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500
Letters to the Editor
Utility of ultrasound biomicroscopy in the diagnosis of topiramate-associated ciliochoroidal effusions causing bilateral acute angle closure Since the introduction of high-frequency ultrasound biomicroscopy (UBM) by Pavlin et al. in the early 1990s, we have improved the determination of mechanisms underlying angle closure.1 Uniquely, UBM enables highresolution visualization of the ciliary body2; it is invaluable in detecting tumours, cysts, oedema, and forward rotation of the ciliary body as a cause for anterior displacement of the iris root and secondary appositional angle closure.3 Perhaps related to the inconvenience of preparing a water bath, the time required for the examination, and the high dependence on operator skill for quality images and meaningful interpretation, it has been confined to research and large institutional settings.4 Our case report illustrates the utility of UBM to detect presumed topiramate-associated ciliochoroidal effusion (CCE) as the underlying cause for bilateral acute angle closure (AAC). A 40-year-old woman presented with a 24-h history of blurred distant vision bilaterally associated with mild headache. Ten days prior she had been started on topiramate 50 mg/day for alcohol dependence and mood stabilization. Clinical examination revealed unaided visual acuity of right count fingers and left 6/90, with intraocular pressures (IOP) of 30 mmHg in each eye. Both pupils were briskly reactive, with no evidence of iris bombè. Bilateral shallow anterior chambers with appositional angle closure were noted on the slit lamp and with gonioscopy. Optic discs were clinically physiological with vertical cup/disc ratios of right 0.5 and left 0.6. Bilateral AAC was diagnosed; when UBM confirmed bilateral CCE, this was regarded as the mechanism responsible for anterior chamber shallowing and the secondary angle closure (Fig. 1). Given the recent commencement of topiramate, it was presumed to be the inciting agent. Topiramate was discontinued and medical treatment was initiated with oral acetazolamide 250 mg four times a day (q.i.d.), and topical atropine 1% twice a day (b.d.), dexamethasone q.i.d., apraclonidine b.d., and timolol maleate 0.5 % b.d. Within 48 h, IOP normalized to right 10 mmHg and left 11 mmHg, the choroidal effusions resorbed and the angles opened to grade 4. A week later, UVA was right 6/6 and left 6/7.5, without evidence of optic disc damage. Acute onset of CCE resulting in AAC and high IOP are amongst serious potential ocular adverse effects of topiramate.5 Although the drug history and bilateral involvement suggested the AAC pathogenesis in our patient, UBM helpfully excluded plateau iris syndrome,3 Competing/conflicts of interest: No stated conflict of interest. Funding sources: No stated funding sources.
Figure 1. Ultrasound biomicroscopy of the patients right eye. A large ciliochoroidal effusion (∗) with secondary appositional angle closure and occlusion of the scleral spur (arrow) is demonstrated. The appearance of the left eye was similar. C, cornea; AC, anterior chamber; I, iris; PC, posterior chamber; CB, ciliary body; S, sclera.
iris cysts and ciliary body tumours. It confirmed our clinical diagnosis and facilitated a rational management approach. Compared with conventional B-scan ultrasound, UBM has greater sensitivity to detect subtle uveal effusion.5 Furthermore, UBM visualizes the anterior chamber structures, ciliary body and choroid, and demonstrates their anatomic relationships. This is useful to discriminate between the various possible pathophysiologic mechanisms underlying AAC in which history and clinical examination may be inconclusive.3 This particularly applies with corneal oedema, where anterior segment examination may be limited. In their series of 56 patients with topiramate-associated AAC, Fraunfelder et al. found that 21 (38%) underwent potentially unnecessary laser or surgical iridectomy.5 UBM helps to minimize confusion of this entity with AAC secondary to pupil block. Despite its inconvenience, UBM is a useful adjunct to the clinical examination. The drawbacks of cumbersome and time-consuming preparation of a scleral cup and water bath are being ameliorated with ‘acoustically invisible’ probe covers. As UBM becomes more convenient to perform and its value increasingly recognized, we anticipate it becoming a regular diagnostic tool for ophthalmologists.
