[Dyslipidaemia and glaucoma]

Endothelial dysfunction and vascular dysregulation play a role in the multifactorial pathogenesis of glaucomatous optic nerve atrophy. Dyslipidaemia as a risk factor for endothelial dysfunction is associated with glaucoma and cardiovascular morbidity and mortality. In additional to a genetic disposition, a potential mechanism for the pathogenesis of endothelial dysfunction could be an additive effect of several risk factors, like dyslipidaemia, smoking, arterial hypertension, diabetes and hyperhomocysteinaemia. This paper reviews the literature concerning the association between dyslipidaemia and glaucomatous disease and explains the possible role of dyslipidaemia for the pathogenesis and progression of glaucoma. The role of exogeneous modifiable risk factors for prevention and therapy of glaucoma and their neutralisation by changing life style like weight reduction, modifications of nutrition and physical activity, are discussed.

Flimmerprovokation im LED-Ganzfeld bei Gesunden und Glaukompatienten

BACKGROUND

Flicker light is an easy method to test sensory function after stress. The aim of this study was to determine the influence of flicker stress on temporal contrast sensitivity in healthy controls and patients with glaucomatous alteration of the optic disk.

METHODS

A commercially available full-field stimulator (Retiport, Roland Consult) equipped with white LEDs was modified to perform psychophysical tests. The patients underwent measurements of the recovery time interval from cessation of flicker stress until recognition of a pregiven flicker contrast after photo stress. In addition, we studied contrast sensitivity with a continuous flickering target and with a flicker burst protocol avoiding adaptation to prevailing flicker. All tests were performed at a constant retinal illumination and at a frequency of 37 Hz for provocation as well as for contrast sensitivity tests.

SUBJECTS

Normal healthy controls (40), "preperimetric" (62), and "perimetric" (52) open-angle glaucoma patients were studied. Exclusion criteria were age lower than 31 years, visual acuity under 0.6, and perimetric mean defect more than 9.5 dB.

RESULTS

Recovery time after flicker stress was significantly longer in patients than in normals and longer in perimetric than in preperimetric patients. Analysis in perimetric patients revealed a larger area under ROC for the provocation test (0.95) than in contrast sensitivity tests (continuous flicker method: 0.90, flicker burst mode: 0.84).

CONCLUSION

High-power LEDs which are installed in modern full-field devices can be used as a helpful tool to study psychophysical properties. In the present study it could be shown that threshold, adaptation, and recovery of temporal transfer characteristics are impaired in many patients with glaucoma.

Laser scanning tomography of the optic nerve vs CSF opening pressure in idiopathic intracranial hypertension

The authors investigated 17 patients with idiopathic intracranial hypertension (IIH), correlating laser scanning tomography of the optic nerve with CSF opening pressure. The decrease in papilla volume and papilla height showed a linear correlation with the opening pressure of the CSF (r = 0.59, p < 0.001; r = 0.63, p < 0.001). If the CSF opening pressure is higher than 20 cm water, an increase of 5 cm water CSF pressure corresponds to a papilla volume increase of 0.95 mm3 as well as a papilla height increase of 0.34 mm.

Two methods of lens opacity measurements in glaucomas

PURPOSE

Determination of lens opacity is important in aging glaucoma patients, because sensory testing may be influenced by increasing lens opacity. Purpose of this study was to measure lens opacity in normals and glaucoma patients using two different techniques, to compare both methods, and to correlate the results with contrast sensitivity testing.

METHODS

94 glaucomatous eyes, 47 ocular hypertensive eyes, and 79 control eyes were studied using the following devices: opacity lens meter (OLM, objective back scatter method), stray light meter (SLM, subjective forward scatter using flicker light), and temporal contrast sensitivity (full-field flicker test). SLM results were separately analyzed at the lower and upper flicker disappearance. All subjects were younger than 66 years and had no significant cataracts.

RESULTS

In patients and in normal subjects OLM readings and SLM findings elicited at the upper disappearance point are significantly correlated with age and with each other (R >0.45, P<0.001), while SLM at the lower disappearance point shows no such correlation. In normals, but not in patients, SLM at the lower disappearance point is significantly correlated with temporal contrast sensitivity.

