ORIGINAL STUDY

Bilateral Same-day Peripheral Iridotomy in the Philadelphia Detection and Treatment Project

Michael Waisbourd, MD,* Anousheh Shafa, BS,* Radha Delvadia, BS,* Harjeet Sembhi, MPH,* Jeanne Molineaux, COA,* Jeffery Henderer, MD,w Laura T. Pizzi, PharmD, MPH,z Jonathan S. Myers, MD,* Lisa A. Hark, PhD, RD,* and L. Jay Katz, MD*

reported in 2 patients (3%) and glare in 1 patient (1.5%). Thirteen Purpose: To report the outcomes of bilateral, same-day laser patients (19.7%) had repeat LPI treatment. All patients success- peripheral iridotomy (LPI) in the Philadelphia Glaucoma Detec- fully tolerated LPI treatment without serious complications. tion and Treatment Project. Conclusions: Performing bilateral, same-day LPI was well tolerated Methods: The Philadelphia Glaucoma Detection and Treatment in a large community-based, glaucoma detection and treatment Project was a community-based initiative aimed to improve project. Applying this treatment strategy may be considered in detection, management, treatment, and follow-up care of individ- similar settings, where patients’ access to care is limited and it uals at high risk for glaucoma. This novel project performed LPI, may be a cost-effective strategy. where 2 received laser therapy on the same day. Of the 1649 patients examined between January 1, 2013 and May 31, 2014, Key Words: glaucoma detection, angle closure, laser peripheral patients who underwent bilateral, same-day LPI were included in iridotomy, bilateral same-day ocular procedures our analysis. Main outcome measures were , intra- (J Glaucoma 2016;25:e821–e825) ocular pressure (IOP), and postoperative rates. Results: A total of 132 eyes of 66 patients underwent bilateral, aser iridotomy is aimed to eliminate the relative - same-day LPI. Mean visual acuity remained unchanged following Llary block component of the angle-closure process.1 The treatment (P = 0.85). Eight patients (12.1%) had IOP spikes American Academy of ’s Preferred Practice >5 mm Hg following treatment, and 4 patients (6.1%) spiked >10 mm Hg. IOP returned to normal in all but 1 patient, who was Pattern Guidelines recommend considering this treatment diagnosed with chronic angle-closure glaucoma. Hyphema was for patients with iridotrabecular contact (ITC) and normal intraocular pressure (IOP) to reduce the risk of developing chronic angle-closure and acute angle-closure crisis.2 Received for publication June 30, 2015; accepted February 2, 2016. Treatment is often performed in both eyes with separate From the *Glaucoma Research Center, Wills Eye Hospital; wDepart- ment of Ophthalmology, Temple University School of Medicine; procedures on different office visits. However, little is and zThomas Jefferson University School of Pharmacy, Phila- known about the outcomes of performing bilateral laser delphia, PA. peripheral iridotomy (LPI) on the same day. The findings and conclusions in this report are those of the authors and Simultaneous bilateral ocular procedures and surgeries do not necessarily represent the official position of the United States 3–8 Centers for Disease Control and Prevention. have been gaining popularity in recent years. Several case Supported by the United States Centers for Disease Control and Pre- series showed that bilateral intravitreal antivascular endo- vention (grant number: 1U58DP004060-01). thelial growth factor injections were well tolerated in office- Lumenis (San Jose, CA) donated the Selecta Duet laser platform. based settings. In 1 study, none of the patients requested Disclosure: L.J.K.: receives consultant fees from Allergan, Alcon, Glaukos Corporation, Aerie Pharmaceuticals, Bausch & Lomb, alternating unilateral injections after receiving bilateral Inotek Corporation, Sensimed AG, Alimera Sciences, ForSight injections,4 and other studies reported similar complication Vision, and Mati Therapeutics; receives payment for lectures, rates to unilateral injections.6,9 Some authors have sug- including service on speakers’ bureaus, from Allergan, Alcon, gested that surgery should be performed bilaterally Merck, and Lumenis; and has stock/stock options in Glaukos 3,10 10 Corporation, Mati Therapeutics, and Aerie Pharmaceuticals. on the same day, as the standard of care. Visual acuity M.W.: received travel/accommodations/meeting expenses payment (VA) improved, patients satisfaction increased, and no from Alcon for the CPE Glaucoma