- Email: [email protected]
The Relationship Between Anterior Chamber Depth and the Presence of Diabetes in the Tanjong Pagar Survey
4. Nieuwenhuys R, Voogd J, Huijzen C. The human central nervous system: a synopsis and atlas. Berlin, Heidelberg, Germany: Springer-Verlag, 1988:119 –132. 5. Saver JL, Kidwell C. Neuroimaging in TIAs. Neurology 2004;62:S22–S25.
The Relationship Between Anterior Chamber Depth and the Presence of Diabetes in the Tanjong Pagar Survey Seang-Mei Saw, Tien Y. Wong, Steven Ting, Athena W. P. Foong, and Paul J. Foster PURPOSE: To examine the relationships of diabetes with anterior chamber depth, axial length, and refraction. DESIGN: Population-based cross-sectional study. METHODS: This analysis included 943 Singapore Chinese subjects ages 40 to 81 years from the Tanjong Pagar Survey. Diabetes was determined by self-report. A-mode ultrasound was used to measure axial dimensions. Refraction was performed with an autorefractor and refined subjectively. RESULTS: There were 140 (11.4%) participants with diabetes. After controlling for age and gender, participants with diabetes had shallower anterior chambers (2.78 vs 2.91 mm, P ⴝ .004) and thicker lenses (4.88 vs 4.75 mm, P ⴝ .003), but similar spherical equivalent refraction (– 0.38 vs – 0.47 diopters [D], P ⴝ .73), axial length (23.09 vs 23.19 mm, P ⴝ .40), and vitreous chamber depth (15.52 vs 15.59 mm, P ⴝ .53). CONCLUSIONS: In the Singapore Chinese population, persons with diabetes have shallower anterior chambers and thicker lenses than those without diabetes. Diabetes may be a risk factor for angle closure glaucoma (ACG). (Am J Ophthalmol 2007;144:325–326. © 2007 by Elsevier Inc. All rights reserved.)
I
T HAS LONG BEEN SUGGESTED THAT DIABETES IS A RISK
factor for the development of glaucoma.1 Most previous studies, however, have been conducted in Caucasian populations, and have focused on the association of diabetes with open angle glaucoma.2,3 Whether diabetes is also a risk factor for angle closure glaucoma (ACG) is less clear, and has not been thoroughly investigated.1 Furthermore, previous studies suggest that diabetes is associated Accepted for publication Mar 23, 2007. From the Department of Ophthalmology (S.-M.S., T.Y.W., S.T., A.W.P.F.); and Department of Community, Occupational and Family Medicine (S.-M.S.), Yong Loo Lin School of Medicine, National University of Singapore, Singapore; and Singapore Eye Research Institute, Singapore (S.-M.S., T.Y.W.). Centre for Eye Research Australia, University of Melbourne, Australia (T.Y.W.); and Institute of Ophthalmology, University College London, London, United Kingdom (P.J.F.). Inquiries to Seang-Mei Saw, Department of Community, Occupational and Family Medicine, Yong Loo Lin School of Medicine, National University of Singapore, 16 Medical Drive, Singapore 117597, Republic of Singapore; e-mail: [email protected]
VOL. 144, NO. 2
with refractive errors. A relationship between diabetes and myopia has been reported in some studies,4 but not in others.5 To our best knowledge, there have been no population-based studies that have examined the relationship of diabetes with anterior chamber depth or axial length. We examined the associations of diabetes with ocular biometry and refractive error in the Tanjong Pagar Survey in Singapore, a population-based, cross-sectional survey of Chinese adults ages 40 to 81 years, conducted in 1997 to 1998.6,7 Detailed methodology has been reported.6,7 In brief, of the 1,232 (71.8% of eligible subjects) who participated, 1,090 (63.4%) attended the clinic examination, and data on refraction and ocular biometry were available in 943 (86.5% of clinic participants). Diabetes was ascertained from a standardized questionnaire by asking, “Have you been