nineteen eyes did not worsen, 43 deteriorated one stage, 31 two stages, and 9 three stages. The median time to first worsening was 7.5 years, to second worsening 18.5 years, and to third worsening 24.5 years. Patients with more advanced stages of damage were not more likely to deteriorate than those with less-marked damage. The intraocular pressure was not significantly lower in the patients who remained stable. Seventeen eyes deteriorated to a visual acuity of 20/200 or worse. Of these, causes other than glaucoma were responsible in at least 60% of the cases.

CONCLUSIONS

Approximately 20% of eyes with open-angle glaucoma remained stable for about 20 years, 43% deteriorated one of five stages, and 9% three of five stages. Seventeen of the eyes lost acuity to a level of 20/200, usually from causes other than glaucoma. Deterioration of field was, on average, first noted at 7.5 years, after which the rate of deterioration slowed.

Visual field progression in patients with initially unilateral visual field loss from chronic open-angle glaucoma

PURPOSE

To investigate visual field progression in patients with initially unilateral glaucomatous visual field loss, and to determine risk factors for progression.

DESIGN

Retrospective observational case series.

PARTICIPANTS

Forty-eight consecutive patients with primary open-angle glaucoma, pseudoexfoliative glaucoma, or pigmentary glaucoma, seen over an 18-month period, who initially had unilateral visual field loss as defined by use of modified Anderson criteria. Patients were followed with standard Humphrey perimetry for a minimum of 2 years.

METHODS

Progression was defined by use of modified Anderson criteria, and Advanced Glaucoma Intervention Study (AGIS) and Collaborative Initial Glaucoma Treatment Study scores.

MAIN OUTCOME MEASURE

Visual field progression.

RESULTS

Three patients (6.2%) had fellow eye progression over a mean follow-up of 76 months and duration of disease of 8.7 years. Fellow eye progression correlated with progression of the first-affected eye (P = 0.044). Ten patients (21%) had progression of the first-affected eye; these eyes had a larger initial cup/disc ratio compared with stable eyes (P = 0.041). Increasing initial AGIS score was associated with progression (P: = 0.003). Kaplan-Meier survival analysis estimated the risk of progression at 5 years to be 25% in first-affected eyes and 7.2% in fellow eyes.

CONCLUSIONS

In this population, the risk of fellow eye progression in patients with initially unilateral visual field loss from open-angle glaucoma is low. Progression is higher in eyes with visual field loss at initial testing, and the risk of progression increases as the level of initial visual field loss increases.

The Bristol shared care glaucoma study: outcome at follow up at 2 years

AIM

To examine the outcome of care for patients with glaucoma followed up by the hospital eye service compared with those followed up by community optometrists.

METHODS

A randomised study with patients allocated to follow up by the hospital eye service or community optometrists was carried out in the former county of Avon in south west England. 403 patients with established or suspected primary open angle glaucoma attending Bristol Eye Hospital and meeting defined inclusion and exclusion criteria were studied. The mean number of missed points on visual field testing in the better eye (using a "better/worse" eye analysis) in each group were measured. The visual field was measured using the Henson semiautomated central field analyser (CFA 3000). Measurements were made by the research team on all patients at baseline before randomisation and again 2 years after randomisation. The mean number of missed points on visual field testing in the worse eye, mean intraocular pressure (mm Hg), and cup disc ratio using a "better/worse" eye analysis in each group at 2 years were also measured. Measurements were made by the research team on all patients at baseline before randomisation and again 2 years after randomisation. An analysis of covariance comparing method of follow up taking into account baseline measurements of outcome variables was carried out. Additional control was considered for age, sex, diagnostic group (glaucoma suspect/established primary open angle glaucoma), and treatment (any/none).

