Blue-on-yellow perimetry with a scanning laser ophthalmoscope: small alterations in the central macula with aging.

The sensitivity of short-wavelength-sensitive (SWS) cone pathways was measured in the central fields of 74 normal subjects, aged 17-86 yr, with healthy maculas. The new fundus perimetry technique used a research scanning laser ophthalmoscope with a small entrance pupil to present blue static perimetry targets on a bright yellow background. Simultaneous infrared imaging aided target positioning and rapid assessment of potential pathology in elderly subjects. Targets were positioned peripheral to fixation, avoiding both the SWS-cone-free area and the peak macular pigment, determined in 11 subjects. Sensitivity declined 0.019 log unit per decade, while intraindividual variability across loci increased. The nasal-temporal asymmetry remained constant. Sensitivity of older subjects was relatively less for the most central targets but was unrelated to transmission through macular pigment. Retinal changes with age occur to differing extents or at differing rates and are readily detectable in the central macula.

Infrared scanning laser tomography of macular cysts.

OBJECTIVE: To perform three-dimensional, noninvasive, quantitative analysis of cystoid macular edema and macular cysts using infrared scanning laser tomography and to correlate findings with visual acuity (VA) as a basis for interventional studies. DESIGN: Cross-sectional, nonrandomized study. PARTICIPANTS: Seventeen patients (29-86 years of age) with macular cysts associated with a broad spectrum of diseases. INTERVENTION: Confocal infrared imaging with scanning laser tomography with the TopSS (790 nm) (Laser Diagnostic Technologies, San Diego, CA) with digitized images was used to perform three-dimensional, quantitative analysis of cysts in the central 5 degrees of the macula. MAIN OUTCOME MEASURES: Measurements of macular cyst number, area, volume, depth, slope, height of the surrounding macular elevation, and correlation with VA. RESULTS: Scanning laser tomography detected macular cysts in all patients. The number per patient ranged from 1 through 15. Cysts were accompanied by surrounding macular elevation in 16 patients (mean macular height, 216 microm). The area covered by cysts in the central 5 degrees was 0.087 to 0.969 mm2, and volume was 0.007 to 0.549 mm3. Visual acuity was significantly poorer in patients with greater cyst area (P = 0.0007), cyst volume (P = 0.0009), macular thickening (P = 0.0002), and cyst depth (P = 0.0013). Cyst number, average slope, and maximum slope, however, did not correlate significantly with VA. Grouping of macular cysts according to macular height and average cyst depth revealed that cysts in a more thickened retina were significantly deeper, had steeper slopes, and corresponded to worse VA. Macular height and average cyst depth were highly associated with each other, suggesting that in eyes with surrounding macular edema, cysts were deeper and may reflect more widespread tissue destruction. Individual confocal tomographic images provided additional information. Neither ophthalmoscopy nor fluorescein angiography delineated features such as retinal folds that suggested vitreous traction or changes in deeper layers that suggested occult choroidal new vessels. CONCLUSIONS: Infrared scanning laser tomography is a rapid and noninvasive imaging method that provides quantitative analysis of macular cysts in addition to qualitative information not seen clinically. Because poor VA is related to severe involvement of the central retina, scanning laser tomography could provide an objective outcome measure for interventional studies.

Infrared imaging of cystoid macular edema.

BACKGROUND: Cystoid macular edema (CME), a cause of central visual loss, is described in various pathologies. Typically, the fluorescein angiogram confirms the diagnosis and provides qualitative information as to the extent of leakage. This study was performed to investigate the features of cysts and quantify the extent of CME using non-invasive infrared imaging. METHODS: Eighteen eyes of 16 successive patients with CME in association with a broad spectrum of diseases were included in the study. The diagnosis of CME was established clinically and confirmed by fluorescein angiography. Digital infrared imaging was performed with a research scanning laser ophthalmoscope with different apertures, providing direct confocal and indirect imaging modes, to discriminate superficial features from deeper ones and to emphasize sources of multiple laterally scattered light. RESULTS: CME was easily detected with infrared imaging in all eyes. Confocal mode visualized the cysts themselves, while indirect mode emphasized borders. Large central cysts were detected as distinct, non-confluent structures. In addition, folds detected with infrared imaging in the macula in 12 of the 18 eyes were not always observed clinically. CONCLUSION: Infrared imaging provides a quick and safe diagnostic tool for patients with CME. The cystoid structures are readily localized and quantified, useful for monitoring CME. Despite differences in the pathophysiology, cysts did not differ qualitatively in a variety of diseases with infrared imaging.

