How Spatial Orientation of Japanese Text Affects Fixation Points in Patients with Bilateral Macular Atrophy

Purpose

To ascertain the retinal area used by patients with bilateral macular atrophy when reading Japanese text of different character sizes written horizontally or vertically. In addition, to determine fixation points as part of the first of a series of studies designed ultimately to enhance the quality of life of these patients through the improvement of reading acuity.

Methods

Seventeen patients (34 eyes) with bilateral macular atrophy were tested to determine the retinal area employed for reading (R fixation point). Sentences were arranged either horizontally or vertically and projected onto the retina using a scanning laser ophthalmoscope. We also determined the fixation point using microperimetry (M fixation point). The positional relationships between these two fixation points and the scotoma were examined.

Results

The R and M fixation points were the same in 20 of the 34 eyes. Multiple R fixation points were found in 11 eyes. The R fixation point was frequently positioned above the lesion when reading horizontally (nine eyes), while it was often positioned in the area nasal to (eight eyes) or temporal to (six eyes) the lesion when reading vertically.

Conclusions

Fixation points changed frequently in these patients with bilateral macular atrophy depending on the spatial orientation of the text. These data should be used in the future to help patients learn how to use the preferred retinal locus to improve their reading skills and enhance their quality of life. Jpn J Ophthalmol 2005;49:462–468?© Japanese Ophthalmological Society 2005     

Scotoma size reduction as an adaptive strategy in age-related macular degeneration

Objective: Retinal areas with reduced sensitivity to light stimuli represent the true scotoma size in patients with age-related macular degeneration (AMD), whereas the perceived visual field defect area that covers a specific target of regard may represent an effective size of the same scotoma. This study was designed to highlight the conceptual difference between the “true scotoma size” and its “effective scotoma size” counterpart.Design: Prospective nonrandomized observational case series.Participants: Ten adults with documented AMD, low vision, and best-corrected visual acuity of 20/50-20/200 in the better eye.Methods: Effective scotoma size and true scotoma size were calculated from measurements with the macular grid test performed with automated perimetry and from microperimetry performed with the Nidek MP-1, respectively.Results: Ten patients aged 70-92 years (mean 81 years) met the inclusion criteria. Mean effective scotoma size measured with the macular grid test was 40.19 (SD 34.88) deg². Mean true scotoma size measured with microperimetry was 75.17 (SD 56.08) deg² (p ≤ 0.003). The log unit change in scotoma size, defined as scotoma utility score, was −55.91%. The effect size observed for the scotoma utility score was 0.74.Conclusions: Effective scotoma size experienced by patients with AMD is significantly smaller than true scotoma size. This reduction may be explained by adaptive variability in eye positions during any single fixation stability attempt, which ultimately results in enhanced visual field perception.     

Differentiating full thickness macular holes from impending macular holes and macular pseudoholes

AIMS—The reliability of scanning laser ophthalmoscope (SLO) microperimetry in differentiating full thickness macular holes from macular pseudoholes and impending macular holes was evaluated.
METHODS—106 eyes with the clinical diagnosis of full thickness macular holes, macular pseudoholes, and impending (stage 1) macular holes were examined for the presence of deep or relative scotoma using SLO microperimetry. The relation between these scotomas and the clinical diagnosis was studied.
RESULTS—Deep and relative scotomas were detected in all 57 eyes with clinically defined full thickness macular holes. In contrast, among 49 eyes diagnosed with macular pseudoholes or impending macular holes, no deep and only one relative scotoma was observed. The sensitivity of the presence of a deep scotoma as an indicator of the clinical diagnosis of a full thickness macular hole was 100% (57 of 57), and the specificity was 100% (49 of 49). The sensitivity of the presence of a relative scotoma was 100% (57 of 57) and the specificity was 98.0% (48 of 49).
CONCLUSION—With SLO microperimetry, full thickness macular holes can be precisely and objectively distinguished from other conditions that mimic macular holes.

