- Email: [email protected]
Resident-performed neodymium:YAG laser posterior capsulotomy
Resident-performed neodymium:YAG laser posterior capsulotomy Khalil Ghasemi Falavarjani, MD, Mohammadreza Aghamirsalim, MD, Kaveh Abri Aghdam, MD, PhD ABSTRACT ● Objective: To investigate the outcomes of resident-performed Nd:YAG laser posterior capsulotomy. Design: Combined retrospective and prospective study. Participants: Patients (N ¼ 301) who underwent Nd:YAG capsulotomy by ophthalmology residents at Rassoul Akram Hospital, Tehran, Iran. Methods: Assessment of visual outcomes and complications and the results of second- and third-year residents. Results: In the retrospective arm, 131 eyes of 129 patients were enrolled. Mean best-corrected visual acuity (BCVA) improved significantly from 1.15 ⫾ 0.26 to 0.54 ⫾ 0.39 logMAR (p o 0.001). Mean intraocular pressure (IOP) before capsulotomy and at the final visit was 13.1 ⫾ 2.34 mm Hg and 13.6 ⫾ 2.17 mm Hg, respectively (P ¼ 0.30). Retinal detachment occurred in 2 eyes (1.5%). No case of intraocular lens decentration or endophthalmitis was detected. In the prospective arm on 173 eyes of 172 patients, mean pre-YAG BCVA was 1.14 ⫾ 0.25 logMAR and increased to 0.51 ⫾ 0.37 logMAR after surgery (p o 0.001). There was no significant difference between pre-laser IOP measurements compared with the 1-month IOP measurements (P ¼ 0.32). The postoperative changes in mean BCVA and IOP between the second- and third-year residents were not significant; however, the applied laser power, the number of laser spots, rate of incomplete capsulotomies, and the amount of total and central laserinduced IOL pits were significantly higher among the second-year residents. Conclusions: Resident-performed capsulotomy appears to be effective with a low complication profile. Despite the lower levels of surgical skills, second-year residents could achieve good visual outcomes. The laser parameters and IOL-related complications improved with increasing surgical experience.
Posterior capsular opacification (PCO) is a common cause of decreased visual acuity (VA) after uneventful extracapsular cataract extraction and intraocular lens (IOL) implantation1,2 A meta-analysis calculated PCO rates after cataract surgery to be 12% at 1 year, 21% at 3 years, and 28% at 5 years after surgery. Overall, 25% of patients undergoing extracapsular cataract surgery develop visually significant PCO within 5 years of the operation.3 PCO is caused by lens epithelial cells that remain in the capsular bag after cataract surgery. The cells migrate, proliferate, and transform to produce Elschnig’s pearls and capsular fibrosis.4 Nd:YAG laser posterior capsulotomy is commonly used to treat PCO. This procedure causes photodisruption of the capsule and thus clears the visual axis.5 Although Nd:YAG laser posterior capsulotomy improves visual function, adverse effects6 such as a rise in intraocular pressure (IOP), IOL damage, subluxation of the intraocular lens, cystoid macular edema, uveitis, or retinal detachment may occur. Ophthalmology residents are required to become proficient in performing Nd:YAG laser capsulotomy during their training. They must be familiar with the technique of laser capsulotomy, and the U.S. Accreditation Council for Graduate Medical Education (ACGME) requires a
minimum of 5 laser capsulotomy surgeries before graduation.7 In Iran, after passing the Comprehensive Medical Residency Entrance Exam and achieving higher marks to choose ophthalmology training programs, residents are accepted into the fully accredited program at different medical universities. The length of training in ophthalmology is 4 years, and the program is divided into 3 parts: observation (first 3 months), comprehensive clinic visits (months 3 to 12), and subspecialty rotations (years 2 to 4). During comprehensive clinic visits, residents visit patients under the supervision of attending ophthalmologists; introductory surgical observation occurs during the first year as well. During the period of subspecialty rotations, residents achieve in-depth understanding in different fields including retinal diseases, pediatric ophthalmology, oculoplastics, glaucoma, and corneal diseases and gain surgical skills in ophthalmic operations. Regular journal clubs, grand rounds, Basic and Clinical Science Course review, case presentation sessions, and other teaching conferences covering all subspecialties of ophthalmology complete the teaching cycle. Tables 1 and 2 presents the required minimum number of procedures for graduating Iranian residents in ophthalmology.8 The aims of this study were to evaluate the outcomes of Nd:YAG laser capsulotomy performed by ophthalmology
& 2016 Canadian Ophthalmological Society. Published by Elsevier Inc. All rights reserved. http://dx.doi.org/10.1016/j.jcjo.2016.11.026 ISSN 0008-4182/16 CAN J OPHTHALMOL — VOL. ], NO. ], ] 2016
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ND:YAG capsulotomies by residents—Ghasemi Falavarjani et al. Table 1—Type and minimum number of the procedures required for graduating ophthalmology residents in Iran, extra-ocular surgeries. Surgeries
Available from the Second Year of Residency
Eyelid Surgeries (at least 30 surgeries) Repair of simple laceration of eyelid and conjunctiva Eyelid and conjunctival laceration repair Chalazion removal Simple surgical ptosis Surgery of congenital ptosis Removal of periorbital simple tumors Blepharoplasty, eyelid reconstruction Tarsoraphy Blepharoraphy Entropion and ectropion surgery Eyelid retraction surgery Canthoplasty Lacrimal System Surgeries (at least 15 surgeries) Canalicular laceration repair Plugging of lacrimal punctom Probing Silicon tube Dacryocystorhinostomy Orbital Surgeries (at least 10 procedures) Orbital fractures repair Orbitotomy (to remove the tumor, foreign body, abscesses, etc.) Evisceration Enucleation Exenteration Orbital decompression Socket repair Excision of conjunctival tumors with or without cryotherapy Optic nerve decompression Strabismus Surgeries (at least 15 procedures) Horizontal rectus muscle surgery Vertical rectus muscle and the inferior oblique muscle surgery Superior oblique muscle surgery Adjustable suture surgery Strabismus reoperation Muscle transposition surgery Injection of botulinum A toxin Surgery for nystagmus (in large recess cases)
residents in a tertiary ophthalmic university center and to determine whether the resident year significantly influences complication rates.
METHODS This was a combined retrospective and prospective study in which 2 sets of results from 301 patients (304 eyes) from the Department of Ophthalmology at Rassoul Akram University Hospital, Tehran, Iran, were analyzed. In the retrospective arm of the study, files of all patients who underwent Nd:YAG laser posterior capsulotomies by ophthalmology residents between March 2011 and March 2014 were retrieved, whereas all patients operated for PCO from March 2014 to December 2014 were recruited into the prospective study. The study design was approved by the Eye Research Center Ethics Committee of the Iran University of Medical Sciences and adhered to the tenets of the Declaration of Helsinki. Retrospective arm
Consecutive patients treated with Nd:YAG capsulotomies by ophthalmology residents at Rassoul Akram
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CAN J OPHTHALMOL — VOL. ], NO. ], ] 2016
Available in the Third and Fourth Year of Residency
Resident Can Only Assist Surgery
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
Hospital during a 3-year period from March 2011 to March 2014 were identified from laser log books and by the retrospective review of scheduling logs for the laser clinic. Included eyes needed to have at least 1 year of follow-up. Exclusion criteria included the following: insufficient data in the medical records; history of intraocular surgery (other than cataract surgery); history of glaucoma; history of uveitis; IOL decentration; and no follow-up visits after treatment.
