SYMPTOMATIC DYNAMIC VITREOMACULAR TRACTION DURING ACCOMMODATION AND HEAD-DOWN POSTURE PRECEDING DEFINITIVE VITREOMACULAR TRACTION SYNDROME Faye E. Mellington, BMBCH,* Larry Benjamin, MBBS†
Purpose: To report a case of progressive vitreomacular traction, definitive optical coherence tomography evidence of established vitreomacular traction, and subsequent spontaneous resolution with posterior vitreous detachment occurrence. Methods: Case report and literature review. This study involved a patient presenting to Retina Clinic at Stoke Mandeville Hospital. Results: Symptomatic improvement after posterior vitreous detachment. Conclusion: Dynamic vitreomacular traction should be suspected in cases of fluctuating central visual disturbance, particularly when associated with accommodation and downward head posture. The authors discuss the possible influence of accommodation and head position. RETINAL CASES & BRIEF REPORTS X:1–1, 2009
From the *Oxford Eye Hospital, John Radcliffe Hospital, Headington, Oxford, UK; and the †Department of Ophthalmology, Stoke Mandeville Hospital, Aylesbury, UK.
toms. No neurologic explanation had been found. Examination revealed visual acuity correctable to 6/6 ⫹ 2 both eyes; refraction: right eye ⫺2.25/⫺0.25 ⫻ 160 (near add ⫹2.75) N5, left eye ⫺2.25/⫺0.50 ⫻ 180 (near add ⫹2.75), N5. Ocular examination, including visual field testing, was unremarkable, and myasthenia gravis was excluded. She was reassured and discharged back to her general practitioner. Four months later, she was re-referred by her general practitioner with continued symptoms, which she believed were more frequent, more pronounced in the right eye, and worse when leaning forward during sustained close work (and when her eyes were not moving). Her symptoms were now interfering with her work as a beautician. Visual acuity was 6/9 ⫹ 2 right eye (6/6 left eye), and the result of the ocular examination was normal. A repeat magnetic resonance imaging (brain and orbits) scan and electrodiagnostic tests were normal. By April 2007, her symptoms were worse, although visual acuity remained
A
52-year-old woman was referred to us from the Neurology department in March 2006 complaining of an 8-month history of a tiny “crazy-paving”like light in the center of both eyes when trying to focus during close work, which resolved on looking away. She had been diagnosed with migraine 1 year previously (and had a normal magnetic resonance imaging brain) but believed that her visual disturbance was completely unlike her occipital migraine sympOral presentation at the Oxford Eye Hospital Postgraduate Teaching, Oxford, UK, September 29, 2008. Neither of the authors has any financial or proprietary interest in any subject mentioned in this study. Reprint requests: Faye Mellington, BMBCh, Department of Ophthalmology, John Radcliffe Hospital, Headley Way, Headington, Oxford, UK; e-mail: [email protected]
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Fig. 1. Serial optical coherence tomography scans to demonstrate vitreomacular traction (VMT) and its resolution in our patient. A, Right eye (November 14, 2007) showing no VMT seen. B, Left eye (November 14, 2007) normal scan. C, Right eye (May 1, 2008) showing VMT. D, Right eye (May 29, 2008) showing right posterior vitreous detachment (PVD) and resolution of VMT with restoration of the foveal pit. E, left eye (May 29, 2008) suspected mild VMT with shallowing of foveal pit.
