11 Fases Del Glaucoma
This document was uploaded by user and they confirmed that they have the permission to share it. If you are author or own the copyright of this book, please report to us by using this DMCA report form. Report DMCA
Overview
Download & View 11 Fases Del Glaucoma as PDF for free.
More details
- Words: 2,539
- Pages: 15
101
CHAPTER 10 EVOLUTION PHASES OF GLAUCOMA
10.1 Introduction In the same manner that Dr. Armarly [1] proposed a practical classification to evaluate the optic nerve condition by dividing the optic disc into 10 parts, and Dr. Raul Reca [2] proposed another one dividing the optic disc into 6 parts, the confocal tomography of the optic nerve suggests a further classification. The previous classifications are based on an analysis of areas (relationship between optic disc area, cup area and rim area) that can be correlated with the areas measured with by the HRT. The tomographic classification is mainly based on the volumes of said structures and only secondarily on areas and other parameters. This is due to the possibility of stereometric and three-dimensional analyses. The advantage provided by volume measurements over area measurements, is that the former are raised to the third power, while the latter are only raised to the second power (whenever change occurs, no matter how slight, there is a greater variation if the value is raised to the cube than if it is raised to the square). 10.2 Parameters used in the classification of evolution As already stated, the main parameters used for the classification were volumes, followed by areas, thickness and slopes. The volumes taken into consideration are the neuroretinal rim volume (NRR) and the cup volume. The most important one, in fact, is the neuroretinal rim volume, but the cup volume is also taken into account since a decrease of the neuroretinal rim volume produces an increase of the cup volume; it is a cause-effect relationship. The same occurs with areas: the cup area (red) increases as the rim area (green and blue) decreases (figure 8.8, chapter 8). The most important parameters used for the classification are listed in figure 10.1 and illustrated in figure 10.2, where the parameters belonging to the optic disc are separated from those that are analyzed in the contour line graph. These latter parameters are: mean RNFL thickness, height variation of contour line, and the area enclosed by the contour line and the reference plane in the contour line height variation diagram (RNFL cross sectional area). As we all know, the reference plane, far from being just another parameter, is the limit on which most parameters strictly depend and with which they
102
Parameters used for classification rim volume cup volume rim area cup area cup shape measure mean RNFL thickness height variation of contour line RNFL cross sectional area Fig. 10.1: Parameters used for classification
Fig. 10.2 have a close relationship. On this account, its position must always be verified, and in a longitudinal study, it must be checked to see that it always remains at the same level. 10.3 Concept and limits of normality The concept of normality is based on the fact that all the optic disc parameters are normal. Nevertheless in clinical practice, sometimes, for one reason or another, the fact that one or two parameters are not within the limits of normality or normal range does not indicate pathology. The concept and limit of normality are outlined in figure 10.3. The limits of normality were obtained from a study on 108 normal volunteers [3]. Figure 10.4 lists the most important limits. For example, for neuroretinal rim volume, the normal inferior limit (0.32 mm3) and not the normal superior limit, is given, since this is used mainly to differentiate a large NRR from an optic disc edema. In some patients a neuroretinal rim volume smaller than 0.32 mm3 may be found in the first tomography, which makes them fall within the classification of borderline. Nevertheless, it must be taken into account that the evolution of these patients sometimes
103
Fig. 10.3: Concept of normality. The value of all parameters mentioned must be within two mean standard deviations of the normal values (normal range). Limits of normality rim volume cup volume rim area cup area cup shape measure mean RNFL thickness height variation of contour line RNFL cross sectional area
min. max. min. max. max. min. min. min.