Gustavo MSM Reis MBBS,1 Oliver CF Lau MBBS BE,1 Chameen Samarawickrama MBBS PhD,1,2 Peter Heydon BSc(Med) MBBS1 and Ivan Goldberg AM FRANZCO1,2 1 Glaucoma Unit, Sydney Eye Hospital and 2Discipline of Ophthalmology, The University of Sydney, Sydney, New South Wales, Australia Received 4 September 2013; accepted 11 September 2013.
© 2014 Royal Australian and New Zealand College of Ophthalmologists
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Letters to the Editor
REFERENCES 1. Pavlin CJ, Harasiewicz K, Sherar MD, Foster FS. Clinical use of ultrasound biomicroscopy. Ophthalmology 1991; 98: 287–95. 2. Pavlin CJ, Vasquez LM, Lee R, Simpson ER, Ahmed IIK. Anterior segment optical coherence tomography and ultrasound biomicroscopy in the imaging of anterior segment tumors. Am J Ophthalmol 2009; 147: 214–9. 3. See JLS. Imaging of the anterior segment in glaucoma. Clin Experiment Ophthalmol 2009; 37: 506–13. 4. Friedman DS, He M. Anterior chamber angle assessment techniques. Surv Ophthalmol 2008; 53: 250–73. 5. Fraunfelder FW, Fraunfelder FT, Keates EU. Topiramate-associated acute, bilateral, secondary angleclosure glaucoma. Ophthalmology 2004; 111: 109–11.
First report of femtosecond laser cataract surgery in a nanophthalmic eye Femtosecond laser cataract surgery (LCS) has established itself as a safe and effective option for routine cataract surgery.1,2 We explore an extension of this application, discussing benefits and limitations of the technique as experienced in the first reported case performed on a patient with nanophthalmos. A 57-year-old female with bilateral nuclear sclerosis presented for cataract surgery. A 40-year history of contact lens usage secondary to axial hypermetropia was elicited. Other than hypothyroidism, she had no systemic conditions of concern. Ocular history comprised right macular scarring, bilateral cataracts and nanophthalmos. Initial refraction in dioptres (D) was +11.75 D/+0.50 × 86 Oculus Dexter (OD), +10.25/+0.25 × 124 Oculus Sinister (OS). On examination best corrected visual acuity (BCVA) was 6/120 OD, 6/18 OS. She was listed for right LCS. Axial length (AL) was documented as 15.99 mm OD, 15.94 mm OS. Intraocular pressure was recorded at 11 and 12 mmHg with an anterior chamber depth of 2.47 mm OD, 2.60 OS. LCS (Alcon LenSx, Aliso Viejo, CA, USA) proceeded as has been previously described with placement of a +44.0-D single piece, monofocal, intraocular lens (Rayner 970C Aspheric, Rayner Intraocular Lenses Limited, Hove, East Sussex, UK).2 The wound was enlarged to accommodate the IOL, and for this reason, sutures were applied to ensure adequate wound apposition. No significant postoperative inflammation or intraocular pressure elevation was noted. Although the operation was uncomplicated, longstanding macular scarring prevented impressive improvement in visual
501 acuity. BCVA 1 month postoperatively was 2/60. She has elected not to proceed with surgery on the fellow eye as yet. Cataract surgery in small eyes is mechanically challenging. The confines of shallow anterior chambers reduce the ability to manoeuvre, thereby increasing the potential for inadvertent damage to collateral structures.3 In addition, IOL power calculations in very short eyes are difficult as disproportionately large refractive errors can result from small inaccuracies in AL measurement.4 In a recent series, AL was found to be inversely related to complication rates with AL less than 19.00 mm representing a 21 times greater risk of any complication (P ≤ 0.0005).3 Specific to LCS, these eyes represent a challenge in terms of access. The patient interfaces across units have been designed to suit the majority of eyes. However, forming a secure seal in highly hypermetropic eyes can be challenging and, in our experience, may necessitate speculum removal. Providing patient cooperation is adequate however, this is not likely to be an insurmountable obstacle. Across a broad spectrum of anatomy encountered in the initial 1500 patients treated through our centre, the recorded suction break rate was just 0.61%.2 There are several putative benefits LCS may offer in these cases. Femtosecond lasers offer higher levels of precision and reduced risk of collateral tissue damage when compared with highly evolved mechanical devices.5 In these eyes in particular, where limited corneal windows are less forgiving to the introduction of scar tissue, this must be perceived as