Each included patient had been previously examined by an attending ophthalmologist and had been referred for Nd:YAG capsulotomy. Pre- and postoperative Snellen best-corrected visual acuity (BCVA), IOP, and complications including IOL decentration, IOL dislocation, endophthalmitis, and retinal detachment were collected from the patients’ files.
ND:YAG capsulotomies by residents—Ghasemi Falavarjani et al. Table 2—Type and minimum number of the procedures required for graduating ophthalmology residents in Iran, intraocular surgery. Available from the Second Available in the Third and Resident Can Only Year of Residency Fourth Year of Residency Assist Surgery
Surgeries Anterior Segment Surgery (at least 120 procedures) Extracapsular cataract extraction Phacoemulsification Lensectomy Lens removal in subluxated cases Lensectomy in traumatic cataract with corneal laceration Laser capsulotomy Secondary IOL implantation Replacement IOL Anterior vitrectomy (for vitreous extraction after cataract surgery) Corneal surgery Conjunctival flap Amniotic membrane transplantation Penetrating keratoplasty Superficial keratectomy DSEAK Simple corneal laceration repair Complex corneal laceration repair Refractive surgery using laser Surface ablation in simple myopia LASIK in simple myopia Collagen cross-linking Other anterior segment surgeries AC washing Anterior vitrectomy— limbal Simple pterygium surgery Complex pterygium surgery Glaucoma Surgery (at least 30 surgeries) Trabeculectomy in adults Trabeculectomy in children Re-trabeculectomy Trabeculotomy Cataract surgery after glaucoma surgery Cataract surgery combined with glaucoma surgery Goniotomy Choroidal tap Shunt placement Endoscopic photocoagulation Laser trabeculoplasty Laser iridoplasty Laser iridotomy Cyclophotocoagulation Vitreoretinal Surgery (at least 20 laser procedures, 20 injections, and 20 surgeries) Panretinal photocoagulation Laser for macular edema Intravitreal injection Scleral buckling Core vitrectomy Pars plana vitrectomy Silicone oil removal
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
DSEAK: descemet stripping endothelial automated keratoplasty; AC: anterior chamber; IOL: intraocular lens; LASIK: laser-assisted in situ keratomileusis.
Prospective arm
All pseudophakic patients who were scheduled for Nd: YAG posterior capsulotomy between March and December 2014 were screened for inclusion in this study. Informed consent was obtained from patients. The inclusion criteria were previous uneventful phacoemulsification with in-the-bag intraocular lens placement and the presence of visually significant PCO. All patients underwent comprehensive ophthalmologic examination including BCVA measurement, slit lamp biomicroscopy, IOP measurement by Goldmann applanation tonometry, and dilated fundus examination. Exclusion criteria were previous history of uveitis, severe contraction of the anterior capsule, and media opacities other than PCO.
Attending ophthalmologists were needed to confirm the presence of definite PCO on slit-lamp biomicroscopy. In our centre, laser capsulotomies are performed mainly by the second- and third-year ophthalmology residents (approximately 42% by the second-year and 58% by the third-year residents, according to the recent 8-year medical records). At the beginning of second year of residency, each resident receives didactics on the correct technique of Nd:YAG posterior capsulotomy from the attending surgeons and fellows. Each resident then performs Z5 procedures under close observation to be able to complete YAG capsulotomies independently. Neither attending physicians nor fellows were involved in the study. CAN J OPHTHALMOL — VOL. ], NO. ], ] 2016
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ND:YAG capsulotomies by residents—Ghasemi Falavarjani et al. Surgical technique
Before laser procedure, mydriasis was accomplished with phenylephrine 5% (Sina Darou, Tehran, Iran) and tropicamide 1% (Sina Darou). After topical anaesthesia with tetracaine 0.5% (Sina Darou), an Abraham capsulotomy contact lens (Ocular Instruments, Bellevue, Wash.) was applied to enhance the visualization of the posterior capsule and allow precise laser focus on it. Using the Q-Switched Nd:YAG laser (Quantel Medical Company, Paris, France ) in a circular pattern, the single bursts were performed starting at 0.5 mJ and gradually increased in power until a 3 to 4 mm capsular opening was created. After treatment, patients were given betamethasone 0.1% eye drops (Sina Darou) 4 times a day for 3 days. Laser power and spot numbers were recorded. The performing resident was unaware of this study, and an independent observer (M.A.) who was a second-year resident not involved in the procedure evaluated the patients immediately after surgery. The size of the posterior capsule opening was evaluated, and capsulotomies o3 mm of opening in the central papillary area or incomplete separation of posterior capsule were considered incomplete. The number of IOL pits due to incorrect laser spots in the whole capsulotomy area and in the central 1 mm of the pupillary space was recorded. IOP was measured before and 1 hour and 1 week after the procedure. Postoperative evaluation included changes in BCVA, IOP elevations, and complications related to the procedure at 1 hour and 1 week postsurgery. If the IOP was 421 mm Hg at 1 hour after the procedure, brimonidine 0.2% eye drops (Sina Darou) were prescribed, and the patient was followed for Z1 month after discontinuation of the eye drops.
Statistical Analysis
Data were analyzed using Software Package for the Statistical Sciences 15.0 (SPSS Inc, Chicago, Ill.). For statistical analysis, the Snellen VA records were converted to logMAR scale. We used the Kolmogorov–Smirnov test to test quantitative variables for normal distribution. Within-group changes from baseline were analyzed using paired t test. Chi-square and
Fisher’s exact tests were used to evaluate differences between second- and third-year complication rates. Means ⫾ SD were used for reporting the continuous variables. A p value o0.05 was considered statistically significant.