0.32 mm3 0.12 mm3 1.37 mm2 0.60 mm2 –0.15 0.17 mm 0.27 mm 0.87 mm2
Fig. 10.4: Limits of normality does not involve optic nerve damage but they remain stable for years, which indicates a physiological or normal decrease of the neuroretinal rim in this group of patients. 10.4 Evolution Phases The glaucomatous optic disc evolution was classified into the following groups: - Normal (N) - Borderline (BL) - Phase 1 (P1) - Phase 2 (P2) - Phase 3 (P3) - Phase 4 (P4) With the exception of the borderline optic disc, the rest of the stages are separated from one another by more than two standard deviations, rendering the separation into different groups more significant. Only the parameters meeting this requirement are mentioned, since most of the remaining ones bear no significant differences between the different evolution stages.
104
Normal rim volume cup volume rim area cup area cup shape measure mean RNFL thickness height variation of contour line RNFL cross sectional area normal visual field
> 0.32 mm3 < 0.12 mm3 > 1.37 mm2 < 0.60 mm2 < –0.15 > 0.17 mm > 0.27 mm > 0.87 mm2
The normal optic disc is characterized by a slightly visible Elschnig's Ring, except in the temporal area. Both poles have important fiber bundles, which correlate with the two camel humps displayed by the contour line diagram (figure 10.5). Borderline rim volume cup volume rim area cup area cup shape measure mean RNFL thickness height variation of contour line RNFL cross sectional area normal visual field
> 0.32 mm3 < 0.12 mm3 > 1.37 mm2 < 0.60 mm2 < –0.15 > 0.17 mm > 0.27 mm > 0.87 mm2
In the borderline optic disc, the neuroretinal rim volume is normal by measuring the entire disc, but if we analyze the rim volume by octants and quadrants, there is a decreased value in one of these sectors. The decrease of the neuroretinal rim volume in this phase does not affect the whole optic disc. It corresponds to Burk's pseudonormal optic disc in which the humps remain unchanged and there is a slight neuroretinal rim loss. Except of the cup increase, no parameters are altered (this is less frequent; figure 10.6). Phase 1 rim volume cup volume rim area cup area cup shape measure normal visual field
0.32 - 0.30 mm3 0.12 - 0.24 mm3 1.37 - 1.20 mm2 0.60 - 1.00 mm2 –0.15 - –0.12
The optic disc in phase 1 is characterized by a generalized decrease of the retinal thickness that can be seen in the contour line diagram as a decreasing distance between the contour line and the reference plane. At the same time a decrease in the height of the camel humps, which correlates with the loss of fiber bundles and with the fact that Elschnig's Ring is more visible than before, can be observed (figure 10.7).
105
Fig. 10.5
Fig. 10.6
Fig. 10.7
106
Phase 2 rim volume cup volume rim area cup area cup shape measure beginning of visual field defects
0.30 - 0.20 mm3 0.24 - 0.48 mm3 1.20 - 0.80 mm2 1.00 - 1.50 mm2 –0.12 - –0.07
The optic disc in phase 2 has already a loss of up to 50% of the total retinal nerve fibers. The disappearance of both humps, which correlates with a great cup increase that invades the superior and the inferior poles, can be seen. The mean RNFL thickness preventing the contour line from approaching the reference plane, remains unchanged (figure 10.8). phase 3 rim volume cup volume rim area cup area cup shape measure visual field defects
0.20 - 0.10 mm3 0.48 - 0.96 mm3 0.80 - 0.40 mm2 1.50 - 1.80 mm2 –0.07 - –0.02
The optic disc in phase 3 is characterized by a great decrease of the mean RNFL thickness, which causes the approach of the contour line towards the reference plane. (When localized defects occur, the contour line reaches the reference plane in the damaged areas.) The summation image allows the bottom of the cup and Elschnig's Ring to be clearly seen in their full extend. The cup surface covers almost the whole the optic disc surface. The NRR persists like a thin hale around it (figure 10.9). Phase 4 rim volume cup volume rim area cup area cup shape measure visual field in stage 3 (terminal)
0.10 - 0.00 mm3 > 0.96 mm3 0.40 - 0.00 mm2 > 1.80 mm2 >= 0
The optic disc in phase 4 is characterized by a final decrease of the retinal thickness, where the contour line diagram is parallel to the reference plane, and in the places where there is no NRR left the contour line height variation diagram is below the reference plane. This fact correlates with the appearance of white regions in the analysis of the surfaces and with the presence of absolute visual field defects (figure 10.10).