     

Diagnosis of retinal diseases. Comparison between multifocal ERG and fundus perimetry - a case study

Background. There are new methods available for function testing of the macula, i.e. multifocal Electroretinography (mfERG) as well as fundus perimetry with the scanning laser ophthalmoscope (SLO). The value and clinical impact of these methods have still to be evaluated. We wanted to compare the results from patients having undergone both examinations. Patients and methods. A total of 33 eyes from 25 patients (visual acuity 0.03–0.8) aged 14–79 years were examined using fundus perimetry with the SLO. In addition, multifocal ERG was performed in all eyes, where 61 local ERGs inside the 30° visual field were recorded. We compared the depth of the scotoma with the reduction of the amplitudes during mfERG taking the fixation status into consideration. Results. Examination time was comparable for both examination techniques. There was good concordance for eyes with retinitis pigmentosa with only central response. In contrast, patients with juvenile macular dystrophy demonstrated different results with comparable size of the defect while sometimes an enlarged pathology during mfERG was observed. Correlation between pathology findings observed in mfERG and fundus changes was difficult due to the change of the point of fixation caused by central scotoma. In age-related macular degeneration correlation of the findings was less obvious. Discussion. The different setting with supra-threshold stimuli during ERG in contrast to near-threshold stimulus presentation during perimetry, might be the reason for differences even in the beginning of retinal diseases. In addition, reduced stability of fixation leads to artifacts during mfERG while it may be compensated for in fundus perimetry. Both methods are of additional value and demonstrate different results depending on the disease.     

Use of scanning laser ophthalmoscope microperimetry in clinically significant macular edema in type 2 diabetes mellitus

PURPOSE: We used scanning laser ophthalmoscope (SLO) microperimetry to evaluate scotomas in patients with clinically significant diabetic macular edema (CSME) in type 2 diabetes mellitus. METHODS: We studied 19 patients (mean age = 63 years; range, 45-78 years) (19 eyes). SLO microperimetry was performed in all eyes. We divided patients into three groups as follows: dense scotoma, relative scotoma, and no scotoma. The following variables were documented: age; duration of diabetes, hemoglobin A(1c) levels; logarithm of the minimum angle of resolution (Log(MAR)) visual acuity; refractive power; a history of panretinal photocoagulation; presence or absence of proliferative diabetic retinopathy, vitreomacular separation, and cystoid changes; the type of macular edema; and stability of fixation. All variables were compared in the three groups. RESULTS: We identified 4 eyes (21.1%) with dense scotoma, 10 (52.6%) with relative scotoma, and 5 (26.3%) with no scotoma. There were significant differences in log(MAR) visual acuity among those with dense scotoma (1.4 +/- 0.5), relative scotoma (0.6 +/- 0.2), and no scotoma (0.2 +/- 0.3) (P <.05), and in the prevalence of cystoid changes, diffuse edema, and unstable fixation among those with dense scotoma (75%, 75%, and 100%, respectively), relative scotoma (20%, 30% and 50%, respectively) and no scotoma (0%, 0% and 0%, respectively) (P <.05). CONCLUSIONS: Macular scotoma was observed by SLO microperimetry in 74% of the patients in this study. A scotoma in CSME is related to the formation of cystoid changes and the type of macular edema. In eyes with CSME in type 2 diabetes mellitus, a scotoma in the macula causes visual acuity impairment and unstable fixation.     

The relationship between scotoma displacement and preferred retinal loci in low-vision patients with age-related macular degeneration

Objective: Adaptive strategies in low-vision patients with age-related macular degeneration use preferred retinal loci (PRLs) for the purpose of achieving better visual function. In the process of redirecting the eye toward the PRL, central scotomata are displaced eccentrically. The consequential effect of the first on the second may offer an indirect method for PRL identification. The purpose of this study was to clarify the relationship between scotoma displacement and PRL location.Design: Prospective, nonrandomized, observational case series.Participants: Forty-one adults with a confirmed diagnosis of age-related macular degeneration.Methods: Scotoma characteristics were obtained with automated perimetry. PRL topography was obtained with the Nidek MP-1 instrument. Outcome measures selected for this study were scotoma displacement and PRL eccentricities estimates.Results: We tested 16 males and 25 females aged 70-98 years (mean 82.5 [SD 6.71] years) with best-corrected visual acuity of 0.81 (SD 0.24) logMar units (20/128). PRL location logically matched scotoma displacement in 30 study subjects (73.17%, p < 0.00432). In this subgroup (n = 30), PRL eccentricity (5.55 [SD 3.35]°) was almost identical to scotoma displacement eccentricity (5.22 [SD l.98]°) (p < 0.65).Conclusions: Scotoma displacement recorded with macular perimetry methods offers reasonable indirect estimates of PRL location.     

