Contemporary Approach to Narrow Angles

Abstract

Glaucoma is the leading cause of irreversible blindness worldwide. Among all glaucoma types,
primary angle closure glaucoma (PACG) affects approximately 23 million people worldwide, and
is responsible for 50% of glaucoma-related blindness, highlighting the devastating consequences
of this disease. The main mechanism of PACG is relative pupillary block. High-risk populations are
female gender, Asian ethnicity, high hyperopia, short axial length, and a thick/anteriorly positioned
lens. This review discusses the clinical diagnosis, classification, and management of patients with
a narrow angle with and without intraocular pressure (IOP) elevation and glaucomatous optic
nerve damage, including laser peripheral iridotomy (LPI), endocycloplasty (ECPL), lens extraction,
and goniosynechialysis.

Keywords:

Glaucoma, Gonioscopy, Laser Peripheral Iridotomy, Lens Extraction, Narrow Angle

References
1. Kingman S. Glaucoma is second leading cause of blindness globally. Bull World Health Organ 2004;82:887–888.

2. Quigley HA, Broman AT. The number of people with glaucoma worldwide in 2010 and 2020. Br J Ophthalmol 2006;90:262–267.

3. Quigley HA. Number of people with glaucoma worldwide. Br J Ophthalmol 1996;80:389–393.

4. Stefan C, Iliescu DA, Batras M, Timaru CM, De Simone A. Plateau iris–Diagnosis and treatment. Rom J Ophthalmol 2015;59:14–18.

5. Verma S, Nongpiur ME, Oo HH, Atalay E, Goh D, Wong TT, et al. Plateau iris distribution across anterior segment optical coherence tomography defined subgroups of subjects with primary angle closure glaucoma. Invest Ophthalmol Vis Sci 2017;58:5093–5097.

6. Moghimi S, Kiaroudi M, Coh P, Li Y, He M, Lin SC. Comparison of anterior chamber parameters in patients with plateau iris configuration and pupillary block using ASOCT. J Glaucoma 2017;26:153–158.

7. Leung CK, Cheung CY, Li H, et al. Dynamic analysis of dark-light changes of the anterior chamber angle with anterior segment OCT. Invest Ophthalmol Vis Sci. 2007;48(9):4116-4122.

8. Aptel F, Denis P. Optical coherence tomography quantitative analysis of iris volume changes after pharmacologic mydriasis. Ophthalmology 2010;117:3–10.

9. Quigley HA, Silver DM, Friedman DS, He M, Plyler RJ, Eberhart CG, et al. Iris cross-sectional area decreases with pupil dilation and its dynamic behavior is a risk factor in angle closure. J Glaucoma 2009;18:173–179.

10. Day AC, Baio G, Gazzard G, Bunce C, Azuara-Blanco A, Munoz B, et al. The prevalence of primary angle closure glaucoma in European derived populations: A systematic review. Br J Ophthalmol 2012;96:1162–1167.

11. Foster PJ, Baasanhu J, Alsbirk PH, Munkhbayar D, Uranchimeg D, Johnson GJ. Glaucoma in Mongolia. A population-based survey in Hövsgöl province, northern Mongolia. Arch Ophthalmol 1996;114:1235–1241.

12. Yazdani S, Akbarian S, Pakravan M, Afrouzifar M. Prevalence of angle closure in siblings of patients with primary angle-closure glaucoma. J Glaucoma 2015;24:149–153.

13. Amerasinghe N, Zhang J, Thalamuthu A, He M, Vithana EN, Viswanathan A, et al. The heritability and sibling risk of angle closure in Asians. Ophthalmology 2011;118:480– 485.

14. Vithana EN, Khor CC, Qiao C, Nongpiur ME, George R, Chen LJ, et al. Genome-wide association analyses identify three new susceptibility loci for primary angle closure glaucoma. Nat Genet 2012;44:1142–1146.

15. Fontana ST, Brubaker RF. Volume and depth of the anterior chamber in the normal aging human eye. Arch Ophthalmol 1980;98:1803–1808.

16. Lee DA, Brubaker RF, Ilstrup DM. Anterior chamber dimensions in patients with narrow angles and angleclosure glaucoma. Arch Ophthalmol 1984;102:46–50.

17. Marchini G, Pagliarusco A, Toscano A, Tosi R, Brunelli C, Bonomi L. Ultrasound biomicroscopic and conventional ultrasonographic study of ocular dimensions in primary angle-closure glaucoma. Ophthalmology 1998;105:2091–2098.