107
Fig. 10.8
Fig. 10.9
Fig. 10.10
108
Fig 10.11 In figure 10.11, all six phases are summarized. In the normal optic disc, as well as in the borderline disc, Elschnig’s Ring can only be seen in the temporal sector, whereas in all other phases it can almost be seen in its full extend, due to fiber atrophy. The bottom of the cup is more clearly seen from phase 2 on. If the brightness of the retina in each section are observed, it is noticed that it decreases steadily from normality to phase 4. The cup shape measure changes rapidly. In phase 2 the cup slope is almost perpendicular, and in phases 3 and 4 bayonet-shaped vessels are revealed. The small vessels become more and more evident and their contours are more visible as they become more definite (this is due to the atrophy of the retinal nerve fibers). Nevertheless, at first glance, the condition of the optic disc in phase 4 may seem better than in phase 3. Also, the time elapsed between the normal and the borderline optic disc, or between the borderline optic disc and the disc in phase 1 may seem the same. This is clearly solved with a stereometric analysis of the surfaces. Figure 10.12 shows the six phases in the "Measure" menu, with the color coded analysis of the surfaces. In the normal optic disc, the cup is seen surrounded by a large NRR and not centered in the optic disc. This occurs in normal conditions due to the great entrance of fibers at the superior and inferior poles. In the borderline optic disc, it is possible to see how the cup area increases at the expense of a rim area decrease. Simultaneously, the cup becomes central and its area invades the tilted neuroretinal rim area, thus reducing its separation from the flat neuroretinal rim. In the optic disc of phase 1, the cup area continues to increase and the cup gets closer to the flat neuroretinal rim, leaving a thin separation covered by the tilted neuroretinal rim. The total surface of the NRR decreases markedly. In the optic disc in phase 2, the cup increases considerably and starts to become slightly eccentric, and the tilted rim disappears completely in these reagions. Consequently, the cup surface borders the flat rim surface. This fact can sometimes cause localized defects and, together with the diffuse atrophy of the rest of the retina, it correlates with the onset of the visual field defects in this phase. In the optic disc in phase 3, the cup almost covers the complete optic disc region. The tilted rim has almost com-
109
Fig. 10.12 pletely disappeared. Only a thin flat rim margin separates the cup from the external optic disc margin. This small volume of NRR keeps the visual function unchanged; this is correlated with the rapid visual field loss produced when the remaining NRR is damaged. In the optic disc in stage 4, the cup has occupied almost all the optic disc surface and in some sectors, where the NRR has been completely destroyed, the cup touches the external optic disc margin, making the total absence of the NRR evident in that sector. White regions can occur in stage 4 which are due to the fact that the retinal surface is below the level of the reference plane in the most badly damaged sectors. These lesions produce absolute optic disc defects of bad prognosis.
110 10.5 Clinical Cases Case 1: Male, 64 years of age, left eye. Visus with correction: sph -1, cyl -0.25 in 0 degree, with diagnosis of open angle glaucoma, diagnosed 8 years ago. The intraocular pressure monitored with daily pressure curve during these 8 years, shows at 7 o’clock in the morning 33 mm Hg. The other pressures taken at 9.00 a.m. and 13 , 15, 18 , 21 and 24 hours were below 19 mm Hg. These figures where partially changed with medical therapy and the intraocular pressure at 7 o’clock in the morning changed to 24-28 mm Hg. At this moment the computerized perimetry with Octopus is normal and the HRT indicates that the optic nerve head is in phase 1 (figures 10.13 and 10.14).
