Visual outcome and major surgical complications of extracapsular cataract extraction versus manual small-incision cataract surgery performed by resident doctors at tertiary care institute as part of learning curve

Shekhar Akarkar; Ugam P. S Usgaonkar

doi:10.4103/jcor.jcor_8_18

ORIGINAL ARTICLE

Year : 2019 | Volume : 7 | Issue : 2 | Page : 65-70

Visual outcome and major surgical complications of extracapsular cataract extraction versus manual small-incision cataract surgery performed by resident doctors at tertiary care institute as part of learning curve

Shekhar Akarkar, Ugam P. S Usgaonkar
Department of Ophthalmology, Goa Medical College, Bambolim, Goa, India

Date of Submission	20-Mar-2018
Date of Acceptance	29-Jan-2019
Date of Web Publication	21-Aug-2019

Correspondence Address:
Shekhar Akarkar
Department of Ophthalmology, Goa Medical College, Bambolim - 403 202, Goa
India

Source of Support: None, Conflict of Interest: None

Check

DOI: 10.4103/jcor.jcor_8_18

Abstract

Background: Cataract surgery has its own learning curve to the resident doctors. Our resident doctors are trained in extracapsular cataract extraction (ECCE) and manual small-incision cataract surgery (MSICS). In ECCE and initial cases of MSICS, they are trained to do can-opener capsulotomy (COC) and then they are trained in continuous curvilinear capsulorrhexis (CCC). Aim: We designed a study to compare the visual outcome and major surgical complications of resident doctor performed ECCE versus MSICS at our institute. Setting and Design: This was a hospital-based study in ophthalmology department (retrospective study). Materials and Methods: A total of 239 patients with visually significant cataract presenting to our outpatient department were enrolled in the study. Data of consecutive cataract surgeries done by 10 junior residents (JRs) from March to August 2017 were analyzed. First-year residents were trained for ECCE (JR1 group) for 6 months. During the same time period, 2^nd-year residents were trained for MSICS (with COC) for first 3 months (JR2 group). Then, as a part of learning curve, 2^nd-year residents were then trained for MSICS (with CCC) for next 3 months (JR3 group). Data were analyzed using the Chi-square test, percentages. Results: Out of 239 cataract surgeries performed by residents over a 6-month period, ECCE were 52 (21.8%) and MSICS were 187 (78.2%) cases. Both the surgeries in MSICS (2^nd-year residents) and ECCE (1^st-year residents) had good visual outcome (94.6% vs. 84.6%). The overall major surgical complication rate for MSICS was 7.0% while that for ECCE was 11.5%. Conclusion: We conclude that both surgeries can be taught to beginner surgeons with good visual outcome. Both surgeries have safe learning curve with good visual results when done under supervision as evidenced by a low rate of major surgical complications.

Keywords: Extracapsular cataract extraction, learning curve, major surgical complications, manual small-incision cataract surgery, resident cataract surgeries

How to cite this article:
Akarkar S, Usgaonkar UP. Visual outcome and major surgical complications of extracapsular cataract extraction versus manual small-incision cataract surgery performed by resident doctors at tertiary care institute as part of learning curve. J Clin Ophthalmol Res 2019;7:65-70

How to cite this URL:
Akarkar S, Usgaonkar UP. Visual outcome and major surgical complications of extracapsular cataract extraction versus manual small-incision cataract surgery performed by resident doctors at tertiary care institute as part of learning curve. J Clin Ophthalmol Res [serial online] 2019 [cited 2023 Mar 24];7:65-70. Available from: https://www.jcor.in/text.asp?2019/7/2/65/264899