Photoreceptor images of normal eyes and of eyes with macular dystrophy obtained in vivo with an adaptive optics fundus camera

Purpose

To report on images of the human photoreceptor mosaic acquired in vivo with a newly developed, compact adaptive optics (AO) fundus camera.

Methods

The photoreceptors of two normal subjects and a patient with macular dystrophy were examined by using an AO fundus camera equipped with a liquid crystal phase modulator. In the eye with macular dystrophy, the fixation point in the AO images was identified using scanning laser ophthalmoscope (SLO) microperimetric image superimposed on a color fundus photograph.

Results

Photoreceptor cells were detected as bright dots approximately 4 μm in diameter in normal subjects. In the eye with macular dystrophy, the fixation point was located within the bull’s eye lesion and uniform small whitish spots with irregular patchiness were observed in the AO images of this area. The distance between the small spots was 3–4 μm. In other parts of the bull’s eye retinal lesion, the whitish spots were larger and of different sizes.

Conclusions

The photoreceptor mosaic could be identified in photographs of eyes of normal subjects and an eye with macular dystrophy in vivo by an AO fundus camera. In the eye with macular dystrophy, a relatively uniform photoreceptor mosaic was observed around the fixation point, whereas presumed debris of photoreceptor degradation was observed in the other bull’s eye retinal lesion.     

Long-term Retention of Dye After Indocyanine Green-Assisted Internal Limiting Membrane Peeling

Purpose

To evaluate dye retention in the fundus after indocyanine green (ICG)-assisted internal limiting membrane peeling.

Methods

Ten eyes with stage 3 or 4 nondiabetic idiopathic macular hole (MH group) and six eyes with diffuse diabetic macular edema (DM group) were studied. The fundus was examined with 780-nm infrared illumination by a scanning laser ophthalmoscope (SLO) after ICG-assisted internal limiting membrane peeling. The postoperative follow-up period ranged from 6 to 12 months (mean ± SD, 3.7 ± 2.6 months).

Results

Fluorescence from ICG was detected in all studied eyes in both groups up to 6 months after surgery. At 9 months after surgery, ICG fluorescence was visible in all eyes of the DM group, but in only one-third of eyes of the MH group. No fluorescence was detected in fellow eyes that had not been operated on.

Conclusion

The present study using SLO revealed that ICG remains in the fundus for over 6 months after surgery. The results also suggested that a longer time might be required for dye clearance from the diabetic retina than from the nondiabetic retina.?Jpn J Ophthalmol 2006;50:349–353 © Japanese Ophthalmological Society 2006     

Multimodal evaluation of macular function in age-related macular degeneration

Objective

To evaluate macular function using multimodality in eyes with age-related macular degeneration (AMD) at various stages.

Methods

Macular function in 20 control eyes (20 subjects), 17 eyes (17 patients) with large drusen, 18 eyes (18 patients) with drusenoid pigment epithelial detachment (PED), and 19 eyes (19 patients) with neovascular AMD was examined using a Landolt chart for visual acuity; retinal sensitivity was measured by microperimetry; and focal macular electroretinography (fmERG) was performed. In all of these eyes, retinal morphology was examined using optical coherence tomography.

Results

Eyes with neovascular AMD showed morphologic changes in the neurosensory retina as well as marked deterioration of macular function in all parameters measured with a Landolt chart, fmERG, and microperimetry. Eyes with large drusen showed only minimal morphologic changes in the neurosensory retina. In this large drusen group, although retinal sensitivity at the central point was significantly decreased (P = 0.0063), the other parameters of macular function were well preserved. In eyes with drusenoid PED, the structure of the neurosensory retina was well preserved, while the foveal thickness was significantly increased (P = 0.013). The macular function of these eyes was significantly deteriorated, with the VA, amplitude of the a-wave and b-wave, and retinal sensitivity being markedly decreased. In addition, the area of PED correlated with the latency of the a-wave and b-wave and with the retinal sensitivity within the central 4° or 8° region.

Conclusion

Multimodal evaluation demonstrated a significant decrease in macular function in drusenoid PED and in neovascular AMD.     

Structural and functional assessment by hemispheric asymmetry testing of the macular region in preperimetric glaucoma

Purpose

To investigate structural measurements of the macular area in preperimetric glaucoma (PG) patients using spectral domain optical coherence tomography with two functional measurements [10-2 Humphrey visual field (HFA) and 10-2 Microperimeter-1 (MP-1)] and by macular symmetry testing.