RESULTS Retrospective arm
We evaluated 131 eyes of 129 patients. The mean age of the patients was 63.65 ⫾ 9.8 years; 56 were male (43.8%) and 73 female (56.2%). Mean follow-up time was 43.2 ⫾ 2.1 months, and 118 cases (90.1%) had follow-up of 42 years. Mean BCVA improved significantly from 1.15 ⫾ 0.26 logMAR to 0.54 ⫾ 0.39 logMAR (p o 0.001). BCVA improvement of Z3 lines, Z2 lines, and Zone line was found in 42 eyes (32%), 53 (40%), and 32 eyes (24.4%), respectively. In all, 127 of 131 eyes (96.9%) had a BCVA improvement of Z1 lines. Mean IOP before capsulotomy and at the final visit was 13.1 ⫾ 2.34 mm Hg and 13.6 ⫾ 2.17 mm Hg, respectively (P ¼ 0.30). During follow-up, 16 eyes had IOP 421 mm Hg: a rise in IOP of 45 mm Hg and 410 mm Hg was found in 15 eyes (11.4%) and 1 eye (0.7%), respectively. These eyes were treated with antiglaucoma eye drops, and the IOP returned to normal within 2 to 4 weeks. Rhegmatogenous retinal detachment (RRD) occurred in 2 eyes (1.5%) during follow-up: One patient developed an RRD in the left eye 18 months after the laser capsulotomy, which was 5 years after uneventful phacoemulsification. The other patient developed an RRD 5 months after receiving capsulotomy for dense PCO of the left eye, which developed 4 years after an uneventful phacoemulsification. There were no predisposing risk factors for occurrence of RRD in these eyes. No case of IOL decentration or endophthalmitis was detected. Prospective arm
We included 173 eyes of 172 patients. Twelve residents (6 second-year and 6 third-year) performed Nd:YAG laser
Table 3—Characteristics of the eyes after laser capsulotomy performed by second- and third-year residents. Total No. of eyes (%) Laser power (mJ) No. of laser spots No. of eyes with incomplete capsulotomy (%) No. of eyes with IOL pits (%) No. of eyes with central IOL pits (%) No. of total IOL pits (%) No. of central IOL pits Change in BCVA (logMAR) IOP before Nd:YAG capsulotomy (mm Hg) IOP at 1 hour after Nd:YAG capsulotomy (mm Hg) IOP at 1 week after procedure (mm Hg)
173 2.79 ⫾ 0.90 30.36 ⫾ 13.54 34 (19.6) 157 (90.7) 64 (36.9) 9.56 ⫾ 7.37 3.37 ⫾ 2.76 2.33 ⫾ 1.03 13.29 ⫾ 2.37 14.97 ⫾ 3.95 13.77 ⫾ 2.17
IOL, intraocular lens; BCVA, best corrected visual acuity; IOP, intraocular pressure. n
†
t test. Fisher’s exact test.
‡ 2
χ test.
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Second-Year Resident Group 107 2.89 33.44 24 125 55 11.54 4.28 2.33 13.11 14.78 13.82
(62) ⫾ 0.96 ⫾ 13.92 (15.6) (72) (31.8) ⫾ 7.49 ⫾ 2.53 ⫾ 1.14 ⫾ 2.35 ⫾ 4.13 ⫾ 2.34
Third-Year Resident Group 66 2.53 22.38 10 32 9 4.41 1.03 2.32 13.76 15.46 13.64
(38) ⫾ 0.64 ⫾ 8.37 (5.7) (18.7) (5.2) ⫾ 3.68 ⫾ 1.74 ⫾ 0.71 ⫾ 2.39 ⫾ 3.44 ⫾ 1.74
p Value 0.256 0.01* o0.001* o0.01† o0.001† o0.001 (%)‡ o0.001* o0.001* 0.987* 0.435* 0.360* 0.644*
ND:YAG capsulotomies by residents—Ghasemi Falavarjani et al. posterior capsulotomies. The mean age of the patients was 64.3 ⫾ 8.98 years. There were 73 male (43.2 %) and 99 female (56.8%) patients. Table 3 presents the characteristics of Nd:YAG laser posterior capsulotomies. Mean pre-YAG capsulotomy BCVA was 1.14 ⫾ 0.25 logMAR and improved to 0.51 ⫾ 0.37 logMAR after capsulotomy surgery (p o 0.001). BCVA improved by Z3 lines in 59 eyes (34.1%), by 2 lines in 65 eyes (37.5%), and by 1 line in 46 eyes (26.5%). BCVA in 3 eyes (1.7%) failed to improve (2 eyes [1.1%] with diabetic retinopathy and 1 eye [0.6%] with age-related macular degeneration). The rise of IOP 1 hour after the capsulotomy was significant in both groups (Table 3). IOP of 421 mm Hg was found in 15 eyes (8.6%). In these eyes, brimonidine eye drops were prescribed, which were discontinued after 1 week and no eye had a rise of IOP 1 month after the procedure. There was no statistically significant difference between pre-laser IOP measurements compared with the 1-month IOP measurements (P ¼ 0.32). The postoperative changes in mean BCVA and IOP between the second- and third-year residents were not significant; however, the applied laser power, the number of laser spots, rate of incomplete capsulotomies, and the amount of total and central laserinduced IOL pits were significantly higher among the second-year residents (Table 3). No significant difference was found between the 2 groups of residents in terms of IOP changes (Table 3). No case of IOL decentration, vitreous presentation in the anterior chamber, or retinal detachment was observed.
DISCUSSION PCO is a common post-cataract surgery complication that is frequently managed in training centres where residents serve as the primary surgeons with attending supervision. It is important to investigate the outcomes of surgery at training centres, both to reassure patients that they are receiving the standard of care and good results and to determine areas for training improvement. Although a number of studies have evaluated resident complication rates in ophthalmic surgeries,9–11 limited research has been performed on the outcomes associated with the residentperformed Nd:YAG posterior capsulotomy. In the present study, we showed that the year of residency does not significantly influence the post-capsulotomy IOP or BCVA. IOL-related complication rates of second- and third-year resident surgeons do significantly differ, likely due to the effect of the learning curve. In the retrospective and prospective parts of the present study, BCVA improved similarly in 96.9 % and 98.3 % of eyes treated by ophthalmology residents. There are several studies on the influence of size of Nd:YAG laser posterior capsulotomy on visual function. Aslam and Dhillon12 reported that capsulotomy area has no significant correlation with eventual visual outcome in terms of contrast sensitivity, near and distance VA, or glare readings. Yilmaz et al.13
reported that the size of posterior capsulotomy does not significantly affect refraction and VA. Hayashi et al.14 found that contrast VA and glare VA with a small capsulotomy were significantly worse than those with a large capsulotomy, but BCVA was not affected significantly. We considered capsulotomies o3 mm as incomplete cases and did not measure the contrast or glare sensitivity in this study. Rise of IOP is one of the most common complications of posterior capsulotomy.15 Pollack et al.16 found elevation of IOP in 3% of their patients, whereas Brown et al.17 reported that the rate of IOP rise was 4% after Nd:YAG capsulotomy. Skolnick et al.18 reported that 5.3% of their patients developed IOP elevations within the first hour and 6.8% within the first week; none required long-term medical management or laser or surgical intervention. In the retrospective arm of the present study, 7.5 %, 1.2 %, and 0.6 % of eyes had a rise in IOP of 10 mm Hg or more within the first hour, within the first week, and at the final visit, respectively. Moreover, no patient needed antiglaucoma eye drops to control IOP 1 month after capsulotomy. IOP increases in the retrospective part of the present study were higher than previous studies. It is notable that previous studies have not given any information about the effect of capsulotomy size on the post-laser IOP increases, and this issue may play an important role regardless of the energy used due to the released inflammatory products. Karahan et al.15 divided 68 patients into 2 groups based on the postoperative capsulotomy size (cut-off diameter: 3.9 mm). They reported that patients who