Cataract surgery presents its own learning curve to the resident doctors. Large-incision extracapsular cataract extraction (ECCE) with rigid posterior chamber intraocular lens implantation was initial surgical technique taught to residents.^[1] Now, the trend has changed toward using smaller incisions and performs sutureless surgeries. Majority of the residents, especially in developing countries, learn the sutureless manual small-incision cataract surgery (MSICS) technique initially, followed by phacoemulsification.^[2],[3] Some training programs, in developed countries, start by teaching phacoemulsification as the first technique of cataract removal.^[4],[5],[6] Training standards across India are varied in teaching institutes for residency. As per residency evaluation and adherence design study III for ophthalmology residency training in India (READS III),^[7] exposure to cataract surgery for residents was adequate but not uniform and MSICS is the most common cataract surgery taught presently. Literature shows meta-analysis study to compare the safety and efficacy of MSICS and phacoemulsification.^[8] However, out of these very few studies have evaluated the safety, efficacy, and complication rates of MSICS during residency training.^[9],[10] Ours is a tertiary hospital with postgraduate training programme. During the training programme, junior residents are trained first in ECCE followed by MSICS and last few cases they are taught phacoemulsification. After the first 6 months of starting MSICS, the residents start operating cataract surgeries independently. We took retrospective data to evaluate for major surgical complications and visual outcome of resident performed MSICS (for first 6 months of starting MSICS) and compared it with resident performed ECCE during that period as a part of stepwise training approach for cataract surgery. Furthermore, we tried to evaluate other minor complications which are frequently encountered by resident surgeon. Learning continuous curvilinear capsulorrhexis (CCC) is an important step during training stage as a round, well-centered CCC is the critical step in phacoemulsification. For this reason, MSICS cases were analyzed in two groups with can-opener capsulotomy (COC) and CCC to look for any increased risk for complications as beginner surgeon makes switchover from COC to CCC.

Materials and Methods

This retrospective study was conducted at our tertiary institute (Government Medical College with five postgraduate seats every year) and for which the ethics committee clearance was obtained from the Institutional Ethics Committee of our institute.

Data of initial consecutive cataract surgeries performed by junior resident (JR) doctors between March and August 2017 were analyzed. In this period, 239 eyes of 239 patients with visually significant cataract presenting to our outpatient department were assigned to JRs for cataract surgery. Prior informed consent was obtained from each patient. The preoperative, operative, and postoperative data were recorded and analyzed. ECCE surgeries were performed by 1^st-year residents (junior residents Group 1 [JR1]). JR1 group consisted of five residents and they had observed at least 30 ECCE/MSICS cases and are the first assistant to 30 cases, 3 months before starting their surgeries. Their ECCE surgeries for 6 months (March–August) were included in JR1 group where all steps were performed by them under supervision. Any difficulty in surgical steps or any complications were managed by senior resident/consultant in-charge. MSICS was performed by 2^nd-year residents (five residents) already trained in ECCE and had performed at least 30 ECCE cases. Their initial MSICS cases for first 3 months were done with COC and were grouped as junior residents Group 2 (JR2). Then, the same 2^nd-year residents were trained for MSICS surgeries with CCC after 3 months of starting MSICS and grouped as junior residents Group 3 (JR3). Cases with rhexis extension/tear were converted to COC and were included in JR3 group. No cases performed by JRs from March to August were excluded from the study. All cases were performed under the supervision of senior resident/consultant.

Preoperative data collection for each eye included the patient age and gender, preoperative visual acuity, details of slit-lamp examination of the anterior segment, and preexisting ocular conditions likely to influence either the operative course or the final visual acuity. Lens Opacities Classification System III classification was used for grading of cataract.^[11] The intraocular pressure was recorded by applanation tonometry in all cases. The posterior pole was examined with slit-lamp biomicroscopy using +90 D or +78 D lens. Indirect ophthalmoscopy was done to evaluate the retinal periphery. The status of the other eye was similarly documented. In the case of nonvisibility of posterior segment, B-scan was performed for the eye. Axial length measurements and keratometry recordings were done, and Sanders-Retzlaff-Kraff II formula^[12] was used to calculate the intraocular lens (IOL) power required. The systemic status of the patient was evaluated to ensure fitness for surgery under local anesthesia. Operative data included the name of the JR who performed cataract surgery, senior resident/consultant in-charge, date of the surgery, and technique of surgery employed – including the details of each step and details of the IOL implanted. The occurrence of any intraoperative complication was documented along with the details of the subsequent management.

