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490
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Figure 2. Intraocular pressure (IOP) values along the time before and after transcorneal oxygen therapy (TOT) corresponding to case one and case two. Twelve hours after admission of both patients, the treatment was applied, and a significant reduction of IOP was observed. IOP dropped from 38 mmHg to 24 mmHg after the first session of TOT in both cases. Case one and case two received four (at 12 h, 16 h, 20 h and 24 h) and three (at 12 h, 16 h and 20 h) sessions of TOT, respectively.
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hyphema should be recommended if IOP register is higher than 24 mmHg over 24-h period despite maximum therapy or if IOP increases repeatedly above 30 mm Hg.1 In the present report, TOT was the best treatment option to control raised IOP associated with hyphema. This procedure is cheap, easy, non-invasive, effective and also well tolerated. The recommended dose of oxygen, the number of sessions and duration of TOT should be evaluated in larger studies. We suggest applying TOT in patients with suspect or confirmed sickle trait with raised IOP which not respond to medical treatment.
Noel Padrón-Pérez MD FEBO,1 Marta Castany-Aregall MD,1,2 Alfredo Pueyo MD1 and Amadeu Carceller MD3 1 Department of Ophthalmology, Vall d’Hebron University Hospital, 2Department of Surgery, Faculty of Medicine, Autonomous University of Barcelona, and 3Department of Ophthalmology, IMO Barcelona, Barcelona, Spain Received 13 December 2014; accepted 19 December 2014.
REFERENCES 1. Walton W, Von Hagen S, Grigorian R, Zarbin M. Management of traumatic hyphema. Surv Ophthalmol 2002; 47: 297–334. 2. Goldberg MF, Tso MO. Sickled erythrocytes, hyphema, and secondary glaucoma: VII. The passage of sickled erythrocytes out of the anterior chamber of the human
and monkey eye: light and electron microscopic studies. Ophthalmic Surg 1979; 10: 89–123. 3. Jampol LM, Orlin C, Cohen SB, Zanetti C, Lehman E, Goldberg MF. Hyperbaric and transcorneal delivery of oxygen to the rabbit and monkey anterior segment. Arch Ophthalmol 1988; 106: 825–9. 4. Sharifipour F, Idani E, Zamani M, Helmi T, Cheraghian B. Oxygen tension in the aqueous humor of human eyes under different oxygenation conditions. J Ophthalmic Vis Res 2013; 8: 119–25. 5. Benner JD. Transcorneal oxygen therapy for glaucoma associated with sickle cell hyphema. Am J Ophthalmol 2000; 130: 514–5.
Necrotizing dacryometaplasia: a rare lacrimal lesion mimicking malignancy A 71-year-old woman presented with a two-week history of painless, left upper eyelid swelling. There was no history of trauma, radiation or surgery in the region. Eye examination demonstrated equal vision of 20/20, no proptosis and full range of extraocular movements. There was a palpable, non-tender firm mass at the left superotemporal orbit with no associated lymphadenopathy. Computerized Conflict of interest: No stated conflict of interest. Funding sources: No stated funding sources.
© 2014 Royal Australian and New Zealand College of Ophthalmologists
Letters to the Editor
491
tomography (CT) scan of the orbits confirmed left lacrimal gland enlargement. The gland was of heterogeneous density and showed heterogeneous contrast enhancement with nodular hypo-enhancing areas. There was no bone erosion or destruction (Fig. 1). An anterior orbitotomy and biopsy of the left lacrimal gland confirmed a well-encapsulated firm gland. Histopathology demonstrated extensive interstitial sclerosis with almost complete loss of acini and large areas of coagulative necrosis. The necrotic areas were partially surrounded by palisading histiocytes and occasional multi-nucleated histiocytes. There was a generalized, patchy dense lymphoid cell infiltrate. Special stains for acid fast bacilli and fungi were negative. There were no features of atypia. Squamous metaplasia of residual lacrimal gland cells was not seen, and the histological features were consistent with necrotizing dacryometaplasia. Sarcoidosis and vasculitis were excluded based on biopsy appearance and a normal ACE, ENA, ANA and ANCA. The patient was commenced on oral steroids for two weeks post–surgery, and her symptoms resolved. At 12 months post-surgery, she remains symptom free with no evidence of disease recurrence (Fig. 2). Necrotizing dacryometaplasia appears analogous to necrotizing sialometaplasia (NS), an inflammatory condition which affects the minor salivary glands and other sites with salivary tissue, and was first described in 1973.1 Its lacrimal gland analogue appears to be a very rare con-
Figure 1. Computerized tomography orbits. Heterogeneous density lacrimal gland enlargement is much greater on the left side.