good at 6/6 right eye, 6/6 ⫺ 2 left eye. She was referred to a consultant neuro-ophthalmologist for a second opinion. She now described a spot (which was different in the two eyes) in the center of her vision when reading, suggesting macular etiology. It was more likely to occur in bright light and was induced on slit-lamp examination in the clinic. The results of the macular autofluorescence and optical coherence tomography (OCT) seemed normal (Figure 1). Eight months later, right visual acuity had dropped to 6/12 ⫹ 1 (6/6 left eye), and she was aware of a constant right central scotoma (Figure 2). Repeat OCT showed definitive right vitreomacular traction (Figure 1, showing OCT series). She was given an Amsler chart to monitor the progress. Just 4 weeks
later, right visual acuity had improved objectively and subjectively (6/6 ⫹ 2 right eye, 6/6 ⫺ 1 left eye). Optical coherence tomography showed right posterior vitreous detachment and mild left vitreomacular traction (Figure 1). Improvement continued such that by July 2008, visual acuity was 6/5 ⫺ 2 both eyes. She had a permanent “black squiggle” in her right vision but “had to look for it.” She also had a “jagged bit” that lasted 5 minutes in the center of her left vision after focusing for ⬃20 minutes. Optical coherence tomography showed sustained left vitreomacular traction, with the foveal pit slightly flattened (Figure 3).
Comment
Fig. 2. Patient’s drawing of visual symptoms.
Vitreomacular traction syndrome occurs as a result of incomplete separation of the posterior vitreous from the retina, with persistent macular adherence causing traction on the posterior retina. The near response is a synkinesis of accommodation, miosis, and convergence. Movement of the vitreous during the near response may cause fluctuating vitreomacular traction. There is considerable evidence supporting vitreous movement during accommodation, although its role (active or passive) remains controversial.
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Fig. 3. Later optical coherence tomography scans taken on July 14, 2008. A, Right eye shows posterior vitreous detachment (PVD) and no vitreomacular traction (VMT). B, Persistent left VMT.
Hensen and Voelckers (cited in Luedde1) cut a scleral window in the eyes of dogs to expose the ciliary muscle and then stimulated the ciliary nerves to demonstrate inward shrinking of the ciliary muscle and simultaneous outward bulging of the choroid. When they completely bisected the globe and excited the ciliary nerves, the vitreous nearest the lens bulged forward and peripheral vitreous sank inward. Koke2 reported a forward axial movement of the tertiary vitreous and changes in the posterior portion of the secondary vitreous in the living cat eye during accommodation after the injection of radio-opaque material and by using physostigmine to induce ciliary muscle contraction. Later, Suzuki3 reported movement of the vitreous against the back of the lens during accommodation in cats. The head-downward position compounds the issue: it allows greater lens (and consequently, vitreous) movement in accommodation compared with other head positions. When the eye is strongly accommodated, the lens moves in the direction of gravity. Hess4 reported that the lens moved forward an additional 0.15 mm on maximal accommodation when the head was facing down. This effect was later confirmed by Fincham5 (who measured a 0.2-mm shorter cornealens distance in head-down position in accommodated eyes compared with head-up position) and Gallagher6 (who measured far and near points in 12 eyes for head facing upward, straight ahead, and downward). Gallagher showed a significant effect of head position on amplitude of accommodation (mean head upward amplitude of accommodation ⫽ 5.6 D, straight ahead 6.1 D, downward 6.7 D). Increasing age potentiates the problem. According to the Hess-Gullstrand theory of presbyopia, the increasing size of the lens with age creates a hammock effect of the zonules, with increased zonular slackness on attempted accommodation.7 This allows the lens (and therefore the vitreous) to move more under the influence of gravity. Because the light reflex is intrinsically linked to the near reflex, with only ⬃5% of the postganglionic myelinated short ciliary nerves being pupillomotor and the remaining designated for the ciliary muscle, it
is entirely plausible that the association of our patient’s symptoms with bright light resulted from the reflex ciliary contraction coupled to the light reflex, with subsequent increased vitreous movement and traction. Increased lens movement caused by convergence was reported by Jampel and Mindel8 in 1967. They observed a striking forward movement of the lens in macaque monkeys on stimulation of extraocular muscle contraction during accommodation. We propose that increased vitreous movement caused by light-reflex-induced miosis and in the near response, particularly when associated with downward head position, caused increased vitreomacular traction, disturbance of photoreceptor orientation and stimulation, and consequently, the metamorphopsia described by our patient. Recent advances in OCT image quality with improved resolution have made established vitreomacular traction syndrome much easier to diagnose. In contrast, intermittent dynamic vitreomacular traction, by its very nature, may easily be missed on standard OCT unless it is suspected and specifically looked for. Furthermore, OCT lacks the resolution to detect subtle misalignments of the photoreceptor layer, making the diagnosis of early, periodic vitreomacular traction particularly challenging. The diagnosis should, however, be suspected in cases of fluctuating central visual disturbance, particularly when associated with accommodation and downward head posture. We would advocate, where possible, an OCT after induction of symptoms and ideally with the eye in accommodative and nonaccommodative states. This may enable earlier diagnosis and minimize overinvestigation and patient anxiety. Key words: accommodation, head posture, near response, vitreomacular traction syndrome.