Patients with uncontrolled diabetes, uncontrolled hypertension, and active infection anywhere in the body were not assigned for JRs for ECCE and MSICS surgeries. High-risk patients with zonular weakness, posterior polar cataracts, corneal pathology, postuveitic cataracts, pseudoexfoliation, patients younger than 45 years, traumatic cataracts, and one-eyed patient were not assigned for residents for both ECCE and MSICS groups. For ECCE and MSICS in JR2 group, patients with diabetes and hypertension were not assigned. However, controlled diabetes and hypertension were assigned for MSICS in JR3 group.

The surgeries were done under local anesthesia (peribulbar anesthesia). For ECCE, after cleaning and draping the eye, a barraquer speculum was applied. Superior rectus bridle suture was applied using 4-0 silk. Conjunctival dissection was done. Limbal scratch incision was given from 10 to 2 o'clock. A stab incision was made at 10 o'clock position with 15° side port blade. After staining capsule with trypan blue dye, COC was done using bent 26G needle cystitome. A 12–14-mm corneoscleral section was made with the help of corneal scissors. Hydrodissection was done. Nucleus was delivered with the help of pressure-counter pressure method using wire vectis. Cortical matter was cleaned up by two-way Simcoe cannula. A 6.5-mm diameter optic rigid polymethylmethacrylate (PMMA) posterior chamber IOL was put. All maneuvering procedures in anterior chamber were done under viscoelastic substances. Incision closed with five interrupted 10-0 monofilament nylon sutures and anterior chamber formed.

In MSICS, after cleaning and draping the eye, a barraquer speculum was applied. A superior rectus bridle suture was applied with 4'0 silk. A fornix-based conjunctival flap was made from 10 to 2 o'clock position. A 6.0–7.0-mm long, straight scleral incision was made with a No. 15 blade about 1–2-mm posterior to the limbus. A sclerocorneal tunnel was dissected with a crescent, with 1–2-mm dissection into the cornea (and always cutting backward with the sides of the crescent). A paracentesis was made at 10 o'clock position with a 15° side port blade. Trypan blue dye was used to stain the anterior capsule. Viscoelastic was injected into the anterior chamber. A COC with the help of cystitome was performed in cases of JR2 group. In case of JR3 group, a large capsulorrhexis (6.0–7.0 mm) was performed with the help of a cystitome through the paracentesis. Whenever the capsulorrhexis threatened to extend to the periphery, it was converted to a COC. If the size of the rhexis was deemed insufficient for prolapsing of the nucleus into the anterior chamber, two relaxing incisions were made on the rhexis margin. The anterior chamber was entered with a keratome and the internal opening was extended up to 7–8 mm, taking care to cut inward. Hydrodissection was performed. The nucleus was prolapsed into the anterior chamber either during hydrodissection or using a sinskey hook, and the nucleus was delivered out with the help of wire vectis. Cortical cleanup was performed with a two-way Simcoe cannula. A 6.5-mm PMMA posterior chamber IOL was implanted into the bag, under viscoelastic. Viscoelastic was removed and paracentesis was hydrated. Wound was checked for the absence of leak and if present, it was sutured. Conjunctival flap reposited over the incision.