Figure 2. Low (a) and medium (b) power views, respectively, of an area of coagulative necrosis with adjacent lacrimal gland excretory duct remnants, without residual acini.
dition, first reported in 2007.2 This is only the second reported case in the literature. As such, there is no certainty that NS and dacryometaplasia are one and the same entity. There is a large body of evidence describing what happens to salivary gland cases, which may not be the same outcome in the lacrimal gland. Therefore the following discussion must by necessity be an extrapolation from salivary gland data. Pathophysiology of NS appears related to traumatic ischaemia.1,3,4 Risk factors include local anaesthetic administration, radiation and recent surgery in the area of the lesion.3,4 Tsuji et al. recently suggested that typical features of NS on magnetic resonance imaging might assist diagnosis and that gallium scintigraphy indicated an inflammatory rather than malignant process.4 The prognosis of NS of the salivary glands is excellent with most cases showing spontaneous healing within two to three months.3,4 Recurrence is unusual.3 Necrotizing dacryometaplasia may, like NS, mimic malignancy both clinically and histologically. The clinical differential diagnosis of a lacrimal gland mass includes non-epithelial and epithelial lesions.5 Non-epithelial lesions include inflammatory and lymphoproliferative lesions. Epithelial lesions may be benign or malignant.5 Lymphoproliferative and malignant lesions become more common in patients with lacrimal gland swelling in an older age group, similar to our patient.4 The preoperative presumed differential diagnosis of this case included benign and malignant neoplasia and nonneoplastic entities such as inflammatory pseudotumour, subacute necrotizing dacryoadenitis and radiation injury.1 Our patient did not have a history of local anaesthetic administration, radiation or recent surgery in the area of the lesion. Blood tests excluded sarcoidosis and vasculitis. Histological criteria previously used to distinguish NS from a malignant lesion include squamous metaplastic tissue conforming to the outline of salivary ducts without any atypia but with presence of necrotic tissue.4 While the current case lacked the presence of the squamous metaplasia characteristically seen in NS,4 in other respects the findings were analogous to that entity. At the 1-year review following biopsy, there was no evidence of disease. Necrotizing dacryometaplasia is a newly recognized/ reported entity. Further cases are needed to confirm the typical clinical, imaging and histological features as well as prognosis over the long term.
(a)
© 2014 Royal Australian and New Zealand College of Ophthalmologists
(b)
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492
Letters to the Editor
Brent Skippen MBBS MPH,1 Andrew Gal FRCPA2 and Krishna Tumuluri FRANZCO3 1 Ophthalmology, University Hospital of Wales, Cardiff, UK; and 2Laverty Pathology, North Ryde, and 3Ophthalmology, Westmead and Liverpool Hospitals, Sydney, New South Wales, Australia Received 16 December 2014; accepted 19 December 2014.
REFERENCES 1. Abrams AM, Melrose RJ, Howell FV. Necrotizing sialometaplasia. A disease simulating malignancy. Cancer 1973; 32: 130–5. 2. Fernando BS, Thaung C, Ataullah S, Chakravarthi R, Bonshek R, Sloan P. Necrotizing metaplasia of lacrimal gland/necrotizing dacryometaplasia. Histopathology 2007; 51: 578–80. 3. Brannon RB, Fowler CB, Hartman KS. Necrotizing sialometaplasia. A clinicopathologic study of sixty-nine cases and review of the literature. Oral Surg Oral Med Oral Pathol 1991; 72: 317–25. 4. Tsuji T, Nishide Y, Hakano H, Kida K, Satoh K. Imaging findings of necrotizing sialometaplasia of the parotid gland: case report and literature review. Dentomaxillofac Radiol 2014; 43: 20140127. 5. Shields CL, Shields JA, Eagle RC, Rathmell JP. Clinicopathologic review of 142 cases of lacrimal gland lesions. Ophthalmology 1989; 96: 431–5.