told by a doctor that you have diabetes?” followed by questions on its treatment (that is, diet, pills, or insulin injections).7 The interviewers were masked to ocular data. A-mode ultrasound was used to measure axial length, anterior chamber depth, lens thickness, and vitreous chamber depth. Auto-keratometer was used to measure corneal curvature radius along two meridians. Refraction was performed with an autorefractor and further refined subjectively.6 Spherical equivalent refraction was defined as the sum of the spherical power and half the cylindrical power, in diopters (D). Education, housing type, and income were ascertained from a structured interview.6 Because the results were similar between the two eyes, only data on right eyes are presented. We used analysis of covariance to determine mean ocular biometric parameters and refraction, initially adjusting for age and gender, and then further for education, housing type and income. Statistical analyses were performed using SPSS 14.0 (SPSS Science Inc, Chicago, Illinois, USA). Of the 1,232 subjects, there were 140 (11.4%) with diabetes. The Table shows that, after controlling for age and gender, subjects with diabetes compared with without diabetes have shallower mean anterior chambers (2.78 vs 2.91 mm, P ⫽ .004) and thicker lenses (4.88 vs 4.75 mm, P ⫽ .003), but similar spherical equivalent refraction, axial length, vitreous chamber depth, and corneal curvature. Findings were essentially similar after further multivariate analysis. Diabetes has long been known to be a key risk factor for open angle glaucoma.1–3 We now demonstrate in this Chinese population in Singapore that persons with diabetes have shallower anterior chambers than persons without diabetes, independent of age, gender, and socioeconomic factors. These data support the concept that diabetes may be a risk factor for the development of ACG. The finding that persons with diabetes have thicker lenses is consistent to reports of higher rates of cataract in persons with diabetes.7 We did not find an association between diabetes with refraction, which is consistent with findings from the Blue Mountains Eye Study.5
BRIEF REPORTS
325
TABLE. Means of Ocular Biometry and Refraction (Right Eyes) by Diabetes Status Diabetes
Models
Absent (n ⫽ 1,092)
Present (n ⫽ 140)
P value
Age and gender* Multivariate† Age and gender* Multivariate† Age and gender* Multivariate† Age and gender* Multivariate† Age and gender* Multivariate† Age and gender* Multivariate†
23.19 23.19 2.91 2.91 4.75 4.75 15.59 15.59 0.54 0.54 ⫺0.47 ⫺0.47
23.09 23.09 2.78 2.78 4.88 4.88 15.52 15.52 0.54 0.54 ⫺0.38 ⫺0.39
.40 .42 .004 .004 .003 .003 .53 .54 .71 .77 .73 .74
Mean Ocular Biometry and Refraction Measurements
Axial length (mm) Anterior chamber depth (mm) Lens thickness (mm) Vitreous chamber depth (mm) Corneal curvature radius (mm) Refraction (D)
*Analysis of covariance models adjusted for age and gender. † Analysis of covariance models adjusted for age, gender, education, housing type, and income.
4. Tarczy-Hornoch K, Lai MY, Varma R, Los Angeles Latino Eye Study Group. Myopic refractive error in adult Latinos: the Los Angeles Latino Eye Study. Invest Ophthalmol Vis Sci 2006; 47:1845–1851. 5. Attebo K, Ivers RQ, Mitchell P. Refractive errors in an older population: the Blue Mountains Eye Study. Ophthalmology 1999;106:1066 –1072. 6. Wong TY, Foster PJ, Hee J, et al. The prevalence and risk factors for refractive errors in adult Chinese residents in Singapore. Invest Ophthalmol Vis Sci 2000;41:2486 –2494. 7. Foster PJ, Wong TY, Machin D, et al. Risk factors for nuclear, cortical and posterior subcapsular cataracts in the Chinese population of Singapore: the Tanjong Pagar Survey. Br J Ophthalmol 2003;87:1112–1120.