In cases of any major complications, case was taken over by a senior person, either senior resident or consultant in-charge. The intraoperative complications (including the operative step involved) were documented. Postoperatively, visual acuity and complete anterior and posterior segment examination along with the postoperative complications if any were documented. Major surgical complications were defined as follows: (1) iridodialysis, (2) posterior capsular rupture or zonulodialysis with vitreous loss with successful IOL implantation, (3) posterior capsular rupture or zonulodialysis with vitreous loss without IOL implantation, (4) suprachoroidal hemorrhage, (5) choroidal detachment, (6) endophthalmitis, and (7) other complications (a) nucleus drop, (b) IOL drop, (c) Descemet's membrane detachment, (d) Toxic Anterior Segment Syndrome (TASS), (e) vitreous hemorrhage, and (f) retinal detachment. Minor complications were noted such as (1) premature entry with tunnel suturing in case of MSICS, (2) postoperative lens matter aspiration, (3) postoperative iris in section, and (4) optic capture. Visual outcome was assessed with full spectacle correction at 6-week postoperatively best-corrected visual acuity (BCVA). Good visual outcome is defined as 6/6–6/18 (available and best correction grades ≥85% and >90%, respectively), borderline outcome as <6/18–6/60 (available and best correction <5%, respectively), and poor outcome as <6/60 (available and best correction ≤5% for each type).^[13] In case of ECCE patients, the visual outcome at 6 weeks was with sutures in situ, and suture removal was done at 3 months. Statistical analysis was performed using the Chi-square test. P < 0.05 was taken as statistically significant. Categorical variables are expressed as frequency (percentage). All analysis were performed using SPSS version 11.0 for Windows (IBM Corporation, Armonk, New York, United States).

Results

During the 6-month period (March–August 2017), 239 cataract surgeries were done by 10 JRs at our institute. Fifty-two surgeries (21.8%) were done by JR1 (ECCE), 82 (34.3%) by JR2 (MSICS with COC), and 105 (43.9%) by JR3 (MSICS with CCC) groups. Total MSICS (2^nd-year residents) cases were 187 (78.2%). Major surgical complications were seen in 13 (7.0%) of MSICS (2^nd-year residents) cases and 6 (11.5%) of ECCE (1^st-year residents) cases. P =0.28, thus the surgical technique in our study did not significantly appear to affect the major surgical complication rate. The rate of major surgical complications was 11.5% (6) for JR1 (ECCE), 7.3% (6) for JR2 (MSICS with COC), and 6.7% (7) for JR3 (MSICS with CCC), which was statistically not significant (P = 0.30 comparing JR1 vs. JR3 complication rate and 0.86 comparing JR2 and JR 3). [Table 1] shows the factors associated with major surgical complications including age, gender, type of cataract, surgeon, and type of surgery. P value is not significant for age, gender, and type of surgery and surgeon comparisons. P value is statistically significant in case of nuclear sclerosis (NS) 3± Posterior subcapsular cataract (PSCC) 3 versus NS2 ± PSC2 and very significant in case of NS4 versus NS2 ± PSC2. P value is not significant in case of mature/hypermature cataract versus NS2 ± PSC2. [Table 2] shows the distribution of specific major surgical complications in MSICS (2^nd-year residents) and ECCE (1^st-year residents) patients. The rate of vitreous loss for MSICS (2^nd-year residents) surgeries was 4.3% (8) while that of ECCE (1^st-year residents) surgeries was 7.7% (4). [Table 3] shows the surgical step at which vitreous loss was documented for the surgeries. Overall, in six cases (75.0%) of MSICS (2^nd-year residents), vitreous loss was noted during nucleus extraction, and in all cases of ECCE (1^st-year residents), it was noted during irrigation/aspiration or cortex removal. [Table 4] shows the percentage of minor complications; premature entry with tunnel suturing (in case of MSICS) was 7.5% (14), postoperative iris in section was 1.7% (4), postoperative lens matter aspiration was 1.7% (4), and optic capture was 0.8% (2). In ECCE, higher percentage of iris in section was seen postoperatively, 3.9% (3). [Table 5] shows the preoperative and postoperative BCVA in MSICS (2^nd-year residents) and ECCE (1^st-year residents) groups at 6 weeks postoperatively. 94.6% of patients of MSICS (2^nd-year residents) and 84.6% of patients of ECCE (1^st-year residents) had good visual outcome. Causes for decreased visual outcome in ECCE patients were aphakia (2), choroidal detachment (1), high astigmatism because of sutures (3), and optic capture (2). In MSICS, decreased visual outcome was because of aphakia (5), choroidal detachment (1), TASS (1), iridodialysis (1), posterior capsular rent (PCR) with IOL implantation secondary to macular edema (1), and 1 case of early corneal decompensation. Nucleus drop patient underwent vitrectomy with lensectomy and scleral-fixated IOL, and his postoperative vision was 6/9. TASS patient was treated with systemic steroids and frequent antibiotic steroid eye drops (1 hourly) with resolution of hypopyon and inflammation within 5 days. Aphakic patients were posted for secondary IOL implantation after 2 months postoperatively. The other cases with complications had good visual outcome.