Methods

Fifteen eyes of 15 PG subjects with a retinal nerve fiber layer defect in the inferior hemisphere and 15 eyes of 15 normal control subjects were enrolled. Macular symmetry testing was performed between the superior and inferior zones by comparing zone thickness in each hemisphere. Perimetric sensitivity asymmetry was calculated with two functional measurements. Structure–function relationships between macular symmetry testing and the mean retinal sensitivity of the corresponding hemifield or perimetric sensitivity asymmetry were calculated using Spearman’s rank correlation and linear regression.

Results

Macular zone thickness in the abnormal hemispheres was significantly less than that in normal hemispheres in PG eyes and the corresponding hemispheres in control eyes (P < 0.001). Macular symmetry testing was significantly lower in PG eyes compared to control eyes (P < 0.001). HFA (10-2) and MP-1 (10-2) correlated significantly (rs = 0.81, P < 0.0001). Macular symmetry testing values were significantly correlated with perimetric sensitivity and perimetric sensitivity asymmetry with two functional measurements (rs = 0.61, P = 0.02; HFA and rs = 0.68, P = 0.006; MP-1).

Conclusions

Our results suggest that macular asymmetry analysis can reveal the structure–functional relationship in PG eyes.     

Association of preoperative photoreceptor displacement and improved central scotoma after idiopathic macular hole surgery

OBJECTIVE: To investigate the relationship between preoperative photoreceptor displacement and postoperative scotoma after unilateral idiopathic macular hole surgery. DESIGN: Prospective nonrandomized comparative self-controlled trial. PARTICIPANTS: Twenty patients who underwent successful surgery for unilateral idiopathic macular hole participated in the study. METHODS: Kinetic perimetry using red and green filter glasses, black binocular fixation targets, and red and green selective monocular stimuli was performed preoperatively. Scanning laser ophthalmoscope (SLO) microperimetry was performed preoperatively and postoperatively. RESULTS: Sixteen patients had photoreceptor displacement preoperatively. In preoperative SLO microperimetry, all eyes with a macular hole had a scotoma; postoperatively, 12 of 16 had no scotoma. All four eyes with no preoperative photoreceptor displacement were noted to have a postoperative scotoma. The prevalence of postoperative scotoma in patients with preoperative photoreceptor displacement (4 of 16; 25%) was significantly lower than that in patients without preoperative photoreceptor displacement (4 of 4; 100%) (P = 0.03). CONCLUSIONS: The presence or absence of photoreceptor displacement preoperatively should affect postsurgical visual function. Photoreceptor damage may occur in eyes without photoreceptor displacement preoperatively, resulting in scotoma postoperatively.     

Atypical presentation of acute macular neuroretinopathy with tiny parafoveal reddish-brown lesions

Purpose

To report two cases of acute macular neuroretinopathy with unusually small parafoveal lesions, which showed later recurrent lesions either in the same eye or the fellow eye.

Methods

Observational case series.

Patients

In case 1, a 48-year-old woman developed a sudden onset of a tiny paracentral scotoma associated with a small reddish-brown paracentral lesion. A new paracentral lesion with a corresponding scotoma developed 1 year later. In case 2, a 39-year-old man with diabetes type 1 developed a pracentral scotoma OS with a corresponding small reddish-brown lesion. Two months later, a similar lesion with a corresponding scotoma developed in the fellow eye.

Conclusions

Acute macular neuroretinopathy may present with tiny paracentral lesions difficult to detect with fundus examination, and may be associated with recurrent lesions either in the same eye or the fellow eye.     

Filling-in phenomenon in patients with age-related macular degeneration: differences regarding uni- or bilaterality of central scotoma