The major limitation of our study was that diabetes status was self-reported. This could lead to underreporting of diabetes and possible misclassification biases. Nonetheless, the prevalence of diabetes in this study population was generally similar to the prevalence of diabetes reported from other studies in Singapore. In conclusion, our study showed that Chinese persons with diabetes have shallower anterior chambers and thicker lenses, suggesting diabetes may be a risk factor for the development of ACG. This hypothesis would require confirmation from prospective studies evaluating the risk of ACG among persons with and without diabetes. THIS STUDY WAS SUPPORTED BY THE NATIONAL MEDICAL Research Council, Singapore and the British Council for the Prevention of Blindness, London, England, and the International Glaucoma Association, London, England. The authors indicate no financial conflict of interest. Dr Foster received lecture fees to speak for Pfizer and Allergan. Involved in design and conduct of the study (S.M.S., T.Y.W., S.T., P.F.); collection (P.F.); management (S.T., P.F.); analysis (S.T., S.M.S., T.Y.W.); interpretation of the data (S.M.S., T.Y.W., S.T., A.F., P.F.); and preparation, review, or approval of the manuscript (S.M.S., T.Y.W., S.T., A.F., P.F.). Informed written consent was obtained, as was ethics approval and IRB from the Singapore National Eye Centre.
Ocular Involvement as the Initial Manifestation of T-Cell Chronic Lymphocytic Leukemia Carmen J. Calfa, Izidore S. Lossos, Phillip Ruiz, and Janet L. Davis
REFERENCES PURPOSE: To present a case of T-cell chronic lymphocytic
1. Friedman DS, Wilson MR, Liebmann JM, et al. An evidencebased assessment of risk factors for the progression of ocular hypertension and glaucoma. Am J Ophthalmol 2004;138: 19 –31. 2. Mitchell P, Smith W, Chey T, Healey PR. Open-angle glaucoma and diabetes: the Blue Mountains Eye Study, Australia. Ophthalmology 1997;104:712–718. 3. Dielemans I, de Jong PT, Stolk R, et al. Primary open-angle glaucoma, intraocular pressure, and diabetes mellitus in the general elderly population: the Rotterdam Study. Ophthalmology 1996;103:1271–1275.
326
AMERICAN JOURNAL
leukemia (T-CLL) manifesting as an intraocular lymphoma. DESIGN: Interventional case report. Accepted for publication Mar 21, 2007. From the Department of Medicine, Hematology-Oncology, University of Miami Miller School of Medicine and Sylvester Comprehensive Cancer Center (C.J.C., I.S.L., P.R.); and University of Miami Miller School of Medicine Bascom Palmer Eye Institute (J.D.), Miami, Florida. Inquiries to Janet L. Davis, University of Miami Miller School of Medicine, Bascom Palmer Eye Institute, 900 NW 17th Street, Miami, FL 33136; e-mail: [email protected] OF
OPHTHALMOLOGY
AUGUST 2007
The Relationship Between Anterior Chamber Depth and the Presence of Diabetes in the Tanjong Pagar Survey Seang-Mei Saw, Tien Y. Wong, Steven Ting, Athena W. P. Foong, and Paul J. Foster PURPOSE: To examine the relationships of diabetes with anterior chamber depth, axial length, and refraction. DESIGN: Population-based cross-sectional study. METHODS: This analysis included 943 Singapore Chinese subjects ages 40 to 81 years from the Tanjong Pagar Survey. Diabetes was determined by self-report. A-mode ultrasound was used to measure axial dimensions. Refraction was performed with an autorefractor and refined subjectively. RESULTS: There were 140 (11.4%) participants with diabetes. After controlling for age and gender, participants with diabetes had shallower anterior chambers (2.78 vs 2.91 mm, P ⴝ .004) and thicker lenses (4.88 vs 4.75 mm, P ⴝ .003), but similar spherical equivalent refraction (– 0.38 vs – 0.47 diopters [D], P ⴝ .73), axial length (23.09 vs 23.19 mm, P ⴝ .40), and vitreous chamber depth (15.52 vs 15.59 mm, P ⴝ .53). CONCLUSIONS: In the Singapore Chinese population, persons with diabetes have shallower anterior chambers and thicker lenses than those without diabetes. Diabetes may be a risk factor for angle closure glaucoma (ACG). (Am J Ophthalmol 2007;144:325–326. © 2007 by Elsevier Inc. All rights reserved.)