underwent a larger capsulotomy had higher IOP elevation. They recommended using apraclonidine hydrochloride 0.5% twice daily for at least 5 days in either glaucomatous or nonglaucomatous eyes. Permanent damage to the IOL in the form of pit marks or cracks is a common complication after laser capsulotomy6 and may result in measurable visual impairment. Prevalence of accidental Nd:YAG laser damage or pitting of the IOL has been reported to be between 40% and 81%.19,20 Our literature review identified that to date no studies have counted the number of total and central Nd:YAG laserinduced IOL pits and correlated them with the year of residency. The amount of total and central laser-induced IOL pits, as evaluated in the prospective arm of the study, was significantly higher among the second-year residents. A possible explanation for our findings is the influence of the learning curve, which causes differences between resident performances on first cases compared with later cases. The incidence rate of retinal detachment after Nd:YAG capsulotomy varies between 0.5% and 3.6%.21 The rate of rhegmatogenous RD after resident-performed capsulotomies in the study by Skolnick et al.18 was 1.5%. Our results in the retrospective study (1.5%) are consistent with the aforementioned studies. Cystoid macular edema (CME) is a known serious complication of Nd:YAG capsulotomy; in a series of 897 Nd:YAG laser posterior capsulotomies, Steinert et al.22 CAN J OPHTHALMOL — VOL. ], NO. ], ] 2016
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ND:YAG capsulotomies by residents—Ghasemi Falavarjani et al. reported a rate of 0.89% for CME. This complication did not develop in any of the patients in our series. We did not perform fluorescein angiography or optical coherence tomography to detect visually insignificant CME. The present study has notable limitations. Like other retrospective studies, the retrospective design of one arm of this study could give rise to selection bias, and the level of training of the resident who performed the procedures was not known for this arm of the study. Another limitation is that we did not compare our resident outcomes to outcomes of attending surgeons. A comparison to YAG capsulotomy performed by attending physicians would be very helpful in knowing if there is a difference between third-year residents and attending physicians. In other words, it would be interesting to know if third-year residents will be able to achieve complete competency in their third year of ophthalmology training. Given the high incidence and high number of IOL pitting seen in YAG capsulotomies performed by second-year residents, it would be very helpful to have patients fill out a quality of vision questionnaire to determine if there are any subjective adverse visual outcomes, such as seeing lines, glare, and halo. Another limitation was that we did not match the cases on the basis of PCO density and the resident year. Furthermore, the results of IOP changes in the prospective arm were based on short-term follow-up. Strengths of this study are a good sample size and prevention of observer bias by masking the operating residents. To our knowledge, no studies to date have compared the results of Nd:YAG laser posterior capsulotomy between the second- and third-year ophthalmology residents.
CONCLUSION Resident-performed Nd:YAG capsulotomy appears to be effective with a low complication profile comparable to those reported in the literature. There was evidence of a difference between resident performances on first cases compared with later cases, possibly indicating the effect of experience on procedure performance.
7. Required Minimum Number of Procedures for Graduating Residents in Ophthalmology Review Committee for Ophthalmology. 〈www.acgme.org/acgmeweb/portals/0/pfassets/programresources/ 240_oph_minimum_numbers.pdf〉. Accessed July 28, 2015. 8. Educational Program and Requirements for Ophthalmology Residency Training in Iran. 〈cgme.behdasht.gov.ir/uploads/264_ 920_71_CurriculumTakh_Cheshm.pdf〉. Accessed February 11, 2016. 9. Falavarjani KG, Aghamirsalim M, Modarres M, et al. Endophthalmitis after resident-performed intravitreal bevacizumab injection. Can J Ophthalmol. 2015;50:33-6. 10. Lowry EA, Greninger DA, Porco TC, Naseri A, Stamper RL, Han Y. A comparison of resident-performed argon and selective laser trabeculoplasty in patients with open-angle glaucoma. J Glaucoma. 2016;25:e157-61. 11. Kwong A, Law SK, Kule RR, et al. Long-term outcomes of residentversus attending-performed primary trabeculectomy with mitomycin C in a United States residency program. Am J Ophthalmol. 2014;157:1190-201. 12. Aslam TM, Dhillon B. Neodymium:YAG laser capsulotomy: a clinical morphological analysis. Graefes Arch Clin Exp Ophthalmol. 2002;240:972-6. 13. Yilmaz S, Ozdil MA, Bozkir N, Maden A. The effect of Nd:YAG laser capsulotomy size on refraction and visual acuity. J Refract Surg. 2006;22:719-21. 14. Hayashi K, Nakao F, Hayashi H. Influence of size of neodymium: yttrium-aluminium-garnet laser posterior capsulotomy on visual function. Eye (Lond). 2010;24:101-6. 15. Karahan E, Tuncer I, Zengin MO. The effect of ND:YAG laser posterior capsulotomy size on refraction, intraocular pressure, and macular thickness. J Ophthalmol. 2014;2014:846385. 16. Pollack IP, Brown RH, Crandall AS, Robin AL, Stewart RH, White GL. Prevention of the rise in intraocular pressure following neodymium: YAG posterior capsulotomy using topical 1% apraclonidine. Arch Ophthalmol. 1988;106:754-7. 17. Brown RH, Stewart RH, Lynch MG, et al. ALO 2145 reduces the intraocular pressure elevation after anterior segment laser surgery. Ophthalmology. 1988;95:378-83. 18. Skolnick KA, Perlman JI, Long DM, Kernan JM. Neodymium:YAG laser posterior capsulotomies performed by residents at a Veterans Administration Hospital. J Cataract Refract Surg. 2000;26: 597-601. 19. Flohr MJ, Robin AL, Kelley JS. Early complications following Qswitched neodymium: YAG laser posterior capsulotomy. Ophthalmology. 1985;92:360-3. 20. Terry AC, Stark WJ, Maumenee AE, Fagadau W. NeodymiumYAG laser for posterior capsulotomy. Am J Ophthalmol. 1983;96: 716-20. 21. Min JK, An JH, Yim JH. A new technique for Nd:YAG laser posterior capsulotomy. Int J Ophthalmol. 2014;7:345-9. 22. Steinert RF, Puliafito CA, Kumar SR, Dudak SD, Patel S. Cystoid macular edema, retinal detachment, and glaucoma after Nd:YAG laser posterior capsulotomy. Am J Ophthalmol. 1991;112:373-80.
REFERENCES 1. Apple DJ, Solomon KD, Tetz MR, et al. Posterior capsule opacification. Surv Ophthalmol. 1992;37:73-116. 2. Hashemi H, Mohammadi S, Majdi M, Fotouhi A, Khabazkhoob M. Posterior capsule opacification after cataract surgery and its determinants. Iran J Ophthalmol. 2012;24:3-8. 3. Schaumberg DA, Dana MR, Christen WG, Glynn RJ. A systematic overview of the incidence of posterior capsule opacification. Ophthalmology. 1998;105:1213-21. 4. Bhargava R, Kumar P, Sharma SK, Kaur A. A randomized controlled trial of peeling and aspiration of Elschnig pearls and neodymium: yttrium-aluminium-garnet laser capsulotomy. Int J Ophthalmol. 2015;8:590-6. 5. Vasavada AR, Praveen MR. Posterior capsule opacification after phacoemulsification: annual review. Asia Pac J Ophthalmol (Phila). 2014;3:235-40. 6. Karahan E, Er D, Kaynak S. An overview of Nd:YAG laser capsulotomy. Med Hypothesis Discov Innov Ophthalmol. 2014;3:45-50.