Spatial extent of pigment epithelial detachments in age-related macular degeneration.

OBJECTIVE: To quantify the spatial extent of pigment epithelial detachment (PED) associated with age-related macular degeneration (AMD) using a rapid, noninvasive method. DESIGN: Prospective, cross-sectional study. PARTICIPANTS: The authors tested 32 eyes of 21 patients (13 women and 8 men) with AMD 56 to 91 years of age (mean = 72.8 years). The authors retested seven eyes of six patients. INTERVENTION: Three-dimensional imaging and quantification of PED were performed in each subject using confocal infrared imaging (790 nm) with a Topographic Scanning System (TopSS). The data consisted of a series of 32 images within a 3-mm-depth range requiring 0.9 second. Three-dimensional calculations were made from the series. MAIN OUTCOME MEASURE: Height, diameter, area, volume, and slope of each PED were obtained with two calculation methods. The Ellipse Method used a graphics tool to draw elliptical borders circumscribing the region of interest in the image. The software automatically calculated the values for all parameters for the region inside the ellipse, with the retinal reference plane adjusted to match the height of the surrounding retina. The User-Defined Region Method differed in that the region of interest was drawn manually. RESULTS: PEDs were easily detected in all patients using the TopSS. Maximum height of all PEDs above the reference plane ranged from 0.204 to 1.818 mm (mean = 0.57 mm). The diameter was 0.501 to 5.151 mm (mean = 2.711 mm), area was 0.179 to 20.402 mm2 (mean = 6.585 mm2), and volume was 0.012 to 13.981 mm3 (mean = 2.173 mm3). Intraobserver variability was low, with correlations between first and second measurements for the first visit ranging from r = 0.906 to 0.997 for slope and diameter, respectively. CONCLUSIONS: Three-dimensional analysis with the TopSS provides objective outcome measures not obtainable with typical clinical methods such as fundus photography and angiography. Height and volume are crucial in determining whether neovascularization is worsening or persistent after photocoagulation. More longitudinal data are needed to determine whether tomographic data reduce the need for angiography. Unique to scanning laser tomography, exudative features were imaged at different depths.

Diabetic macular edema: risk factors and concomitants.

PURPOSE: To investigate the systemic and ocular factors associated with diffuse macular edema in patients with diabetic retinopathy (DR) and compare with patients with focal or no macular edema. METHODS: From 160 consecutive patients with DR, we obtained medical and ocular histories, blood pressure and visual acuity. Macular edema was determined by biomicroscopy and stereoscopic fundus photography. Fluorescein angiography was used in the characterization of its leakage, and the vitreoretinal relationship was performed by preset lens biomicroscopy. RESULTS: Among adult-onset diabetes mellitus (DM) patients, 55% had diffuse, 23.5% had focal and 21.5% had no macular edema (p=0.01). The risk of developing diffuse macular edema was 3.2 times greater in patients with high blood pressure (HBP) (95% confidence interval (CI), 1.5 to 6.9). Patients with cardiovascular disease (CVD) had a higher prevalence of diffuse (58.0%) than focal (26.0%) or no maculopathy (16.0%) (p=0.01). The odds for development of diffuse macular edema was 3.4 times greater in patients with vitreomacular adhesion (95% CI, 1.15 to 13.30) than in those with complete posterior vitreoretinal attachment or vitreoretinal separation. The odds for development of diffuse macular edema were 6.2 (95% CI, 1.83 to 21.04) and 7.7 times greater (95% CI, 3.12 to 19.12) in patients with PPDR and PDR, respectively, in comparison with those with NPDR. CONCLUSIONS: In this study, adult-onset DM, HBP, CVD, vitreomacular adhesion and advanced retinopathy were associated with increased risk of development of diffuse diabetic macular edema.

Quantitative analysis of macular holes with scanning laser tomography.