18. Nongpiur ME, He M, Amerasinghe N, Friedman DS, Tay WT, Baskaran M, et al. Lens vault, thickness, and position in Chinese subjects with angle closure. Ophthalmology 2011;118:474–479.

19. Moghimi S, Vahedian Z, Zandvakil N, Mohammdi M, Fakhraie G, Nassiri N, et al. Role of lens vault in subtypes of angle closure in Iranian subjects. Eye 2014;28:337– 343.

20. Ozaki M, Mizoguchi T, Nongpiur ME, Aung T. Lens vault as a risk factor for angle closure in Japanese. Invest Ophthalmol Vis Sci 2011;52:6273–6273.

21. European Glaucoma Society Terminology and Guidelines for Glaucoma. 4th Edition - Chapter 2: Classification and terminology. Supported by the EGS Foundation: Part 1: Foreword; Introduction; Glossary; Chapter 2 Classification and Terminology. Br J Ophthalmol 2017;101:73–127.

22. Aung T, Ang LP, Chan SP, Chew PT. Acute primary angle-closure: Long-term intraocular pressure outcome in Asian eyes. Am J Ophthalmol 2001;131:7–12.

23. Wright C, Tawfik MA, Waisbourd M, Katz LJ. Primary angle-closure glaucoma: An update. Acta Ophthalmol 2016;94:217–225.

24. Van Herick W, Shaffer RN, Schwartz A. Estimation of width of angle of anterior chamber. Incidence and significance of the narrow angle. Am J Ophthalmol 1969;68:626–629.

25. Varma DK, Simpson SM, Rai AS, Ahmed II. Undetected angle closure in patients with a diagnosis of open-angle glaucoma. Can J Ophthalmol 2017;52:373–378.

26. Vijaya L, George R, Baskaran M, Arvind H, Raju P, Ramesh SV, et al. Prevalence of primary open-angle glaucoma in an urban south Indian population and comparison with a rural population. The Chennai Glaucoma Study. Ophthalmology 2008;115:648–654.e1.

27. Fremont AM, Lee PP, Mangione CM, Kapur K, Adams JL, Wickstrom SL, et al. Patterns of care for open-angle glaucoma in managed care. Arch Ophthalmol 2003;121:777–783.

28. Stanley J, Huisingh CE, Swain TA, McGwin G Jr, Owsley C, Girkin CA, et al. Compliance with primary open-angle glaucoma and primary open-angle glaucoma suspect preferred practice patterns in a retail-based eye clinic. J Glaucoma 2018;27:1068–1072.

29. Forbes M. Gonioscopy with corneal indentation. A method for distinguishing between appositional closure and synechial closure. Arch Ophthalmol 1966;76:488– 492.

30. Allingham RR. JI KFD, Freedman SF, MD SEM, Rhee DJ. Shields Textbook of glaucoma. 6th Edition ed: Lippincott Williams & Wilkins; 2011.

31. Scheie HG. Width and pigmentation of the angle of the anterior chamber; A system of grading by gonioscopy. AMA Arch Opthalmol 1957;58:510–512.

32. Shaffer RN. Primary glaucomas. Gonioscopy, ophthalmoscopy and perimetry. Trans Am Acad Ophthalmol Otolaryngol 1960;64:112–127.

33. Spaeth GL. The normal development of the human anterior chamber angle: A new system of descriptive grading. Trans Ophthalmol Soc UK 1971;91:709–739.

34. Ahmed R, Khan B, Chen M, Robinson MR, Lee SS. A Multicenter study assessing inter-examiner agreement of gonioscopic shaffer grading in patients with open-angle glaucoma and/or ocular hypertension. Invest Ophthalmol Vis Sci 2016;57:3043–3043.

35. Pavlin CJ, Harasiewicz K, Sherar MD, Foster FS. Clinical use of ultrasound biomicroscopy. Ophthalmology 1991;98:287–295.

36. Barkana Y, Dorairaj SK, Gerber Y, Liebmann JM, Ritch R. Agreement between gonioscopy and ultrasound biomicroscopy in detecting iridotrabecular apposition. Arch Ophthalmol 2007;125:1331–1335.