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Footnotes and Disclosure: The authors have no proprietary or commercial interest in any materials discussed in this article. From the Eye Research Center, Rassoul Akram Hospital, Iran University of Medical Sciences, Tehran, Iran. Originally received Aug. 1, 2016. Accepted Nov. 16, 2016. Correspondence to Kaveh Abri Aghdam, MD, PhD, Department of Ophthalmology, Eye Research Center, Rassoul Akram Hospital, Sattarkhan-Niayesh Street, Tehran 14456-13131, Iran; [email protected].
Posterior capsular opacification (PCO) is a common cause of decreased visual acuity (VA) after uneventful extracapsular cataract extraction and intraocular lens (IOL) implantation1,2 A meta-analysis calculated PCO rates after cataract surgery to be 12% at 1 year, 21% at 3 years, and 28% at 5 years after surgery. Overall, 25% of patients undergoing extracapsular cataract surgery develop visually significant PCO within 5 years of the operation.3 PCO is caused by lens epithelial cells that remain in the capsular bag after cataract surgery. The cells migrate, proliferate, and transform to produce Elschnig’s pearls and capsular fibrosis.4 Nd:YAG laser posterior capsulotomy is commonly used to treat PCO. This procedure causes photodisruption of the capsule and thus clears the visual axis.5 Although Nd:YAG laser posterior capsulotomy improves visual function, adverse effects6 such as a rise in intraocular pressure (IOP), IOL damage, subluxation of the intraocular lens, cystoid macular edema, uveitis, or retinal detachment may occur. Ophthalmology residents are required to become proficient in performing Nd:YAG laser capsulotomy during their training. They must be familiar with the technique of laser capsulotomy, and the U.S. Accreditation Council for Graduate Medical Education (ACGME) requires a
minimum of 5 laser capsulotomy surgeries before graduation.7 In Iran, after passing the Comprehensive Medical Residency Entrance Exam and achieving higher marks to choose ophthalmology training programs, residents are accepted into the fully accredited program at different medical universities. The length of training in ophthalmology is 4 years, and the program is divided into 3 parts: observation (first 3 months), comprehensive clinic visits (months 3 to 12), and subspecialty rotations (years 2 to 4). During comprehensive clinic visits, residents visit patients under the supervision of attending ophthalmologists; introductory surgical observation occurs during the first year as well. During the period of subspecialty rotations, residents achieve in-depth understanding in different fields including retinal diseases, pediatric ophthalmology, oculoplastics, glaucoma, and corneal diseases and gain surgical skills in ophthalmic operations. Regular journal clubs, grand rounds, Basic and Clinical Science Course review, case presentation sessions, and other teaching conferences covering all subspecialties of ophthalmology complete the teaching cycle. Tables 1 and 2 presents the required minimum number of procedures for graduating Iranian residents in ophthalmology.8 The aims of this study were to evaluate the outcomes of Nd:YAG laser capsulotomy performed by ophthalmology
& 2016 Canadian Ophthalmological Society. Published by Elsevier Inc. All rights reserved. http://dx.doi.org/10.1016/j.jcjo.2016.11.026 ISSN 0008-4182/16 CAN J OPHTHALMOL — VOL. ], NO. ], ] 2016
1
ND:YAG capsulotomies by residents—Ghasemi Falavarjani et al. Table 1—Type and minimum number of the procedures required for graduating ophthalmology residents in Iran, extra-ocular surgeries. Surgeries
Available from the Second Year of Residency
Eyelid Surgeries (at least 30 surgeries) Repair of simple laceration of eyelid and conjunctiva Eyelid and conjunctival laceration repair Chalazion removal Simple surgical ptosis Surgery of congenital ptosis Removal of periorbital simple tumors Blepharoplasty, eyelid reconstruction Tarsoraphy Blepharoraphy Entropion and ectropion surgery Eyelid retraction surgery Canthoplasty Lacrimal System Surgeries (at least 15 surgeries) Canalicular laceration repair Plugging of lacrimal punctom Probing Silicon tube Dacryocystorhinostomy Orbital Surgeries (at least 10 procedures) Orbital fractures repair Orbitotomy (to remove the tumor, foreign body, abscesses, etc.) Evisceration Enucleation Exenteration Orbital decompression Socket repair Excision of conjunctival tumors with or without cryotherapy Optic nerve decompression Strabismus Surgeries (at least 15 procedures) Horizontal rectus muscle surgery Vertical rectus muscle and the inferior oblique muscle surgery Superior oblique muscle surgery Adjustable suture surgery Strabismus reoperation Muscle transposition surgery Injection of botulinum A toxin Surgery for nystagmus (in large recess cases)
residents in a tertiary ophthalmic university center and to determine whether the resident year significantly influences complication rates.
METHODS This was a combined retrospective and prospective study in which 2 sets of results from 301 patients (304 eyes) from the Department of Ophthalmology at Rassoul Akram University Hospital, Tehran, Iran, were analyzed. In the retrospective arm of the study, files of all patients who underwent Nd:YAG laser posterior capsulotomies by ophthalmology residents between March 2011 and March 2014 were retrieved, whereas all patients operated for PCO from March 2014 to December 2014 were recruited into the prospective study. The study design was approved by the Eye Research Center Ethics Committee of the Iran University of Medical Sciences and adhered to the tenets of the Declaration of Helsinki. Retrospective arm
Consecutive patients treated with Nd:YAG capsulotomies by ophthalmology residents at Rassoul Akram
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Available in the Third and Fourth Year of Residency
Resident Can Only Assist Surgery
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
Hospital during a 3-year period from March 2011 to March 2014 were identified from laser log books and by the retrospective review of scheduling logs for the laser clinic. Included eyes needed to have at least 1 year of follow-up. Exclusion criteria included the following: insufficient data in the medical records; history of intraocular surgery (other than cataract surgery); history of glaucoma; history of uveitis; IOL decentration; and no follow-up visits after treatment.
Each included patient had been previously examined by an attending ophthalmologist and had been referred for Nd:YAG capsulotomy. Pre- and postoperative Snellen best-corrected visual acuity (BCVA), IOP, and complications including IOL decentration, IOL dislocation, endophthalmitis, and retinal detachment were collected from the patients’ files.