Fellows course. Research complications could be attributed to procedures performed Support: Iridex Corporation; Diopsys Inc.; Heidelberg; Allergan; bilaterally.3,8 Moreover, the risk of postoperative endoph- OrCam; Merck, Partridge Foundation; Pennsylvania Department of Health; United States Centers for Disease Control and Pre- thalmitis was as low as published rates for unilateral sur- vention. L.A.H: receives research support from the United States gery.9 The bilateral approach also generated substantial Centers for Disease Control and Prevention. H.S.: Receives savings in health care and non–health care-related research support from the United States Centers for Disease Con- 5,11,12 trol and Prevention. L.T.P: Receives research support from Thomas costs. In 2010, 2 unilateral cataract surgeries totaled Jefferson University. J.H. Receives Research Support from CMS. $1566, compared with $1059 for 1 bilateral cataract surgery J.S.M. receives consultant fees from Alcon, Allergan, Inotek, (32.4% reduction) in Canada.7 Reichert. Receives payment for lectures from Alcon and Allergan. In January 2013, the Wills Eye Glaucoma Research Receives Research Support from Aerie, Alcon, Allergan, Haag- Center initiated The Philadelphia Glaucoma Detection and Streit, Merck. The other authors have no conflict of interest to declare. Treatment Project. This unique project mobilized com- Reprints: Michael Waisbourd, MD, Wills Eye Hospital Glaucoma munity partners to plan, develop, and implement an inte- Research Center, Philadelphia, PA 19107 (e-mail: mwaisbourd@ grated community-based intervention to improve detection, willseye.org). management, treatment, and follow-up care of Philadel- Copyright r 2016 Wolters Kluwer Health, Inc. All rights reserved. DOI: 10.1097/IJG.0000000000000409 phians at high risk for glaucoma. At the community sites,

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LPI was performed for high-risk persons on both eyes during the same day. The purpose of this study was to investigate the outcomes of performing bilateral, same-day LPI in community setting.

METHODS The Institutional Review Board of Wills Eye Hospital approved the study and the study was in accordance with HIPAA regulations. Researchers from the Wills Eye Glaucoma Research Center retrospectively reviewed the records of patients who were examined in a community- based glaucoma detection and treatment project. The design and methodology of this project are described in detail elsewhere.13 In brief, the target population of this project was the underserved Philadelphia population composed of African FIGURE 1. The Philadelphia Glaucoma Detection and Treatment Americans over age 50 and other individuals over age 60. Project. A van transports the intervention team to the community With the help of local community partners (eg, government site, along with all the necessary equipment for examination, treatment, and follow-up. Following a slit-lamp examination, agencies, nonprofit organizations, and community-based , and automated perimetry, laser peripheral organizations) that serve African Americans and older iridotomy was performed bilaterally on the same day onsite adults, we conducted glaucoma-awareness educational (Courtesy: Roger Barone, Wills Eye Hospital). workshops at the community, in which audiences learned about glaucoma, with an emphasis on the importance of also used pretreatment and posttreatment to reduce the risk early detection and treatment. Persons at risk who attended of a postoperative IOP spike. An YAG LPI was performed the workshop were invited to attend glaucoma-detection at energy levels of 5 to 15 mJ, typically using between 1 and examinations. 3 pulses, depending on the thickness of the stroma and A 5-person screening team comprised of a the iris pigment. Thicker and darker irides were treated with (glaucoma specialist or fellow), a mobile unit coordinator, more power than light-colored irides. The position of the an ophthalmic technician, and 2 coordinators performed LPI was most often at the 3 or 9 o’clock position. Indi- the examinations at community sites. A large van trans- viduals had their IOP checked postprocedure (after 30 min ported the intervention team, along with all the necessary to 2 h) and then were discharged. Patients were given equipment for examination, treatment, and follow-up care postoperative steroid drops, and