I
T HAS LONG BEEN SUGGESTED THAT DIABETES IS A RISK
factor for the development of glaucoma.1 Most previous studies, however, have been conducted in Caucasian populations, and have focused on the association of diabetes with open angle glaucoma.2,3 Whether diabetes is also a risk factor for angle closure glaucoma (ACG) is less clear, and has not been thoroughly investigated.1 Furthermore, previous studies suggest that diabetes is associated Accepted for publication Mar 23, 2007. From the Department of Ophthalmology (S.-M.S., T.Y.W., S.T., A.W.P.F.); and Department of Community, Occupational and Family Medicine (S.-M.S.), Yong Loo Lin School of Medicine, National University of Singapore, Singapore; and Singapore Eye Research Institute, Singapore (S.-M.S., T.Y.W.). Centre for Eye Research Australia, University of Melbourne, Australia (T.Y.W.); and Institute of Ophthalmology, University College London, London, United Kingdom (P.J.F.). Inquiries to Seang-Mei Saw, Department of Community, Occupational and Family Medicine, Yong Loo Lin School of Medicine, National University of Singapore, 16 Medical Drive, Singapore 117597, Republic of Singapore; e-mail: [email protected]
VOL. 144, NO. 2
with refractive errors. A relationship between diabetes and myopia has been reported in some studies,4 but not in others.5 To our best knowledge, there have been no population-based studies that have examined the relationship of diabetes with anterior chamber depth or axial length. We examined the associations of diabetes with ocular biometry and refractive error in the Tanjong Pagar Survey in Singapore, a population-based, cross-sectional survey of Chinese adults ages 40 to 81 years, conducted in 1997 to 1998.6,7 Detailed methodology has been reported.6,7 In brief, of the 1,232 (71.8% of eligible subjects) who participated, 1,090 (63.4%) attended the clinic examination, and data on refraction and ocular biometry were available in 943 (86.5% of clinic participants). Diabetes was ascertained from a standardized questionnaire by asking, “Have you been told by a doctor that you have diabetes?” followed by questions on its treatment (that is, diet, pills, or insulin injections).7 The interviewers were masked to ocular data. A-mode ultrasound was used to measure axial length, anterior chamber depth, lens thickness, and vitreous chamber depth. Auto-keratometer was used to measure corneal curvature radius along two meridians. Refraction was performed with an autorefractor and further refined subjectively.6 Spherical equivalent refraction was defined as the sum of the spherical power and half the cylindrical power, in diopters (D). Education, housing type, and income were ascertained from a structured interview.6 Because the results were similar between the two eyes, only data on right eyes are presented. We used analysis of covariance to determine mean ocular biometric parameters and refraction, initially adjusting for age and gender, and then further for education, housing type and income. Statistical analyses were performed using SPSS 14.0 (SPSS Science Inc, Chicago, Illinois, USA). Of the 1,232 subjects, there were 140 (11.4%) with diabetes. The Table shows that, after controlling for age and gender, subjects with diabetes compared with without diabetes have shallower mean anterior chambers (2.78 vs 2.91 mm, P ⫽ .004) and thicker lenses (4.88 vs 4.75 mm, P ⫽ .003), but similar spherical equivalent refraction, axial length, vitreous chamber depth, and corneal curvature. Findings were essentially similar after further multivariate analysis. Diabetes has long been known to be a key risk factor for open angle glaucoma.1–3 We now demonstrate in this Chinese population in Singapore that persons with diabetes have shallower anterior chambers than persons without diabetes, independent of age, gender, and socioeconomic factors. These data support the concept that diabetes may be a risk factor for the development of ACG. The finding that persons with diabetes have thicker lenses is consistent to reports of higher rates of cataract in persons with diabetes.7 We did not find an association between diabetes with refraction, which is consistent with findings from the Blue Mountains Eye Study.5
BRIEF REPORTS
325
TABLE. Means of Ocular Biometry and Refraction (Right Eyes) by Diabetes Status Diabetes
Models
Absent (n ⫽ 1,092)
Present (n ⫽ 140)
P value
Age and gender* Multivariate† Age and gender* Multivariate† Age and gender* Multivariate† Age and gender* Multivariate† Age and gender* Multivariate† Age and gender* Multivariate†
23.19 23.19 2.91 2.91 4.75 4.75 15.59 15.59 0.54 0.54 ⫺0.47 ⫺0.47
23.09 23.09 2.78 2.78 4.88 4.88 15.52 15.52 0.54 0.54 ⫺0.38 ⫺0.39
.40 .42 .004 .004 .003 .003 .53 .54 .71 .77 .73 .74
Mean Ocular Biometry and Refraction Measurements
Axial length (mm) Anterior chamber depth (mm) Lens thickness (mm) Vitreous chamber depth (mm) Corneal curvature radius (mm) Refraction (D)
*Analysis of covariance models adjusted for age and gender. † Analysis of covariance models adjusted for age, gender, education, housing type, and income.