ND:YAG capsulotomies by residents—Ghasemi Falavarjani et al. Table 2—Type and minimum number of the procedures required for graduating ophthalmology residents in Iran, intraocular surgery. Available from the Second Available in the Third and Resident Can Only Year of Residency Fourth Year of Residency Assist Surgery
Surgeries Anterior Segment Surgery (at least 120 procedures) Extracapsular cataract extraction Phacoemulsification Lensectomy Lens removal in subluxated cases Lensectomy in traumatic cataract with corneal laceration Laser capsulotomy Secondary IOL implantation Replacement IOL Anterior vitrectomy (for vitreous extraction after cataract surgery) Corneal surgery Conjunctival flap Amniotic membrane transplantation Penetrating keratoplasty Superficial keratectomy DSEAK Simple corneal laceration repair Complex corneal laceration repair Refractive surgery using laser Surface ablation in simple myopia LASIK in simple myopia Collagen cross-linking Other anterior segment surgeries AC washing Anterior vitrectomy— limbal Simple pterygium surgery Complex pterygium surgery Glaucoma Surgery (at least 30 surgeries) Trabeculectomy in adults Trabeculectomy in children Re-trabeculectomy Trabeculotomy Cataract surgery after glaucoma surgery Cataract surgery combined with glaucoma surgery Goniotomy Choroidal tap Shunt placement Endoscopic photocoagulation Laser trabeculoplasty Laser iridoplasty Laser iridotomy Cyclophotocoagulation Vitreoretinal Surgery (at least 20 laser procedures, 20 injections, and 20 surgeries) Panretinal photocoagulation Laser for macular edema Intravitreal injection Scleral buckling Core vitrectomy Pars plana vitrectomy Silicone oil removal
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
DSEAK: descemet stripping endothelial automated keratoplasty; AC: anterior chamber; IOL: intraocular lens; LASIK: laser-assisted in situ keratomileusis.
Prospective arm
All pseudophakic patients who were scheduled for Nd: YAG posterior capsulotomy between March and December 2014 were screened for inclusion in this study. Informed consent was obtained from patients. The inclusion criteria were previous uneventful phacoemulsification with in-the-bag intraocular lens placement and the presence of visually significant PCO. All patients underwent comprehensive ophthalmologic examination including BCVA measurement, slit lamp biomicroscopy, IOP measurement by Goldmann applanation tonometry, and dilated fundus examination. Exclusion criteria were previous history of uveitis, severe contraction of the anterior capsule, and media opacities other than PCO.
Attending ophthalmologists were needed to confirm the presence of definite PCO on slit-lamp biomicroscopy. In our centre, laser capsulotomies are performed mainly by the second- and third-year ophthalmology residents (approximately 42% by the second-year and 58% by the third-year residents, according to the recent 8-year medical records). At the beginning of second year of residency, each resident receives didactics on the correct technique of Nd:YAG posterior capsulotomy from the attending surgeons and fellows. Each resident then performs Z5 procedures under close observation to be able to complete YAG capsulotomies independently. Neither attending physicians nor fellows were involved in the study. CAN J OPHTHALMOL — VOL. ], NO. ], ] 2016
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ND:YAG capsulotomies by residents—Ghasemi Falavarjani et al. Surgical technique
Before laser procedure, mydriasis was accomplished with phenylephrine 5% (Sina Darou, Tehran, Iran) and tropicamide 1% (Sina Darou). After topical anaesthesia with tetracaine 0.5% (Sina Darou), an Abraham capsulotomy contact lens (Ocular Instruments, Bellevue, Wash.) was applied to enhance the visualization of the posterior capsule and allow precise laser focus on it. Using the Q-Switched Nd:YAG laser (Quantel Medical Company, Paris, France ) in a circular pattern, the single bursts were performed starting at 0.5 mJ and gradually increased in power until a 3 to 4 mm capsular opening was created. After treatment, patients were given betamethasone 0.1% eye drops (Sina Darou) 4 times a day for 3 days. Laser power and spot numbers were recorded. The performing resident was unaware of this study, and an independent observer (M.A.) who was a second-year resident not involved in the procedure evaluated the patients immediately after surgery. The size of the posterior capsule opening was evaluated, and capsulotomies o3 mm of opening in the central papillary area or incomplete separation of posterior capsule were considered incomplete. The number of IOL pits due to incorrect laser spots in the whole capsulotomy area and in the central 1 mm of the pupillary space was recorded. IOP was measured before and 1 hour and 1 week after the procedure. Postoperative evaluation included changes in BCVA, IOP elevations, and complications related to the procedure at 1 hour and 1 week postsurgery. If the IOP was 421 mm Hg at 1 hour after the procedure, brimonidine 0.2% eye drops (Sina Darou) were prescribed, and the patient was followed for Z1 month after discontinuation of the eye drops.
Statistical Analysis
Data were analyzed using Software Package for the Statistical Sciences 15.0 (SPSS Inc, Chicago, Ill.). For statistical analysis, the Snellen VA records were converted to logMAR scale. We used the Kolmogorov–Smirnov test to test quantitative variables for normal distribution. Within-group changes from baseline were analyzed using paired t test. Chi-square and
Fisher’s exact tests were used to evaluate differences between second- and third-year complication rates. Means ⫾ SD were used for reporting the continuous variables. A p value o0.05 was considered statistically significant.
RESULTS Retrospective arm
We evaluated 131 eyes of 129 patients. The mean age of the patients was 63.65 ⫾ 9.8 years; 56 were male (43.8%) and 73 female (56.2%). Mean follow-up time was 43.2 ⫾ 2.1 months, and 118 cases (90.1%) had follow-up of 42 years. Mean BCVA improved significantly from 1.15 ⫾ 0.26 logMAR to 0.54 ⫾ 0.39 logMAR (p o 0.001). BCVA improvement of Z3 lines, Z2 lines, and Zone line was found in 42 eyes (32%), 53 (40%), and 32 eyes (24.4%), respectively. In all, 127 of 131 eyes (96.9%) had a BCVA improvement of Z1 lines. Mean IOP before capsulotomy and at the final visit was 13.1 ⫾ 2.34 mm Hg and 13.6 ⫾ 2.17 mm Hg, respectively (P ¼ 0.30). During follow-up, 16 eyes had IOP 421 mm Hg: a rise in IOP of 45 mm Hg and 410 mm Hg was found in 15 eyes (11.4%) and 1 eye (0.7%), respectively. These eyes were treated with antiglaucoma eye drops, and the IOP returned to normal within 2 to 4 weeks. Rhegmatogenous retinal detachment (RRD) occurred in 2 eyes (1.5%) during follow-up: One patient developed an RRD in the left eye 18 months after the laser capsulotomy, which was 5 years after uneventful phacoemulsification. The other patient developed an RRD 5 months after receiving capsulotomy for dense PCO of the left eye, which developed 4 years after an uneventful phacoemulsification. There were no predisposing risk factors for occurrence of RRD in these eyes. No case of IOL decentration or endophthalmitis was detected. Prospective arm
We included 173 eyes of 172 patients. Twelve residents (6 second-year and 6 third-year) performed Nd:YAG laser
Table 3—Characteristics of the eyes after laser capsulotomy performed by second- and third-year residents. Total No. of eyes (%) Laser power (mJ) No. of laser spots No. of eyes with incomplete capsulotomy (%) No. of eyes with IOL pits (%) No. of eyes with central IOL pits (%) No. of total IOL pits (%) No. of central IOL pits Change in BCVA (logMAR) IOP before Nd:YAG capsulotomy (mm Hg) IOP at 1 hour after Nd:YAG capsulotomy (mm Hg) IOP at 1 week after procedure (mm Hg)
173 2.79 ⫾ 0.90 30.36 ⫾ 13.54 34 (19.6) 157 (90.7) 64 (36.9) 9.56 ⫾ 7.37 3.37 ⫾ 2.76 2.33 ⫾ 1.03 13.29 ⫾ 2.37 14.97 ⫾ 3.95 13.77 ⫾ 2.17
IOL, intraocular lens; BCVA, best corrected visual acuity; IOP, intraocular pressure. n
†
t test. Fisher’s exact test.