CONCLUSIONS

Both devices can be used for quantifying lens opacity in glaucoma. SLM readings with increasing light intensity at the lower disappearance point seems to be more influenced by the individual flicker sensitivity than determination of the upper flicker disappearance. Therefore, using the SLM in glaucoma patients, the threshold measurements based on the upper disappearance of the flicker should be used instead of the suggested mean threshold measurements.

The diagnostic value of optic nerve imaging in early glaucoma

In the last decade, new imaging techniques have been added to conventional fundus photography and have been evaluated for use in early glaucoma. They all measure the loss of neuroretinal rim or retinal nerve fiber layer as a correlate to glaucomatous ganglion cell and axon loss. The value of optic disc photography, planimetry, laser scanning tomography, laser scanning polarimetry, and optical coherence tomography for the diagnosis of glaucomatous eyes in a preperimetric or early perimetric stage is analyzed on the basis of sensitivity, specificity, and receiver operating characteristics (ROC) curves. It becomes clear that all these techniques allow a more or less semi-automated evaluation of the optic disc and retinal nerve fiber layer but still have their limitations in the diagnosis of a very early, preperimetric stage of the glaucoma disease.

[Early childhood cataract in hereditary UDP-galactose-4-epimerase deficiency--a case report]

BACKGROUND

Increased plasma galactitol levels may lead to development of bilateral pediatric cataract.

PATIENT

A 3-year-old boy was found to suffer from a bilateral zonular cataract. Extracapsular lensectomy with posterior capsulotomy, transpupillar anterior vitrectomy and posterior chamber lens implantation were performed during a 4-month-interval.

RESULTS

The epimerase-activity in red cells of the index patient was found to be significantly decreased (11.2 mumol/h/g Hb; normal range; 19-35). From other family members, such as the brother (16.8), the father (16.0) and the grandfather (15.6), a diminished red cell activity was observed. The mother whose epimerase activity was considerably lower than that of the above mentioned family members (13.3) showed also a zonular bilateral cataract.

CONCLUSIONS

Investigation of enzymes and polyols of galactose metabolism as well as consultation of the concerned families are recommended for clarification of cataract development.

Merkel cell carcinoma: clinicopathologic correlation, management, and follow-up in five patients

PURPOSE

To review the clinicopathologic features, management and follow-up in five patients with periocular Merkel cell carcinoma (MCC).

METHODS

In this case series study we reviewed the clinical records and histopathologic findings of five consecutive patients with MCC, treated and followed between May 1991 and November 1998.

RESULTS

Four patients were female and one was male. Their mean age at the time of surgery was 80 years (range: 69-86 years). Patients presented with a painless, nonulcerated, rapidly growing, solitary reddish or violaceous nodule, ranging in size from 11 to 21 mm, located in the upper eyelid in 4 patients and in the left eyebrow in one patient. Management included excision with frozen section control in three patients, and excision with wide surgical margins in two patients. Histopathologically, all tumors exhibited round cells of intermediate size and scanty cytoplasm, and large, round to oval vesicular nuclei with finely dispersed chromatin and one to three inconspicuous nucleoli. Mitotic figures were numerous. No patient had regional or extraregional metastases at diagnosis. Local recurrence or distant metastases were not detectable during a mean follow-up period of 45 months (range: 32-61 months). This outcome contrasts with the high incidence of local recurrence and early nodal metastasis reported in previous publications.

CONCLUSIONS

Early diagnosis and aggressive, histologically controlled surgical treatment of this rare, highly malignant tumor may provide a longer disease-free period. Further investigation is necessary to determine the prognostic factors for recurrence and survival.

Reduced recovery of temporal contrast sensitivity after flicker stress in patients with glaucoma

PURPOSE

To compare recovery of temporal contrast sensitivity after flicker stress between control subjects and patients with glaucoma.