OBJECTIVE: The purpose of the study is to establish objective, quantitative, and reproducible three-dimensional analysis for macular holes with scanning laser tomography and to correlate measurements with visual acuity. DESIGN: The authors performed a cross-sectional, nonrandomized study. PARTICIPANTS: The authors examined 28 full-thickness macular holes of 23 patients aged 61 to 84 years. INTERVENTION: Confocal infrared imaging with scanning laser tomography using the TopSS (790 nm, 10 degrees field) three-dimensional measurements and macular hole analysis were performed. MAIN OUTCOME MEASURES: Area, depth, and volume parameters for both macular holes and rims were obtained in two ways: (1) reference plane for analysis equal to height of the retina (offset surface distance [OSD] 0) or (2) equal to height of the surrounding edematous rim of the hole (OSD user). Correlation of measurements with visual acuity and groups of macular holes was performed. Reproducibility from three image series per subject and intraobserver variability from ten measurements in four subjects were computed. RESULTS: Scanning laser tomography could detect macular hole and rim features in all subjects. Infrared images provided clinically useful information that may help explain macular hole pathophysiology. Based on quantitative, three-dimensional measurements, holes were assigned to four groups: large, small, shallow, and average. Groups varied significantly (P < 0.05) for the majority of measurements. Visual acuity correlated significantly (P < 0.05) with macular hole volume, depth, slope, and rim height with OSD user only, but not with hole area. Holes computed with OSD user were deeper and of greater volume. Reproducibility was excellent for hole area, slope, and rim area; good for hole volume and depth; variable for rim volume; and improved with OSD user. Intraobserver variability was low in each group. CONCLUSIONS: Scanning laser tomography is a reproducible three-dimensional imaging technique providing objective and quantitative clinical information in assessing, grouping, and managing macular holes. By setting the OSD to rim height, additional information of rim height and hole volume was provided and correlated with visual acuity. In addition, more reliable differences among macular hole groups were found. Axial measurements such as macular hole depth, volume, and rim height may be more important for visual acuity than hole area indicating their possible predictive value for outcome measures.

Role of the vitreous and macular edema in branch retinal vein occlusion.

BACKGROUND AND OBJECTIVE: To determine the relationship between macular edema associated with branch retinal vein occlusion (BRVO) and the condition of the vitreous. PATIENTS AND METHODS: The authors retrospectively studied 58 patients (58 eyes) who underwent vitreous examination. The eyes were classified as having vitreomacular attachment (VMA) or vitreomacular separation (VMS), and were divided into two groups based on the mean age of the patients. RESULTS: Macular edema was found in 39 (67%) of the eyes. The prevalence of VMA was 81% (22 of 27 eyes) in group 1 (patients who were 64 years old or younger) and 45% (14 of 31 eyes) in group 2 (patients who were older than 64 years). Although no significant relationship was found, 77% (17 of 22) of the eyes with VMA in group 1 had macular edema. The incidence of macular edema was significantly higher in eyes with VMA (93%, 13 of 14) than in eyes with VMS (41%, 7 of 17, P = .009) in group 2. CONCLUSION: The authors' findings suggest that VMA may influence the presence of macular edema associated with BRVO.

Ocular conditions associated with posterior vitreous detachment in young patients.

BACKGROUND AND OBJECTIVE: To investigate the ocular conditions associated with posterior vitreous detachment (PVD) in young patients. PATIENTS AND METHODS: The vitreous conditions of 861 patients younger than 30 years were studied retrospectively and examined biomicroscopically. RESULTS: In the first and second decades of life, retinitis pigmentosa, nondiabetic retinal vascular disorders, and a history of ocular contusion were most commonly associated with PVD. In the third decade of life, proliferative diabetic retinopathy was overwhelmingly the condition most commonly associated with PVD. CONCLUSION: This study delineated the ocular pathologic conditions associated with PVD in young patients. These findings may be useful in the management of PVD in patients younger than 30 years.

Vitreomacular observations. II. Data on the pathogenesis of idiopathic macular breaks.