a significant benefit. Furthermore, the significant difficulties of constructing a capsulorhexis in a restricted space are effectively eliminated if the capsulotomy can be formed by LCS. A recent study reported 100% success in the achievement of completed capsulotomies using LCS.1 The resultant reduction in intraocular manipulation ought to reduce the potential for injury to adjacent structures and should help maintain endothelial cell numbers. The reduced effective phacoemulsification power reported with LCS should add to this endothelial advantage.1 By reducing intraocular manipulation, automating capsulotomy construction and lens fragmentation, and reducing the effective phacoemulsification time, LCS is expected to provide a surgical advantage for cataract extraction in nanophthalmic eyes. Our case increases confidence in the potential represented. However, limitations of current patient interfaces and the necessity of patient compliance prevent the technology from being a viable option for all eyes. Additional reports are warranted, but we hope that our experience will stimulate further consideration of LCS as a possible means of reducing complications in these challenging cases.
Competing/conflicts of interest: No stated conflict of interest. Funding sources: No stated funding sources. © 2013 Royal Australian and New Zealand College of Ophthalmologists
Aifric Isabel Martin MRCOphth,1 Paul Hughes FRANZCO2 and Chris Hodge BAppSc(Orth)1 1 Vision Eye Institute, Chatswood, and 2Vision Eye Institute, Hurstville, New South Wales, Australia Received 24 September 2013; accepted 29 September 2013.
500
Letters to the Editor
Utility of ultrasound biomicroscopy in the diagnosis of topiramate-associated ciliochoroidal effusions causing bilateral acute angle closure Since the introduction of high-frequency ultrasound biomicroscopy (UBM) by Pavlin et al. in the early 1990s, we have improved the determination of mechanisms underlying angle closure.1 Uniquely, UBM enables highresolution visualization of the ciliary body2; it is invaluable in detecting tumours, cysts, oedema, and forward rotation of the ciliary body as a cause for anterior displacement of the iris root and secondary appositional angle closure.3 Perhaps related to the inconvenience of preparing a water bath, the time required for the examination, and the high dependence on operator skill for quality images and meaningful interpretation, it has been confined to research and large institutional settings.4 Our case report illustrates the utility of UBM to detect presumed topiramate-associated ciliochoroidal effusion (CCE) as the underlying cause for bilateral acute angle closure (AAC). A 40-year-old woman presented with a 24-h history of blurred distant vision bilaterally associated with mild headache. Ten days prior she had been started on topiramate 50 mg/day for alcohol dependence and mood stabilization. Clinical examination revealed unaided visual acuity of right count fingers and left 6/90, with intraocular pressures (IOP) of 30 mmHg in each eye. Both pupils were briskly reactive, with no evidence of iris bombè. Bilateral shallow anterior chambers with appositional angle closure were noted on the slit lamp and with gonioscopy. Optic discs were clinically physiological with vertical cup/disc ratios of right 0.5 and left 0.6. Bilateral AAC was diagnosed; when UBM confirmed bilateral CCE, this was regarded as the mechanism responsible for anterior chamber shallowing and the secondary angle closure (Fig. 1). Given the recent commencement of topiramate, it was presumed to be the inciting agent. Topiramate was discontinued and medical treatment was initiated with oral acetazolamide 250 mg four times a day (q.i.d.), and topical atropine 1% twice a day (b.d.), dexamethasone q.i.d., apraclonidine b.d., and timolol maleate 0.5 % b.d. Within 48 h, IOP normalized to right 10 mmHg and left 11 mmHg, the choroidal effusions resorbed and the angles opened to grade 4. A week later, UVA was right 6/6 and left 6/7.5, without evidence of optic disc damage. Acute onset of CCE resulting in AAC and high IOP are amongst serious potential ocular adverse effects of topiramate.5 Although the drug history and bilateral involvement suggested the AAC pathogenesis in our patient, UBM helpfully excluded plateau iris syndrome,3 Competing/conflicts of interest: No stated conflict of interest. Funding sources: No stated funding sources.