Looking deeper than (just) below the surface The editorial by Sutton and Lawless is to us – as workers in a different subspecialty – a welcome refresher from the jargon at the cutting edge of laser refractive surgery.1 We share their concerns about premature adoption of trends based on theoretical concepts, and would like to comment on some of their statistical recommendations. We agree that methodology and reporting are paramount, but ‘P’ values, significant or otherwise, do not just blur the line between statistical and clinical significance; they simply cannot assess clinical significance. Furthermore, as a ‘P’ value is based on the assumption that the null hypothesis is true, it cannot be used as evidence against it.2 These and other well-known deficiencies of this dominant conventional statistical method have been elegantly detailed elsewhere, and include an erudite editorial in this journal.2,3 While we agree, furthermore, that inclusion of effect sizes are important and that confidence intervals (CI) provide more information than the ‘P’ value, CIs are based on the same concepts as the P value and – as the relevant editorial mentions – like that ‘pesty’ (or ‘pesky’, our own idiosyncratic preference) measure have no inferential
Competing/conflicts of interest: No stated conflict of interest. Funding sources: No stated funding sources.
meaning.3 Moreover, while the point estimate is more ‘likely’ than the other values in the interval, the CIs do not convey any distributional information either. There is no information on the probability or ‘believability’ of the values in the interval.4 Meta-analyses provide some advantages and may increase the sample size and power as Sutton and Lawless note, but when analysed in a conventional manner, they still use the same faulty ‘P’ value and CIs. Standard metaanalyses combine evidence, but do not have a measure of evidence that can be directly combined.5 The combined ‘P’ value is based on the average effect of the combined studies and the pooled standard error. This ‘P’ value for the average is quite different from the ‘P’ value of the individual studies and does not reveal support that individual studies may actually provide for a different but common hypothesis.5 A Bayesian approach – on the other hand – uses sound measures of evidence that permit sensible compilation of evidence. Such an approach provides the direct probability of outcomes that are considered to be of clinical interest as well as a range of parameter values (credible intervals) that have a direct probability interpretation, something which CIs are frequently (and wrongly) considered to offer.4 Is it not time to discard the traditional yet obviously deficient ‘P’ values and CIs for the philosophically and inferentially sound alternative? Meta-analyses do ‘avoid the narrative of the literature review’; however, they still require a qualitative narrative for explanations of similarities and differences found among studies and this is beyond the realm of ordinary statistics.6 Statistics are important, but whether in analysis of basic data, or as part of meta-analysis, ‘statistics serve as fallible pattern recognition devices; explanation of the origin of the observed patterns is beyond the scope of these devices’.6
Ravi Thomas MD FRANZCO,1 Kerrie Mengersen PhD,2 Aleysha Thomas BSc2 and Mark J Walland FRANZCO3 1 Queensland Eye Institute & School of Medicine, University of Queensland and 2School of Mathematical Sciences, Queensland University of Technology, Brisbane, Queensland, and 3Glaucoma Investigation and Research Unit, Royal Victorian Eye and Ear Hospital, Melbourne, Victoria, Australia
REFERENCES 1. Sutton G, Lawless M. ‘Looking beneath the surface’. Clin Experiment Ophthalmol 2014; 42: 309–10. 2. Goodman SN. Toward evidence-based medical statistics. 1: the P value fallacy. Ann Intern Med 1999; 130: 995– 1004. 3. Casson RJ. The pesty P value. Clin Experiment Ophthalmol 2011; 39: 849–50. 4. Kruschke JK. Doing Bayesian Analysis. Oxford: Elsevier, 2011.