BACKGROUND: The pathogenesis of idiopathic macular breaks is still uncertain. Their formation has been ascribed to anteriorly oriented intravitreous traction and to shrinkage of the prefoveal cortical vitreous. The validity of both hypotheses is considered in this paper. METHODS: In order to clarify the pathogenesis of idiopathic macular breaks 127 consecutive patients had their vitreous examined and photographed with the El Bayadi-Kajiura precorneal lens and a slit-lamp microscope. RESULTS: A comparison with 127 matched controls demonstrated that the vitreous was significantly more often attached in eyes with a macular break than in controls (P < 0.01). In eyes with a macular break the vitreous was significantly more often attached in early cases (Gass stage 1) than in Gass stages 3 and 4 (P < 0.01). Still photographs and observation of the movements of the operculum demonstrated that, in some cases of stage 3 and also in stage 4, it moved inside the partially liquefied posterior vitreous, anteriorly to the retinal surface and frequently without evidence of posterior vitreous detachment over the macular area. The following anatomical features characterize the vitreomacular area: extremely thin hyaloid membrane (< 100 microns) and inner limiting lamina (10 nm) that adhere strongly to each other and to the underlying Mueller cells. There is no evidence that these structures can shrink selectively to cause a macular break. The premacular vitreous gel contains collagen fibers that attach posteriorly to the macula and anteriorly to the vitreous base. CONCLUSIONS: Our working hypothesis is that when detachment of the posterior vitreous is abnormally delayed, anteroposterior traction by collagen fibers may pull a foveal operculum off the retina. Our observations make this hypothesis attractive. However, the generally accepted hypothesis of Johnson and Gass cannot be entirely dismissed. In reality, since the two hypotheses are not mutually exclusive, they may both the partially correct.

Vitreous changes during ocular inflammation induced by interleukin 1 beta.

To determine the mechanisms of vitreous changes during ocular inflammation, we investigated these changes, focusing on the collagen, in an experimental model of ocular inflammation induced by intravitreal injection of interleukin 1 beta in rabbits. Inflammation caused gel contraction, with release of a watery liquid from the gel, and increases in the amount of insoluble material and high-molecular-weight components of the vitreous collagen, presumably due to extensive cross-links of the collagen molecules. The cross-links of vitreous collagen may promote vitreous gel contraction and the release of watery liquid from the gel.

Evidence of cross-link formation of vitreous collagen during experimental ocular inflammation.

PURPOSE: To determine the mechanisms of vitreous changes during ocular inflammation. METHODS: We investigated vitreous changes, with special emphasis on collagen, in an experimental model of ocular inflammation induced by intravitreal injection of endotoxin (Escherichia coli) in rabbits. RESULTS: Inflammation caused gel contraction and loss of elasticity, accompanied by release of a water-like liquid from the gel, and increases in the amount of insoluble material and high-molecular-weight components of vitreous collagen, presumably due to extensive cross-links of the collagen molecules. Those changes were partially inhibited by intravitreal injection of superoxide dismutase. CONCLUSIONS: The cross-links of vitreous collagen may promote vitreous gel contraction and release of a water-like liquid from the gel. Superoxide anion may play a role in this process.

[Role of the vitreous in central retinal vein occlusion].

To investigate the role of the vitreous in eyes with central retinal vein occlusion, especially in relation to neovascularization and macular edema, we conducted a retrospective chart review of the vitreous condition of 150 patients (150 eyes) with central retinal vein occlusion. Based on fluorescein angiography findings and color photographs, eyes with central retinal vein occlusion were classified as ischemic or nonischemic. In ischemic cases, retinal or optic disc neovascularization, or both, developed in eight (57%) of 14 eyes without complete posterior vitreous detachment at the final examination. The prevalence of neovascularization was significantly higher than in eyes with complete posterior vitreous detachment (0%, 0/43) at the final examination (p < 0.01). In nonischemic cases, the prevalence of no posterior vitreous detachment or partial posterior vitreous detachment with vitreomacular adhesion was significantly higher in eyes with macular edema (76%, 28/37) than in eyes without it (23%, 13/56) at the final examination (p < 0.01). Complete posterior vitreous detachment may protect against retinal or optic disc neovascularization in eyes with severe central retinal vein occlusion. Vitreomacular adhesion may cause persistent macular edema in eyes with mild central retinal vein occlusion.

Spontaneous resolution of foveal detachments and macular breaks.

