Glaucoma and Drusen of the Optic Nerve Head

Purpose: to present 28 patients with optic nerve head drusen (ONHD). Ten had coexisting glaucoma. We tried to evaluate if there was any correlation between the clinical picture of ONHD and the visual field defects and whether glaucoma exacerbated any of the clinical parameters in these patients. Methods: basic clinical examination, Goldmann applanation tonometry, visual field, HRT II, Ishihara colour testing, pupil reaction, central corneal thickness, corneal endothelial cell count, VER and laboratory investigations were performed in all patients. Results: There was an abnormal retinal nerve fiber layer (RNFL) thickness and visual field defects in 90% of patients. There was no correlation between the clinical picture of ONHD and the visual field defects among patients. This correlation was found in individual patients when an interocular comparison was made.     

Comparison of Optic Nerve Head Microvasculature Between Normal-Tension Glaucoma and Nonarteritic Anterior Ischemic Optic Neuropathy

PurposeTo compare the microvasculature of the optic nerve head (ONH) and peripapillary tissues in eyes with normal-tension glaucoma (NTG) and nonarteritic anterior ischemic optic neuropathy (NAION) using optical coherence tomography angiography (OCTA).MethodsThirty-eight eyes with treatment-naïve NTG, 38 eyes with NAION matched for retinal nerve fiber layer (RNFL) thickness in each superior and inferior quadrant, and 38 healthy eyes matched by age were included. ONH and peripapillary retinal microvasculature was evaluated in en face images obtained using OCTA. Vessel density (VD) was calculated as the percent area occupied by vessels in the measured region in each layer segmented into the prelaminar tissue (PLT), lamina cribrosa (LC), and peripapillary retina (PR).ResultsVDs in the PLT and LC were lower in NTG eyes than in both NAION and healthy eyes (P ≤ 0.008), and did not differ between the NAION and healthy eyes. VDs in the PR did not differ between the NTG and NAION eyes. In intersectoral comparisons, VDs in the PLT (P = 0.030) and LC (P = 0.028) were lower in the affected than in the unaffected sector of eyes with NTG, but the differences did not occur in eyes with NAION. VD in the PR was lower in the affected than in the unaffected sector in both NTG and NAION eyes (both P < 0.001).ConclusionsDespite similar degrees of RNFL loss and VD decreases in the PR, VDs in the ONH differed between eyes with NTG and NAION, indicating different mechanisms of vascular impairment and ONH damage in each condition.     

Scanning Laser Polarimetry (SLP) for Optic Nerve Head Drusen

Optic nerve head drusen (ONHD) are either clinically invisible or clearly protruding from the disc, in the later case leading to the condition of an irregular, indistinct disc margin or a swollen disc on biomicroscopy. They also may cause visual field defects, even with slow progression. Scanning laser polarimetry (SLP) has been proposed as a rapid, objective and reproducible technology for retinal nerve fiber layer (RNFL) assessment and clinical studies have demonstrated that SLP can help to distinguish between normal andglaucomatous eyes, identify glaucoma suspects and correlates well with visual field defects.The purpose of this study was to evaluate the potential applicabilityof SLP in 20 consecutive patients with optic nerve head drusen (18 bilateral) thatwere clinically visible (22 eyes) and invisible (16 eyes). RNFL thickness was studied in patients with and without visual field defects.Patients with visual field defects and ONHD were significantly olderand had a small, but significant reduction of visual acuity. Some global SLP parameters (average thickness, ellipse average) were significantly different between subjects with normal and abnormal visual fields. The comparison of the groups with visible and invisible drusen showed that there was no difference in demographic or perimetric data. RNFL thickness measurements were also very similar in both groups.Clinical visibility of drusen was not correlated with RNFL thinningas measured with the GDx^TM. SLP assessment, however, was well correlated with functional loss. This objective, non-invasive technology may be an additional option for RNFL evaluation in this condition and an especially useful tool for long-term follow-up.     

OCT检测视网膜神经纤维层厚度及视盘参数在青光眼早期诊断应用

目的 通过光学相干断层成像术(OCT)检测视网膜神经纤维层(RNFL)厚度及视盘结构参数,结合视野改变,探讨OCT在青光眼早期诊断中的应用价值.方法 采用OCT对34只眼疑似闭角型青光眼(SG)患者、36只眼慢性闭角型青光眼(CACG)早中期患者、10只眼正常人行RNFL及视盘扫描,观察各组的RNFL厚度及视盘结构的图像特征;将各象限RNFL厚度和平均RNFL厚度的均数进行总体比较及任意两组间比较;将视乳头水平、垂直杯盘比及杯/盘面积比的均数进行比较;将平均RNFL厚度与视野指数进行相关分析.结果 三组间各象限RNFL厚度、平均RNFL厚度、视盘参数差异有统计学意义(P<0.05);正常人与SG组下方、上方及平均RNFL厚度差异有统计学意义(P<0.05);正常人与CACG早中期组各象限RNFL厚度及平均RNFL厚度差异均有统计学意义(P<0.05);CACG早中期组与SG组上方、下方、鼻侧及平均RNFL厚度差异有统计学意义(P相似文献   

Effect of Topical Unoprostone Isopropyl on Optic Nerve Head Circulation in Controls and in Normal-Tension Glaucoma Patients