Fig. 10.13
Fig. 10.14
111 Case 2: Patient with 72 years of age (male), with diagnosis of chronic glaucoma with narrow angle. The patient was treated because of hypertension for 15 years. (Intraocular pressure without medication: 31 mm Hg, with medical therapy: 24 mm Hg.) Peripherical iridectomy with YAG laser was performed. Later, trabeculoplasty with Argon laser. After these procedures, the monitoring of the intraocular pressure was done with daily pressure curve: mean 17 mm Hg, variability 1.5. HRT presents in the left eye optic disc in phase 2, which is in correlation with a border-line visual field (figures 10.15 and 10.16).
Fig. 10.15
Fig. 10.16
112 Case 3: Patient with 57 years of age (female), left eye, with diagnosis of open angle glaucoma and myopia. Visus: 10/20 with sph. -5.00. The intraocular pressure measured with daily pressure curve shows a mean of 23 mm Hg, variability 1.6. The computerized perimetry presents a visual field in stage III, with M.D. 18.9 and C.L.V. 96.4. The HRT shows an optic disc in phase 3 (figures 10.17 and 10.18).
Fig. 10.17
Fig. 10.18
113 Case 4: Patient with 65 years of age (female), with diagnosis of open angle glaucoma, made 20 years ago. The trabeculoplasty was performed 5 years ago. The monitoring of intraocular pressure was made with spot check pressure and not with daily pressure curve. The pressures taken by other ophthalmologists were 25 mm Hg. The actual visus with a correction of sph. 0.75 is 18/20. Computerized perimetry shows a visual field in stage III., with M.D. 23.2 and C.L.V. 60.5. The HRT shows an optic disc in phase 4, where the only retinal nerve fiber bundle present is the papillo-macular one (figures 10.19 and 10.20).
Fig. 10.19
Fig. 10.20
114 Bibliography 1.
Armarly MF: Genetic determination of cup/disk ratio of the optic nerve. Arch. Ophthalmol 1967;78:35-43.
2.
Reca R: In: Sampaolesi R (ed.): Glaucoma; Edit. Panamericana, Buenos Aires, Argentina, 1991, pp. 305-306.
3.
Sampaolesi JR, Sampaolesi R: Lecture: Study of normality in the optic nerve head with HRT, in “Curso y Simposio Argentino de Glaucoma, July 1995, Buenos Aires, Argentina.
115
CHAPTER 10 EVOLUTION PHASES OF GLAUCOMA
10.1 Introduction In the same manner that Dr. Armarly [1] proposed a practical classification to evaluate the optic nerve condition by dividing the optic disc into 10 parts, and Dr. Raul Reca [2] proposed another one dividing the optic disc into 6 parts, the confocal tomography of the optic nerve suggests a further classification. The previous classifications are based on an analysis of areas (relationship between optic disc area, cup area and rim area) that can be correlated with the areas measured with by the HRT. The tomographic classification is mainly based on the volumes of said structures and only secondarily on areas and other parameters. This is due to the possibility of stereometric and three-dimensional analyses. The advantage provided by volume measurements over area measurements, is that the former are raised to the third power, while the latter are only raised to the second power (whenever change occurs, no matter how slight, there is a greater variation if the value is raised to the cube than if it is raised to the square). 10.2 Parameters used in the classification of evolution As already stated, the main parameters used for the classification were volumes, followed by areas, thickness and slopes. The volumes taken into consideration are the neuroretinal rim volume (NRR) and the cup volume. The most important one, in fact, is the neuroretinal rim volume, but the cup volume is also taken into account since a decrease of the neuroretinal rim volume produces an increase of the cup volume; it is a cause-effect relationship. The same occurs with areas: the cup area (red) increases as the rim area (green and blue) decreases (figure 8.8, chapter 8). The most important parameters used for the classification are listed in figure 10.1 and illustrated in figure 10.2, where the parameters belonging to the optic disc are separated from those that are analyzed in the contour line graph. These latter parameters are: mean RNFL thickness, height variation of contour line, and the area enclosed by the contour line and the reference plane in the contour line height variation diagram (RNFL cross sectional area). As we all know, the reference plane, far from being just another parameter, is the limit on which most parameters strictly depend and with which they