References 1.
Luedde WH. Hensen and Voelckers’s experiments on the mechanism of accommodation: an interpretation. Trans Am Ophthalmol Soc 1927;25:250 –267.
4 2. 3. 4. 5. 6.
RETINAL CASES & BRIEF REPORTSℜ Koke MP. Mechanism of accommodation. Arch Ophthalmol 1942;27:950 –968. Suzuki H. Observations on the intraocular changes associated with accommodation. Jpn J Ophthalmol 1971;15:47–58. Hess C. Arbeiten aus dem gebiete der Akommodationsiehr. Graefes Arch Ophthalmol 1996/1897;47:43. Fincham EF. The mechanism of accommodation. Br J Ophthalmol Monograph Suppl 1937;8:5– 80. Gallagher JT. The effect of gravity direction change on am-
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plitude of accommodation [master’s thesis]. Indiana University; 1972. Gullstrand A. Appendix IV. The mechanism of accommodation. In: Southall JPC, ed. Helmholtz’s Treatise on Physiological Optics. Vol. 1. 3rd ed. Rochester, NY: Optical Society of America; 1924:382– 415. Jampel RS, Mindel J. The nucleus for accommodation in the midbrain of the macaque. Invest Ophthalmol Vis Sci 1967;6: 40 –50.
Purpose: To report a case of progressive vitreomacular traction, definitive optical coherence tomography evidence of established vitreomacular traction, and subsequent spontaneous resolution with posterior vitreous detachment occurrence. Methods: Case report and literature review. This study involved a patient presenting to Retina Clinic at Stoke Mandeville Hospital. Results: Symptomatic improvement after posterior vitreous detachment. Conclusion: Dynamic vitreomacular traction should be suspected in cases of fluctuating central visual disturbance, particularly when associated with accommodation and downward head posture. The authors discuss the possible influence of accommodation and head position. RETINAL CASES & BRIEF REPORTS X:1–1, 2009
From the *Oxford Eye Hospital, John Radcliffe Hospital, Headington, Oxford, UK; and the †Department of Ophthalmology, Stoke Mandeville Hospital, Aylesbury, UK.