Purpose The purpose of this study was to explore the presence of the filling-in phenomenon in patients with uni- or bilateral central scotoma (CS) resulting from natural history or laser photocoagulation of choroidal neovascularization in age-related macular degeneration (AMD).Methods Sixteen consecutive patients with unilateral CS and 14 patients with bilateral CS were assessed (44 eyes) with a scanning laser ophthalmoscope (SLO). Scotoma was delineated by scotometry with a point (1°×1°) moving radially from the periphery to the center of the lesion. In addition, patients underwent a line test, consisting of a horizontal line moving vertically and a vertical line moving horizontally, from the periphery to the center. The lines were longer than the macular lesion and were projected onto the retina. Patients were asked to indicate when the lines seemed interrupted. The perceptual filling-in phenomenon was considered to be present when limits of the perceived scotoma, determined by the line test, were smaller than those assessed by scotometry. In patients with bilateral CS, the results were analyzed to distinguish the less or more severely affected eye.Results In all eyes, the limits of the scotoma obtained with the scotometry test corresponded to the anatomic edges of the macular lesion. In patients with bilateral CS, the filling-in phenomenon was observed in 12 out of 14 (85%) less severely affected eyes, but only in one (7%) of their more severely affected eyes. In patients with unilateral CS, the phenomenon was observed in only one out of 16 (6%) eyes.Conclusion These results suggest that the filling-in phenomenon mostly occurs in patients with bilateral central scotoma, and almost always in their less affected eye. Thus, it did usually not occur in an eye if the fellow eye was better.     

Assessment of visual function in choroidal neovascularization with scanning laser microperimetry and simultaneous indocyanine green angiography

Background: Clinical management and treatment of diseases with choroidal neovascularization (CNV) are mainly based on visual acuity, which may give an incomplete picture of the associated visual dysfunctions. With the advent of new experimental treatment modalities such as alfa-interferon, radiation, or surgical excision of CNV, it is increasingly important to develop better methods for characterizing the associated visual function. Microperimetry with the scanning laser ophthalmoscope (SLO) allows precise point-to-point correlation between visual function and the macular pathology. However, precise delineation of CNV is a prerequisite for accurate correlation of the functional results with the CNV. Methods: A total of 40 eyes with CNV secondary to age-related macular degeneration were evaluated with static manual microperimetry using the SLO to quantitate relative and absolute scotomata within the CNV. For precise delineation of the CNV, indocyanine green (ICG) angiography was simultaneously performed, allowing stimulus presentation at any desired retinal location under visual feedback of the angiogram. Results: A relative scotoma was detected in 19 and an absolute scotoma in 21 out of 40 eyes. The depth of the scotomata was correlated with the duration of symptoms (P<0.01). Eyes with well-defined CNV had significantly deeper scotomas than eyes with occult CNV (P<0.005). Conclusion: Microperimetry using the SLO and simultaneous ICG angiography demonstrated relative and absolute scotoma within the CNV. The depth of the scotoma may guide the ophthalmologist in selecting the adequate treatment.Presented in part at Macula: New Frontier, An International Symposium, Kansas City, Missouri, 1994     

Static and dynamic retinal fixation stability in microperimetry

Objective

To compare static (during a pure fixation task) versus dynamic (during microperimetry) quantification of fixation stability using microperimetry in normal and pathologic eyes, by means of 2 available (clinical and bivariate contour ellipse area [BCEA]) classification methods.

Design

Prospective comparative observational study.

Participants

One hundred and forty-nine eyes (110 patients) with different macular diseases and 171 normal eyes (109 subjects).

Methods

In all eyes studied, fixation stability was acquired during an isolated fixation task (static fixation) and during microperimetry (dynamic fixation). All fixation data were analyzed and compared by means of a clinical classification and by means of BCEA quantification.

Results

Pathologic eyes were classified as follows: 41 eyes with diabetic macular edema (DME group), 13 eyes with vitreoretinal interface disease, 60 eyes with age-related macular degeneration (AMD group), and 35 eyes with primary open-angle glaucoma. Fixation stability was not uniform among groups according to clinical classification in both static and dynamic modalities (p < 0.0001). AMD group showed larger BCEA areas compared with all other groups (p < 0.0001). All pathologic groups showed more unstable fixation in dynamic fashion according to both clinical and BCEA methods (p < 0.0001). The variation of fixation stability of control group in dynamic task was highlighted only by BCEA analysis (p < 0.0001). A deterioration of retinal fixation according to clinical method matches a significant increase in BCEA areas (p < 0.0001).

Conclusions

The detection of clinical fixation stability changes improves when acquired in the dynamic modality. BCEA analysis provides more accurate evaluation of fixation stability and may detect minimal quantitative changes of the fixation area. However, a standard clinical classification can also detect changes in fixation stability in pathologic eyes. Both methods are useful tools in the evaluation of fixation stability.     