37. Mansoori T, Sarvepally VK, Balakrishna N. Plateau iris in primary angle closure glaucoma: An ultrasound biomicroscopy study. J Glaucoma 2016;25:e82–6.

38. Sharifi E, Biebesheimer JB, Ishikawa H, Lin S. Ultrasound biomicroscopy: Effect of upright versus supine positioning on anterior chamber width using a new probe. Invest Ophthalmol Vis Sci 2007;48:1209–1209.

39. Izatt JA, Hee MR, Swanson EA, Lin CP, Huang D, Schuman JS, et al. Micrometer-scale resolution imaging of the anterior eye in vivo with optical coherence tomography. Arch Ophthalmol 1994;112:1584–1589.

40. Nolan WP, See JL, Chew PT, Friedman DS, Smith SD, Radhakrishnan S, et al. Detection of primary angle closure using anterior segment optical coherence tomography in Asian eyes. Ophthalmology 2007;114:33–39.

41. Sakata LM, Lavanya R, Friedman DS, Aung HT, Gao H, Kumar RS, et al. Comparison of gonioscopy and anterior segment ocular coherence tomography in detecting angle closure in different quadrants of the anterior chamber angle. Ophthalmology 2008;115:769–774.

42. Hu CX, Mantravadi A, Zangalli C, Ali M, Faria BM, Richman J, et al. Comparing gonioscopy with visante and cirrus optical coherence tomography for anterior chamber angle assessment in glaucoma patients. J Glaucoma 2016;25:177–183.

43. Lai I, Mak H, Lai G, Yu M, Lam DS, Leung CK. Anterior chamber angle imaging with swept-source optical coherence tomography: Measuring peripheral anterior synechia in glaucoma. Ophthalmology 2013;120:1144–1149.

44. Baskaran M, Ho SW, Tun TA, How AC, Perera SA, Friedman DS, et al. Assessment of circumferential angleclosure by the iris-trabecular contact index with sweptsource optical coherence tomography. Ophthalmology 2013;120:2226–2231.

45. Melese EK, Chan JD, Blieden LS, Chuang AZ, Baker LA, Bell NP, et al. Determination and validation of thresholds of anterior chamber parameters by dedicated anterior segment optical coherence tomography. Am J Ophthalmol 2016;169:208–217.

46. Perera SA, Baskaran M, Friedman DS, Tun TA, Htoon HM, Kumar RS, et al. Use of EyeCam for imaging the anterior chamber angle. Invest Ophthalmol Vis Sci 2010;51:2993–2997.

47. Baskaran M, Perera SA, Nongpiur ME, Tun TA, Park J, Kumar RS, et al. Angle assessment by EyeCam, goniophotography, and gonioscopy. J Glaucoma 2012;21:493–497.

48. Murakami Y, Wang D, Burkemper B, Lin SC, Varma R. A population-based assessment of the agreement between grading of goniophotographic images and gonioscopy in the Chinese–American Eye Study (CHES). Invest Ophthalmol Vis Sci 2016;57:4512–4516.

49. Shi Y, Yang X, Marion KM, Francis BA, Sadda SR, Chopra V. Novel and semiautomated 360-degree gonioscopic anterior chamber angle imaging in under 60 seconds. Ophthalmol Glaucoma 2019;2:215–223.

50. Teixeira F, Sousa DC, Leal I, Barata A, Neves CM, Pinto LA. Automated gonioscopy photography for iridocorneal angle grading. Eur J Ophthalmol 2020;30:112–118.

51. Matsuo M, Mizoue S, Nitta K, Takai Y, Sugihara K, Tanito M. Intraobserver and interobserver agreement among anterior chamber angle evaluations using automated 360-degree gonio-photos. PLoS One 2021;16:e0251249.

52. Madu CT, Phelps T, Schuman JS, Zambrano R, Lee TF, Panarelli J, et al. Automated 360-degree goniophotography with the NIDEK Gonioscope GS-1 for glaucoma. PLoS One 2023;18:e0270941.

53. Li W, Chen Q, Jiang Z, Deng G, Zong Y, Shi G, et al. Automatic anterior chamber angle measurement for ultrasound biomicroscopy using deep learning. J Glaucoma 2020;29:81–85.

54. Wang W, Wang L, Wang X, Zhou S, Lin S, Yang J. A deep learning system for automatic assessment of anterior chamber angle in ultrasound biomicroscopy images. Transl Vis Sci Technol 2021;10:21.