advised to use them 4 (Fig. 1). The glaucoma evaluation consisted of ocular, times daily for 4 days. Follow-up appointments were medical, and family history, VA, corneal pachymetry, scheduled at the community sites 4 to 6 weeks’ post- biomicroscopy of the anterior segment, IOP measurement operative and 4 to 6 months’ postoperative. using Goldmann applanation tonometer, , The current study reviewed the charts of patients who optic-nerve evaluation by indirect biomicroscopy, visual underwent bilateral same-day LPI. Patients who were field testing using Octopus 300 Visual Field Analyzer advised to have LPI in 1 eye or those who had bilateral (Haag-Streit Inc., Bern, Switzerland), and fundus color LPIs on separate visits were excluded. In some cases, cat- photography (Volk Pictor; Optomed Oy Ltd, Oulu, aract surgery was suggested to improve vision and possibly Finland). further deepen the angle. However, even in these cases, Upon completion of the examination, the physician LPI was initially performed to relieve pupillary block reviewed examination results of each individual. If the component. The following parameters were recorded: individual was diagnosed with glaucoma based on the optic demographic characteristics, including age, sex, race, and nerve appearance and perimetry or was considered a glau- ethnicity; cup to disc ratio and disc damage likelihood coma suspect, the physician discussed and wrote down the scale14; preoperative and postoperative VA and IOP; recommended treatment and follow-up plan. Individuals gonioscopy grading including angle deepening, defined as who were diagnosed with definite open-angle glaucoma and ITC of <180 degrees following treatment; use of post- required treatment were offered treatment by selective laser operative IOP-lowering medications; and postoperative or medications (timolol maleate or generic complications including IOP spike >5 and >10 mm Hg, prostaglandin analogs). For individuals diagnosed with VA decrease of >2 lines, hyphema, glare or ghost images, primary angle-closure suspect (PACS), primary angle clo- persistent inflammatory response, or other known compli- sure, or primary angle-closure glaucoma,2 LPI was advised. cations of LPI. Angle closure was defined as >180 degrees of ITC in pri- mary gaze on gonioscopy. All laser procedures were per- Statistical Analysis formed using the Selecta Duet (Lumenis, San Jose, CA). Demographic and eye measurement information was Patients were encouraged to undergo the LPI treatments summarized using means and SDs, medians and ranges bilaterally on the same day. Patients were offered the option (when skewed), or counts and percentages, as appropriate. to receive the treatments on 2 separate visits if they Race groups and sexes were compared using the non- preferred. parametric Mann-Whitney test for continuous variables In patients who were advised to have LPI, the proce- and the Fisher exact test for categorical variables. For dure was explained in detail and an informed consent form change in acuity at the eye level, mixed effects linear was obtained. Topical pilocarpine and anesthetics were regression was used to account for correlation between eyes instilled before the procedure. Topical brimonidine was from the same subject and repeated measurements. e822 | www.glaucomajournal.com Copyright r 2016 Wolters Kluwer Health, Inc. All rights reserved. Copyright r 2016 Wolters Kluwer Health, Inc. All rights reserved. J Glaucoma Volume 25, Number 10, October 2016 Bilateral Same-day Laser Peripheral Iridotomy

TABLE 1. Demographic and Clinical Characteristics of Patients TABLE 2. Rates of IOP Spikes Following Bilateral Same-day LPI, Who Underwent Same-day Bilateral LPI in the Philadelphia Need for Repeat Treatment, and Additional Complications Glaucoma Detection and Treatment Project Variables No. Patients [n (%)] Characteristics Data IOP spikes Patients [n (eyes)] 66 (132) Post-LPI > 5 mm Hg 8 (12.1) Age [mean (SD)] (y) 68.8 (10.0) Post-LPI > 10 mm Hg 4 (6.1) Sex: female [n (%)] 44 (67) Requiring IOP-lowering medications 6 (9.1) Race [n (%)] Repeat LPI treatment 13 (19.7) African American 34 (51.5) Additional complications Asian 16 (24.2) Glare/ghost images 1 (1.5) White 11 (16.7) Hyphema 2 (3.0) Hispanic 5 (7.6) Vision loss of >2 Snellen lines 0 IOP [median (range)] Corneal decompensation 0 Pre-LPI 15 (9-32) Post-LPI* 14 (6-60) IOP indicates intraocular