‡ 2
χ test.
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Second-Year Resident Group 107 2.89 33.44 24 125 55 11.54 4.28 2.33 13.11 14.78 13.82
(62) ⫾ 0.96 ⫾ 13.92 (15.6) (72) (31.8) ⫾ 7.49 ⫾ 2.53 ⫾ 1.14 ⫾ 2.35 ⫾ 4.13 ⫾ 2.34
Third-Year Resident Group 66 2.53 22.38 10 32 9 4.41 1.03 2.32 13.76 15.46 13.64
(38) ⫾ 0.64 ⫾ 8.37 (5.7) (18.7) (5.2) ⫾ 3.68 ⫾ 1.74 ⫾ 0.71 ⫾ 2.39 ⫾ 3.44 ⫾ 1.74
p Value 0.256 0.01* o0.001* o0.01† o0.001† o0.001 (%)‡ o0.001* o0.001* 0.987* 0.435* 0.360* 0.644*
ND:YAG capsulotomies by residents—Ghasemi Falavarjani et al. posterior capsulotomies. The mean age of the patients was 64.3 ⫾ 8.98 years. There were 73 male (43.2 %) and 99 female (56.8%) patients. Table 3 presents the characteristics of Nd:YAG laser posterior capsulotomies. Mean pre-YAG capsulotomy BCVA was 1.14 ⫾ 0.25 logMAR and improved to 0.51 ⫾ 0.37 logMAR after capsulotomy surgery (p o 0.001). BCVA improved by Z3 lines in 59 eyes (34.1%), by 2 lines in 65 eyes (37.5%), and by 1 line in 46 eyes (26.5%). BCVA in 3 eyes (1.7%) failed to improve (2 eyes [1.1%] with diabetic retinopathy and 1 eye [0.6%] with age-related macular degeneration). The rise of IOP 1 hour after the capsulotomy was significant in both groups (Table 3). IOP of 421 mm Hg was found in 15 eyes (8.6%). In these eyes, brimonidine eye drops were prescribed, which were discontinued after 1 week and no eye had a rise of IOP 1 month after the procedure. There was no statistically significant difference between pre-laser IOP measurements compared with the 1-month IOP measurements (P ¼ 0.32). The postoperative changes in mean BCVA and IOP between the second- and third-year residents were not significant; however, the applied laser power, the number of laser spots, rate of incomplete capsulotomies, and the amount of total and central laserinduced IOL pits were significantly higher among the second-year residents (Table 3). No significant difference was found between the 2 groups of residents in terms of IOP changes (Table 3). No case of IOL decentration, vitreous presentation in the anterior chamber, or retinal detachment was observed.
DISCUSSION PCO is a common post-cataract surgery complication that is frequently managed in training centres where residents serve as the primary surgeons with attending supervision. It is important to investigate the outcomes of surgery at training centres, both to reassure patients that they are receiving the standard of care and good results and to determine areas for training improvement. Although a number of studies have evaluated resident complication rates in ophthalmic surgeries,9–11 limited research has been performed on the outcomes associated with the residentperformed Nd:YAG posterior capsulotomy. In the present study, we showed that the year of residency does not significantly influence the post-capsulotomy IOP or BCVA. IOL-related complication rates of second- and third-year resident surgeons do significantly differ, likely due to the effect of the learning curve. In the retrospective and prospective parts of the present study, BCVA improved similarly in 96.9 % and 98.3 % of eyes treated by ophthalmology residents. There are several studies on the influence of size of Nd:YAG laser posterior capsulotomy on visual function. Aslam and Dhillon12 reported that capsulotomy area has no significant correlation with eventual visual outcome in terms of contrast sensitivity, near and distance VA, or glare readings. Yilmaz et al.13
reported that the size of posterior capsulotomy does not significantly affect refraction and VA. Hayashi et al.14 found that contrast VA and glare VA with a small capsulotomy were significantly worse than those with a large capsulotomy, but BCVA was not affected significantly. We considered capsulotomies o3 mm as incomplete cases and did not measure the contrast or glare sensitivity in this study. Rise of IOP is one of the most common complications of posterior capsulotomy.15 Pollack et al.16 found elevation of IOP in 3% of their patients, whereas Brown et al.17 reported that the rate of IOP rise was 4% after Nd:YAG capsulotomy. Skolnick et al.18 reported that 5.3% of their patients developed IOP elevations within the first hour and 6.8% within the first week; none required long-term medical management or laser or surgical intervention. In the retrospective arm of the present study, 7.5 %, 1.2 %, and 0.6 % of eyes had a rise in IOP of 10 mm Hg or more within the first hour, within the first week, and at the final visit, respectively. Moreover, no patient needed antiglaucoma eye drops to control IOP 1 month after capsulotomy. IOP increases in the retrospective part of the present study were higher than previous studies. It is notable that previous studies have not given any information about the effect of capsulotomy size on the post-laser IOP increases, and this issue may play an important role regardless of the energy used due to the released inflammatory products. Karahan et al.15 divided 68 patients into 2 groups based on the postoperative capsulotomy size (cut-off diameter: 3.9 mm). They reported that patients who underwent a larger capsulotomy had higher IOP elevation. They recommended using apraclonidine hydrochloride 0.5% twice daily for at least 5 days in either glaucomatous or nonglaucomatous eyes. Permanent damage to the IOL in the form of pit marks or cracks is a common complication after laser capsulotomy6 and may result in measurable visual impairment. Prevalence of accidental Nd:YAG laser damage or pitting of the IOL has been reported to be between 40% and 81%.19,20 Our literature review identified that to date no studies have counted the number of total and central Nd:YAG laserinduced IOL pits and correlated them with the year of residency. The amount of total and central laser-induced IOL pits, as evaluated in the prospective arm of the study, was significantly higher among the second-year residents. A possible explanation for our findings is the influence of the learning curve, which causes differences between resident performances on first cases compared with later cases. The incidence rate of retinal detachment after Nd:YAG capsulotomy varies between 0.5% and 3.6%.21 The rate of rhegmatogenous RD after resident-performed capsulotomies in the study by Skolnick et al.18 was 1.5%. Our results in the retrospective study (1.5%) are consistent with the aforementioned studies. Cystoid macular edema (CME) is a known serious complication of Nd:YAG capsulotomy; in a series of 897 Nd:YAG laser posterior capsulotomies, Steinert et al.22 CAN J OPHTHALMOL — VOL. ], NO. ], ] 2016
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ND:YAG capsulotomies by residents—Ghasemi Falavarjani et al. reported a rate of 0.89% for CME. This complication did not develop in any of the patients in our series. We did not perform fluorescein angiography or optical coherence tomography to detect visually insignificant CME. The present study has notable limitations. Like other retrospective studies, the retrospective design of one arm of this study could give rise to selection bias, and the level of training of the resident who performed the procedures was not known for this arm of the study. Another limitation is that we did not compare our resident outcomes to outcomes of attending surgeons. A comparison to YAG capsulotomy performed by attending physicians would be very helpful in knowing if there is a difference between third-year residents and attending physicians. In other words, it would be interesting to know if third-year residents will be able to achieve complete competency in their third year of ophthalmology training. Given the high incidence and high number of IOL pitting seen in YAG capsulotomies performed by second-year residents, it would be very helpful to have patients fill out a quality of vision questionnaire to determine if there are any subjective adverse visual outcomes, such as seeing lines, glare, and halo. Another limitation was that we did not match the cases on the basis of PCO density and the resident year. Furthermore, the results of IOP changes in the prospective arm were based on short-term follow-up. Strengths of this study are a good sample size and prevention of observer bias by masking the operating residents. To our knowledge, no studies to date have compared the results of Nd:YAG laser posterior capsulotomy between the second- and third-year ophthalmology residents.