55. Jiang W, Yan Y, Cheng S, Wan S, Huang L, Zheng H, et al. Deep learning-based model for automatic assessment of anterior angle chamber in ultrasound biomicroscopy. Ultrasound Med Biol 2023;49:2497–2509.

56. Li W, Chen Q, Jiang C, Shi G, Deng G, Sun X. Automatic anterior chamber angle classification using deep learning system and anterior segment optical coherence tomography images. Transl Vis Sci Technol 2021;10:19.

57. Wanichwecharungruang B, Kaothanthong N, Pattanapongpaiboon W, Chantangphol P, Seresirikachorn K, Srisuwanporn C, et al. Deep learning for anterior segment optical coherence tomography to predict the presence of plateau iris. Transl Vis Sci Technol 2021;10:7.

58. Soh ZD, Tan M, Nongpiur ME, Yu M, Qian C, Tham YC, et al. Deep learning-based quantification of anterior segment OCT parameters. Ophthalmol Sci 2023;4:100360.

59. Wilensky JT, Kaufman PL, Frohlichstein D, Gieser DK, Kass MA, Ritch R, et al. Follow-up of angle-closure glaucoma suspects. Am J Ophthalmol 1993;115:338– 346.

60. He M, Jiang Y, Huang S, Chang DS, Munoz B, Aung T, et al. Laser peripheral iridotomy for the prevention of angle closure: A single-centre, randomised controlled trial. Lancet 2019;393:1609–1618.

61. Yuan Y, Wang W, Xiong R, Zhang J, Li C, Yang S, et al. Fourteen-year outcome of angle-closure prevention with laser iridotomy in the zhongshan angle-closure prevention study: Extended follow-up of a randomized controlled trial. Ophthalmology 2023;130:786–794.

62. Baskaran M, Kumar RS, Friedman DS, Lu QS, Wong HT, Chew PT, et al. The Singapore Asymptomatic Narrow Angles Laser Iridotomy Study: Five-year results of a randomized controlled trial. Ophthalmology 2022;129:147–158.

63. Yoo K, Apolo G, Zhou S, Burkemper B, Lung K, Song B, et al. Rates and patterns of diagnostic conversion from anatomical narrow angle to primary angle-closure glaucoma in the United States. Ophthalmol Glaucoma 2023;6:169–176.

64. European Glaucoma Society Terminology and Guidelines for Glaucoma. 4th Edition - Chapter 3: Treatment principles and options Supported by the EGS Foundation: Part 1: Foreword; Introduction; Glossary; Chapter 3 Treatment principles and options. Br J Ophthalmol 2017;101:130–195.

65. EyeWiki (American Academy of Ophthalmology). Laser peripheral iridotomy. https://eyewiki.aao.org/ Laser_Peripheral_Iridotomy. Published 2022. Accessed August 2023.

66. Day AC, Foster PJ. How large should an iridotomy be? Br J Ophthalmol 2011;95:747–748.

67. Rosenberg LF, Krupin T, Ruderman J, McDaniel DL, Siegfried C, Karalekas DP, et al. Apraclonidine and anterior segment laser surgery. Comparison of 0.5% versus 1.0% apraclonidine for prevention of postoperative intraocular pressure rise. Ophthalmology 1995;102:1312–1318.

68. Chen TC, Ang RT, Grosskreutz CL, Pasquale LR, Fan JT. Brimonidine 0.2% versus apraclonidine 0.5% for prevention of intraocular pressure elevations after anterior segment laser surgery. Ophthalmology 2001;108:1033–1038.

69. Spaeth GL, Idowu O, Seligsohn A, Henderer J, Fonatanarosa J, Modi A, et al. The effects of iridotomy size and position on symptoms following laser peripheral iridotomy. J Glaucoma 2005;14:364–367.

70. Vera V, Naqi A, Belovay GW, Varma DK, Ahmed II. Dysphotopsia after temporal versus superior laser peripheral iridotomy: A prospective randomized paired eye trial. Am J Ophthalmol 2014;157:929–935.

71. Islam N, Franks WA. Therapeutic corneal tattoo following peripheral iridotomy complication. Eye 2006;20:389– 390.

72. Srinivasan K, Zebardast N, Krishnamurthy P, Abdul Kader M, Raman GV, Rajendrababu S, et al. Comparison of new visual disturbances after superior versus nasal/temporal laser peripheral iridotomy: A prospective randomized trial. Ophthalmology 2018;125:345–351.