toms. No neurologic explanation had been found. Examination revealed visual acuity correctable to 6/6 ⫹ 2 both eyes; refraction: right eye ⫺2.25/⫺0.25 ⫻ 160 (near add ⫹2.75) N5, left eye ⫺2.25/⫺0.50 ⫻ 180 (near add ⫹2.75), N5. Ocular examination, including visual field testing, was unremarkable, and myasthenia gravis was excluded. She was reassured and discharged back to her general practitioner. Four months later, she was re-referred by her general practitioner with continued symptoms, which she believed were more frequent, more pronounced in the right eye, and worse when leaning forward during sustained close work (and when her eyes were not moving). Her symptoms were now interfering with her work as a beautician. Visual acuity was 6/9 ⫹ 2 right eye (6/6 left eye), and the result of the ocular examination was normal. A repeat magnetic resonance imaging (brain and orbits) scan and electrodiagnostic tests were normal. By April 2007, her symptoms were worse, although visual acuity remained
A
52-year-old woman was referred to us from the Neurology department in March 2006 complaining of an 8-month history of a tiny “crazy-paving”like light in the center of both eyes when trying to focus during close work, which resolved on looking away. She had been diagnosed with migraine 1 year previously (and had a normal magnetic resonance imaging brain) but believed that her visual disturbance was completely unlike her occipital migraine sympOral presentation at the Oxford Eye Hospital Postgraduate Teaching, Oxford, UK, September 29, 2008. Neither of the authors has any financial or proprietary interest in any subject mentioned in this study. Reprint requests: Faye Mellington, BMBCh, Department of Ophthalmology, John Radcliffe Hospital, Headley Way, Headington, Oxford, UK; e-mail: [email protected]
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Fig. 1. Serial optical coherence tomography scans to demonstrate vitreomacular traction (VMT) and its resolution in our patient. A, Right eye (November 14, 2007) showing no VMT seen. B, Left eye (November 14, 2007) normal scan. C, Right eye (May 1, 2008) showing VMT. D, Right eye (May 29, 2008) showing right posterior vitreous detachment (PVD) and resolution of VMT with restoration of the foveal pit. E, left eye (May 29, 2008) suspected mild VMT with shallowing of foveal pit.
good at 6/6 right eye, 6/6 ⫺ 2 left eye. She was referred to a consultant neuro-ophthalmologist for a second opinion. She now described a spot (which was different in the two eyes) in the center of her vision when reading, suggesting macular etiology. It was more likely to occur in bright light and was induced on slit-lamp examination in the clinic. The results of the macular autofluorescence and optical coherence tomography (OCT) seemed normal (Figure 1). Eight months later, right visual acuity had dropped to 6/12 ⫹ 1 (6/6 left eye), and she was aware of a constant right central scotoma (Figure 2). Repeat OCT showed definitive right vitreomacular traction (Figure 1, showing OCT series). She was given an Amsler chart to monitor the progress. Just 4 weeks
later, right visual acuity had improved objectively and subjectively (6/6 ⫹ 2 right eye, 6/6 ⫺ 1 left eye). Optical coherence tomography showed right posterior vitreous detachment and mild left vitreomacular traction (Figure 1). Improvement continued such that by July 2008, visual acuity was 6/5 ⫺ 2 both eyes. She had a permanent “black squiggle” in her right vision but “had to look for it.” She also had a “jagged bit” that lasted 5 minutes in the center of her left vision after focusing for ⬃20 minutes. Optical coherence tomography showed sustained left vitreomacular traction, with the foveal pit slightly flattened (Figure 3).
Comment
Fig. 2. Patient’s drawing of visual symptoms.
Vitreomacular traction syndrome occurs as a result of incomplete separation of the posterior vitreous from the retina, with persistent macular adherence causing traction on the posterior retina. The near response is a synkinesis of accommodation, miosis, and convergence. Movement of the vitreous during the near response may cause fluctuating vitreomacular traction. There is considerable evidence supporting vitreous movement during accommodation, although its role (active or passive) remains controversial.
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Fig. 3. Later optical coherence tomography scans taken on July 14, 2008. A, Right eye shows posterior vitreous detachment (PVD) and no vitreomacular traction (VMT). B, Persistent left VMT.