Assessment of serous macular detachment in eyes with diabetic macular edema by use of spectral-domain optical coherence tomography

Background

The introduction of optical coherence tomography (OCT) has brought new potentialities for an objective evaluation of macular diseases. The purpose of the present study was to assess the serous macular detachment (SMD) in eyes with diabetic macular edema (DME) by use of spectral-domain OCT.

Methods

In this prospective study were included 79 eyes of 46 patients with diabetic retinopathy and DME. All patients underwent examination of best-corrected visual acuity (BCVA), non-contact slit-lamp fundus biomicroscopy, fluorescein angiography and OCT. Spectral-domain OCT (OCT/SLO Combination Imaging System, OPKO/OT Inc., Toronto, Ontario, Canada) was used to evaluate retinal morphology and the presence of macular traction (vitreomacular and/or from epiretinal membranes) on B-scans, C-scans and C-scan OCT/SLO fundus image overlays. With OCT were measured retinal thickness, volume, diameter of intraretinal cystoid spaces, diameter and height of SMD. The correlation of retinal thickness and volume with BCVA in all eyes with DME and the relation of SMD to retinal thickness, volume, BCVA, macular traction and ischemia were assessed.

Results

The SMD was diagnosed only by means of OCT in nine eyes (11.4%) of five patients. In eight of nine eyes it was combined with intermediate (300–600 µm) or severe (>600 µm) cystoid spaces, and in one eye with simple macular edema. Retinal thickness and volume correlated with BCVA (r?=?0.464, P?<?0.0001 and r?=?0.480, P?<?0.0001). The SMD height did not correlate with retinal thickness, volume or BCVA. Six eyes with SMD had macular ischemia, and five eyes had severe ischemia in retinal periphery. Macular traction was: absent in three eyes, questionable (without distortion of retinal contour from partial posterior vitreous detachment and/or epiretinal membrane) in three eyes, and definite (with distortion of retinal contour) in three eyes.

Conclusions

Spectral-domain OCT provided valuable information on retinal morphology and was particularly useful in diagnosing sub-clinical SMD in eyes with DME. It disclosed the presence and strength of macular traction either by partially detached posterior hyaloid or by epiretinal membranes. C-scans and C-scan OCT/SLO fundus image overlays added complementary information for the extent and location of the pathological features. Larger studies which follow subjects longitudinally are needed to explain the pathogenesis and determine the prognosis of SMD.     

The effect of prism on preferred retinal locus

Background

Whether prism, especially base‐up prism, affects the area of the retina used for fixation in a patient with central scotoma has been a controversial subject for 35 years. Our pilot study employed microperimetry to evaluate the effect of base‐up prism on the fixation locus, or preferred retinal locus (PRL), in subjects with central scotoma.

Methods

We used a microperimeter to assess the PRL in 13 visually impaired subjects with central scotoma under four conditions: no lens, a lens with no prism (control lens), 6^Δ base‐up, and 10^Δ base‐up. The PRL was measured in degrees in horizontal and vertical co‐ordinates from the centre of the optic disc using graphical analysis.

Results

The PRL with the control lens was not significantly different from the PRL with no lens. The preferred retinal loci with the two powers of prism were compared to the control lens and showed a superior shift in 22 of 26 cases (84.6 per cent). The amount of movement was significantly different from zero (p = 0.001 for 6^Δ and p = 0.004 for 10^Δ). The vertical movement with the 10^Δ prism (1.73 ± 1.73 degrees) was not significantly greater (p = 0.562) than with the 6^Δ prism (1.37 ± 1.08 degrees). The shift was significantly less than the prism powers used (p < 0.001), and the amount of vertical relocation was not significantly different from the amount of horizontal movement.

Conclusion

In our study, base‐up prism appears to shift the PRL in the direction of the prism base most of the time, but our findings do not support the use of prism as a way of predictably relocating the PRL. More study is indicated to evaluate whether such a small shift is clinically or functionally significant.