102
Parameters used for classification rim volume cup volume rim area cup area cup shape measure mean RNFL thickness height variation of contour line RNFL cross sectional area Fig. 10.1: Parameters used for classification
Fig. 10.2 have a close relationship. On this account, its position must always be verified, and in a longitudinal study, it must be checked to see that it always remains at the same level. 10.3 Concept and limits of normality The concept of normality is based on the fact that all the optic disc parameters are normal. Nevertheless in clinical practice, sometimes, for one reason or another, the fact that one or two parameters are not within the limits of normality or normal range does not indicate pathology. The concept and limit of normality are outlined in figure 10.3. The limits of normality were obtained from a study on 108 normal volunteers [3]. Figure 10.4 lists the most important limits. For example, for neuroretinal rim volume, the normal inferior limit (0.32 mm3) and not the normal superior limit, is given, since this is used mainly to differentiate a large NRR from an optic disc edema. In some patients a neuroretinal rim volume smaller than 0.32 mm3 may be found in the first tomography, which makes them fall within the classification of borderline. Nevertheless, it must be taken into account that the evolution of these patients sometimes
103
Fig. 10.3: Concept of normality. The value of all parameters mentioned must be within two mean standard deviations of the normal values (normal range). Limits of normality rim volume cup volume rim area cup area cup shape measure mean RNFL thickness height variation of contour line RNFL cross sectional area
min. max. min. max. max. min. min. min.
0.32 mm3 0.12 mm3 1.37 mm2 0.60 mm2 –0.15 0.17 mm 0.27 mm 0.87 mm2
Fig. 10.4: Limits of normality does not involve optic nerve damage but they remain stable for years, which indicates a physiological or normal decrease of the neuroretinal rim in this group of patients. 10.4 Evolution Phases The glaucomatous optic disc evolution was classified into the following groups: - Normal (N) - Borderline (BL) - Phase 1 (P1) - Phase 2 (P2) - Phase 3 (P3) - Phase 4 (P4) With the exception of the borderline optic disc, the rest of the stages are separated from one another by more than two standard deviations, rendering the separation into different groups more significant. Only the parameters meeting this requirement are mentioned, since most of the remaining ones bear no significant differences between the different evolution stages.
104
Normal rim volume cup volume rim area cup area cup shape measure mean RNFL thickness height variation of contour line RNFL cross sectional area normal visual field
> 0.32 mm3 < 0.12 mm3 > 1.37 mm2 < 0.60 mm2 < –0.15 > 0.17 mm > 0.27 mm > 0.87 mm2
The normal optic disc is characterized by a slightly visible Elschnig's Ring, except in the temporal area. Both poles have important fiber bundles, which correlate with the two camel humps displayed by the contour line diagram (figure 10.5). Borderline rim volume cup volume rim area cup area cup shape measure mean RNFL thickness height variation of contour line RNFL cross sectional area normal visual field
> 0.32 mm3 < 0.12 mm3 > 1.37 mm2 < 0.60 mm2 < –0.15 > 0.17 mm > 0.27 mm > 0.87 mm2
In the borderline optic disc, the neuroretinal rim volume is normal by measuring the entire disc, but if we analyze the rim volume by octants and quadrants, there is a decreased value in one of these sectors. The decrease of the neuroretinal rim volume in this phase does not affect the whole optic disc. It corresponds to Burk's pseudonormal optic disc in which the humps remain unchanged and there is a slight neuroretinal rim loss. Except of the cup increase, no parameters are altered (this is less frequent; figure 10.6). Phase 1 rim volume cup volume rim area cup area cup shape measure normal visual field
0.32 - 0.30 mm3 0.12 - 0.24 mm3 1.37 - 1.20 mm2 0.60 - 1.00 mm2 –0.15 - –0.12
The optic disc in phase 1 is characterized by a generalized decrease of the retinal thickness that can be seen in the contour line diagram as a decreasing distance between the contour line and the reference plane. At the same time a decrease in the height of the camel humps, which correlates with the loss of fiber bundles and with the fact that Elschnig's Ring is more visible than before, can be observed (figure 10.7).
