ACTA OPHTHALMOLOGICA (1992) Supplement 204
SECTION 1
The relation between the sagittal and transversal diameters in eyes with retinal detachment
W. Eissa, M. Skurczynski, I? Lewandowski and J. Kasprzak Department of Ophthalmology (Head: Prof. T. Kecik), Warsaw Medical Academy Abstract. Using A-mode ultrasonography,the axial length and the width (transversalor equatorial diameter) of both eyes - fellow and affected - have been measured in patients with retinal detachment. For comparison, the same measurementshave been performed in healthy controls. The patients have been divided into different groups. It was found that there are some changes in the relation between the axial length and the width of the eyes in patients with retinal detachment, accordingto the comparison with healthy people, in most cases. Key words: Retinal detachment - ocular diameters - ultra-
sound measurement.
Our idea was to study the association between axial length and equatorial diameter of the eyeball in patients with retinal detachment. All measurements were performed ultrasonographically using A-mode (Sonomed 2000). In 1984 a study with a similar scope was performed by Meyer-Schwickerath & Gerke (1984). Measuring the equatorial diameter is based on topographical analysis of the dimensions of normal emmetropic eyes. Previously such knowledge has been gained from anatomical studies and from measurements of the eye dimensions by radiological, optical and ultrasonographical means (DukeElder 1961, Wolff 1969, Francois & Goes 1977).
70 healthy control eyes. The retinal detachment group included 17 eyes with aphakic detachment and 22 eyes with posttraumatic retinal detachment. In the latter subgroups there were 5 eyes that might be counted in both groups. They have been left out from Table 2 which composes the 'clean' cases only. 3)
Ultrasound method Measurement of the axial length using the average of eight measurements. 11. Measurement of the equatorial diameter. 1. The examined eye must be in maximum adduction. 2. The measurements start 8-12 mm from limbus, to 16-20 mm temporally. 3. The supporting contact glass (for the transducer) to the eyeball in cases where measurements were guided by the special contact device. The limbus should be seen at the nasal edge of the cut part of the contact glass, through which measurements are made, and the cornea is completely covered (Fig. 1).
I.
Material and methods
Full ophthalmologicalexamination and ultrasonographic measurements were performed in 289 eyes. The study excluded cases with squint, nystagmus, conjunctivitis, uveitis, and cases of retinal detachment in which retinal tears could not be demonstrated. The eyes examined were grouped as follows, cf Table 1. 1) 114 eyes with rhegmatogeneous retinal detachment. 2) 105 fellow eyes. 16
Fig. 1. The measurement of the equatorial diameter guided by a special contact lens device.
4. The direction of the ultrasound probe should
coincide with the horizontal meridian of the eyeball. The measurements being performed accurately the recordings will increase until maximum, and with a maximum eye wall echo, and then decline. Any movement of the eye or any unintended movement of the examiner’s hand during the examination will give artifacts. The largest satisfactory reading is accepted as the equatorial diameter. The use of the special contact glass enchances the accuracy and increases the likelihood of getting accurate measurements through the observation of the limbus. The movement of the tip of the
transducer along a straight line is ensured by following the cut part of the contact lens, which further reduces the artifacts due to unintended movements of the examiner’s hand.