Figure 1. Ultrasound biomicroscopy of the patients right eye. A large ciliochoroidal effusion (∗) with secondary appositional angle closure and occlusion of the scleral spur (arrow) is demonstrated. The appearance of the left eye was similar. C, cornea; AC, anterior chamber; I, iris; PC, posterior chamber; CB, ciliary body; S, sclera.
iris cysts and ciliary body tumours. It confirmed our clinical diagnosis and facilitated a rational management approach. Compared with conventional B-scan ultrasound, UBM has greater sensitivity to detect subtle uveal effusion.5 Furthermore, UBM visualizes the anterior chamber structures, ciliary body and choroid, and demonstrates their anatomic relationships. This is useful to discriminate between the various possible pathophysiologic mechanisms underlying AAC in which history and clinical examination may be inconclusive.3 This particularly applies with corneal oedema, where anterior segment examination may be limited. In their series of 56 patients with topiramate-associated AAC, Fraunfelder et al. found that 21 (38%) underwent potentially unnecessary laser or surgical iridectomy.5 UBM helps to minimize confusion of this entity with AAC secondary to pupil block. Despite its inconvenience, UBM is a useful adjunct to the clinical examination. The drawbacks of cumbersome and time-consuming preparation of a scleral cup and water bath are being ameliorated with ‘acoustically invisible’ probe covers. As UBM becomes more convenient to perform and its value increasingly recognized, we anticipate it becoming a regular diagnostic tool for ophthalmologists.
Gustavo MSM Reis MBBS,1 Oliver CF Lau MBBS BE,1 Chameen Samarawickrama MBBS PhD,1,2 Peter Heydon BSc(Med) MBBS1 and Ivan Goldberg AM FRANZCO1,2 1 Glaucoma Unit, Sydney Eye Hospital and 2Discipline of Ophthalmology, The University of Sydney, Sydney, New South Wales, Australia Received 4 September 2013; accepted 11 September 2013.
© 2014 Royal Australian and New Zealand College of Ophthalmologists
bs_bs_banner
Letters to the Editor
REFERENCES 1. Pavlin CJ, Harasiewicz K, Sherar MD, Foster FS. Clinical use of ultrasound biomicroscopy. Ophthalmology 1991; 98: 287–95. 2. Pavlin CJ, Vasquez LM, Lee R, Simpson ER, Ahmed IIK. Anterior segment optical coherence tomography and ultrasound biomicroscopy in the imaging of anterior segment tumors. Am J Ophthalmol 2009; 147: 214–9. 3. See JLS. Imaging of the anterior segment in glaucoma. Clin Experiment Ophthalmol 2009; 37: 506–13. 4. Friedman DS, He M. Anterior chamber angle assessment techniques. Surv Ophthalmol 2008; 53: 250–73. 5. Fraunfelder FW, Fraunfelder FT, Keates EU. Topiramate-associated acute, bilateral, secondary angleclosure glaucoma. Ophthalmology 2004; 111: 109–11.