RESULTS

From examination of patient notes, 2780 patients with established or suspected glaucoma were identified. Of these, 752 (27.1%) fulfilled the entry criteria. For hospital and community follow up group respectively, mean number of missed points on visual field testing at 2 year follow up for better eye was 7.9 points and 6.8 points; for the worse eye 20.2 points and 18.4 points. Similarly, intraocular pressure was 19.3 mm Hg and 19.3 mm Hg (better eye), and 19.1 mm Hg and 19.0 mm Hg (worse eye); cup disc ratio at 2 year follow up was 0.72 and 0.72 (better eye), and 0.74 and 0.74 for hospital and community follow up group respectively. No significant differences in any of the key visual variables were found between the two groups before or after adjusting for baseline values and age, sex, treatment, and type of glaucoma.

CONCLUSIONS

It is feasible to set and run shared care schemes for a proportion of patients with suspected and established glaucoma using community optometrists. After 2 years (a relatively short time in the life of a patient with glaucoma), there were no marked or statistically significant differences in outcome between patients followed up in the hospital eye service or by community optometrists. Decisions to implement such schemes need to be based on careful consideration of the costs of such schemes and local circumstances, including geographical access and the current organisation of glaucoma care within the hospital eye service.

Management of ocular hypertension and open angle glaucoma: clinical practice and computer-assisted decision-making

PURPOSE

To evaluate the feasibility of computerized decision support in the management of patients with open angle glaucoma or ocular hypertension.

METHOD

Based on a Swedish consensus document a computer program was developed, which provided one of 25 different recommendations for appropriate action. In 373 patient visits to seven different eye clinics, the program's recommendations were compared to the actual decisions made by the responsible ophthalmologists.

RESULTS

Notable differences were observed between the clinics' management strategies, especially regarding follow-up frequency and start or increase of anti-glaucoma treatment. The program's recommendations conformed with the clinical decisions in 23 to 92% of the cases when a standard management strategy was simulated. The concordance increased to 93 to 100%, when policy differences between the clinics were taken into account.

CONCLUSION

Clinical decision-making in the management of patients with ocular hypertension or open angle glaucoma can be implemented in a computer program. The optimum management protocol remains to be defined.

Rate of progression in open-angle glaucoma estimated from cross-sectional prevalence of visual field damage

PURPOSE

To estimate the rate of visual field loss in persons with open-angle glaucoma.

METHODS

The visual field data obtained by Goldmann perimetry from 151 persons with open-angle glaucoma from the Baltimore Eye Survey were graded on a nine-level severity scale. Approximately one half of these persons had previously diagnosed glaucoma and were being treated. Using regression analysis, their scores were compared to other features, including age, vertical cup/disk ratio, treatment status, gender, race, and intraocular pressure. These data were used to estimate the average rate of progressive field loss and blindness in glaucoma.

RESULTS

Among 112 black subjects, the severity of visual field damage was significantly associated with age (P < .02), history of glaucoma treatment (P < .04), and intraocular pressure (P < .0001). Using the relationship between age and damage, we estimated that the rate of deterioration of black glaucoma subjects was two grading levels per decade, which is consistent with previous reports. For 39 white subjects, the inclusion of age improved the model relationship between damage score and other variables. The best estimate of individual damage rate for whites was similar to that in blacks. However, the statistical association of age and damage in whites was less strong than in blacks, possibly because of fewer white subjects in the sample.

CONCLUSIONS

While glaucoma is a frequent cause of visual disability, rate of progressive visual field loss is not sufficient to lead to bilateral blindness in the majority of those affected. Aggressiveness of glaucoma therapy should be related to the rate of visual field loss stressing confirmation of field progression.

Relationship between optic disc cupping change and intraocular pressure control in adult glaucoma patients

BACKGROUND

Until recently, there has been a paucity of quantitative evidence for intraocular pressure (IOP)-dependent optic disc cupping change in adult glaucoma patients. Therefore, we investigated the relationship between optic disc cupping change and IOP control.