73. Congdon N, Yan X, Friedman DS, Foster PJ, van den Berg TJ, Peng M, et al. Visual symptoms and retinal straylight after laser peripheral iridotomy: The Zhongshan Angle-Closure Prevention Trial. Ophthalmology 2012;119:1375–1382.

74. Kavitha S, Ramulu PY, Venkatesh R, Palaniswamy K, Kader MA, Raman GV, et al. Resolution of visual dysphotopsias after laser iridotomy: Six-month follow-up. Ophthalmology 2019;126:469–471.e1.

75. Fresco BB, Trope GR. Opaque contact lenses for YAG laser iridotomy occlusion. Optom Vis Sci 1992;69:656– 657.

76. Burris TE, Holmes-Higgin DK, Silvestrini TA. Lamellar intrastromal corneal tattoo for treating iris defects (artificial iris). Cornea 1998;17:169–173.

77. Reed JW, Beran RF. Elimination of monocular diplopia by corneal tattooing. Ophthalmic Surg 1988;19:437–439.


78. Waisbourd M, Shafa A, Delvadia R, Sembhi H, Molineaux J, Henderer J, et al. Bilateral same-day laser peripheral iridotomy in the Philadelphia glaucoma detection and treatment project. J Glaucoma 2016;25:e821–5.

79. Radhakrishnan S, Chen PP, Junk AK, Nouri-Mahdavi K, Chen TC. Laser peripheral iridotomy in primary angle closure: A report by the American Academy of Ophthalmology. Ophthalmology 2018;125:1110–1120.

80. Golan S, Levkovitch-Verbin H, Shemesh G, Kurtz S. Anterior chamber bleeding after laser peripheral iridotomy. JAMA Ophthalmol 2013;131:626–629.

81. Galvis V, Tello A, Carreño NI, Sánchez WA, Frederick GA, Blanco NA. Massive hyphaema following laser iridotomy in a patient on dual antiplatelet therapy (aspirin plus ticagrelor): Case report and literature review. Sultan Qaboos Univ Med J 2019;19:e63–7.

82. Cohen JS, Bibler L, Tucker D. Hypopyon following laser iridotomy. Ophthalmic Surg 1984;15:604–606.

83. Lederer CM Jr, Price PK. Posterior synechiae after laser iridectomy. Ann Ophthalmol 1989;21:61–64.

84. Vijaya L, Asokan R, Panday M, George R. Is prophylactic laser peripheral iridotomy for primary angle closure suspects a risk factor for cataract progression? The Chennai Eye Disease Incidence Study. Br J Ophthalmol 2017;101:665–670.

85. Tan AM, Loon SC, Chew PT. Outcomes following acute primary angle closure in an Asian population. Clin Exp Ophthalmol 2009;37:467–472.

86. Lim LS, Husain R, Gazzard G, Seah SK, Aung T. Cataract progression after prophylactic laser peripheral iridotomy: Potential implications for the prevention of glaucoma blindness. Ophthalmology 2005;112:1355–1359.

87. Jiang Y, Chang DS, Foster PJ, He M, Huang S, Aung T, et al. Immediate changes in intraocular pressure after laser peripheral iridotomy in primary angle-closure suspects. Ophthalmology 2012;119:283–288.

88. Robin AL, Pollack IP. A comparison of neodymium: YAG and argon laser iridotomies. Ophthalmology 1984;91:1011–1016.

89. Del Priore LV, Robin AL, Pollack IP. Neodymium: YAG and argon laser iridotomy. Long-term follow-up in a prospective, randomized clinical trial. Ophthalmology 1988;95:1207–1211.

90. Robin AL, Pollack IP. Q-switched neodymium-YAG laser iridotomy in patients in whom the argon laser fails. Arch Ophthalmol 1986;104:531–535.

91. Schwartz LW, Moster MR, Spaeth GL, Wilson RP, Poryzees E. Neodymium-YAG laser iridectomies in glaucoma associated with closed or occludable angles. Am J Ophthalmol 1986;102:41–44.

92. Klapper RM. Q-switched neodymium: YAG laser iridotomy. Ophthalmology 1984;91:1017–1021. 93. Small KM, Maslin KF. Malignant glaucoma following laser iridotomy. Aust N Z J Ophthalmol 1995;23:339–341.

