Multiple Sclerosis and Related Disorders (2014) 3, 735–737
Available online at www.sciencedirect.com
journal homepage: www.elsevier.com/locate/msard
COMMENTARY
Kestenbaum's capillary number test - A forgotten sign?$ Elizabeth D. Hawkesa,1, James E. Neffendorfb,n,1 a
Department of Ophthalmology, Sussex Eye Hospital, Brighton, UK Department of Ophthalmology, King's College Hospital, London, UK
b
Received 7 August 2014; received in revised form 22 September 2014; accepted 24 September 2014
Kestenbaum's sign, also known as the capillary number test, was first described in 1947 by Alfred Kestenbaum as a method to quantify the degree of optic atrophy (Clinical Methods of Neuro-ophthalmologic Examination by Alfred Kestenbaum, 1947). The original description succinctly describes the technique to perform the test; “In order to set a numerical value on the degree of atrophy, the vessels which pass over the margin of the disk may be counted. One starts at the twelve o'clock point and counts all vessels crossing the margin, counting separately the arterioles, the veins and the small vessels. “Small vessels” means the vessels which cannot be recognized as arteries or as veins. The number of vessels passing over the margin in normal eyes is fairly constant. Without dilatation of the pupil, usually 9 large vessels (4 or 5 veins and 4 or 5 arteries) and about 10 small vessels can be seen.” Since the original account, Kestenbaum's sign has appeared only sporadically in the peer reviewed literature, and in our experience is rarely used by (and often unknown ☆
The manuscript represents valid work and has not been published/being considered elsewhere for publication. n Correspondence to: Department of Ophthalmology, Normanby Building, King's College Hospital, Denmark Hill, London, SE5 9RS, UK. Tel.: +44 203 2991297; fax: +44 203 2991721. E-mail address: [email protected] (J.E. Neffendorf). 1 Denotes joint first authorship. http://dx.doi.org/10.1016/j.msard.2014.09.087 2211-0348/& 2014 Elsevier B.V. All rights reserved.
by) clinicians. It is described in case reports in 1984 and 1964 showing a decreased count in a patients with optic atrophy (Newsome, 1984; Lyle, 1964). However, we believe the quantification is rarely, if at all, measured in clinical practice. Figure 1A shows a patient with severe optic atrophy, and the Kestenbaum sign score of 1 clearly reflects this. Figure 1B shows a classic example of where Kestenbaum's test can aid the diagnosis of borderline optic atrophy. The optic disc could be passed as normal, although careful examination would reveal the lack of the normal healthy pink hue in the temporal sector. Kestenbaum's sign gives a score of 2–3, which can help solidify the diagnosis. Furthermore, this objective measure is helpful when examining the patient at subsequent clinic visits when the degree of pallor could easily be forgotten unless photographed. Figure 1C shows an early glaucomatous disc, which could be mistaken as being normal, but Kestenbaum count shows a score of 6 and again, this score can be used for objective clinical assessment, in conjunction with optical coherence tomography (OCT), over long follow-up time periods to assess disease progression. Figure 1D shows a healthy disc, for comparison, with a Kestenbaum score of 9–10. Optic atrophy results from dysfunction and subsequent axonal degeneration at the optic nerve head, most often due to optic neuritis and glaucoma (You et al., 2013). Whilst technology such as OCT and magnetic resonance imaging has an ever increasing role in the diagnostic criteria of these disorders, the importance of accurate clinical diagnosis in
736
E.D. Hawkes, J.E. Neffendorf
Figure 1 (A) Kestenbaum's sign in severe optic atrophy. A score of 1 highlights severe disease. (B) Kestenbaum's sign in borderline optic atrophy. The optic disc here may be passed as normal. However, if the number of small vessels traversing the disc margin (which are not obviously arteries, veins or branches thereof) is counted, only 2–3 (arrowed) can be scored, which is well below the normal level of 9–10. (C) An early glaucomatous disc with a Kestenbaum score of 6. (D) A healthy optic disc. A large number of capillaries can be counted (Kestenbaum score: 9–10). Their course from disc surface arterioles to peripapillary retinal capillaries is evident.
raising suspicion, should not be forgotten. Classically, the presence of optic nerve pallor is seen as the hallmark of optic nerve damage resulting in atrophy. The aetiology of optic atrophy can often be difficult to establish. One study claimed that retrospective review of history and examination findings typically explain the aetiology, when initially the diagnosis was unexplained, whereas neuroimaging is only diagnostic in approximately 20% of cases (Lee and Chau, 2005). This further demonstrates the relevance of clinical examination and the need for basic observation with e.g. Kestenbaum's sign which can be assessed easily with the direct ophthalmoscope, particularly if a slit-lamp examination or technology such as OCT is not immediately available as in most non-ophthalmology clinics.