pressure, LPI, laser peripheral iridotomy. VA logMar [median (range)]w VA pre-LPI logMAR 0.18 (0-1) VA post-LPI logMARz 0.18 (0-1) Thirteen patients (19.7%) required repeat treatment Optic disc [median (range)] on a separate follow-up visit. There were no differences by C/D ratio 0.50 (0.1-0.9) race (P = 0.52) or sex (P = 0.26) in the rates of patients DDLS 3 (1-8) who required repeat treatment. Two complications occur- *IOP post-LPI: 30 minutes to 2 hours following the procedure. red aside from an IOP spike: glare/ghost images and tran- wOne eye with no light perception was excluded. sient hyphema. No subjects had VA decrease >2 lines in zVA post-LPI: in the following follow-up visit. either eye. C/D indicates cup to disc; DDLS, disc damage likelihood scale; IOP, intraocular pressure; logMAR, log of the minimum angle of resolution; LPI, laser peripheral iridotomy; VA, visual acuity. DISCUSSION Our study assessed the clinical outcomes of performing bilateral LPI on the same day in the Philadelphia Glau- RESULTS coma Detection and Treatment Project. This initiative The Philadelphia Glaucoma Detection and Treatment enrolled 1649 individuals from 43 community sites in the Project enrolled 1649 patients between January 1, 2013 and greater Philadelphia area, and the Wills Eye team per- May 31, 2014. Of those, 138 (8.4%) were advised to have formed examinations and treatments in community set- LPI, 86 (5.2%) underwent this procedure, and 71 (4.3%) tings. Overall, 132 eyes of 66 patients underwent LPI had the procedure bilaterally on the same day. Of those 71, bilaterally on the same day and the procedure was well we excluded 5 subjects due to missing data; therefore, 66 tolerated with low rates of complications. subjects (132 eyes) were included in the analysis. Known complications of LPI include immediate IOP The demographic and clinical characteristics of these rise,15 ,16 marked inflammation,17 visual shadows, patients are shown in Table 1. ghost images, crescents, lines,18 cataract progression,19 Of the total 116 eyes for which gonioscopy data were dislocation,20 and other lens-related and -related available, 90 eyes (77.6%) had angle deepening. Potential pathologies, including corneal decompensation.21–26 Per- reasons for angles not deepening include plateau iris con- forming LPIs on 2 separate visits could possibly reduce the figuration and phacomorphic component. Of the total 132 rate of complications occurring in both eyes simulta- eyes that underwent the recommended same-day bilateral neously. In the current study, the most commonly reported LPI, 101 eyes (76.5%) were diagnosed with PACS, 20 eyes complication was an IOP spike, which was treated medi- (15%) were diagnosed with primary angle closure, and 11 cally in 6 (9.1%) patients. All but 1 patient responded well, eyes (8.3%) already had a diagnosis of glaucoma. Mean returning to normal IOP values. This patient, diagnosed (95% CI) LogMAR VA was 0.19 (0.16 to 0.23) at baseline with primary angle-closure glaucoma, required continuous and 0.19 (0.15 to 0.23) on the visit following the LPI use of glaucoma medications following bilateral IOP spikes. (P = 0.85) (mixed effects model). African Americans had the highest rate of >10 mm Hg IOP The rates of IOP spikes (first IOP measured following spike. However, when compared with other groups, this the LPI) are described in Table 2. The majority of the patients difference did not reach statistical significance, possibly due were female (67%) and either African American (51.5%) or to the small sample size. It is plausible that African Asian (24.2%). Overall, 8 (12.1%) participants had IOP spike American individuals, who often have thicker irides,27 have >5 mm Hg and 4 (6.1%) had IOP spike >10 mm Hg. more dispersion of pigment during the LPI, which may Asian individuals had the highest proportion of IOP cause higher IOP spikes. It may be prudent to perform this spikes, based on 5 mm Hg increase (n = 4/16, 25.0%), fol- procedure with caution in these patients, especially when lowed by African Americans (n = 4/34, 11.8%). Using the performing the procedure bilaterally on the same day. In 10 mm Hg increase criteria, African Americans experienced addition, it is possible that patients with extensive PAS may spikes more frequently than Asians (n = 3/34, 8.8% and develop IOP spikes, and therefore treatments should be n = 1/16, 6.0%, respectively). Patients of other ethnicities done cautiously. Additional adverse events in our cohort had no spikes at either level. None of these differences in the included hyphema (n = 2, 3%) and ghost images (n = 1, rate of IOP spikes between ethnic groups reached statistical 1.5%). The rate of complications is comparable with, or significance (P = 0.30 and 0.86 for spikes >5 and >10 mm lower than, the rate reported in other prospective stud- Hg, respectively). ies.15,16,28 A screening program for angle closure in