94. Kumar RS, Baskaran M, Friedman DS, Xu Y, Wong HT, Lavanya R, et al. Effect of prophylactic laser iridotomy on corneal endothelial cell density over 3 years in primary angle closure suspects. Br J Ophthalmol 2013;97:258– 261.

95. Hou YC, Chen CC, Wang IJ, Hu FR. Recurrent herpetic keratouveitis following YAG laser peripheral iridotomy. Cornea 2004;23:641–642.

96. Anderson JE, Gentile RC, Sidoti PA, Rosen RB. Stage 1 macular hole as a complication of laser iridotomy. Arch Ophthalmol 2006;124:1658–1660.

97. Obana A, Gohto Y, Ueda N, Miki T, Cho A, Suzuki Y. Retinal and subhyaloid hemorrhage as a complication of laser iridectomy for primary angle-closure glaucoma. Arch Ophthalmol 2000;118:1449–1451.

98. Choplin NT, Bene CH. Cystoid macular edema following laser iridotomy. Ann Ophthalmol 1983;15:172–173.

99. Krasnov MM. Q-switched laser iridectomy and Qswitched laser goniopuncture. Adv Ophthalmol 1977;34:192–196.

100. Kimbrough RL, Trempe CS, Brockhurst RJ, Simmons RJ. Angle-closure glaucoma in nanophthalmos. Am J Ophthalmol 1979;88:572–579.

101. Ritch R. Argon laser treatment for medically unresponsive attacks of angle-closure glaucoma. Am J Ophthalmol 1982;94:197–204.

102. Ritch R, Tham CC, Lam DS. Argon laser peripheral iridoplasty (ALPI): An update. Surv Ophthalmol 2007;52:279–288.

103. He M, Friedman DS, Ge J, Huang W, Jin C, Lee PS, et al. Laser peripheral iridotomy in primary angle-closure suspects: biometric and gonioscopic outcomes: The Liwan Eye Study. Ophthalmology 2007;114:494–500.

104. Peterson JR, Anderson JW, Blieden LS, Chuang AZ, Feldman RM, Bell NP. Long-term outcome of argon laser peripheral iridoplasty in the management of plateau iris syndrome eyes. J Glaucoma 2017;26:780–786.

105. Ritch R, Tham CC, Lam DS. Long-term success of argon laser peripheral iridoplasty in the management of plateau iris syndrome. Ophthalmology 2004;111:104–108.

106. Bourdon H, Aragno V, Baudouin C, Labbé A. Iridoplasty for plateau iris syndrome: A systematic review. BMJ Open Ophthalmol 2019;4:e000340.

107. Tran HV, Liebmann JM, Ritch R. Iridociliary apposition in plateau iris syndrome persists after cataract extraction. Am J Ophthalmol 2003;135:40–43.

108. Lam DS, Lai JS, Tham CC, Chua JK, Poon AS. Argon laser peripheral iridoplasty versus conventional systemic medical therapy in treatment of acute primary angleclosure glaucoma: A prospective, randomized, controlled trial. Ophthalmology 2002;109:1591–1596.

109. Chew P, Chee C, Lim A. Laser treatment of severe acute angle closure glaucoma in dark Asian irides: The role of iridoplasty. 1991.

110. Jin JC, Anderson DR. Laser and unsutured sclerotomy in nanophthalmos. Am J Ophthalmol 1990;109:575–580. 111. EyeWiki (American Academy of Ophthalmology). Iridoplasty. https://eyewiki.aao.org/Iridoplasty#cite_note- :6-24. Published 2023.

112. Razeghinejad MR, Banifatemi M. Ocular biometry in angle closure. J Ophthalmic Vis Res 2013;8:17–24.

113. Tomlinson A, Leighton DA. Ocular dimensions in the heredity of angle-closure glaucoma. Br J Ophthalmol 1973;57:475–486.

114. Qi Y. Ultrasonic evaluation of the lens thickness to axial length factor in primary closure angle glaucoma. Yan Ke Xue Bao 1993;9:12–14.

115. Ünsal E, Eltutar K, Muftuoglu IK. Morphologic changes in the anterior segment using ultrasound biomicroscopy after cataract surgery and intraocular lens implantation. Eur J Ophthalmol 2017;27:31–38.

116. Pereira FA, Cronemberger S. Ultrasound biomicroscopic study of anterior segment changes after phacoemulsification and foldable intraocular lens implantation. Ophthalmology 2003;110:1799–1806.