4. Tarczy-Hornoch K, Lai MY, Varma R, Los Angeles Latino Eye Study Group. Myopic refractive error in adult Latinos: the Los Angeles Latino Eye Study. Invest Ophthalmol Vis Sci 2006; 47:1845–1851. 5. Attebo K, Ivers RQ, Mitchell P. Refractive errors in an older population: the Blue Mountains Eye Study. Ophthalmology 1999;106:1066 –1072. 6. Wong TY, Foster PJ, Hee J, et al. The prevalence and risk factors for refractive errors in adult Chinese residents in Singapore. Invest Ophthalmol Vis Sci 2000;41:2486 –2494. 7. Foster PJ, Wong TY, Machin D, et al. Risk factors for nuclear, cortical and posterior subcapsular cataracts in the Chinese population of Singapore: the Tanjong Pagar Survey. Br J Ophthalmol 2003;87:1112–1120.
The major limitation of our study was that diabetes status was self-reported. This could lead to underreporting of diabetes and possible misclassification biases. Nonetheless, the prevalence of diabetes in this study population was generally similar to the prevalence of diabetes reported from other studies in Singapore. In conclusion, our study showed that Chinese persons with diabetes have shallower anterior chambers and thicker lenses, suggesting diabetes may be a risk factor for the development of ACG. This hypothesis would require confirmation from prospective studies evaluating the risk of ACG among persons with and without diabetes. THIS STUDY WAS SUPPORTED BY THE NATIONAL MEDICAL Research Council, Singapore and the British Council for the Prevention of Blindness, London, England, and the International Glaucoma Association, London, England. The authors indicate no financial conflict of interest. Dr Foster received lecture fees to speak for Pfizer and Allergan. Involved in design and conduct of the study (S.M.S., T.Y.W., S.T., P.F.); collection (P.F.); management (S.T., P.F.); analysis (S.T., S.M.S., T.Y.W.); interpretation of the data (S.M.S., T.Y.W., S.T., A.F., P.F.); and preparation, review, or approval of the manuscript (S.M.S., T.Y.W., S.T., A.F., P.F.). Informed written consent was obtained, as was ethics approval and IRB from the Singapore National Eye Centre.
Ocular Involvement as the Initial Manifestation of T-Cell Chronic Lymphocytic Leukemia Carmen J. Calfa, Izidore S. Lossos, Phillip Ruiz, and Janet L. Davis
REFERENCES PURPOSE: To present a case of T-cell chronic lymphocytic
1. Friedman DS, Wilson MR, Liebmann JM, et al. An evidencebased assessment of risk factors for the progression of ocular hypertension and glaucoma. Am J Ophthalmol 2004;138: 19 –31. 2. Mitchell P, Smith W, Chey T, Healey PR. Open-angle glaucoma and diabetes: the Blue Mountains Eye Study, Australia. Ophthalmology 1997;104:712–718. 3. Dielemans I, de Jong PT, Stolk R, et al. Primary open-angle glaucoma, intraocular pressure, and diabetes mellitus in the general elderly population: the Rotterdam Study. Ophthalmology 1996;103:1271–1275.
326
AMERICAN JOURNAL
leukemia (T-CLL) manifesting as an intraocular lymphoma. DESIGN: Interventional case report. Accepted for publication Mar 21, 2007. From the Department of Medicine, Hematology-Oncology, University of Miami Miller School of Medicine and Sylvester Comprehensive Cancer Center (C.J.C., I.S.L., P.R.); and University of Miami Miller School of Medicine Bascom Palmer Eye Institute (J.D.), Miami, Florida. Inquiries to Janet L. Davis, University of Miami Miller School of Medicine, Bascom Palmer Eye Institute, 900 NW 17th Street, Miami, FL 33136; e-mail: [email protected] OF
OPHTHALMOLOGY
AUGUST 2007