Maximum Cup Depth Research Articles

The effect of the menstrual cycle on optic nerve head analysis in healthy women

To determine the effect of the menstrual cycle on optic nerve head topographic analysis in normally menstruating, healthy women. The study included single eyes selected randomly from each of 52 healthy women with regular menstrual cycles. All subjects underwent a complete ocular examination. Optic nerve head topographic analyses were performed using a confocal scanning laser ophthalmoscope, the Heidelberg Retinal Tomograph II (HRT II, software version 1.6). The analyses were repeated three times during the menstrual cycle: in the follicular phase (days 7-10 of the cycle), at ovulation, and in the late luteal phase (days 1-3 before menstrual bleeding). Serum oestradiol, progesterone and luteinizing hormone levels were measured at each menstrual phase. Fourteen subjects were excluded from the study. The mean age of the subjects (n = 38) was 25.6 +/- 3.7 years (range 21-34 years). Blood oestradiol levels were significantly lower in the late luteal phase (35.8 pg/ml) (p < 0.0001). The mean disc area of the subjects was 1.94 +/- 0.33 mm(2). The neuroretinal rim area decreased significantly during the luteal phase (p < 0.001). However, the linear cup : disc ratio, cup : disc area ratio and the cup area were significantly higher during the luteal phase (p < 0.001). These observations raise the possibility that sex hormone fluctuations which occur during a normal menstrual cycle in healthy women significantly alter neuroretinal rim area and cup variables of the optic nerve head. These findings should be taken into consideration in the clinical follow-up of young women with glaucoma.

Analysis of Optic Disc Change Using the Heidelberg Retina Tomograph in an Acquired Pit of the Optic Nerve

A 51-year-old woman diagnosed as having normal-tension glaucoma developed an acquired pit of the optic nerve. The optic disc was viewed by the Heidelberg Retina Tomograph (HRT; Heidelberg Engineering, Heidelberg, Germany) before and after development of an acquired pit of the optic nerve. HRT parameters and cross-sectional images of the optic disc were compared. Maximum cup depth at the site of the acquired pit of the optic nerve increased after development of the acquired pit of the optic nerve (from 1.200 to 2.432 mm). The neuroretinal rim area and volume in the inferotemporal octant were reduced (rim area from 0.070 to 0.010 mm2, rim volume from 0.009 to 0.001 mm3). The morphologic changes in the optic disc were also detected topographically and reflectively.

Fluorescein filling defects and quantitative morphologic analysis of the optic nerve head in glaucoma.

To evaluate absolute filling defects of the optic nerve head in normal tension glaucoma (NTG) and primary open-angle glaucoma (POAG) and to compare the filling defects with topographic analysis of the optic disc. Twenty-five patients with NTG, 25 patients with POAG, and 25 age-matched controls were included. Fluorescein angiograms were performed by means of a scanning laser ophthalmoscope. The extent of absolute filling defects of the optic nerve head was assessed using digital image analysis of early-phase angiograms. Topographic measurements of the optic disc were acquired using the Heidelberg Retina Tomograph II. Absolute filling defects were significantly larger (P =.001) and were seen more often (P<.001) in patients with NTG (n = 18) and POAG (n = 19) compared with controls (n = 3). Rim area (P =.006), rim volume (P =.007), cup-disc area ratio (P =.008), linear cup-disc ratio (P =.005), maximum cup depth (P =.002), cup shape measure (P =.03), and nerve fiber layer thickness (P =.008) and cross-sectional area (P =.006) were significantly different between patients with glaucoma and controls. Absolute filling defects were significantly correlated with cup area (r = 0.31; P =.007), rim area (r = -0.38; P<.001), rim volume (r = -0.35; P =.002), cup-disc area ratio (r = 0.49; P<.001), linear cup-disc ratio (r = 0.48; P<.001), cup shape measure (r = 0.27; P =.02), and nerve fiber layer thickness (r = -0.33; P =.004) and cross-sectional area (r = -0.30; P =.009). Fluorescein filling defects of the optic disc are present in NTG and POAG. The extent of these filling defects is correlated with the morphologic disc damage.