Table 1: Factors associated with major surgical complications

Click here to view

Table 2: Comparison for specific major surgical complications in manual small.incision cataract surgery and extracapsular cataract extraction patients

Click here to view

Table 3: Surgical step at which vitreous loss was documented for the surgeries

Click here to view

Table 4: Comparison of minor surgical complications in manual small.incision cataract surgery and extracapsular cataract extraction patients

Click here to view

Table 5: Best.corrected visual acuity at postoperative 6 weeks in manual small.incision cataract surgery and extracapsular cataract extraction patients, n (%)

Click here to view

Discussion

Cataract surgery has its own learning curve. At our center, ECCE and MSICS were done by resident doctors with acceptable visual results as per the WHO standard.^[13] Greater number of surgeries are done in JR2 and JR3 (MSICS) group as they are more trained as compared to JR1 (ECCE) group. ECCE done by JR1 had a high rate of complications (11.5%) as compared to MSICS done by JR2 and JR3 (7.0%). Major complication rates are compared between ECCE (1^st-year residents) and MSICS (2^nd-year residents) as it depends on the experience of surgeon. Both ECCE and MSICS have statistically not significant rate of complications and have safer learning curve under supervision.

A large retrospective study by Haripriya et al.^[9] report four surgeon groups, that is, staff, fellows, residents, and visiting trainees. Surgical distribution was 26% phacoemulsification, 67% MSICS, and 7% ECCE. The overall complication rate was 1.1% for phacoemulsification, 1.01% for MSICS, and 2.6% for ECCE. The overall intraoperative complication rate was 0.79% for staff, 1.19% for fellows, 2.06% for residents, and 5% for visiting trainees. Complications rates for resident performed MSICS were 1.25% and for ECCE 3.39%. Another study by Khanna et al.^[10] compared the safety and efficacy of phacoemulsification and MSICS during their learning curve in a large residency and fellowship training people. Overall complications were seen more in the MSICS group as compared with the phacoemulsification group (15.1% vs. 7.1%). These two studies reported that MSICS was safe during the learning phase for residents and trainees. Slightly higher rates of complications in our study might be because of less sample size as compared to these studies. Meta-analysis study by Gogate et al.^[8] to compare the safety and efficacy of MSICS and phacoemulsification indicated no difference in safety between techniques.

Majority of the complications were noted in the irrigation/aspiration stage in ECCE done by 1^st-year residents. MSICS done by 2^nd-year residents group had a higher complication rates at the nucleus extraction step and irrigation/aspiration. Difficulty in nucleus extraction step may be related to the size of CCC and prolapsing of nucleus out of CCC margin. All these steps require careful supervision and training. Haripriya et al.^[9] reported that with the MSICS technique, irrespective of surgeon experience, complications were equally likely to occur during the nucleus removal and cortex aspiration steps. Between 2005 and 2009, the rate of vitreous loss in published resident series numbering at least 1000 cases ranged from 1.3% to 6.1%.^{[14],[15],[16],[17],[18],[19],[20]} Browning and Cobo^[1] reported a 9% vitreous loss and 14% PCR in the first 25 cases of the average residents experience with ECCE. Rate of vitreous loss in our study was comparable to these studies.

Age, gender, and type of surgery did not appear to significantly affect the complication rate. Complications rates were found to be significantly higher in Grade 3 nuclear sclerosis (NS3) and Grade 3 posterior subcapsular cataract (PSC3) and much higher in Grade 4 nuclear sclerosis (NS4) as compared to Grade 2 type of cataract. It was not significant when Grade 2 cataract was compared with mature/hypermature cataract. The complication rate was found to be higher in ECCE (1^st-year residents) though statistically not significant reflecting their learning curve. Haripriya et al.^[9] reported that the rate of intraoperative complications increased with decreasing surgical experience (0.79% for staff, 1.19% for fellows, 2.06% for residents, and 5% for visiting trainees).