PURPOSE: To evaluate the mechanism of spontaneous resolution of foveal detachments and idiopathic macular breaks. METHODS: We reviewed the records of 139 consecutive eyes (94 patients) with either a foveal detachment or a macular break in patients who were examined between 1989 and 1992. There were 26 men and 68 women (mean age, 66.9 +/- 6.9 years). They were either unoperated on or observed during the period that preceded surgery. Each patient underwent complete ophthalmic examination in addition to slit-lamp photography of the vitreomacular interface and microperimetry with the scanning laser ophthalmoscope. RESULTS: Eight eyes demonstrated spontaneous resolution. A foveal detachment was noted in five eyes (five patients) and a stage 2 macular break in three eyes (three patients). The mean duration of observation was 33 months (range, one to 144 months). Resolution of the foveal detachments occurred without the development of posterior vitreous detachment. In each eye, the presence of a pseudo-operculum, indicating vitreofoveal separation, was accompanied by flattening of the foveal detachment without detectable posterior vitreous detachment. The three eyes with stage 2 macular break resolved after premature development of a posterior vitreous detachment. CONCLUSIONS: Foveal detachment and macular break resolution seem to result from the release or weakening of vitreous traction on the fovea. Reattachment of the foveal retina preserves fair to good visual acuity. Surgical intervention is contraindicated (1) in eyes in which foveal detachment flattens and develops a pseudo-operculum and (2) when a posterior vitreous detachment develops in an eye with a stage 2 macular break. Careful biomicroscopic vitreous examination and microperimetry with the scanning laser ophthalmoscope are extremely useful methods for adequate examination of these patients.

Natural outcomes of stage 1, 2, 3, and 4 idiopathic macular holes.

AIMS: A study was carried out to ascertain the natural outcome of each stage of idiopathic macular hole. METHODS: One hundred and fifty four eyes with different stages of idiopathic macular holes were retrospectively studied: stage 1 (40 eyes), 2 (25 eyes), 3 (58 eyes), and 4 (31 eyes). RESULTS: Of 27 of 40 eyes with a stage 1 lesion with posterior vitreous attachment to the macula initially, nine (33%) eyes developed a full thickness macular hole. No stage 1 lesions with posterior vitreous separation from the macula initially progressed to full thickness holes. Twenty one (84%) of 25 eyes with a stage 2 lesion, 32 (55%) of 58 eyes with a stage 3 lesion, and five (16%) of 31 eyes with a stage 4 lesion underwent macular hole enlargement during the median follow up period of 3 years. Visual acuity decreased two or more lines of Snellen equivalent during the follow up period in 12 (30%) eyes with a stage 1 lesion, 17 (68%) eyes with a stage 2 lesion, 17 (29%) eyes with a stage 3 lesion, and four (13%) eyes with a stage 4 lesion. The percentage was significantly higher in eyes with stage 2 lesions than the other stages (p < 0.01). CONCLUSION: The results suggest that the different stages of idiopathic macular holes have different natural outcomes, and the management depends on the stage at presentation.

Prognosis of stage 2 macular holes.

PURPOSE: We ascertained the natural course of stage 2 idiopathic macular holes to determine better treatment possibilities. METHODS: We reviewed 48 eyes with stage 2 idiopathic macular holes and followed them up for more than two years. At each examination, best-corrected Snellen visual acuity was measured by a physician masked to the hypothesis of the study. RESULTS: Stage 2 lesions progressed to stage 3 or 4 during the follow-up period in 32 (67%) and 14 (29%) of 48 eyes, respectively; two eyes (4%) remained in stage 2. In 41 (85%) of 48 eyes, the hole size enlarged during the follow-up: 32 (94%) of 34 eyes had vitreomacular attachment and nine (64%) of 14 eyes had vitreomacular separation at the final examination, for a statistically significant difference in prevalence (P = .03). Visual acuity decreased two or more Snellen lines during the follow-up period in 34 (71%) of 48 eyes, the prevalence of which was significantly higher in eyes with vitreomacular attachment at the final examination (28 of 34, 82%) than in eyes with vitreomacular separation at the final examination (six of 14, 43%) (P = .01). CONCLUSION: Even though vitreomacular separation may improve the prognosis of a macular hole, stage 2 lesions usually will develop an enlarged hole and decreased visual acuity.