© 2014 Royal Australian and New Zealand College of Ophthalmologists
490
Letters to the Editor
60
IOP-case 1
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Figure 2. Intraocular pressure (IOP) values along the time before and after transcorneal oxygen therapy (TOT) corresponding to case one and case two. Twelve hours after admission of both patients, the treatment was applied, and a significant reduction of IOP was observed. IOP dropped from 38 mmHg to 24 mmHg after the first session of TOT in both cases. Case one and case two received four (at 12 h, 16 h, 20 h and 24 h) and three (at 12 h, 16 h and 20 h) sessions of TOT, respectively.
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hyphema should be recommended if IOP register is higher than 24 mmHg over 24-h period despite maximum therapy or if IOP increases repeatedly above 30 mm Hg.1 In the present report, TOT was the best treatment option to control raised IOP associated with hyphema. This procedure is cheap, easy, non-invasive, effective and also well tolerated. The recommended dose of oxygen, the number of sessions and duration of TOT should be evaluated in larger studies. We suggest applying TOT in patients with suspect or confirmed sickle trait with raised IOP which not respond to medical treatment.
Noel Padrón-Pérez MD FEBO,1 Marta Castany-Aregall MD,1,2 Alfredo Pueyo MD1 and Amadeu Carceller MD3 1 Department of Ophthalmology, Vall d’Hebron University Hospital, 2Department of Surgery, Faculty of Medicine, Autonomous University of Barcelona, and 3Department of Ophthalmology, IMO Barcelona, Barcelona, Spain Received 13 December 2014; accepted 19 December 2014.
REFERENCES 1. Walton W, Von Hagen S, Grigorian R, Zarbin M. Management of traumatic hyphema. Surv Ophthalmol 2002; 47: 297–334. 2. Goldberg MF, Tso MO. Sickled erythrocytes, hyphema, and secondary glaucoma: VII. The passage of sickled erythrocytes out of the anterior chamber of the human
and monkey eye: light and electron microscopic studies. Ophthalmic Surg 1979; 10: 89–123. 3. Jampol LM, Orlin C, Cohen SB, Zanetti C, Lehman E, Goldberg MF. Hyperbaric and transcorneal delivery of oxygen to the rabbit and monkey anterior segment. Arch Ophthalmol 1988; 106: 825–9. 4. Sharifipour F, Idani E, Zamani M, Helmi T, Cheraghian B. Oxygen tension in the aqueous humor of human eyes under different oxygenation conditions. J Ophthalmic Vis Res 2013; 8: 119–25. 5. Benner JD. Transcorneal oxygen therapy for glaucoma associated with sickle cell hyphema. Am J Ophthalmol 2000; 130: 514–5.
Necrotizing dacryometaplasia: a rare lacrimal lesion mimicking malignancy A 71-year-old woman presented with a two-week history of painless, left upper eyelid swelling. There was no history of trauma, radiation or surgery in the region. Eye examination demonstrated equal vision of 20/20, no proptosis and full range of extraocular movements. There was a palpable, non-tender firm mass at the left superotemporal orbit with no associated lymphadenopathy. Computerized Conflict of interest: No stated conflict of interest. Funding sources: No stated funding sources.
© 2014 Royal Australian and New Zealand College of Ophthalmologists
Letters to the Editor
491
tomography (CT) scan of the orbits confirmed left lacrimal gland enlargement. The gland was of heterogeneous density and showed heterogeneous contrast enhancement with nodular hypo-enhancing areas. There was no bone erosion or destruction (Fig. 1). An anterior orbitotomy and biopsy of the left lacrimal gland confirmed a well-encapsulated firm gland. Histopathology demonstrated extensive interstitial sclerosis with almost complete loss of acini and large areas of coagulative necrosis. The necrotic areas were partially surrounded by palisading histiocytes and occasional multi-nucleated histiocytes. There was a generalized, patchy dense lymphoid cell infiltrate. Special stains for acid fast bacilli and fungi were negative. There were no features of atypia. Squamous metaplasia of residual lacrimal gland cells was not seen, and the histological features were consistent with necrotizing dacryometaplasia. Sarcoidosis and vasculitis were excluded based on biopsy appearance and a normal ACE, ENA, ANA and ANCA. The patient was commenced on oral steroids for two weeks post–surgery, and her symptoms resolved. At 12 months post-surgery, she remains symptom free with no evidence of disease recurrence (Fig. 2). Necrotizing dacryometaplasia appears analogous to necrotizing sialometaplasia (NS), an inflammatory condition which affects the minor salivary glands and other sites with salivary tissue, and was first described in 1973.1 Its lacrimal gland analogue appears to be a very rare con-
Figure 1. Computerized tomography orbits. Heterogeneous density lacrimal gland enlargement is much greater on the left side.