Purpose To evaluate the effect of unoprostone isopropyl on microcirculation in the optic nerve head (ONH) of controls and patients with normal-tension glaucoma (NTG).Methods Thirty healthy volunteers were randomly placed in a placebo group or a control group. For ten NTG patients, one eye was selected to receive the placebo drops and the contralateral eye received the unoprostone in a masked fashion. In both studies, the intraocular pressure (IOP) and the parameters of the blood hemodynamics of the ONH were obtained before and at 1 and 2 h after the instillation. Blood flow measurements were made with a scanning laser Doppler flowmeter.Results In both control subjects and NTG patients, the changes in the IOPs after the instillation of either unoprostone or the placebo were not significant because almost all of the NTG patients had IOPs lower than 15 mmHg. Although the hemodynamic parameters were not significantly changed in the placebo-treated eyes of the controls, the eyes of the controls treated with unoprostone had mean blood velocity and flow values that were significantly higher than the baseline values 1 and 2 h after instillation (P < 0.01). The velocity values of the controls treated with unoprostone were significantly higher than in those controls receiving the placebo at 2 h postinstillation (P = 0.027). The values for the three circulation parameters (volume, velocity, flow) were significantly higher than the baseline values after instillation in the eyes of the NTG patients treated with unoprostone (P < 0.05). In contrast, none of these parameters was significantly different from the baseline in the eyes of NTG patients treated with placebo.Conclusions These results showed that unoprostone significantly increased microcirculation in the ONH in control subjects and in NTG patients without reducing the IOP significantly. Jpn J Ophthalmol 2005;49:287–293 © Japanese Ophthalmological Society 2005     

Functional imaging of the retinal microvasculature by Scanning Laser Doppler Flowmetry

Purpose: to image functionally perfused retinal vessels and to assess quantitatively the intercapillary space of the retinal microvasculature.Method: The base offunctional imaging and the quantitative assessment of the retinal vasculature is the two-dimensional map of the retina encoded by the laser Doppler frequency shift. By Scanning Laser Doppler Flowmetry (HRF. Heidelberg Engineering) the laser Doppler frequency shift of 16.384 retinal sites (256 pixels × 64 lines, spatial resolution10 m) of a retinal area of 2.7 × 0.7 mm was gained. The image processing was performed by a recently described algorithm (AFFPIA). Using the data of the laser Doppler frequency shift of every retinal site, a color-coded retinal image was establishedshowing perfused vessels and capillaries. By automatic pattern analysis of this image vessels and capillaries were identified and segmented. Based on this image the distances in [m] of every retinal site to the next vessel or capillary were calculated ("distanceto next capillary'). The functional imaging of the retinal perfusion was demonstrated in (1) normal retina, (2) retinal arterial occlusion, and (3) proliferative retinopathy. Intraobserverreliability of the quantitative assessment of the parameter ``distance to next capillary' was estimated by measuring 10 eyes of 10 subjects at 5 different days by one observer. Interobserver reliability of the quantitative assessment was evaluated by analysing10 perfusion maps by 5 different operators. In 93 eyes of 71 normal subjects (mean age 40.4 15 years) the juxtapapillary retina was quantitatively evaluated.Results: Qualitative evaluation: The functional images of the retinal perfusion of eyes with normal retina, with retinal arterial occlusion, and with proliferative retinopathy correspondedwell with the fluorescein angiography. Perfused vessels and capillaries became visible in a high local resolution. Quantititative assessment: The coefficient of reliability of the introobserver and interobserver reproducibility of the parameter ``mean distance to next capillary' was 0.74, and 0.95, respectively. The quantitative assessment of the perfusion showed that the major part of the retinal sites (>700%) had distancesto the next capillary lower than 30 m 46% of the retinal area had distances to the next capillary from 0–20 lm 26% of the retina had distances from 20–30 m, 12% of the retina had distances from 30–40 m 7% of the retina had distances from 40–50 m, 4% of the retina had distances from 50–60 m, and 4% of the retinal sites showed distances to the next capillary greater than 60 m. The mean distance tothe next capillary or vessel was calculated with 21 ± 6.5 m.Conclusion: By non-invasive Scanning Laser Doppler Flowmetry in combination with adequate softwareit is possible to perform a functional imaging of the retinal vasculature and to measure all index for the functional density of retinal capillaries and vessels.     

Topographic Characteristics of the Optic Nerve Head Measured with Scanning Laser Tomography in Normal Japanese Subjects

Purpose

Few studies have been performed regarding the topographic information obtained with the Heidelberg retina tomograph (HRT) in normal Japanese. In this study, we examined the factors influencing optic disc parameters and hemisphere symmetry obtained with the HRT in normal Japanese subjects.

Methods

Mean values and the standard deviation range for the main HRT parameters were evaluated in 223 eyes of 223 normal Japanese subjects. The influence of age, sex, and disc size on HRT topographic data was analyzed. The superior and inferior hemisphere topographic parameters were compared.

Results

Disc area showed a significant difference by sex (P = 0.0493). Rim volume (r = ?0.208, P = 0.019), height variation contour (r = ?0.275, P = 0.001), and mean retinal nerve fiber layer (RNFL) thickness (r = ?0.366, P = 0.001) declined with age. All parameters except height variation contour and mean RNFL thickness showed a clinically significant correlation with disc size (?0.159 < r < 0.719, P < 0.01). Cup parameters in the superior hemisphere were significantly greater than those in the inferior hemisphere. In contrast, rim parameters in the superior hemisphere were significantly smaller than those in the inferior hemisphere.

Conclusions

Some factors, namely, sex, age, and disc size, affected the optic disc parameters in the HRT measurements. Possible parameter asymmetry between the two hemispheres should be considered in normal eyes. Jpn J Ophthalmol 2005;49:469–476 © Japanese Ophthalmological Society 2005