[Natural outcome of idiopathic macular hole].

To ascertain the natural outcome of idiopathic macular holes, we studied 186 eyes with the disorder: stages 1 (48 eyes), 2 (30 eyes), 3 (71 eyes), and 4 (37 eyes), which were followed for over twelve months. In 11 (23%) eyes with stage 1 lesions full-thickness macular hole developed during the follow-up period, and in 12 (25%) eyes visual acuity decreased two or more Snellen lines. Twenty-five (83%) and 21 (70%) eyes with stage 2 lesions, 39 (55%) and 22 (31%) eyes with stage 3 lesions, and 7 (19%) and 5 (14%) eyes with stage 4 lesions had enlarged macular holes and decreased visual acuity during the follow-up, respectively. The present results suggest that different stages of macular holes have different natural outcomes and the treatment should be based on their stages.

[Observing idiopathic macular break by scanning laser ophthalmoscope vitreous videography].

We used vitreous videography in conjunction with the scanning laser ophthalmoscope (SLO) to evaluate the pathogenesis of idiopathic macular breaks. The fundamental aspect of this method is videographic documentation of the mobile posterior vitreous and an operculum. The high reflectivity from the vitreous gel using the SLO clearly showed the mobility of the operculum and the posterior vitreous in the idiopathic macular breaks. In some cases without posterior vitreous detachment, the operculum initially was suspended superior to the macular break and anterior to the retinal surface. Upon ocular movement, the operculum moved down smoothly in front of the macular break. The findings of these vitreous videographs using the SLO suggest that anteriorly oriented vitreous traction is one cause of idiopathic macular breaks.

Course of vitreomacular traction syndrome.

PURPOSE: Although the course of vitreomacular traction syndrome is necessary to treat patients or to establish the value of the surgical technique, little information is available about its course. In this study, we ascertained the natural history of vitreomacular traction syndrome. METHODS: We retrospectively studied 53 consecutive symptomatic eyes with vitreomacular traction syndrome. RESULTS: In 43 (81%) of 53 eyes with cystoid macular changes at the diagnostic examination, 29 (67%) of 43 had cystoid changes that persisted during the median follow-up period of 60 months. The visual acuities at the time of the final examination decreased two Snellen lines or more from the initial measurement in 34 (64%) of 53 eyes. During the follow-up period, six (11%) of 53 eyes developed complete posterior vitreous detachment. The number of eyes with resolved cystoid changes or stable visual acuity was significantly higher when complete vitreomacular separation occurred (six of six) than when it did not (three [8%] of 37, P = .01; 13 [28%] of 47, P = .01). CONCLUSIONS: Most symptomatic eyes with vitreomacular traction syndrome underwent a further decrease in visual acuity. Complete vitreomacular separation, which occurs infrequently in eyes with the disorder, allows resolution of cystoid changes and improvement of visual acuity.

Role of the vitreous in central retinal vein occlusion.

PURPOSE: The role of the vitreous in eyes with CRVO and its relationship to neovascularization and macular edema, in particular, were investigated. METHODS: A retrospective chart review of the vitreous condition of 136 patients (136 eyes) with CRVO was performed. Based on fluorescein angiography findings and color photographs, eyes with CRVO were classified as either ischemic or nonischemic. RESULTS: In ischemic cases, retinal or optic disc neovascularization or both developed in 8 (57%) of 14 eyes with no or partial posterior vitreous detachment (PVD) at the final examination. The prevalence of neovascularization was significantly higher than in eyes with complete PVD (0%, 0 of 38) at the final examination (P < 0.01). No significant relationship was found between iris neovascularization development and the vitreous condition or between the prevalence of PVD and macular edema. In nonischemic eyes, the prevalence of no PVD or partial PVD with vitreomacular attachment was significantly higher in those with macular edema (76%, 25 of 33) than in eyes without (25%, 13 of 51) at the final examination (P < 0.01). CONCLUSION: Complete PVD may protect against retinal or optic disc neovascularization in eyes with severe CRVO. Vitreomacular attachment may cause persistent macular edema in eyes with mild CRVO.