Acute Conformational Changes in the Optic Nerve Head With Rapid Intraocular Pressure Elevation: Implications for LASIK Surgery

BACKGROUND AND OBJECTIVE: To investigate the effects of acute intraocular pressure (IOP) elevation on optic disc morphology. PATIENTS AND METHODS: Ophthalmodynamometry was used to increase the IOP of normal, healthy eyes. Confocal scanning laser ophthalmoscopy of the optic nerve head using the Heidelberg Retinal Tomograph II (Heidelberg GmbH, Heidelberg, Germany) and IOP measurements were obtained before, during, and after IOP elevation. RESULTS: Sixteen eyes of 16 normal volunteers (mean age, 32.8 ± 11.9 years) were enrolled. Rim area, rim volume, cup area, cup volume, cup-to-disc ratio, mean cup depth, maximum cup depth, mean retinal nerve fiber layer (RNFL) thickness, and RNFL cross-sectional area showed significant changes during IOP elevation (all P &lt; .05, paired t test). All measured parameters returned to their original values after pressure resolution (all P &gt; .2) except mean RNFL thickness ( P = .03). CONCLUSION: Transient elevation of IOP results in measurable alterations in optic nerve head topography. [Ophthalmic Surg Lasers Imaging 2003;34:334–341.]

Optic disc changes following trabeculectomy: longitudinal and localisation of change

AIMSTo determine whether there were any changes in the optic disc at 2 years after trabeculectomy. To determine the factors that most influenced change and whether change was localised to...

Interobserver variability of optic disk variables measured by confocal scanning laser tomography

PURPOSE: To assess the interobserver variation of confocal laser scanning tomographic measurements of the optic nerve head and to address the question of whether the addition of clinical optic disk photographs is helpful in outlining the optic disk margin and in reducing the observer-related variation of the measurements. PATIENTS AND METHODS: Optic disk variables for 16 eyes of 16 patients with glaucoma, generated by confocal laser scanning laser tomography (Heidelberg Retina Tomograph), were independently evaluated by four experienced glaucoma specialists, and the interobserver variability was calculated. A second separate review by the same observers included the use of clinical stereoscopic color optic nerve head photographs to aid definition of the optic disk margin. RESULTS: Optic disk parameters with the smallest interobserver variation were cup shape measure, maximum cup depth, height variation contour, and mean height contour. The intraobserver variation of these parameters did not increase when clinical optic disk slides were additionally available. Parameters with the highest interobserver variation were volume below surface, volume below reference, volume above surface, and volume above reference. The observer variation of these optic disk parameters increased significantly for two of the four examiners when clinical optic disk slides were additionally available for outlining the optic disk margin. CONCLUSION: Confocal laser scanning tomography of the optic nerve head can be improved significantly if clinical optic disk photographs are additionally available to help in outlining the optic disk margin. Because interobserver variation in the tomographic optic disk measurements can be significant, even if experienced observer are involved, tomographic optic disk measurements may be centralized in reading centers in the case of multicenter studies.

Scanning laser ophthalmoscopy of the optic nerve head in exfoliation glaucoma and ocular hypertension with exfoliation syndrome

AIMSTo study the relation between optic nerve head topography (Heidelberg retina tomograph, HRT) and disc area, visual field index mean defect (MD), and intraocular pressure (IOP), and to see whether...