105
Fig. 10.5
Fig. 10.6
Fig. 10.7
106
Phase 2 rim volume cup volume rim area cup area cup shape measure beginning of visual field defects
0.30 - 0.20 mm3 0.24 - 0.48 mm3 1.20 - 0.80 mm2 1.00 - 1.50 mm2 –0.12 - –0.07
The optic disc in phase 2 has already a loss of up to 50% of the total retinal nerve fibers. The disappearance of both humps, which correlates with a great cup increase that invades the superior and the inferior poles, can be seen. The mean RNFL thickness preventing the contour line from approaching the reference plane, remains unchanged (figure 10.8). phase 3 rim volume cup volume rim area cup area cup shape measure visual field defects
0.20 - 0.10 mm3 0.48 - 0.96 mm3 0.80 - 0.40 mm2 1.50 - 1.80 mm2 –0.07 - –0.02
The optic disc in phase 3 is characterized by a great decrease of the mean RNFL thickness, which causes the approach of the contour line towards the reference plane. (When localized defects occur, the contour line reaches the reference plane in the damaged areas.) The summation image allows the bottom of the cup and Elschnig's Ring to be clearly seen in their full extend. The cup surface covers almost the whole the optic disc surface. The NRR persists like a thin hale around it (figure 10.9). Phase 4 rim volume cup volume rim area cup area cup shape measure visual field in stage 3 (terminal)
0.10 - 0.00 mm3 > 0.96 mm3 0.40 - 0.00 mm2 > 1.80 mm2 >= 0
The optic disc in phase 4 is characterized by a final decrease of the retinal thickness, where the contour line diagram is parallel to the reference plane, and in the places where there is no NRR left the contour line height variation diagram is below the reference plane. This fact correlates with the appearance of white regions in the analysis of the surfaces and with the presence of absolute visual field defects (figure 10.10).
107
Fig. 10.8
Fig. 10.9
Fig. 10.10
108
Fig 10.11 In figure 10.11, all six phases are summarized. In the normal optic disc, as well as in the borderline disc, Elschnig’s Ring can only be seen in the temporal sector, whereas in all other phases it can almost be seen in its full extend, due to fiber atrophy. The bottom of the cup is more clearly seen from phase 2 on. If the brightness of the retina in each section are observed, it is noticed that it decreases steadily from normality to phase 4. The cup shape measure changes rapidly. In phase 2 the cup slope is almost perpendicular, and in phases 3 and 4 bayonet-shaped vessels are revealed. The small vessels become more and more evident and their contours are more visible as they become more definite (this is due to the atrophy of the retinal nerve fibers). Nevertheless, at first glance, the condition of the optic disc in phase 4 may seem better than in phase 3. Also, the time elapsed between the normal and the borderline optic disc, or between the borderline optic disc and the disc in phase 1 may seem the same. This is clearly solved with a stereometric analysis of the surfaces. Figure 10.12 shows the six phases in the "Measure" menu, with the color coded analysis of the surfaces. In the normal optic disc, the cup is seen surrounded by a large NRR and not centered in the optic disc. This occurs in normal conditions due to the great entrance of fibers at the superior and inferior poles. In the borderline optic disc, it is possible to see how the cup area increases at the expense of a rim area decrease. Simultaneously, the cup becomes central and its area invades the tilted neuroretinal rim area, thus reducing its separation from the flat neuroretinal rim. In the optic disc of phase 1, the cup area continues to increase and the cup gets closer to the flat neuroretinal rim, leaving a thin separation covered by the tilted neuroretinal rim. The total surface of the NRR decreases markedly. In the optic disc in phase 2, the cup increases considerably and starts to become slightly eccentric, and the tilted rim disappears completely in these reagions. Consequently, the cup surface borders the flat rim surface. This fact can sometimes cause localized defects and, together with the diffuse atrophy of the rest of the retina, it correlates with the onset of the visual field defects in this phase. In the optic disc in phase 3, the cup almost covers the complete optic disc region. The tilted rim has almost com-
109
Fig. 10.12 pletely disappeared. Only a thin flat rim margin separates the cup from the external optic disc margin. This small volume of NRR keeps the visual function unchanged; this is correlated with the rapid visual field loss produced when the remaining NRR is damaged. In the optic disc in stage 4, the cup has occupied almost all the optic disc surface and in some sectors, where the NRR has been completely destroyed, the cup touches the external optic disc margin, making the total absence of the NRR evident in that sector. White regions can occur in stage 4 which are due to the fact that the retinal surface is below the level of the reference plane in the most badly damaged sectors. These lesions produce absolute optic disc defects of bad prognosis.