METHODS

Forty-three patients with primary open-angle glaucoma and secondary open-angle or normal-tension glaucoma of the Erlangen Glaucoma Registry and 30 healthy control subjects had their temporal contrast sensitivity measured at 37 Hz and their recovery time determined after monocular exposure to 30 seconds of 58% contrast full-field flicker. Recovery time of temporal contrast sensitivity was measured as the time interval from cessation of flicker until twice the threshold value was reached.

RESULTS

Patients with glaucoma had a significant reduction in temporal contrast sensitivity (P < 0.001). Recovery time was also significantly longer in patients with glaucoma (23.8 +/- 24.1 seconds) than in control subjects (7.6 +/- 2.6 seconds; P < 0.001). There was a significant positive correlation between recovery time and mean visual field defect (0.5; P < 0.001) and a significant negative correlation between recovery time and neuroretinal rim area of the optic disc (0.32; P = 0.04).

CONCLUSIONS

Recovery of temporal contrast sensitivity after flicker stress is impaired in some patients with glaucoma. This might be the result of functional impairment of the inner retina, outer retina, or both in glaucoma.

The full-field temporal contrast sensitivity test for glaucoma: influence of cataract

PURPOSE

To determine the influence of lens opacities on temporal contrast sensitivity, measured by the full-field flicker test ("Erlangen flicker test").

METHODS

Thirty-six consecutive patients (mean age 71.1+/-11.6 years, 12 male, 24 female, refractive error -1.5+/-3.8 dpt) with cataract (visual acuity 0.21+/-0.16, retinal acuity 0.56+/-0.32, no glaucoma) were studied. Temporal contrast sensitivity (full-field flicker test, 37.1 Hz) and lens opacity (back scatter Lens Opacity Meter, Interzeag) were measured preoperatively and on the 3rd postoperative day.

STATISTICS

nonparametric tests (Wilcoxon-test, Spearman correlation coefficient, Mann-Whitney U-test).

RESULTS

No significant difference was seen in temporal contrast sensitivity pre- and postoperatively, but there was a significant difference in lens opacity measurements pre- and postoperatively. No significant correlation was found between temporal contrast sensitivity and lens opacity values preoperatively and postoperatively.

CONCLUSION

The temporal contrast sensitivity, measured by the full-field flicker test, seems to be independent of lens opacity due to the range of cataract included in this study. The data indicate that the full-field flicker test is useful for early glaucoma detection even in patients with cataract formations.

Quantitative analysis of visual field and optic disk in glaucoma: retinal nerve fiber bundle-associated analysis

BACKGROUND

A study was performed to evaluate whether visual field analysis using a perimetric nerve fiber bundle map gives information additional to global visual field indices and cumulative defect curves for early glaucoma diagnosis.

METHODS

One hundred and four control subjects, 124 patients with ocular hypertension (OHT), 97 patients with high-tension glaucoma without visual field defects (preHTG) and 91 patients with open-angle glaucoma with visual field defects [30 low-tension glaucoma (LTG), 61 high-tension glaucoma (HTG)] were included in this study. Correlation analyses were performed between (a) global visual field indices and total neuroretinal rim (NRR) area; (b) local mean values of four visual field areas and the NRR area of the corresponding four optic disk sectors; and (c) local mean values of 10 perimetric nerve fiber bundles (PNFB 1-10) according to Weber and Ulrich (1991) and the four optic disk sectors. The correlations were adjusted for global mean defect and total NRR.

RESULTS

There were no significant correlations between NRR area and visual field in control subjects or in patients with OHT or preHTG for all three analyses. Significant correlations were found between the global visual field indices and the total NRR area for LTG and HTG. Significant correlations between local mean defects and NRR area of corresponding optic disk sectors were found only in LTG for the superior and inferior visual field area and the PNFB covering these areas.

CONCLUSION

The method used for visual field analysis and sectorization of the optic disk does not give additional information on visual field defects in patients with normal global visual field indices and a normal cumulative defect curve. The nerve fiber bundle-related visual field analysis allows the topographical determination and quantification of glaucomatous damage.