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Mongolia offered bilateral LPIs to patients with confirmed subjective symptoms such as ghost images or glare. This diagnosis. Treatment outcomes were excellent, with 98% of shortcoming might have resulted in an underestimation of treated eyes showing angle deepening29; however, the the actual rate of these complications. Nevertheless, we reports do not specify how many patients were actually believe that substantial and bothersome symptoms were treated using this strategy and what was the complication reported and recorded by the . Minor compli- rate associated with this treatment.29,30 cations, such as mild hyphema, may not have been Performing bilateral ocular procedures or surgeries, such recorded if the physician did not consider them clinically as intravitreal injections or cataract surgeries, is gaining popu- significant, suggesting a possible underreporting of this larity. The advantages of performing ocular procedures bilat- postoperative complication. However, documented out- erally include fewer office visits and increased convenience for come measures, such as VA, IOP, and number of IOP- patients and their family members.7,10 The reduced number of lowering medications, allowed us to obtain a more visits suggests this strategy would be less costly than performing objective assessment of changes in these parameters. The treatment on 2 separate visits. We developed a simple financial small sample size, relative short follow-up period of 6 model to estimate cost savings of the procedure alone, using a months, and lack of control group are additional limi- perspective. We used a 1-year time horizon and used tations of our study. Moreover, over one third of patients the most recently available data (2013). There were 80,374 LPI who were suggested to have an LPI did not schedule a procedures reimbursed under Medicare (written personal com- follow-up visit, and some elected to have LPIs on 2 dif- munication), of which we assumed all were unilateral. The per- ferent visits. This could have biased our results. Lastly, procedure national average for reimbursement to the physician different clinicians might have evaluated the angle before for the unilateral LPI (CPT code 66761) was $226 per proce- and after performing the LPIs to determine whether it dure.31 The bilateral scenario assumed that half as many pro- deepened. As gonioscopy is, to some extent, a subjective cedures would be performed (40,187) but at 1.5 times the examination, this might have been a confounding factor. reimbursement for the unilateral procedure ($340). Although we In conclusion, performing bilateral, same-day LPI in assumed the US Medicare model is based on all LPI procedures community-based settings was well tolerated and effective being conducted separately, this may not be accurate for all in deepening previously narrow angles. This treatment patients, as some ophthalmologists in the United States may be strategy should be considered especially in similar settings performing bilateral LPI procedures. The model indicates that where access to eye care is limited for a high-risk total physician reimbursements in the unilateral scenario were population. $18,225,608 and in the bilateral scenario would have been $13,669,206, representing a savings to Medicare of $4,556,402 fortheyearofanalysis.Thisisanunderestimateofsavingsasit ACKNOWLEDGMENTS excludes facility and follow-up visit fees. Moreover, there would The authors thank John E. Crews, DPA and Jinan B. be savings to the patient from reduced travel time and costs, as Saaddine MD, MPH from the Vision Health Initiative, well as reduced patient and caregiver productivity losses Division of Diabetes Translation at the Centers for Disease resulting from attending 1 procedure instead of 2. These eco- Control and Prevention for their continuous support in the nomic issues are worth further exploration. Philadelphia Glaucoma Detection and Treatment Project. Another benefit of this program is that the patients were predominantly from underserved, urban communities REFERENCES and were at risk for developing glaucoma. Previous research has shown that this population is less likely than 1. Liebmann JM, Ritch R. Laser surgery for angle closure other patient groups to obtain ocular examinations from an glaucoma. Semin Ophthalmol. 