Minor surgical complications, especially premature entry, which required tunnel suturing were seen with higher percentage as part of learning curve for making tunnel for MSICS. Higher percentage of postoperative iris in section was seen in ECCE.

Visual outcome was good in our patients (94.6% for MSICS by 2^nd-year residents and 84.6% for ECCE by 1^st-year residents). Very few prior reports are there for the visual outcomes and complications in MSICS being performed by trainees. Khanna et al.^[10] reported BCVA (≥6/12) in 84.3% of patients in MSICS group as compared with 88% in phacoemulsification group (P = 0.09) in trainees which is slightly lower as cut-off used is ≥6/12. A study by Gogate et al.^[21] which compared ECCE versus MSICS in community eye care setting had corrected postoperative visual acuity ≥6/18 in 86.7% and 89.8%, respectively. There are other clinical trials which have reported similar results.^{[22],[23],[24],[25]}

In patients having major surgical complications, the low visual outcome was seen in 3 (50%) cases in ECCE and 9 (69.2%) in MSICS cases. Main cause for it was aphakia (5) which was found to have decreased vision at 6-week postoperatively and required secondary IOL at a later date.

There were limitations with this study, one being retrospective and nonrandomized. Others were smaller size of sample and only 6-month period of training was considered. Main point with this study that it was done in resident groups where ECCE is taught as a part of stepwise training and then switch over to MSICS. A prospective randomized controlled trial would be ideal.

However, despite the above-mentioned limitations, the results can be extrapolated to other residency/training programs done in India.

Conclusion

We conclude that ECCE and MSICS have safe learning curve and can be taught to resident doctors with good visual results when done under supervision and a comparable rate of major surgical complications. It is better to start with ECCE in beginners under careful supervision as the size of incision is bigger, handling of nucleus extraction and IOL implantation are technically less difficult. Then, they can be shifted to MSICS with more focus on tunnel formation in initial stages and then on CCC. Nucleus extraction and cortex aspiration steps require supervision during learning stage in both surgeries.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