     

Modified astigmatism dial diagram for locating eccentric fixation in patients with central scotoma

PURPOSE: Patients with central scotoma often develop eccentric fixation on a preferred retinal locus (PRL). Identifying the PRL is one of the first steps in low vision rehabilitation training. We present our evaluation of a simple test designed to locate the eccentric fixation in eyes with central scotoma. METHODS: This was a prospective case series of consecutive patients with age-related macular degeneration and bilateral central scotoma. A numeral was added in the center of an astigmatism dial diagram. After one eye was patched, patients with central scotoma were asked to fixate the dial and describe it, then to look at the 12 o'clock position, and then around the clock. The eccentricity at which the central numeral was best seen was compared with the one determined by scanning laser ophthalmoscopy (SLO). The modified astigmatism dial test and SLO were done independently by two masked investigators. The results of the two methods were expressed in clock hour positions and were considered to be in agreement when they did not differ by more than one hour. RESULTS: Nine consecutive patients (18 eyes) with severe age-related macular degeneration and bilateral central scotoma were tested. The six women and three men ranged in age from 61 to 86 years (mean 75.8 years). The pattern test correlated with SLO findings in 12 (66%) of the 18 eyes. When considering the best-seeing eye of each patient, results showed agreement in eight (88%) out of nine cases. CONCLUSIONS: The modified astigmatism dial test appears useful for establishing the location of the eccentric fixation in the best-seeing eye of patients with bilateral central scotoma, allowing visual rehabilitation training to be started without delay.     

Fourier-domain optical coherence tomography of eyes with idiopathic epiretinal membrane: correlation between macular morphology and visual function

Purpose

The purpose of this study is to evaluate the macular morphological changes associated with idiopathic epiretinal membrane (iERM) using high-resolution Fourier-domain optical coherence tomography (FD-OCT), as they correlate with visual acuity and microperimetry (MP-1).

Methods

In all, 24 eyes (19 subjects) with iERM were imaged prospectively using FD-OCT with axial resolution of 4.5 μm and transverse resolution of 10 to 15 μm. MP-1 and Stratus OCT were carried out in a subset of eyes.

Results

The mean log of the minimum angle of resolution best-corrected visual acuity (BCVA) was 0.18±0.16 (range: −0.08 to 0.48, Snellen equivalent 20/15⁻¹ to 20/60). ERM was visualized in all 24 eyes with FD-OCT and in 17 eyes (85%) of 20 eyes imaged with Stratus OCT. Although BCVA correlated with macular thickening in the central 1 mm sub-field of the Stratus ETDRS (P=0.0005) and macular volume (central 3 mm area) on FD-OCT (P<0.0001), macular thickening on thickness map and volume correlated poorly with decrease in macular sensitivity on MP-1 (P=0.16). On FD-OCT, foveal morphological changes correlated best with decrease in BCVA, the strongest being central foveal thickness (P<0.0001). Other significant changes included blurring of the foveal inner segment–outer segment (IS–OS) junction and/or Verhoeff''s membrane, vitreal displacement of foveal outer nuclear layer and foveal detachment (P<0.05). Foveal IS–OS junction disruption was seen in 25% of eyes on Stratus OCT but in none of the eyes on FD-OCT.

Conclusion

FD-OCT allowed improved visualization of ERM and associated foveal morphological changes that correlated best with BCVA. Macular thickening correlated weakly with decreased macular function as assessed by MP-1.     

黄斑水肿患者中心凹厚度与固视性质及平均敏感度相关性研究

目的 观察黄斑水肿(ME)状态下黄斑中心凹厚度与视功能改变之间的相关性.方法 回顾分析应用光相干断层扫描(OCT)联合微视野计(MP-1)检测的ME患者40例42只眼的临床资料.所有患眼均行验光插片,记录最佳矫正视力(BCVA);采用德国Zeiss-HumphreyOCT仪进行OCT检查;意大利Nidek公司MP-1微视野计进行眼底成像、固视检测和视野检查.OCT及MP-1检查均以视盘颢侧2个视盘直径(DD)、下方1/3 DD作为黄斑中心凹进行检查.采用统计学方法对比分析患眼BCVA、中心凹厚度(CMT)、中心10°的光敏感度(MS)以及同视情况.结果 不同病因ME患者中,CMT与BCVA之间无明显相关性(r=-0.429,P=0.069);CMT与MS之间无明显相关性(r=-0.433,P=0.058).固视分析中,固视稳定组与同视不稳定组CMT差异有统计学意义(F=3.262,P=0.039),中心注视组与偏心注视组比较,CMT差异有统计学意义(F=3.173,P=0.044).结论 ME患者CMT增加,但与BCVA、MS无相关性;CMT增加,同视稳定性下降.固视位置发生偏移,出现偏心注视.