In chronic open-angle glaucoma, disease progression is associated with vascular dysregulation in the form of local vasospasm and systemic hypertension (Flammer and Orgul, 1998). The surface of a healthy optic disc contains a large number of capillaries which are derived from branches of the retinal arterioles and are continuous with the peripapillary retinal capillaries (Figure 1D). These retinal capillaries are supplied solely by the central retinal artery, unless a cilioretinal artery is present, as it is in 5–40% of patients (Hayreh, 1969, 1963). Kestenbaum's sign affords a quantifiable measure of the vascular appearance of the optic disc and would support the contention that end stage disease has a vascular aetiology. Whilst we advocate the use of technology to aid diagnosis and quantification of optic atrophy, we suggest that a simple
Kestenbaum's capillary number test measure such as capillary number count should be implemented as well to raise or lower suspicion of disc abnormality in a borderline case. In addition, when optic discs are viewed in lecture presentations or photographs, a capillary count is useful as this is more tangible than subtle changes such as pallor which may be influenced by viewing angle, projector/screen characteristics and fidelity of the photograph itself. Kestenbaum's sign has never been correlated with more sophisticated measures of optic nerve viability such as OCT and fluorescein angiography. Until this is undertaken, we suggest it has a place as a rapid and useful clinical observation to provide preliminary guidance about the health of an optic nerve.
Conflict of interest The authors declare no conflict of interest with respect to the contents of this article. JN has received support for conference attendance from Thrombogenics. EDH has no funding sources to declare. Both authors contributed to the writing and review of the manuscript.
Acknowledgements None.
737
References Clinical Methods of Neuro-ophthalmologic Examination by Alfred Kestenbaum. William Heinemann (Medical Books) Ltd.; 1947. Flammer J, Orgul S. Optic nerve blood-flow abnormalities in glaucoma. Prog Retin Eye Res 1998;17(2):267–89. Hayreh SS. The cilio-retinal arteries. Br J Ophthalmol 1963;47 (2):71–89. Hayreh SS. Blood supply of the optic nerve head and its role in optic atrophy, glaucoma, and oedema of the optic disc. Br J Ophthalmol 1969;53(11):721–48. Lee AG, Chau FY, Kardon RH, Golnik KC, Wall M. The diagnostic yield of the evaluation for isolated unexplained optic atrophy. Ophthalmology 2005;112(5):757–9. Lyle TK. Optic disc oedema: the differential diagnosis of its causes. J Neurol Sci 1964;64:309–24. Newsome PR. An optometric purview of intraorbital meningioma. Am J Optom Physiol Opt 1984;61(4):274–8. You Y, Gupta VK, Li JC, Klistorner A, Graham SL. Optic neuropathies: characteristic features and mechanisms of retinal ganglion cell loss. Rev Neurosci 2013;24(3):301–21.
Available online at www.sciencedirect.com
journal homepage: www.elsevier.com/locate/msard
COMMENTARY
Kestenbaum's capillary number test - A forgotten sign?$ Elizabeth D. Hawkesa,1, James E. Neffendorfb,n,1 a
Department of Ophthalmology, Sussex Eye Hospital, Brighton, UK Department of Ophthalmology, King's College Hospital, London, UK
b
Received 7 August 2014; received in revised form 22 September 2014; accepted 24 September 2014
Kestenbaum's sign, also known as the capillary number test, was first described in 1947 by Alfred Kestenbaum as a method to quantify the degree of optic atrophy (Clinical Methods of Neuro-ophthalmologic Examination by Alfred Kestenbaum, 1947). The original description succinctly describes the technique to perform the test; “In order to set a numerical value on the degree of atrophy, the vessels which pass over the margin of the disk may be counted. One starts at the twelve o'clock point and counts all vessels crossing the margin, counting separately the arterioles, the veins and the small vessels. “Small vessels” means the vessels which cannot be recognized as arteries or as veins. The number of vessels passing over the margin in normal eyes is fairly constant. Without dilatation of the pupil, usually 9 large vessels (4 or 5 veins and 4 or 5 arteries) and about 10 small vessels can be seen.” Since the original account, Kestenbaum's sign has appeared only sporadically in the peer reviewed literature, and in our experience is rarely used by (and often unknown ☆
The manuscript represents valid work and has not been published/being considered elsewhere for publication. n Correspondence to: Department of Ophthalmology, Normanby Building, King's College Hospital, Denmark Hill, London, SE5 9RS, UK. Tel.: +44 203 2991297; fax: +44 203 2991721. E-mail address: [email protected] (J.E. Neffendorf). 1 Denotes joint first authorship. http://dx.doi.org/10.1016/j.msard.2014.09.087 2211-0348/& 2014 Elsevier B.V. All rights reserved.