117. Huang G, Gonzalez E, Peng PH, Lee R, Leeungurasatien T, He M, et al. Anterior chamber depth, iridocorneal angle width, and intraocular pressure changes after phacoemulsification: narrow vs open iridocorneal angles. Arch Ophthalmol 2011;129:1283–1290.

118. Kim M, Park KH, Kim TW, Kim DM. Anterior chamber configuration changes after cataract surgery in eyes with glaucoma. Korean J Ophthalmol 2012;26:97–103.

119. Lam DS, Leung DY, Tham CC, Li FC, Kwong YY, Chiu TY, et al. Randomized trial of early phacoemulsification versus peripheral iridotomy to prevent intraocular pressure rise after acute primary angle closure. Ophthalmology 2008;115:1134–1140.

120. Husain R, Gazzard G, Aung T, Chen Y, Padmanabhan V, Oen FT, et al. Initial management of acute primary angle closure: A randomized trial comparing phacoemulsification with laser peripheral iridotomy. Ophthalmology 2012;119:2274–2281.

121. Azuara-Blanco A, Burr J, Ramsay C, Cooper D, Foster PJ, Friedman DS, et al.; EAGLE study group. Effectiveness of early lens extraction for the treatment of primary angle-closure glaucoma (EAGLE): A randomised controlled trial. Lancet 2016;388:1389–1397.

122. Tham CC, Kwong YY, Baig N, Leung DY, Li FC, Lam DS. Phacoemulsification versus trabeculectomy in medically uncontrolled chronic angle-closure glaucoma without cataract. Ophthalmology 2013;120:62–67.

123. Teekhasaenee C, Ritch R. Combined phacoemulsification and goniosynechialysis for uncontrolled chronic angle-closure glaucoma after acute angle-closure glaucoma. Ophthalmology 1999;106:669– 674.

124. Tarongoy P, Ho CL, Walton DS. Angle-closure glaucoma: The role of the lens in the pathogenesis, prevention, and treatment. Surv Ophthalmol 2009;54:211–225.

125. Salmon JF. The role of trabeculectomy in the treatment of advanced chronic angle-closure glaucoma. J Glaucoma 1993;2:285–290.

126. Lai JS, Tham CC, Lam DS. Incisional surgery for angle closure glaucoma. Semin Ophthalmol 2002;17:92–99.

127. Bevin TH, Molteno AC, Herbison P. Otago Glaucoma Surgery Outcome Study: Long-term results of 841 trabeculectomies. Clin Exp Ophthalmol 2008;36:731–737.

128. Deokule SP, Molteno AC, Bevin TH, Herbison P. Longterm results of Molteno implant insertion in cases of chronic angle closure glaucoma. Clin Exp Ophthalmol 2007;35:514–519.

129. Tham CC, Leung DY, Kwong YY, Li FC, Lai JS, Lam DS. Effects of phacoemulsification versus combined phaco-trabeculectomy on drainage angle status in primary angle closure glaucoma (PACG). J Glaucoma 2010;19:119–123.

130. Tsai HY, Liu CJ, Cheng CY. Combined trabeculectomy and cataract extraction versus trabeculectomy alone in primary angle-closure glaucoma. Br J Ophthalmol 2009;93:943–948.

131. Tham CC, Kwong YY, Leung DY, et al. Phacoemulsification versus combined phacotrabeculectomy in medically uncontrolled chronic angle closure glaucoma with cataracts. Ophthalmology. 2009;116:725–731.

132. Tham CC, Kwong YY, Leung DY, Lam SW, Li FC, Chiu TY, et al. Phacoemulsification vs phacotrabeculectomy in chronic angle-closure glaucoma with cataract: complications [corrected,corrected]. Arch Ophthalmol 2010;128:303–311.

133. Hamanaka T, Kasahara K, Takemura T. Histopathology of the trabecular meshwork and Schlemm’s canal in primary angle-closure glaucoma. Invest Ophthalmol Vis Sci 2011;52:8849–8861.

134. Dorairaj S, Tam MD, Balasubramani GK. Two-Year clinical outcomes of combined phacoemulsification, goniosynechialysis, and excisional goniotomy for angleclosure glaucoma. Asia Pac J Ophthalmol 2020;10:183–187.