CONCLUSION Resident-performed Nd:YAG capsulotomy appears to be effective with a low complication profile comparable to those reported in the literature. There was evidence of a difference between resident performances on first cases compared with later cases, possibly indicating the effect of experience on procedure performance.
7. Required Minimum Number of Procedures for Graduating Residents in Ophthalmology Review Committee for Ophthalmology. 〈www.acgme.org/acgmeweb/portals/0/pfassets/programresources/ 240_oph_minimum_numbers.pdf〉. Accessed July 28, 2015. 8. Educational Program and Requirements for Ophthalmology Residency Training in Iran. 〈cgme.behdasht.gov.ir/uploads/264_ 920_71_CurriculumTakh_Cheshm.pdf〉. Accessed February 11, 2016. 9. Falavarjani KG, Aghamirsalim M, Modarres M, et al. Endophthalmitis after resident-performed intravitreal bevacizumab injection. Can J Ophthalmol. 2015;50:33-6. 10. Lowry EA, Greninger DA, Porco TC, Naseri A, Stamper RL, Han Y. A comparison of resident-performed argon and selective laser trabeculoplasty in patients with open-angle glaucoma. J Glaucoma. 2016;25:e157-61. 11. Kwong A, Law SK, Kule RR, et al. Long-term outcomes of residentversus attending-performed primary trabeculectomy with mitomycin C in a United States residency program. Am J Ophthalmol. 2014;157:1190-201. 12. Aslam TM, Dhillon B. Neodymium:YAG laser capsulotomy: a clinical morphological analysis. Graefes Arch Clin Exp Ophthalmol. 2002;240:972-6. 13. Yilmaz S, Ozdil MA, Bozkir N, Maden A. The effect of Nd:YAG laser capsulotomy size on refraction and visual acuity. J Refract Surg. 2006;22:719-21. 14. Hayashi K, Nakao F, Hayashi H. Influence of size of neodymium: yttrium-aluminium-garnet laser posterior capsulotomy on visual function. Eye (Lond). 2010;24:101-6. 15. Karahan E, Tuncer I, Zengin MO. The effect of ND:YAG laser posterior capsulotomy size on refraction, intraocular pressure, and macular thickness. J Ophthalmol. 2014;2014:846385. 16. Pollack IP, Brown RH, Crandall AS, Robin AL, Stewart RH, White GL. Prevention of the rise in intraocular pressure following neodymium: YAG posterior capsulotomy using topical 1% apraclonidine. Arch Ophthalmol. 1988;106:754-7. 17. Brown RH, Stewart RH, Lynch MG, et al. ALO 2145 reduces the intraocular pressure elevation after anterior segment laser surgery. Ophthalmology. 1988;95:378-83. 18. Skolnick KA, Perlman JI, Long DM, Kernan JM. Neodymium:YAG laser posterior capsulotomies performed by residents at a Veterans Administration Hospital. J Cataract Refract Surg. 2000;26: 597-601. 19. Flohr MJ, Robin AL, Kelley JS. Early complications following Qswitched neodymium: YAG laser posterior capsulotomy. Ophthalmology. 1985;92:360-3. 20. Terry AC, Stark WJ, Maumenee AE, Fagadau W. NeodymiumYAG laser for posterior capsulotomy. Am J Ophthalmol. 1983;96: 716-20. 21. Min JK, An JH, Yim JH. A new technique for Nd:YAG laser posterior capsulotomy. Int J Ophthalmol. 2014;7:345-9. 22. Steinert RF, Puliafito CA, Kumar SR, Dudak SD, Patel S. Cystoid macular edema, retinal detachment, and glaucoma after Nd:YAG laser posterior capsulotomy. Am J Ophthalmol. 1991;112:373-80.
REFERENCES 1. Apple DJ, Solomon KD, Tetz MR, et al. Posterior capsule opacification. Surv Ophthalmol. 1992;37:73-116. 2. Hashemi H, Mohammadi S, Majdi M, Fotouhi A, Khabazkhoob M. Posterior capsule opacification after cataract surgery and its determinants. Iran J Ophthalmol. 2012;24:3-8. 3. Schaumberg DA, Dana MR, Christen WG, Glynn RJ. A systematic overview of the incidence of posterior capsule opacification. Ophthalmology. 1998;105:1213-21. 4. Bhargava R, Kumar P, Sharma SK, Kaur A. A randomized controlled trial of peeling and aspiration of Elschnig pearls and neodymium: yttrium-aluminium-garnet laser capsulotomy. Int J Ophthalmol. 2015;8:590-6. 5. Vasavada AR, Praveen MR. Posterior capsule opacification after phacoemulsification: annual review. Asia Pac J Ophthalmol (Phila). 2014;3:235-40. 6. Karahan E, Er D, Kaynak S. An overview of Nd:YAG laser capsulotomy. Med Hypothesis Discov Innov Ophthalmol. 2014;3:45-50.
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Footnotes and Disclosure: The authors have no proprietary or commercial interest in any materials discussed in this article. From the Eye Research Center, Rassoul Akram Hospital, Iran University of Medical Sciences, Tehran, Iran. Originally received Aug. 1, 2016. Accepted Nov. 16, 2016. Correspondence to Kaveh Abri Aghdam, MD, PhD, Department of Ophthalmology, Eye Research Center, Rassoul Akram Hospital, Sattarkhan-Niayesh Street, Tehran 14456-13131, Iran; [email protected].