Figure 2. Low (a) and medium (b) power views, respectively, of an area of coagulative necrosis with adjacent lacrimal gland excretory duct remnants, without residual acini.
dition, first reported in 2007.2 This is only the second reported case in the literature. As such, there is no certainty that NS and dacryometaplasia are one and the same entity. There is a large body of evidence describing what happens to salivary gland cases, which may not be the same outcome in the lacrimal gland. Therefore the following discussion must by necessity be an extrapolation from salivary gland data. Pathophysiology of NS appears related to traumatic ischaemia.1,3,4 Risk factors include local anaesthetic administration, radiation and recent surgery in the area of the lesion.3,4 Tsuji et al. recently suggested that typical features of NS on magnetic resonance imaging might assist diagnosis and that gallium scintigraphy indicated an inflammatory rather than malignant process.4 The prognosis of NS of the salivary glands is excellent with most cases showing spontaneous healing within two to three months.3,4 Recurrence is unusual.3 Necrotizing dacryometaplasia may, like NS, mimic malignancy both clinically and histologically. The clinical differential diagnosis of a lacrimal gland mass includes non-epithelial and epithelial lesions.5 Non-epithelial lesions include inflammatory and lymphoproliferative lesions. Epithelial lesions may be benign or malignant.5 Lymphoproliferative and malignant lesions become more common in patients with lacrimal gland swelling in an older age group, similar to our patient.4 The preoperative presumed differential diagnosis of this case included benign and malignant neoplasia and nonneoplastic entities such as inflammatory pseudotumour, subacute necrotizing dacryoadenitis and radiation injury.1 Our patient did not have a history of local anaesthetic administration, radiation or recent surgery in the area of the lesion. Blood tests excluded sarcoidosis and vasculitis. Histological criteria previously used to distinguish NS from a malignant lesion include squamous metaplastic tissue conforming to the outline of salivary ducts without any atypia but with presence of necrotic tissue.4 While the current case lacked the presence of the squamous metaplasia characteristically seen in NS,4 in other respects the findings were analogous to that entity. At the 1-year review following biopsy, there was no evidence of disease. Necrotizing dacryometaplasia is a newly recognized/ reported entity. Further cases are needed to confirm the typical clinical, imaging and histological features as well as prognosis over the long term.
(a)
© 2014 Royal Australian and New Zealand College of Ophthalmologists
(b)
bs_bs_banner
492
Letters to the Editor
Brent Skippen MBBS MPH,1 Andrew Gal FRCPA2 and Krishna Tumuluri FRANZCO3 1 Ophthalmology, University Hospital of Wales, Cardiff, UK; and 2Laverty Pathology, North Ryde, and 3Ophthalmology, Westmead and Liverpool Hospitals, Sydney, New South Wales, Australia Received 16 December 2014; accepted 19 December 2014.
REFERENCES 1. Abrams AM, Melrose RJ, Howell FV. Necrotizing sialometaplasia. A disease simulating malignancy. Cancer 1973; 32: 130–5. 2. Fernando BS, Thaung C, Ataullah S, Chakravarthi R, Bonshek R, Sloan P. Necrotizing metaplasia of lacrimal gland/necrotizing dacryometaplasia. Histopathology 2007; 51: 578–80. 3. Brannon RB, Fowler CB, Hartman KS. Necrotizing sialometaplasia. A clinicopathologic study of sixty-nine cases and review of the literature. Oral Surg Oral Med Oral Pathol 1991; 72: 317–25. 4. Tsuji T, Nishide Y, Hakano H, Kida K, Satoh K. Imaging findings of necrotizing sialometaplasia of the parotid gland: case report and literature review. Dentomaxillofac Radiol 2014; 43: 20140127. 5. Shields CL, Shields JA, Eagle RC, Rathmell JP. Clinicopathologic review of 142 cases of lacrimal gland lesions. Ophthalmology 1989; 96: 431–5.
