|Year : 2020 | Volume
| Issue : 2 | Page : 74-77
Phacoemulsification versus manual-small incision cataract surgery for brunescent cataracts: A retrospective analysis
Sankar Ananthan Ravindran1, PR Aswin1, Madhu Shekhar1, Janani Rajendran2, Siddharth Narendran3, Ravilla D Ravindran4
1 Department of Intraocular Lens and Cataract Services, Aravind Eye Hospital, Madurai, Tamil Nadu, India
2 Department of Paediatric Ophthalmology and Adult Strabismus Services, Aravind Eye Hospital, Madurai, Tamil Nadu, India
3 General Ophthalmology Services, Aravind Eye Hospital, Madurai, Tamil Nadu, India
4 Aravind Eye Care System, Madurai, Tamil Nadu, India
|Date of Submission||10-Nov-2019|
|Date of Decision||13-Nov-2019|
|Date of Acceptance||21-Apr-2020|
|Date of Web Publication||17-Jun-2020|
P R Aswin
Department of Intraocular Lens and Cataract Services, Aravind Eye Hospital, Anna Nagar, Madurai - 625 020, Tamil Nadu
Source of Support: None, Conflict of Interest: None
Background: Brunescent cataracts are associated with higher incidence of ocular comorbidities which predispose to intraoperative and postoperative complications. Objectives: To compare the surgical outcomes of Phacoemulsification (PE) and Manual Small Incision Cataract Surgery (MSICS) in Brunescent cataracts. Patients and Methods: Retrospective observational study of patients who underwent either MSICS or phacoemulsification for brunescent cataracts over a 1-year period were reviewed for complication rates and visual outcomes. Multiple logistic regression analysis using Stata software (version 11.0, Stata Corp LP) performed to find factors associated with surgical complications. P < 0.05 considered statistically significant. Results: A total of 959 eyes of 950 cases with brunescent cataract were reviewed of which 654 underwent MSICS and 305 underwent PE. A total of 53 intraoperative complications were encountered in both groups. PE group had 14 (2.95%) with the commonest being PCR in 9 cases. In the SICS group, 39 complications (5.96%) were noted with PCR in 16 followed by ZD in 12. Postoperative complications were noted in both groups with higher incidence of corneal edema in the PE group. Statistically significant difference in visual outcome was seen after 1 month with PE group (0.21±0.21) having better uncorrected visual acuity (P <0.001) compared to MSICS (0.44±0.26). Conclusions: For developing nations, where cost and training are the rate limiting factors and patients tend to present late with harder and complicated cataracts, MSICS is comparable to PE in terms of complication rates and visual outcomes.
Keywords: Brunescent cataract, hard cataract, manual small-incision cataract surgery, phacoemulsification
|How to cite this article:|
Ravindran SA, Aswin P R, Shekhar M, Rajendran J, Narendran S, Ravindran RD. Phacoemulsification versus manual-small incision cataract surgery for brunescent cataracts: A retrospective analysis. TNOA J Ophthalmic Sci Res 2020;58:74-7
|How to cite this URL:|
Ravindran SA, Aswin P R, Shekhar M, Rajendran J, Narendran S, Ravindran RD. Phacoemulsification versus manual-small incision cataract surgery for brunescent cataracts: A retrospective analysis. TNOA J Ophthalmic Sci Res [serial online] 2020 [cited 2020 Dec 2];58:74-7. Available from: https://www.tnoajosr.com/text.asp?2020/58/2/74/286923
| Introduction|| |
Phacoemulsification (PE) is the gold standard procedure for cataract extraction even in low-and middle-income countries like India, as it offers the advantages of good visual outcome with faster and more predictable wound healing, reduced discomfort to patients, fewer complications, and lesser postoperative astigmatism than conventional extracapsular cataract extraction. The downside however is the added cost, steeper learning curve, and difficulty in handling harder, complicated cataracts. In developing nations, the need of the hour is a quick, economically viable, easy to master, safe technique with good visual outcomes, thus grew the popularity of manual small-incision cataract surgery (MSICS). It is characterized by early wound stability, less postoperative inflammation, less suture-related complications, few postoperative visits, and less damaging effect on the corneal endothelium, while negating the need for expensive equipment and consumables., In rural areas where access to advanced healthcare is limited, more advanced cataracts are encountered. Brown cataracts have been associated with ocular comorbidities, such as loose zonules, low endothelial count, shallow anterior chamber (AC), pseudoexfoliation (PXF), and inadequate pupillary dilatation, and with an increased risk of intraoperative complications. While both techniques have been described in literature with risks and benefits in each, we retrospectively analyzed these two procedures with respect to the rate of intraoperative complications, postoperative complications, and visual outcomes in a large population of patients undergoing surgery for brunescent cataract at single tertiary care eye hospital.