Optic disk topography after medical treatment to reduce intraocular pressure

PURPOSE: We examined changes in optic disk topography using confocal scanning laser ophthalmoscopy after reducing intraocular pressure with administration of latanoprost. METHODS: Twenty-nine patients with glaucoma or ocular hypertension were imaged using the Heidelberg Retina Tomograph before and after the administration of latanoprost to decrease intraocular pressure. Average time between pretreatment and posttreatment imaging was 2.7 ± 1.8 weeks. Heidelberg Retina Tomograph software–measured parameters were mean height of contour, cup area, cup volume, mean cup depth, maximum cup depth, cup shape, rim area, rim volume, cup-to-disk ratio, and retinal nerve fiber thickness. RESULTS: Average intraocular pressure decreased significantly (mean ± SD) by 7.2 ± 5.4 mm Hg (25 ± 16% decrease). No statistically significant changes in measured topographic parameters were found. When data from patients with decreases in intraocular pressure of 7 mm Hg or greater were analyzed separately (mean intraocular pressure decrease = 10.79 ± 4.32 mm Hg, 36 ± 8% decrease), cup area ( P = .005), cup volume ( P = .002), and cup-to-disk ratio ( P = .005) decreased significantly, and rim area ( P = .005) increased significantly. Linear regression analysis of the data from all subjects showed that a change in intraocular pressure after latanoprost administration accounted for 12% or more of the variance in two measured topographic parameters (mean cup depth and cup shape). CONCLUSIONS: These results suggest that, in some patients, moderate decreases in intraocular pressure may affect disk topography, as measured by Heidelberg Retina Tomograph. Intraocular pressure should be considered when analyzing consecutive confocal scanning laser ophthalmoscopy images for glaucomatous progression.

Interocular differences in optic disc topographic parameters in normal subjects

Purpose. To test the interocular differences in optic disc topography in normal subjects by means of confocal scanning laser ophthalmoscopy. Methods. Topographic measurements of the optic disc were evaluated by means of confocal scanning laser ophthalmoscopy (Heidelberg Retina Tomograph) in 314 eyes of 157 healthy volunteers. The examination was started randomly either with the right eye or the left eye. Differences between right and left eyes in disc area, cup area, cup volume, cup/disc area ratio, rim area, rim volume, maximum cup depth, cup shape measure, retinal nerve fiber layer thickness, and retinal nerve fiber cross section area for 360° and for the temporal and nasal regions of the optic nerve head were evaluated by means of Student t-test. The same parameters were assessed in a subgroup of 80 elderly (age > 50 years) healthy subjects. Holm's sequentially rejective method was used for significance correction of multiple comparisons. Results. Significant interocular differences in the average retinal nerve fiber layer thickness (p = 0.0010) and retinal nerve fiber layer cross section area (p = 0.0036) were found, with the right eye showing, on the average, lower values.The left eye showed a larger retinal nerve fiber layer thickness in 94 subjects (59.87%) and a larger retinal nerve fiber cross section area in 101 subjects (64.33%). In the temporal optic disc area there were no statistically significant differences in topometric data (p > 0.05). In the nasal area, significant interocular differences in the retinal nerve fiber layer thickness (p = 0.0002) and retinal nerve fiber layer cross section area (p = 0.0003) were found. Similar results were found when the group of subjects older than 50 years was considered. Conclusions. This study demonstrates systematic interocular differences in optic disc topometric data. Such a finding, be it due to methodological or biological reasons, should be taken in consideration in clinical trials.

Scanning Laser Tomography to Evaluate Optic Discs of Normal Eyes

Purpose: To investigate the effects of age, eye refraction, and disc area on topographic parameters of the optic nerve head in normal volunteers, using the Heidelberg Retina Tomograph. Methods: Seventy-seven eyes of 77 normal volunteers were examined by scanning laser tomography. The topographic parameters analyzed were disc area, cup area, cup/disc area ratio, rim area, cup volume, rim volume, mean cup depth, maximum cup depth, cup shape measure, height variation contour, mean retinal nerve fiber layer thickness (MnRNFLT), and retinal nerve fiber layer (RNFL) cross-section area. The effect of age, refraction, and disc area on each parameter was analyzed by the multiple linear regression model. Results: Significant declines in MnRNFLT and RNFL cross-section area were found with increasing age ( P < .05). The mean cup depth and maximum cup depth were significantly deeper in myopic subjects ( P < .05). Large discs had large cup area, cup/disc area ratio, rim area, cup volume, mean cup depth, cup shape measure ( P < .01), and maximum cup depth ( P < .05). The MnRNFLT was smaller in large discs ( P < .01). Rim volume was unaffected by age, refraction, or disc area. Conclusions: The age, refraction, and disc area were related to several optic disc parameters obtained by the Heidelberg Retina Tomograph. Because of these relationships, care should be taken to analyze the appearance of the optic disc on the basis of these parameters in patients with glaucoma or other diseases. Rim volume appears to be a good parameter for evaluating the optic disc without considering age, refraction, or disc area.