METHODS

The study involved 78 eyes of 78 randomly selected adult patients with early to moderate chronic open-angle glaucoma (CO-AG), treated on various therapeutic regimens, who had had two consecutive successful optic disc analyses with the Rodenstock Optic Nerve Head Analyzer 15.8 +/- 14.8 weeks apart.

RESULTS

The mean initial IOP of 27 eyes (34%) with cupping reversal did not differ from that of 17 eyes (22%) demonstrating progressive deterioration (29.2 +/- 8.8 vs 26.2 +/- 6.1 mmHg, P > 0.5), but the reversal group did have a significantly greater mean IOP decrease than the progression group (-10.8 +/- 7.9 vs-1.0 +/- 7.7 mmHg, P < 0.001) and significantly lower mean final IOP (18.3 +/- 6.1 vs 25.2 +/- 7.9 mmHg, P < 0.003).

CONCLUSION

A decrease of optic disc cupping is more likely with a greater IOP reduction and a lower final IOP, and an increase of cupping is more likely with less or no IOP reduction and a higher final IOP.

The effect of treatment on the results of high-pass resolution perimetry in glaucoma

In order to find out to which extent high-pass resolution perimetry would detect any changes in patients treated for glaucoma, resolution perimetry results were evaluated from 56 glaucoma patients and 15 untreated ocular hypertensive patients followed for 2 to 3 years. Fifty-nine of the 71 examined patients showed lower resolution thresholds, i.e. increased sensitivity, after 2 years, compared to initial values. The threshold decrease was significantly larger in the treated glaucoma patients (median 1.22 dB) than in the untreated ocular hypertensive patients (0.48 dB). The threshold decrease in the untreated ocular hypertensive group corresponds to the previously described learning effect. In 35 of the 56 treated glaucoma patients the thresholds improved more than 0.84 dB, the upper confidence limit in the untreated group, which may indicate a beneficial effect of antiglaucoma therapy in these patients. The threshold change was unrelated to initial resolution threshold and cannot be explained by a 'sorting' effect. The observations in the current study using resolution perimetry indicate that improved visual function can be demonstrated in many patients treated for early glaucoma, at least during the first 2 years of treatment.

Visual field prognosis in early glaucoma. A long-term clinical follow-up

Fifty-four eyes of 45 patients with ocular hypertension developed early glaucomatous optic disc or visual field changes after a mean follow-up of 5.1 years without therapy. These changes initiated antiglaucomatous treatment, and the eyes have been followed further on therapy for 2-14 years (mean 8.0 years) in a retrospective study. The mean intraocular pressure (IOP) was lowered from 28.9 to 19.3 mmHg. Half of the eyes were still without field defects at the end of the study, whereas 7 eyes developed extensive field damage noticeable to the patients. The eyes with deteriorating visual fields could not be differentiated from the stable ones by means of the pre-therapy IOP, nor the mean or peak IOP on treatment. There was an accumulation of topical and general risk factors in the progressive eyes. The results support the importance of taking other risk factors than the IOP into consideration in the management of our glaucoma patients.

Intraocular pressure and the rate of visual field loss in chronic open-angle glaucoma

We measured the rate of change of visual field threshold values over time (mean follow-up, 44.9 +/- 17.4 months) by trend analysis in 40 eyes of 40 patients with chronic open-angle glaucoma. Twenty-eight eyes had stable visual fields, and two eyes had significant visual field improvement. Ten eyes had significant visual field deterioration and showed a correlation between indices of intraocular pressure (standard error of the mean, P = .02; standard deviation, P = .04; and range, P = .05) and the rate of visual field loss in the superonasal region of the visual field, such that the greater the variation of intraocular pressure the greater the rate of loss. The group losing visual fields had a higher mean visual field threshold value and significantly less optic disk pallor and cupping at the start of the study than the stable visual field group. Thus, a significant rate of visual field loss occurred at an earlier stage of the disease and showed a correlation with intraocular pressure in this stage.