2002;17:84–91. ophthalmologist.32–35 The bilateral strategy ensures these 2. AAO PPP Glaucoma Panel, Hoskins Center for Quality Eye Care. Primary angle closure PPP, 2010. Available patients receive treatment for both eyes when necessary. at: http://one.aao.org/preferred-practice-pattern/primary-angle- The prevalence of patients who were advised to closure-ppp–october-2010. Accessed January 28 2014. undergo an LPI in this project (8.4%) was higher than 3. Arshinoff SA, Strube YN, Yagev R. Simultaneous bilateral expected. This finding may be caused by selection bias in cataract surgery. J Cataract Refract Surg. 2003;29:1281–1291. our underserved patient population. These patients may 4. Bakri SJ, Risco M, Edwards AO, et al. Bilateral simultaneous have more advanced , which contribute to the intravitreal injections in the office setting. Am J Ophthalmol. narrowing of their angles by a phacomorphic mechanism. 2009;148:66.e61–69.e61. The 8.4% prevalence of LPI for patients with angle closure 5. Leivo T, Sarikkola AU, Uusitalo RJ, et al. Simultaneous in this study is comparable with previous publications bilateral cataract surgery: economic analysis; Helsinki Simul- taneous Bilateral Cataract Surgery Study Report 2. J Cataract about the high prevalence of PACS among specific ethnic 36–38 Refract Surg. 2011;37:1003–1008. groups internationally, ranging from 5.7% to 17%. 6. Mahajan VB, Elkins KA, Russell SR, et al. Bilateral intra- In this project, a significant proportion of patients vitreal injection of antivascular endothelial growth factor (19.7%) who underwent LPI required repeat treatments. therapy. Retina. 2011;31:31–35. Many of these patients (predominately African American) 7. O’Brien JJ, Gonder J, Botz C, et al. Immediately sequential had thick irides, which may require several treatments to bilateral cataract surgery versus delayed sequential bilateral fully penetrate the iris. The fact that both eyes were treated cataract surgery: potential hospital cost savings. Can J on the same day may have led to more conservative use of Ophthalmol. 2010;45:596–601. energy levels in 1 LPI treatment session. Another option to 8. Serrano-Aguilar P, Ramallo-Farina Y, Cabrera-Hernandez JM, et al. Immediately sequential versus delayed sequential treat individuals with dark thick irides is to pretreat with bilateral cataract surgery: safety and effectiveness. J Cataract low-energy argon laser before performing YAG LPI—a Refract Surg. 2012;38:1734–1742. 39 technique which may lower complication rates. 9. Lima LH, Zweifel SA, Engelbert M, et al. Evaluation of safety A major limitation of this study was its retrospective for bilateral same-day intravitreal injections of antivascular nature. Patients were not directly asked to report specific endothelial growth factor therapy. Retina. 2009;29:1213–1217. e824 | www.glaucomajournal.com Copyright r 2016 Wolters Kluwer Health, Inc. All rights reserved. Copyright r 2016 Wolters Kluwer Health, Inc. All rights reserved. J Glaucoma Volume 25, Number 10, October 2016 Bilateral Same-day Laser Peripheral Iridotomy

10. Arshinoff SA. Same-day cataract surgery should be the 25. Lim LS, Ho CL, Ang LP, et al. Inferior corneal decom- standard of care for patients with bilateral visually significant pensation following laser peripheral iridotomy in the superior cataract. Surv Ophthalmol. 2012;57:574–579. iris. Am J Ophthalmol. 2006;142:166–168. 11. Malvankar-Mehta MS, Filek R, Iqbal M, et al. Immediately 26. Liu DT, Lai JS, Lam DS. Descemet membrane detachment sequential bilateral cataract surgery: a cost-effective procedure. after sequential argon-neodymium:YAG laser peripheral iri- Can J Ophthalmol. 2013;48:482–488. dotomy. Am J Ophthalmol. 2002;134:621–622. 