Changes in Optic Disc Parameters After Intraocular Pressure Reduction in Adult Glaucoma Patients

Purpose: To quantitatively evaluate the change in the optic disc topographic parameters associated with reduction in the intraocular pressure (IOP) after trabeculectomy in adult patients with glaucoma. Methods: A series of 22 patients (mean age: 45.7 ± 15.1 years) with several types of glaucoma were examined for various parameters of optic disc before and after trabeculectomy. Cup area, cup-to-disc area ratio, cup volume, rim volume, mean cup depth, and maximum cup depth were determined by means of laser scanning tomography (LST), and the parameters were correlated with the degree of postsurgical IOP decrease. Results: The IOP in adult glaucoma patients showed significant reductions after trabeculectomy. The values for all topographic parameters examined, except cup volume, showed statistically significant postsurgical changes as compared to the presurgical values. Of all postsurgical changes in parameters, the increase in the rim volume was the most noticeable; it was remarkably evident in those eyes with postsurgical IOP levels less than 15 mm Hg. It was also demonstrated that the anterior displacement of the glaucomatous cupping may occur after surgery. Conclusions: It is obvious that optic disc parameters can change after IOP reduction after successful surgery in adult glaucoma patients as well as in infantile glaucoma patients. The site of changeable glaucomatous optic cupping is topographically variable among patients and it may be related to the presurgical shape of the optic cup.

Reversal of optic disc cupping after glaucoma surgery analyzed with a scanning laser tomograph

Objective To detect and quantitate changes in optic nerve morphology after glaucoma surgery using the Heidelberg Retina Tomograph (HRT, Heidelberg Instruments, Heidelberg, Germany). Design Nonconsecutive observational case series. Participants and intervention The authors prospectively enrolled 21 adult patients undergoing incisional glaucoma surgery for progressive glaucoma damage. Quantitative analysis of the optic nerve head by scanning laser tomography and automated perimetry were performed before and after glaucoma surgery. Main outcome measures Changes in optic nerve parameters were subjected to linear regression analysis with respect to percent of postoperative reduction of intraocular pressure (IOP), as well as with respect to age, refraction, preoperative cup:disc ratio, and change in visual field parameters. Results Seventeen patients had pre- and postoperative images suitable for analysis. Mean IOP at the time of image acquisition before surgery was 30.5 ± 12 mmHg, and after surgery 11.8 ± 5.2 mmHg (mean follow-up, 26 ± 7 weeks). Eleven of 13 (85%) patients having IOP reduction of greater than 40% showed improvement in optic disc parameters. All four patients with less than 25% reduction in IOP showed worsening of most parameters. Changes in optic disc parameters were highly correlated with percent IOP reduction and with age. The parameters in which change most strongly correlated with percent change of IOP were cup area, rim area, cup:disc ratio, and mean cup depth (each, P < 0.005). The age of the patient correlated highly with change in maximum cup depth ( P < 0.005). Refraction and clinically determined cup:disc ratio correlated poorly with changes in measured optic disc parameters. Clinical improvement in visual fields was correlated with the degree of improvement of cup:disc ratio ( P = 0.025). Conclusion Most patients showing a 40% lowering of IOP after glaucoma surgery show improved optic nerve morphology as measured by the HRT. The amount of improvement correlated highly with the percent reduction of IOP.