| Patients and Methods|| |
This was a retrospective study of all patients who presented to our hospital with Lens Opalescence Classification System Grade 4 cataract over 1 year from June 2017 to May 2018. Electronic medical records of the patients were reviewed, and demographic, preoperative, and postoperative data collected included age, gender, preoperative uncorrected visual acuity (UCVA), presence of preoperative comorbidities, intraoperative and postoperative complications, and postoperative UCVA on postoperative day (POD) 1 and 30. Patients with other preoperative vision-impairing pathologies were excluded from the analysis such as corneal opacities and macular disorders. Combined procedures (cataract with penetrating keratoplasty, trabeculectomy, or strabismus surgery), traumatic cataract, and pediatric patients (younger than 15 years) were also excluded. Major intraoperative complications were defined as posterior capsular rupture, zonular dialysis (ZD), iridodialysis, and drop of lens material into vitreous. Postoperative complications were categorized as significant corneal edema defined as increased stromal thickness and Descemet's folds and hazy iris details, fibrinous uveitis, hyphema, and wound leak. Some complications such as Descemet's membrane detachment missed intraoperatively and noted postoperatively were included in postoperative complications. Patients were followed up to POD 30, checked for the presence of any persistent corneal edema and any other complications, and also underwent visual acuity assessment.
All patients underwent examinations on the 1st POD with UCVA, vision with pinhole, and slit-lamp evaluation. On POD 30, UCVA and best-corrected visual acuity along with slit lamp evaluation were checked. A Snellen chart was used at 6 m for visual acuity assessment.
The surgeons were classified into three groups based on years of experience after completion of residency training into < 5, 5–10, and >10 years. The intraoperative and postoperative data were analyzed to note any differences among the three groups and between the two procedures.
Categorical variables were expressed as frequency (percentage). Multiple logistic regression analysis was performed to find the factors associated with the surgical complication. A P < 0.05 was considered statistically significant. All analyses were performed using Stata software (version 11, StataCorp, College Station, TX).
| Results|| |
Among the 959 eyes of 950 cases with brunescent cataract reviewed, 654 (68.2%) underwent MSICS and 305 (31.8%) underwent PE. 503 cases (52.45%) were male and 456 cases (47.55%) were female. Mean age was 66.73 (±8.16) years in the PE group and 68.52 (±8.43) years in the MSICS group, which was found to be statistically significant (P = 0.001), suggesting that more older patients underwent MSICS. Preoperative documentation showed that 105 cases had PXF, 32 cases with shallow AC, 14 cases with associated posterior polar cataract, and three cases with phacodonesis [Table 1]. A total of 53 intraoperative complications were encountered in both groups. PE group had 14 (2.95%) intraoperative complications with the most common being polymerase chain reaction (PCR) in 9 (64.3%) cases followed by ZD in 4 (28.6%). In the SICS group, 39 complications (5.96%) were noted with PCR in 19 (48.7%) followed by ZD in 16 (41%). The only complication that was not encountered in the PE group was iridodialysis, which occurred in 4 (10.3) cases of MSICS.
|Table 1: Demography, preoperative data, surgeon experience, and surgical outcomes|
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The mean postoperative UCVA on POD 1 and POD 30 was 0.42 and 0.21, respectively, for the PE group and 0.42 and 0.44 for the MSICS group, with significant difference seen at POD 30 (P < 0.001). Postoperative complications were noted in both groups with higher incidence of significant corneal edema in the PE group (106 cases, 34.75%) compared to SICS (90 cases), which was statistically significant (P < 0.001) [Table 1].