Results and discussion
Concerning axial length the RD-group showed higher values in general, with no difference to the fellow eye (mean value 24.4 mm), than in the controls (23.0 mm, Table 1).Dividing by type of detachment the subgroup with post-traumatic detachment came closer to the controls (Table 2) than the subgroup with retinal detachment developing after cataract surgery. A longer eye, in the sagittal plane, -apparently entails a relative overTable 1. risk of eventually acquiring retinal detachment, The axial length, equatorial diameter, and the difference bespontaneously or after cataract extraction. In contween the two measurements, in eyes with retinal detachment, fellow eyes, and in controls. Mean values and SD. trast, the posttraumatic detachments are recruited from eyes of normal size, with traction after Number Axial Equatorial Difference of length diameter between intraocular bleeding, etc., appearing as the main (mm) E.D. &AXL pathogenetic mechanism. eyes (mm) (mm) Equatorial measurement mean values appeared Detachedeyes 114 24.221.9 25.1f1.4 0.921.4 Fellow eyes 105 24.4f 1.9 25.22 1.1 0.8f 1.5 similar in the three main groups of Table 1-just Control group 70 23.0f 1.0 25.1f0.9 2.1f0.8 above 25 mm in all. This implies that the difference between the two individucal eye measurements is larger in the controls than in the retinal detachTable 2. ment group (Table 3). The control eyes presented The same parameters as in Table 1, with the retinal detachment group subdivided according to type of detachment with a more elliptical or ovoid shape, with the spontaneous’, after cataract surgery, or post-traumatic. At largest diameter transversally, while the detachbottom controls. ment eyes had a more regular (spheroid) shape. Number Axial Equatorial Difference The importance of dysproportional gross archiof length diameter between E.D. & AXL tecture of the eye for anatomical stability - in partieyes (mm) (mm) (mm) Rhegmatogeneous cular as relevant to developing rhegmatogeneous detachment 80 24.4-+ 1.8 25.1f 1.3 0 . 7 1.3 ~ retinal detachment - still remains obscure. Furspontaneous ther studies are required. 73 24.4f 1.9 25.221.2 0.8f 1.4 Fellow eyes Aphakic retinal detachment Fellow eyes
12
24.0f 1.9 25.2f 1.3
10
24.7f2.4 25.4f 1.2
0.6f 1.9
23.5f 2.2 24.921.6
1.4f 1.7
Post-traumatic retinal 17 detachment 17 Fellow eyes
23.7f 1.9 2 5 . 01.4 ~
1 . 31.6 ~
Control group
23.0f 1.0 25.1f 0.9
2.120.9
70
Table 3 Difference between individual equatorial and sagittal diameters in the three main groups, given as % with a d s e rence of a t least 2 mm. Detached eves Fellow eves Controls Difference mm
>2
25%
29%
References
1.2f 1.6
83%
Duke-Elder WS (1961): The anatomy of the visual system. Vol. 11. pp 75-83. The C.V Mosby Company. Francois J & Goes F (1977): Ultrasonographic study of 100 emetropic eyes. Ophthalmologica 175: 321-327. Meyer-Schwickerath G & Gerke E (1984): Biometric studies of the eyeball and retinal detachment. Brit J Ophthalmol68: 29-31. Wolff E (1968):Anatomy of the eye and orbit. W. Lewis Co.
Authors’ address: Warsaw Medical Academy Klinika Chorob oczu U1. Lindleya 4 02005 Warszawa Poland
17
SECTION 1
The relation between the sagittal and transversal diameters in eyes with retinal detachment
W. Eissa, M. Skurczynski, I? Lewandowski and J. Kasprzak Department of Ophthalmology (Head: Prof. T. Kecik), Warsaw Medical Academy Abstract. Using A-mode ultrasonography,the axial length and the width (transversalor equatorial diameter) of both eyes - fellow and affected - have been measured in patients with retinal detachment. For comparison, the same measurementshave been performed in healthy controls. The patients have been divided into different groups. It was found that there are some changes in the relation between the axial length and the width of the eyes in patients with retinal detachment, accordingto the comparison with healthy people, in most cases. Key words: Retinal detachment - ocular diameters - ultra-
sound measurement.
Our idea was to study the association between axial length and equatorial diameter of the eyeball in patients with retinal detachment. All measurements were performed ultrasonographically using A-mode (Sonomed 2000). In 1984 a study with a similar scope was performed by Meyer-Schwickerath & Gerke (1984). Measuring the equatorial diameter is based on topographical analysis of the dimensions of normal emmetropic eyes. Previously such knowledge has been gained from anatomical studies and from measurements of the eye dimensions by radiological, optical and ultrasonographical means (DukeElder 1961, Wolff 1969, Francois & Goes 1977).
70 healthy control eyes. The retinal detachment group included 17 eyes with aphakic detachment and 22 eyes with posttraumatic retinal detachment. In the latter subgroups there were 5 eyes that might be counted in both groups. They have been left out from Table 2 which composes the 'clean' cases only. 3)
Ultrasound method Measurement of the axial length using the average of eight measurements. 11. Measurement of the equatorial diameter. 1. The examined eye must be in maximum adduction. 2. The measurements start 8-12 mm from limbus, to 16-20 mm temporally. 3. The supporting contact glass (for the transducer) to the eyeball in cases where measurements were guided by the special contact device. The limbus should be seen at the nasal edge of the cut part of the contact glass, through which measurements are made, and the cornea is completely covered (Fig. 1).
I.