References

1.	Browning DJ, Cobo LM. Early experience in extracapsular cataract surgery by residents. Ophthalmology 1985;92:1647-53.
2.	Blumenthal M, Assia E. Extracapsular cataract extraction. In: Nordan LT, Maxwell WA, Davison JA, editors. The Surgical Rehabilitation of Vision. New York: Gower Medical Publishing; 1992. ch 10.
3.	Thomas R, Naveen S, Jacob A, Braganza A. Visual outcome and complications of residents learning phacoemulsification. Indian J Ophthalmol 1997;45:215-9. [PUBMED] [Full text]
4.	Unal M, Yücel I, Sarici A, Artunay O, Devranoǧlu K, Akar Y, et al. Phacoemulsification with topical anesthesia: Resident experience. J Cataract Refract Surg 2006;32:1361-5.
5.	Randleman JB, Wolfe JD, Woodward M, Lynn MJ, Cherwek DH, Srivastava SK, et al. The resident surgeon phacoemulsification learning curve. Arch Ophthalmol 2007;125:1215-9.
6.	Randleman JB, Srivastava SK, Aaron MM. Phacoemulsification with topical anesthesia performed by resident surgeons. J Cataract Refract Surg 2004;30:149-54.
7.	Biswas P, Gogate PM, Maskati QB, Natarajan S, Verma L, Bansal PK, et al. Residency evaluation and adherence design study III: Ophthalmology residency training in India: Then and now-improving with time? Indian J Ophthalmol 2018;66:785-92. [PUBMED] [Full text]
8.	Gogate P, Optom JJ, Deshpande S, Naidoo K. Meta-analysis to compare the safety and efficacy of manual small incision cataract surgery and phacoemulsification. Middle East Afr J Ophthalmol 2015;22:362-9. [PUBMED] [Full text]
9.	Haripriya A, Chang DF, Reena M, Shekhar M. Complication rates of phacoemulsification and manual small-incision cataract surgery at Aravind eye hospital. J Cataract Refract Surg 2012;38:1360-9.
10.	Khanna RC, Kaza S, Palamaner Subash Shantha G, Sangwan VS. Comparative outcomes of manual small incision cataract surgery and phacoemulsification performed by ophthalmology trainees in a tertiary eye care hospital in India: A retrospective cohort design. BMJ Open 2012;2. pii: e001035.
11.	Chylack LT Jr., Wolfe JK, Singer DM, Leske MC, Bullimore MA, Bailey IL, et al. The lens opacities classification system III. The longitudinal study of cataract study group. Arch Ophthalmol 1993;111:831-6.
12.	Dang MS, Raj PP. SRK II formula in the calculation of intraocular lens power. Br J Ophthalmol 1989;73:823-6.
13.	World Health Organization. Vision 2020. The Right to Sight 2007. Global Initiative for Elimination of Avoidable Blindness: Action Plan 2006-2011. Geneva: World Health Organization; 2007.
14.	Dooley IJ, O'Brien PD. Subjective difficulty of each stage of phacoemulsification cataract surgery performed by basic surgical trainees. J Cataract Refract Surg 2006;32:604-8.
15.	Blomquist PH, Rugwani RM. Visual outcomes after vitreous loss during cataract surgery performed by residents. J Cataract Refract Surg 2002;28:847-52.
16.	Bhagat N, Nissirios N, Potdevin L, Chung J, Lama P, Zarbin MA, et al. Complications in resident-performed phacoemulsification cataract surgery at new jersey medical school. Br J Ophthalmol 2007;91:1315-7.
17.	Rutar T, Porco TC, Naseri A. Risk factors for intraoperative complications in resident-performed phacoemulsification surgery. Ophthalmology 2009;116:431-6.
18.	Lee JS, Hou CH, Yang ML, Kuo JZ, Lin KK. A different approach to assess resident phacoemulsification learning curve: Analysis of both completion and complication rates. Eye (Lond) 2009;23:683-7.
19.	Blomquist PH, Sargent JW, Winslow HH. Validation of najjar-awwad cataract surgery risk score for resident phacoemulsification surgery. J Cataract Refract Surg 2010;36:1753-7.
20.	Carricondo PC, Fortes AC, Mourão Pde C, Hajnal M, Jose NK. Senior resident phacoemulsification learning curve (corrected from cure). Arq Bras Oftalmol 2010;73:66-9.
21.	Gogate PM, Deshpande M, Wormald RP, Deshpande R, Kulkarni SR. Extracapsular cataract surgery compared with manual small incision cataract surgery in community eye care setting in Western India: A randomised controlled trial. Br J Ophthalmol 2003;87:667-72.
22.	Gogate P, Deshpande M, Nirmalan PK. Why do phacoemulsification? Manual small-incision cataract surgery is almost as effective, but less expensive. Ophthalmology 2007;114:965-8.
23.	Gogate PM, Kulkarni SR, Krishnaiah S, Deshpande RD, Joshi SA, Palimkar A, et al. Safety and efficacy of phacoemulsification compared with manual small-incision cataract surgery by a randomized controlled clinical trial: Six-week results. Ophthalmology 2005;112:869-74.
24.	Ruit S, Tabin G, Chang D, Bajracharya L, Kline DC, Richheimer W, et al. Aprospective randomized clinical trial of phacoemulsification vs. manual sutureless small-incision extracapsular cataract surgery in Nepal. Am J Ophthalmol 2007;143:32-8.
25.	Gogate P, Ambardekar P, Kulkarni S, Deshpande R, Joshi S, Deshpande M, et al. Comparison of endothelial cell loss after cataract surgery: Phacoemulsification versus manual small-incision cataract surgery: Six-week results of a randomized control trial. J Cataract Refract Surg 2010;36:247-53.