In our study, we found that PE was done by more senior surgeons (65.6%) and MSICS by junior surgeons with < 5 years' experience (40.7%) (P < 0.001).
| Discussion|| |
While PE remains the gold standard in most developed nations, cataract surgery rates in developing countries have improved with the introduction of the economically viable, safe, and comparable technique of MSICS. In rural areas with poor accessibility, patients do not reach the hospital until it is too late,, hence the higher proportion of advanced cataracts in developing countries. Division of the dense nucleus during PE remains a challenge even for experienced cataract surgeons, and the added cost of the machine and disposables prompted surgeons to adopt MSICS as a cost-effective and safe alternative.
In our retrospective analysis of 959 eyes with Brown cataract, both MSICS and PE had good surgical outcomes after surgery. Preoperative comorbidities and ages of the patients were found to be more among the MSICS group compared to PE. Even so, the complication rates encountered with PE (14 cases, 4.59%) and MSICS (39 cases, 5.96%) were not only comparable but also much lesser than those reported by Enany. The one intraoperative complication that we saw in our study that occurred only in the MSICS group was iridodialysis seen in four cases. This could be attributed to the technique of nucleus delivery using the irrigating vectis where the iris can get caught if not performed carefully. Another cause could be poor construction of the sclero-corneal tunnel which is either too deep or insufficient in size for the large nucleus causing iris prolapse during surgery. This can be avoided by proper tunnel construction with adequate side pockets and careful nucleus delivery. The increased incidence of intraoperative ZD in MSICS could be attributed to the difficulty in prolapsing the hard cataract into the anterior chamber which requires a large capsulorrhexis. The increased incidence of pseudoexfoliation and weak zonular support could also be a contributing factor.
PE was associated with higher incidence of postoperative corneal edema compared to MSICS on day 1 which concurs with report by Venkatesh et al. MSICS in our study was however associated with a higher incidence of postoperative wound leak, hyphema, and Descemet's membrane detachment which again could be attributed to the larger incision size and difficulty in nucleus delivery.
Postoperatively, after 1 month, we found PE to be associated with better visual outcomes similar to the reports by Gogate, who suggested the PE gives better UCVA in a larger proportion of patients at 6 weeks. This was attributed to the astigmatism induced by the larger incision in MSICS. The advantage of the larger incision is that grossly subluxated lenses, very hard cataracts, or those with poor endothelial counts are more easily removed.
In our institute, surgeons are first trained to become proficient in MSICS before proceeding to PE this could be the reason behind more senior surgeons performing PE and more junior surgeons performed MSICS, especially in harder cataracts. However, since the difference in the number of surgeries among the groups was grossly different, comparison of outcomes could not be made. In a previous study by Haripriya et al., the authors had suggested that even for less experienced surgeons, MSICS is a good starting point.
The biggest problem encountered during PE of hard cataracts is the excessive use of energy required in nucleus disassembly. With cataract surgery evolving, newer advances such as the Femtosecond laser and the miLoop, even hard Brown cataracts can be first disassembled before emulsification thus using minimal phaco energy., The downside however is the cost of the procedure, instrument, and consumables, which may not be affordable or available to all. Being economically viable, easier to master, and safe even in the hands of less experienced surgeons, MSICS helps reach many more people especially in lower economic regions.,
The authors do however acknowledge the limitations of this study owing to its retrospective nature such as the difference in the number of cases between the two groups, the variation in surgeon experience, and the short follow-up period of the patients.
| Conclusion|| |
Brown cataract still remains a challenge for many surgeons in view of the hardness of the cataract and the higher incidence of intraoperative and postoperative complications. While PE is the gold standard technique, the higher energy needed in tackling these hard cataracts can result in more endothelial damage and corneal edema, thus requiring more experience and skill level. MSICS is a good and safe alternative even among the beginners in handling brown cataracts as it causes less endothelial damage and provides comparable visual outcomes. In developing nations, PE in view of its higher cost and steeper learning curve is yet to find its foothold, and thus, MSICS being faster, less expensive, and safer remains in most situations, a more feasible technique for many surgeons.
In conclusion, for developing nations where cost and training are the rate limiting factors, where patients tend to present late with harder and complicated cataracts, MSICS is the procedure that serves the need for low-cost, high-volume, high-quality cataract surgery for all.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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