by) clinicians. It is described in case reports in 1984 and 1964 showing a decreased count in a patients with optic atrophy (Newsome, 1984; Lyle, 1964). However, we believe the quantification is rarely, if at all, measured in clinical practice. Figure 1A shows a patient with severe optic atrophy, and the Kestenbaum sign score of 1 clearly reflects this. Figure 1B shows a classic example of where Kestenbaum's test can aid the diagnosis of borderline optic atrophy. The optic disc could be passed as normal, although careful examination would reveal the lack of the normal healthy pink hue in the temporal sector. Kestenbaum's sign gives a score of 2–3, which can help solidify the diagnosis. Furthermore, this objective measure is helpful when examining the patient at subsequent clinic visits when the degree of pallor could easily be forgotten unless photographed. Figure 1C shows an early glaucomatous disc, which could be mistaken as being normal, but Kestenbaum count shows a score of 6 and again, this score can be used for objective clinical assessment, in conjunction with optical coherence tomography (OCT), over long follow-up time periods to assess disease progression. Figure 1D shows a healthy disc, for comparison, with a Kestenbaum score of 9–10. Optic atrophy results from dysfunction and subsequent axonal degeneration at the optic nerve head, most often due to optic neuritis and glaucoma (You et al., 2013). Whilst technology such as OCT and magnetic resonance imaging has an ever increasing role in the diagnostic criteria of these disorders, the importance of accurate clinical diagnosis in
736
E.D. Hawkes, J.E. Neffendorf
Figure 1 (A) Kestenbaum's sign in severe optic atrophy. A score of 1 highlights severe disease. (B) Kestenbaum's sign in borderline optic atrophy. The optic disc here may be passed as normal. However, if the number of small vessels traversing the disc margin (which are not obviously arteries, veins or branches thereof) is counted, only 2–3 (arrowed) can be scored, which is well below the normal level of 9–10. (C) An early glaucomatous disc with a Kestenbaum score of 6. (D) A healthy optic disc. A large number of capillaries can be counted (Kestenbaum score: 9–10). Their course from disc surface arterioles to peripapillary retinal capillaries is evident.
raising suspicion, should not be forgotten. Classically, the presence of optic nerve pallor is seen as the hallmark of optic nerve damage resulting in atrophy. The aetiology of optic atrophy can often be difficult to establish. One study claimed that retrospective review of history and examination findings typically explain the aetiology, when initially the diagnosis was unexplained, whereas neuroimaging is only diagnostic in approximately 20% of cases (Lee and Chau, 2005). This further demonstrates the relevance of clinical examination and the need for basic observation with e.g. Kestenbaum's sign which can be assessed easily with the direct ophthalmoscope, particularly if a slit-lamp examination or technology such as OCT is not immediately available as in most non-ophthalmology clinics.
In chronic open-angle glaucoma, disease progression is associated with vascular dysregulation in the form of local vasospasm and systemic hypertension (Flammer and Orgul, 1998). The surface of a healthy optic disc contains a large number of capillaries which are derived from branches of the retinal arterioles and are continuous with the peripapillary retinal capillaries (Figure 1D). These retinal capillaries are supplied solely by the central retinal artery, unless a cilioretinal artery is present, as it is in 5–40% of patients (Hayreh, 1969, 1963). Kestenbaum's sign affords a quantifiable measure of the vascular appearance of the optic disc and would support the contention that end stage disease has a vascular aetiology. Whilst we advocate the use of technology to aid diagnosis and quantification of optic atrophy, we suggest that a simple
Kestenbaum's capillary number test measure such as capillary number count should be implemented as well to raise or lower suspicion of disc abnormality in a borderline case. In addition, when optic discs are viewed in lecture presentations or photographs, a capillary count is useful as this is more tangible than subtle changes such as pallor which may be influenced by viewing angle, projector/screen characteristics and fidelity of the photograph itself. Kestenbaum's sign has never been correlated with more sophisticated measures of optic nerve viability such as OCT and fluorescein angiography. Until this is undertaken, we suggest it has a place as a rapid and useful clinical observation to provide preliminary guidance about the health of an optic nerve.
Conflict of interest The authors declare no conflict of interest with respect to the contents of this article. JN has received support for conference attendance from Thrombogenics. EDH has no funding sources to declare. Both authors contributed to the writing and review of the manuscript.
Acknowledgements None.
737
References Clinical Methods of Neuro-ophthalmologic Examination by Alfred Kestenbaum. William Heinemann (Medical Books) Ltd.; 1947. Flammer J, Orgul S. Optic nerve blood-flow abnormalities in glaucoma. Prog Retin Eye Res 1998;17(2):267–89. Hayreh SS. The cilio-retinal arteries. Br J Ophthalmol 1963;47 (2):71–89. Hayreh SS. Blood supply of the optic nerve head and its role in optic atrophy, glaucoma, and oedema of the optic disc. Br J Ophthalmol 1969;53(11):721–48. Lee AG, Chau FY, Kardon RH, Golnik KC, Wall M. The diagnostic yield of the evaluation for isolated unexplained optic atrophy. Ophthalmology 2005;112(5):757–9. Lyle TK. Optic disc oedema: the differential diagnosis of its causes. J Neurol Sci 1964;64:309–24. Newsome PR. An optometric purview of intraorbital meningioma. Am J Optom Physiol Opt 1984;61(4):274–8. You Y, Gupta VK, Li JC, Klistorner A, Graham SL. Optic neuropathies: characteristic features and mechanisms of retinal ganglion cell loss. Rev Neurosci 2013;24(3):301–21.