Change in Optic Disk Topography After Trabeculectomy

To investigate the relationship between optic disk topography and intraocular pressure before and after trabeculectomy with confocal scanning laser ophthalmoscopy. The eyes of 49 consecutive patients undergoing trabeculectomy at a university-based glaucoma practice underwent preoperative and postoperative imaging using a confocal scanning laser ophthalmoscope (Heidelberg Retina Tomograph). Three images of one eye of each patient were obtained with a 15-degree field of view. Preoperative images were obtained approximately 2 months before surgery (mean +/- SD, 2.4 +/- 1.6 months). Postoperative images were obtained at least 3 months after surgery (mean, 4.5 +/- 2.6 months). Mean preoperative intraocular pressure, postoperative intraocular pressure, and percent change in intraocular pressure respectively were 23.1 +/- 6.8 mm Hg, 12.7 +/- 7.1 mm Hg, and 43.8% +/- 29.9%. A significant association (P < .01) was found between percent decrease in intraocular pressure and decreases in cup area, cup volume, and cup/disk area ratio as well as between percent decrease in intraocular pressure and increases in rim area, rim volume, mean height contour, retinal cross-section area, and height in contour. Between 11.7% and 31.2% of the variability (R2) in these parameters was explained by the percent change in intraocular pressure. Topography changes were more strongly associated with percent change than with mean change in intraocular pressure. We found no association between percent decrease in intraocular pressure and reference plane height or maximum cup depth. Changes in optic nerve topography were associated with reduction in intraocular pressure after trabeculectomy.

Optic Nerve Head Topography in Ocular Hypertensive Eyes Using Confocal Scanning Laser Ophthalmoscopy

To compare measurements of optic nerve topography of ocular hypertensive patients with those of normal subjects and primary open-angle glaucoma patients. Three age-matched study groups of 46 ocular hypertensive patients, 46 primary open-angle glaucoma patients, and 46 normal subjects were recruited from patients and volunteers of a glaucoma referral practice. Optic nerve topography was measured using a confocal scanning laser tomograph, the Heidelberg Retina Tomograph. The following optic nerve parameters were evaluated: disk area, cup/disk area ratio, cup shape, height in contour, rim area, rim volume, maximum cup depth, cup area, cup volume, retinal height, and retinal cross-section area. For this cross-sectional study, analysis of variance was used to evaluate overall differences among the three subject groups and the Tukey-Kramer multiple comparison test to evaluate differences between the means of two groups. Statistically significant differences among study groups were found for all topographic optic nerve parameters evaluated. Despite considerable overlap in optic nerve parameter measurements among the study groups, mean values of ocular hypertensive eyes were intermediate between those for normal and primary open-angle glaucoma eyes. Statistically significant differences were found between ocular hypertensive and glaucomatous eyes for all optic nerve parameters measured, and between ocular hypertensive and normal eyes for disk area, height in contour, rim area, and rim volume. In age-matched groups, mean measurements of certain topographic optic nerve parameters of ocular hypertensive eyes differ from those of normal and glaucomatous eyes.

Quantitative assessment of the optic nerve head with the laser tomographic scanner.

We describe the use of a laser tomographic scanner to objectively measure optic nerve head topography. A laser beam is focused on the optic disc using confocal imaging. Reflected light is detected only if it originates from a small region around the focal place of the special optics. Optic disc parameters are calculated from the measured values of confocal reflected light. In five glaucomatous eyes, maximum cup depth was between 0.33 mm and 0.58 mm. Cup volume was between 0.10 mm3 and 0.65 mm3; it correlated well with ophthalmoscopy. Compared with conventional imaging systems, the laser tomographic scanner has certain advantages: 1) images can be obtained with miotic pupils; 2) clarity of media is not important; 3) low light intensity is employed; and 4) a real time image is obtained.