First report of femtosecond laser cataract surgery in a nanophthalmic eye Femtosecond laser cataract surgery (LCS) has established itself as a safe and effective option for routine cataract surgery.1,2 We explore an extension of this application, discussing benefits and limitations of the technique as experienced in the first reported case performed on a patient with nanophthalmos. A 57-year-old female with bilateral nuclear sclerosis presented for cataract surgery. A 40-year history of contact lens usage secondary to axial hypermetropia was elicited. Other than hypothyroidism, she had no systemic conditions of concern. Ocular history comprised right macular scarring, bilateral cataracts and nanophthalmos. Initial refraction in dioptres (D) was +11.75 D/+0.50 × 86 Oculus Dexter (OD), +10.25/+0.25 × 124 Oculus Sinister (OS). On examination best corrected visual acuity (BCVA) was 6/120 OD, 6/18 OS. She was listed for right LCS. Axial length (AL) was documented as 15.99 mm OD, 15.94 mm OS. Intraocular pressure was recorded at 11 and 12 mmHg with an anterior chamber depth of 2.47 mm OD, 2.60 OS. LCS (Alcon LenSx, Aliso Viejo, CA, USA) proceeded as has been previously described with placement of a +44.0-D single piece, monofocal, intraocular lens (Rayner 970C Aspheric, Rayner Intraocular Lenses Limited, Hove, East Sussex, UK).2 The wound was enlarged to accommodate the IOL, and for this reason, sutures were applied to ensure adequate wound apposition. No significant postoperative inflammation or intraocular pressure elevation was noted. Although the operation was uncomplicated, longstanding macular scarring prevented impressive improvement in visual
501 acuity. BCVA 1 month postoperatively was 2/60. She has elected not to proceed with surgery on the fellow eye as yet. Cataract surgery in small eyes is mechanically challenging. The confines of shallow anterior chambers reduce the ability to manoeuvre, thereby increasing the potential for inadvertent damage to collateral structures.3 In addition, IOL power calculations in very short eyes are difficult as disproportionately large refractive errors can result from small inaccuracies in AL measurement.4 In a recent series, AL was found to be inversely related to complication rates with AL less than 19.00 mm representing a 21 times greater risk of any complication (P ≤ 0.0005).3 Specific to LCS, these eyes represent a challenge in terms of access. The patient interfaces across units have been designed to suit the majority of eyes. However, forming a secure seal in highly hypermetropic eyes can be challenging and, in our experience, may necessitate speculum removal. Providing patient cooperation is adequate however, this is not likely to be an insurmountable obstacle. Across a broad spectrum of anatomy encountered in the initial 1500 patients treated through our centre, the recorded suction break rate was just 0.61%.2 There are several putative benefits LCS may offer in these cases. Femtosecond lasers offer higher levels of precision and reduced risk of collateral tissue damage when compared with highly evolved mechanical devices.5 In these eyes in particular, where limited corneal windows are less forgiving to the introduction of scar tissue, this must be perceived as a significant benefit. Furthermore, the significant difficulties of constructing a capsulorhexis in a restricted space are effectively eliminated if the capsulotomy can be formed by LCS. A recent study reported 100% success in the achievement of completed capsulotomies using LCS.1 The resultant reduction in intraocular manipulation ought to reduce the potential for injury to adjacent structures and should help maintain endothelial cell numbers. The reduced effective phacoemulsification power reported with LCS should add to this endothelial advantage.1 By reducing intraocular manipulation, automating capsulotomy construction and lens fragmentation, and reducing the effective phacoemulsification time, LCS is expected to provide a surgical advantage for cataract extraction in nanophthalmic eyes. Our case increases confidence in the potential represented. However, limitations of current patient interfaces and the necessity of patient compliance prevent the technology from being a viable option for all eyes. Additional reports are warranted, but we hope that our experience will stimulate further consideration of LCS as a possible means of reducing complications in these challenging cases.
Competing/conflicts of interest: No stated conflict of interest. Funding sources: No stated funding sources. © 2013 Royal Australian and New Zealand College of Ophthalmologists
Aifric Isabel Martin MRCOphth,1 Paul Hughes FRANZCO2 and Chris Hodge BAppSc(Orth)1 1 Vision Eye Institute, Chatswood, and 2Vision Eye Institute, Hurstville, New South Wales, Australia Received 24 September 2013; accepted 29 September 2013.