Material and methods
Full ophthalmologicalexamination and ultrasonographic measurements were performed in 289 eyes. The study excluded cases with squint, nystagmus, conjunctivitis, uveitis, and cases of retinal detachment in which retinal tears could not be demonstrated. The eyes examined were grouped as follows, cf Table 1. 1) 114 eyes with rhegmatogeneous retinal detachment. 2) 105 fellow eyes. 16
Fig. 1. The measurement of the equatorial diameter guided by a special contact lens device.
4. The direction of the ultrasound probe should
coincide with the horizontal meridian of the eyeball. The measurements being performed accurately the recordings will increase until maximum, and with a maximum eye wall echo, and then decline. Any movement of the eye or any unintended movement of the examiner’s hand during the examination will give artifacts. The largest satisfactory reading is accepted as the equatorial diameter. The use of the special contact glass enchances the accuracy and increases the likelihood of getting accurate measurements through the observation of the limbus. The movement of the tip of the
transducer along a straight line is ensured by following the cut part of the contact lens, which further reduces the artifacts due to unintended movements of the examiner’s hand.
Results and discussion
Concerning axial length the RD-group showed higher values in general, with no difference to the fellow eye (mean value 24.4 mm), than in the controls (23.0 mm, Table 1).Dividing by type of detachment the subgroup with post-traumatic detachment came closer to the controls (Table 2) than the subgroup with retinal detachment developing after cataract surgery. A longer eye, in the sagittal plane, -apparently entails a relative overTable 1. risk of eventually acquiring retinal detachment, The axial length, equatorial diameter, and the difference bespontaneously or after cataract extraction. In contween the two measurements, in eyes with retinal detachment, fellow eyes, and in controls. Mean values and SD. trast, the posttraumatic detachments are recruited from eyes of normal size, with traction after Number Axial Equatorial Difference of length diameter between intraocular bleeding, etc., appearing as the main (mm) E.D. &AXL pathogenetic mechanism. eyes (mm) (mm) Equatorial measurement mean values appeared Detachedeyes 114 24.221.9 25.1f1.4 0.921.4 Fellow eyes 105 24.4f 1.9 25.22 1.1 0.8f 1.5 similar in the three main groups of Table 1-just Control group 70 23.0f 1.0 25.1f0.9 2.1f0.8 above 25 mm in all. This implies that the difference between the two individucal eye measurements is larger in the controls than in the retinal detachTable 2. ment group (Table 3). The control eyes presented The same parameters as in Table 1, with the retinal detachment group subdivided according to type of detachment with a more elliptical or ovoid shape, with the spontaneous’, after cataract surgery, or post-traumatic. At largest diameter transversally, while the detachbottom controls. ment eyes had a more regular (spheroid) shape. Number Axial Equatorial Difference The importance of dysproportional gross archiof length diameter between E.D. & AXL tecture of the eye for anatomical stability - in partieyes (mm) (mm) (mm) Rhegmatogeneous cular as relevant to developing rhegmatogeneous detachment 80 24.4-+ 1.8 25.1f 1.3 0 . 7 1.3 ~ retinal detachment - still remains obscure. Furspontaneous ther studies are required. 73 24.4f 1.9 25.221.2 0.8f 1.4 Fellow eyes Aphakic retinal detachment Fellow eyes
12
24.0f 1.9 25.2f 1.3
10
24.7f2.4 25.4f 1.2
0.6f 1.9
23.5f 2.2 24.921.6
1.4f 1.7
Post-traumatic retinal 17 detachment 17 Fellow eyes
23.7f 1.9 2 5 . 01.4 ~
1 . 31.6 ~
Control group
23.0f 1.0 25.1f 0.9
2.120.9
70
Table 3 Difference between individual equatorial and sagittal diameters in the three main groups, given as % with a d s e rence of a t least 2 mm. Detached eves Fellow eves Controls Difference mm
>2
25%
29%
References
1.2f 1.6
83%
Duke-Elder WS (1961): The anatomy of the visual system. Vol. 11. pp 75-83. The C.V Mosby Company. Francois J & Goes F (1977): Ultrasonographic study of 100 emetropic eyes. Ophthalmologica 175: 321-327. Meyer-Schwickerath G & Gerke E (1984): Biometric studies of the eyeball and retinal detachment. Brit J Ophthalmol68: 29-31. Wolff E (1968):Anatomy of the eye and orbit. W. Lewis Co.
Authors’ address: Warsaw Medical Academy Klinika Chorob oczu U1. Lindleya 4 02005 Warszawa Poland
17