110 10.5 Clinical Cases Case 1: Male, 64 years of age, left eye. Visus with correction: sph -1, cyl -0.25 in 0 degree, with diagnosis of open angle glaucoma, diagnosed 8 years ago. The intraocular pressure monitored with daily pressure curve during these 8 years, shows at 7 o’clock in the morning 33 mm Hg. The other pressures taken at 9.00 a.m. and 13 , 15, 18 , 21 and 24 hours were below 19 mm Hg. These figures where partially changed with medical therapy and the intraocular pressure at 7 o’clock in the morning changed to 24-28 mm Hg. At this moment the computerized perimetry with Octopus is normal and the HRT indicates that the optic nerve head is in phase 1 (figures 10.13 and 10.14).
Fig. 10.13
Fig. 10.14
111 Case 2: Patient with 72 years of age (male), with diagnosis of chronic glaucoma with narrow angle. The patient was treated because of hypertension for 15 years. (Intraocular pressure without medication: 31 mm Hg, with medical therapy: 24 mm Hg.) Peripherical iridectomy with YAG laser was performed. Later, trabeculoplasty with Argon laser. After these procedures, the monitoring of the intraocular pressure was done with daily pressure curve: mean 17 mm Hg, variability 1.5. HRT presents in the left eye optic disc in phase 2, which is in correlation with a border-line visual field (figures 10.15 and 10.16).
Fig. 10.15
Fig. 10.16
112 Case 3: Patient with 57 years of age (female), left eye, with diagnosis of open angle glaucoma and myopia. Visus: 10/20 with sph. -5.00. The intraocular pressure measured with daily pressure curve shows a mean of 23 mm Hg, variability 1.6. The computerized perimetry presents a visual field in stage III, with M.D. 18.9 and C.L.V. 96.4. The HRT shows an optic disc in phase 3 (figures 10.17 and 10.18).
Fig. 10.17
Fig. 10.18
113 Case 4: Patient with 65 years of age (female), with diagnosis of open angle glaucoma, made 20 years ago. The trabeculoplasty was performed 5 years ago. The monitoring of intraocular pressure was made with spot check pressure and not with daily pressure curve. The pressures taken by other ophthalmologists were 25 mm Hg. The actual visus with a correction of sph. 0.75 is 18/20. Computerized perimetry shows a visual field in stage III., with M.D. 23.2 and C.L.V. 60.5. The HRT shows an optic disc in phase 4, where the only retinal nerve fiber bundle present is the papillo-macular one (figures 10.19 and 10.20).
Fig. 10.19
Fig. 10.20
114 Bibliography 1.
Armarly MF: Genetic determination of cup/disk ratio of the optic nerve. Arch. Ophthalmol 1967;78:35-43.
2.
Reca R: In: Sampaolesi R (ed.): Glaucoma; Edit. Panamericana, Buenos Aires, Argentina, 1991, pp. 305-306.
3.
Sampaolesi JR, Sampaolesi R: Lecture: Study of normality in the optic nerve head with HRT, in “Curso y Simposio Argentino de Glaucoma, July 1995, Buenos Aires, Argentina.
115