135. Gupta S, Sethi A, Yadav S, Azmira K, Singh A, Gupta V. Safety and efficacy of incisional goniotomy as an adjunct with phacoemulsification in primary angleclosure glaucoma. J Cataract Refract Surg 2021;47:504–511.

136. Chira-Adisai T, Mori K, Kobayashi A, Ueno M, Ikeda Y, Sotozono C, et al. Outcomes of combined gonioscopy-assisted transluminal trabeculotomy and goniosynechialysis in primary angle closure: A retrospective case series. Int Ophthalmol 2021;41:1223–1231.

137. Sharkawi E, Artes PH, Lindegger DJ, Dari ML, Wardani ME, Pasquier J, et al. Gonioscopy-assisted transluminal trabeculotomy in primary angle-closure glaucoma. Graefes Arch Clin Exp Ophthalmol 2021;259:3019–3026.

138. Fontana L, De Maria M, Iannetta D, Moramarco A. Gonioscopy-assisted transluminal trabeculotomy for chronic angle-closure glaucoma: Preliminary results. Graefes Arch Clin Exp Ophthalmol 2022;260:545–551.

139. Chansangpetch S, Lau K, Perez CI, Nguyen N, Porco TC, Lin SC. Efficacy of cataract surgery with trabecular microbypass stent implantation in combined-mechanism angle closure glaucoma patients. Am J Ophthalmol 2018;195:191–198.

140. Chen DZ, Sng CC, Sangtam T, Thomas A, Shen L, Huang PK, et al. Phacoemulsification vs phacoemulsification with micro-bypass stent implantation in primary angle closure and primary angle closure glaucoma: A randomized single-masked clinical study. Clin Exp Ophthalmol 2020;48:450–461.

141. Laroche D, Brown A, Ng C. Clear lensectomy, goniosynechiolysis and hydrus microstent in a patient with mixed mechanism glaucoma. J Natl Med Assoc 2020;112:339–343.

142. Sng CC, Chew PT, Htoon HM, Lun K, Jeyabal P, Ang M. Case series of combined XEN implantation and phacoemulsification in Chinese eyes: One-year outcomes. Adv Ther 2019;36:3519–3529.

143. Uram M. Endoscopic cyclophotocoagulation in glaucoma management. Curr Opin Ophthalmol 1995;6:19–29.

144. Uram M. Combined phacoemulsification, endoscopic ciliary process photocoagulation, and intraocular lens implantation in glaucoma management. Ophthalmic Surg 1995;26:346–352.

145. Chen J, Cohn RA, Lin SC, Cortes AE, Alvarado JA. Endoscopic photocoagulation of the ciliary body for treatment of refractory glaucomas. Am J Ophthalmol 1997;124:787–796.

146. Lai IS, Chan NC, Ling A, Baig NB, Chan PP, Wang YM, et al. Combined phacoemulsification-endoscopic cyclophotocoagulation versus phacoemulsification alone in primary angle-closure glaucoma: A pilot randomized controlled trial. Ophthalmol Glaucoma 2021;4:589–596.

147. Wu X, Wang Y, Liu X, Li ZH, Deng LQ, Chen DS, et al. Outcomes of chronic angle-closure glaucoma treated by phacoemulsification and endocyclophotocoagulation with or without endoscopically goniosynechialysis. Int J Ophthalmol 2022;15:1273–1278.

148. Netland PA, Mansberger SL, Lin S. Uncontrolled intraocular pressure after endoscopic cyclophotocoagulation. J Glaucoma 2007;16:265– 267.

149. Podbielski DW, Varma DK, Tam DY, Ahmed II. Glaucoma Today: Endocycloplasty. https://glaucomatoday.com/ articles/2010-oct/endocycloplasty. Published 2010.

150. Ahmed II, Podbielski DW, Naqi A, et al. Endoscopic cycloplasty in angle closure glaucoma secondary to plateau iris. American Glaucoma Society (AGS) Annual Meeting; March 5-8, 2009; San Diego, CA.

151. Pathak-Ray V. Intermediate results of phacoendocycloplasty in an exclusive cohort of angle closure glaucoma: potential for change. Int Ophthalmol. 2019;39(10):2257-2265.

152. Pathak-Ray V, Choudhari N. Phaco-endocycloplasty versus Phacotrabeculectomy in Primary Angle- Closure Glaucoma: A Prospective Randomized Study. Ophthalmol Glaucoma. 2020;3(6):434-442.