Hensen and Voelckers (cited in Luedde1) cut a scleral window in the eyes of dogs to expose the ciliary muscle and then stimulated the ciliary nerves to demonstrate inward shrinking of the ciliary muscle and simultaneous outward bulging of the choroid. When they completely bisected the globe and excited the ciliary nerves, the vitreous nearest the lens bulged forward and peripheral vitreous sank inward. Koke2 reported a forward axial movement of the tertiary vitreous and changes in the posterior portion of the secondary vitreous in the living cat eye during accommodation after the injection of radio-opaque material and by using physostigmine to induce ciliary muscle contraction. Later, Suzuki3 reported movement of the vitreous against the back of the lens during accommodation in cats. The head-downward position compounds the issue: it allows greater lens (and consequently, vitreous) movement in accommodation compared with other head positions. When the eye is strongly accommodated, the lens moves in the direction of gravity. Hess4 reported that the lens moved forward an additional 0.15 mm on maximal accommodation when the head was facing down. This effect was later confirmed by Fincham5 (who measured a 0.2-mm shorter cornealens distance in head-down position in accommodated eyes compared with head-up position) and Gallagher6 (who measured far and near points in 12 eyes for head facing upward, straight ahead, and downward). Gallagher showed a significant effect of head position on amplitude of accommodation (mean head upward amplitude of accommodation ⫽ 5.6 D, straight ahead 6.1 D, downward 6.7 D). Increasing age potentiates the problem. According to the Hess-Gullstrand theory of presbyopia, the increasing size of the lens with age creates a hammock effect of the zonules, with increased zonular slackness on attempted accommodation.7 This allows the lens (and therefore the vitreous) to move more under the influence of gravity. Because the light reflex is intrinsically linked to the near reflex, with only ⬃5% of the postganglionic myelinated short ciliary nerves being pupillomotor and the remaining designated for the ciliary muscle, it
is entirely plausible that the association of our patient’s symptoms with bright light resulted from the reflex ciliary contraction coupled to the light reflex, with subsequent increased vitreous movement and traction. Increased lens movement caused by convergence was reported by Jampel and Mindel8 in 1967. They observed a striking forward movement of the lens in macaque monkeys on stimulation of extraocular muscle contraction during accommodation. We propose that increased vitreous movement caused by light-reflex-induced miosis and in the near response, particularly when associated with downward head position, caused increased vitreomacular traction, disturbance of photoreceptor orientation and stimulation, and consequently, the metamorphopsia described by our patient. Recent advances in OCT image quality with improved resolution have made established vitreomacular traction syndrome much easier to diagnose. In contrast, intermittent dynamic vitreomacular traction, by its very nature, may easily be missed on standard OCT unless it is suspected and specifically looked for. Furthermore, OCT lacks the resolution to detect subtle misalignments of the photoreceptor layer, making the diagnosis of early, periodic vitreomacular traction particularly challenging. The diagnosis should, however, be suspected in cases of fluctuating central visual disturbance, particularly when associated with accommodation and downward head posture. We would advocate, where possible, an OCT after induction of symptoms and ideally with the eye in accommodative and nonaccommodative states. This may enable earlier diagnosis and minimize overinvestigation and patient anxiety. Key words: accommodation, head posture, near response, vitreomacular traction syndrome.
References 1.
Luedde WH. Hensen and Voelckers’s experiments on the mechanism of accommodation: an interpretation. Trans Am Ophthalmol Soc 1927;25:250 –267.
4 2. 3. 4. 5. 6.
RETINAL CASES & BRIEF REPORTSℜ Koke MP. Mechanism of accommodation. Arch Ophthalmol 1942;27:950 –968. Suzuki H. Observations on the intraocular changes associated with accommodation. Jpn J Ophthalmol 1971;15:47–58. Hess C. Arbeiten aus dem gebiete der Akommodationsiehr. Graefes Arch Ophthalmol 1996/1897;47:43. Fincham EF. The mechanism of accommodation. Br J Ophthalmol Monograph Suppl 1937;8:5– 80. Gallagher JT. The effect of gravity direction change on am-
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8.
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plitude of accommodation [master’s thesis]. Indiana University; 1972. Gullstrand A. Appendix IV. The mechanism of accommodation. In: Southall JPC, ed. Helmholtz’s Treatise on Physiological Optics. Vol. 1. 3rd ed. Rochester, NY: Optical Society of America; 1924:382– 415. Jampel RS, Mindel J. The nucleus for accommodation in the midbrain of the macaque. Invest Ophthalmol Vis Sci 1967;6: 40 –50.