Looking deeper than (just) below the surface The editorial by Sutton and Lawless is to us – as workers in a different subspecialty – a welcome refresher from the jargon at the cutting edge of laser refractive surgery.1 We share their concerns about premature adoption of trends based on theoretical concepts, and would like to comment on some of their statistical recommendations. We agree that methodology and reporting are paramount, but ‘P’ values, significant or otherwise, do not just blur the line between statistical and clinical significance; they simply cannot assess clinical significance. Furthermore, as a ‘P’ value is based on the assumption that the null hypothesis is true, it cannot be used as evidence against it.2 These and other well-known deficiencies of this dominant conventional statistical method have been elegantly detailed elsewhere, and include an erudite editorial in this journal.2,3 While we agree, furthermore, that inclusion of effect sizes are important and that confidence intervals (CI) provide more information than the ‘P’ value, CIs are based on the same concepts as the P value and – as the relevant editorial mentions – like that ‘pesty’ (or ‘pesky’, our own idiosyncratic preference) measure have no inferential
Competing/conflicts of interest: No stated conflict of interest. Funding sources: No stated funding sources.
meaning.3 Moreover, while the point estimate is more ‘likely’ than the other values in the interval, the CIs do not convey any distributional information either. There is no information on the probability or ‘believability’ of the values in the interval.4 Meta-analyses provide some advantages and may increase the sample size and power as Sutton and Lawless note, but when analysed in a conventional manner, they still use the same faulty ‘P’ value and CIs. Standard metaanalyses combine evidence, but do not have a measure of evidence that can be directly combined.5 The combined ‘P’ value is based on the average effect of the combined studies and the pooled standard error. This ‘P’ value for the average is quite different from the ‘P’ value of the individual studies and does not reveal support that individual studies may actually provide for a different but common hypothesis.5 A Bayesian approach – on the other hand – uses sound measures of evidence that permit sensible compilation of evidence. Such an approach provides the direct probability of outcomes that are considered to be of clinical interest as well as a range of parameter values (credible intervals) that have a direct probability interpretation, something which CIs are frequently (and wrongly) considered to offer.4 Is it not time to discard the traditional yet obviously deficient ‘P’ values and CIs for the philosophically and inferentially sound alternative? Meta-analyses do ‘avoid the narrative of the literature review’; however, they still require a qualitative narrative for explanations of similarities and differences found among studies and this is beyond the realm of ordinary statistics.6 Statistics are important, but whether in analysis of basic data, or as part of meta-analysis, ‘statistics serve as fallible pattern recognition devices; explanation of the origin of the observed patterns is beyond the scope of these devices’.6
Ravi Thomas MD FRANZCO,1 Kerrie Mengersen PhD,2 Aleysha Thomas BSc2 and Mark J Walland FRANZCO3 1 Queensland Eye Institute & School of Medicine, University of Queensland and 2School of Mathematical Sciences, Queensland University of Technology, Brisbane, Queensland, and 3Glaucoma Investigation and Research Unit, Royal Victorian Eye and Ear Hospital, Melbourne, Victoria, Australia
REFERENCES 1. Sutton G, Lawless M. ‘Looking beneath the surface’. Clin Experiment Ophthalmol 2014; 42: 309–10. 2. Goodman SN. Toward evidence-based medical statistics. 1: the P value fallacy. Ann Intern Med 1999; 130: 995– 1004. 3. Casson RJ. The pesty P value. Clin Experiment Ophthalmol 2011; 39: 849–50. 4. Kruschke JK. Doing Bayesian Analysis. Oxford: Elsevier, 2011.
© 2014 Royal Australian and New Zealand College of Ophthalmologists