12. Sarikkola AU, Uusitalo RJ, Hellstedt T, et al. Simultaneous 27. Lee RY, Huang G, Porco TC, et al. Differences in iris bilateral versus sequential bilateral cataract surgery: Helsinki thickness among African Americans, Caucasian Americans, Simultaneous Bilateral Cataract Surgery Study Report 1. Hispanic Americans, Chinese Americans, and Filipino-Amer- J Cataract Refract Surg. 2011;37:992–1002. icans. J Glaucoma. 2013;22:673–678. 13. Hark L, Waisbourd M, Sembhi H, et al. Improving access to 28. Vera V, Naqi A, Belovay GW, et al. Dysphotopsia after eye care among persons at high-risk for glaucoma in temporal versus superior laser peripheral iridotomy: a pro- Philadelphia: design and methodology. The Philadelphia spective randomized paired eye trial. Am J Ophthalmol. Glaucoma Detection and Treatment Project. Ophthalmic 2014;157:929–935. Epidemiol. (In press). 29. Nolan WP, Foster PJ, Devereux JG, et al. YAG laser 14. Spaeth GL, Henderer J, Liu C, et al. The disc damage iridotomy treatment for primary angle closure in east Asian likelihood scale: reproducibility of a new method of estimating eyes. Br J Ophthalmol. 2000;84:1255–1259. the amount of optic nerve damage caused by glaucoma. Trans 30. Yip JL, Foster PJ, Uranchimeg D, et al. Randomised Am Ophthalmol Soc. 2002;100:181–185. Discussion 185–186. controlled trial of screening and prophylactic treatment to 15. Jiang Y, Chang DS, Foster PJ, et al. Immediate changes in prevent primary angle closure glaucoma. Br J Ophthalmol. intraocular pressure after laser peripheral iridotomy in primary 2010;94:1472–1477. angle-closure suspects. Ophthalmology. 2012;119:283–288. 31. Ingenix. National Fee Analyzer: Charge Data for Evaluating 16. Golan S, Levkovitch-Verbin H, Shemesh G, et al. Anterior Fees Nationally. Salt Lake City, UT: Ingenix; 2013. chamber bleeding after laser peripheral iridotomy. JAMA 32. Lee BW, Murakami Y, Duncan MT, et al. Patient-related and Ophthalmol. 2013;131:626–629. system-related barriers to glaucoma follow-up in a county 17. Siam GA, de Barros DS, Gheith ME, et al. Post-peripheral hospital population. Invest Ophthalmol Vis Sci. 2013;54: iridotomy inflammation in patients with dark pigmentation. 6542–6548. Ophthalmic Surg Imaging. 2008;39:49–53. 33. Murakami Y, Lee BW, Duncan M, et al. Racial and ethnic 18. Spaeth GL, Idowu O, Seligsohn A, et al. The effects of disparities in adherence to glaucoma follow-up visits in a iridotomy size and position on symptoms following laser county hospital population. Arch Ophthalmol. 2011;129: peripheral iridotomy. J Glaucoma. 2005;14:364–367. 872–878. 19. Lim LS, Husain R, Gazzard G, et al. Cataract progression 34. Potamitis T, Chell PB, Jones HS, et al. Non-attendance at after prophylactic laser peripheral iridotomy: potential impli- ophthalmology outpatient clinics. J R Soc Med. 1994;87: cations for the prevention of glaucoma blindness. Ophthalmol- 591–593. ogy. 2005;112:1355–1359. 35. Ung C, Murakami Y, Zhang E, et al. The association between 20. Moore SP, Smith M, Rattigan S, et al. Lens dislocation compliance with recommended follow-up and glaucomatous following YAG laser peripheral iridotomy. Ophthalmic Surg disease severity in a county hospital population. Am J Lasers Imaging. 2010;9:1–2. Ophthalmol. 2013;156:362–369. 21. Athanasiadis Y, de Wit DW, Nithyanandrajah GA, et al. 36. Arkell SM, Lightman DA, Sommer A, et al. The prevalence of Neodymium:YAG laser peripheral iridotomy as a possible glaucoma among Eskimos of northwest Alaska. Arch Oph- cause of zonular dehiscence during thalmol. 1987;105:482–485. cataract surgery. Eye (Lond). 2010;24:1424–1425. 37. Casson RJ, Newland HS, Muecke J, et al. Gonioscopy findings 22. Gaynor BD, Stamper RL, Cunningham ET Jr. Presumed and prevalence of occludable angles in a Burmese population: activation of herpetic keratouveitis after Argon laser peripheral the Meiktila Eye Study. Br J Ophthalmol. 2007;91: iridotomy. Am J Ophthalmol. 2000;130:665–667. 856–859. 23. Hou YC, Chen CC, Wang IJ, et al. Recurrent herpetic 38. Salmon JF, Mermoud A, Ivey A, et al. The prevalence of keratouveitis following YAG laser peripheral iridotomy. primary angle closure glaucoma and open angle glaucoma in Cornea. 2004;23:641–642. Mamre, western Cape, South . Arch Ophthalmol. 24. Landers J, Craig J. Decompression retinopathy and corneal 1993;111:1263–1269. oedema following Nd:YAG laser peripheral iridotomy. Clin 39. de Silva DJ, Gazzard G, Foster P. Laser iridotomy in dark Experiment Ophthalmol. 2006;34:182–184. irides. Br J Ophthalmol. 2007;91:222–225.

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