Dr. Rohit Sreenath, Dr. Sheetal Brar, Dr. Sri Ganesh
TITLE- Immediate Sequential Bilateral Cataract Surgery (ISBCS)- A five year retrospective analysis of 2470 eyes from a tertiary care eye centre in South India
Contributors
Dr. Sri Ganesh , MS, DNB
Dr. Sheetal Brar, MS
Dr Rohit Sreenath, MS
Department(s) and institution(s) affiliation of all authors : Nethradhama Superspeciality Eye Hospital, Bengaluru, Karnataka, India
Corresponding Author:
Name : Dr. Rohit S
Address: Nethradhama Superspeciality Eye Hospital, 256/14, Kanakapura main road, 7th Block, Jayanagar, Bengaluru, Karnataka, India-560070
Phone numbers: +919597705921
E-mail address: therocksays07@gmail.com
Total number of pages: 12
Word counts: Abstract – 258, Text- 2637
Source(s) of support: Nil
Conflict of interest and financial disclosure- Nil
ABSTRACT
Purpose: To Evaluate the safety and benefits of Immediate Sequential bilateral cataract surgery (ISBCS).
Methods: Retrospective data analysis of patients who underwent immediate sequential bilateral phacoemulsification with Foldable IOL implantation under topical anesthesia from January 2011 to Sep 2016. Inclusion criteria were visually significant bilateral cataract and axial length of 21.0 to 26.5mm. The exclusion criteria’s can be broadly divided into conditions that may predispose to increased intraoperative complications like posterior capsule rent and vitreous loss, post-operative complications like infections, corneal decompensation, retinal detachment (RD), Cystoid Macular Edema (CME) and inaccurate IOL power calculation. Any intraoperative and postoperative complications were noted.
Results: Best corrected visual acuity improved from 0.40 ± 0.17 to 0.08± 0.10 (logmar). Targeted post-operative refraction of ±0.5D achieved in 92.05% patients. Complications were 11(0.45%) posterior capsular tears, 1.94% (n=48) post-operative rise in Intraocular pressure (IOP), 1.25 % (n=31) prolonged post-operative inflammation and 0.08% (2) unilateral cystoid macular edema (CME). No sight threating complications like endophthalmitis, retinal detachment, corneal edema and intraocular haemorrhage’s. 38 patients (76 eyes- 3%) underwent B/L FLACS (Femtosecond laser Assisted Cataract Surgery) out of which 23 patients (46 eyes- 1.86% ) underwent FLACS with Multifocal IOL. 1 Down’s patient underwent B/L Cataract Surgery under IV Sedation.
Conclusion: IBSCS can be taken up as a preferred practice in eligible cases which can benefit the patient and the health care provider in terms of early visual rehabilitation, cost effectiveness and time saving. In cases of pediatric cataract requiring general anesthesia and in special situations like debilitated and Down‘s patient’s it is the ideal procedure.
Key words: Immediate Sequential bilateral cataract surgery (ISBCS)
Trial registration number: CTRI REF NO – REF/2014/03/006647
INTRODUCTION:
Cataract surgery is the most common surgical procedure performed worldwide.1 The innovations in cataract surgery have lead to decrease in incision size from 8mm to small 0.9 mm clear corneal, self-sealing incisions and foldable intraocular lenses due to which, the visual rehabilitation of patients has accelerated to the extent of few minutes. In addition, refinement in the IOL power calculating formulae and advanced biometry techniques, have improved the precision of IOL power calculation with 90- 95% eyes achieving post-operative spherical equivalent within ±1.0 Diopter (D).2,3
However, inspite of these technological advancements in the field of cataract surgery, the date back teaching “do not operate both the eyes simultaneously” remains unchanged, the greatest fear in doing so being visually threating endophthalmitis and post-operative refractive surprises.7
In this era of evidence based clinical practice, numerous tudies have provided enough supporting data in favour of Immediate Sequential Bilateral Cataract Surgery (ISBCS) being a safe and economic procedure. 4-7 Also, the benefits of second eye surgery than only first eye in terms of good visual outcome and .patient’s satisfaction has already been proved.28-31
This aim of this retrospective study was to report a large data of 2470 eyes who underwent ISBCS within a span of 5 years and compare our results on safety, risks and benefits to the previously published reports. To our knowledge, this is the largest data from India and second largest in the world on ISBCS being reported from a single centre, NABH accredited tertiary eye hospital of South India.
PATIENTS AND METHODS:
A retrospective collection of data was done from the electronic medical records for all the adult patients who underwent Immediate Sequential Bilateral Cataract surgery from January 2011 to September 2016. The study was approved by the ethics committee of Nethradhama Superspeciality Eye Hospital , Bangalore and was conducted in accordance with the tenets of Declaration of Helsinky.
ISBCS was considered in patients with visually significant bilateral cataract, axial lengths within the range of 21.0 to 26.5mm, patients opting for multifocal implants and surgery under topical or general anesthesia.
The exclusion criteria were – conditions predisposing to increased intraoperative complications such as posterior capsule rent and vitreous loss, post-operative complications such as infections, corneal decompensation, retinal detachment (RD), Cystoid Macular Edema (CME) and inaccurate IOL power calculation. Ocular comorbidities that required a combined surgery (trabeculotomy or vitreoretinal surgery) was also excluded. (Table 1)
All patients underwent a thorough preoperative eye examination and necessary investigations according to the hospital protocol. Biometry was performed using IOL Master 500 (Carl Zeiss Meditec AG) or A-scan device (Pac Scan Plus, Sonomed) in case of dense cataracts. SRK- T formula was used for IOL power calculation to achieve the planned refraction.
OPERATIVE PROTOCOL FOR ISBCS : All the cases were performed by a single experienced surgeon ( S.G.) under topical anesthesia of 4% lidocaine( LOX 4 % , NEON Laboratories Ltd , Andheri(East), Mumbai ) and intracameral anesthesia of 1% lidocaine with 1 in 2,00,00 adrenalin ( AstraZeneca Hebbal, Bengaluru, ). Utmost care was taken to maintain strict asepsis intraoperatively. Each eye was treated as a separate procedure with complete segregation of the two procedures. Preoperatively, 5% povidone iodine was used to paint the conjunctival sac, lid, nose, forehead and cheek on both sides at the same time. The eye with advanced cataract was operated first, which was then draped with a sterile plastic drape covering the lashes and orifices of meibomian glands followed by application of a speculum. All the eyes underwent a standard phacoemulsification procedure using a temporal 2.8mm clear corneal incision with a diamond blade, followed by implantation of foldable IOLs in the capsular bag. Leak proof wound sealing was ensured at the end of the surgery.
Before operating the second eye, both the surgeon and the assistant changed their gowns and gloves. The second eye was cleaned and prepared again in a similar manner as the first eye. A new trolley with separate full cycle autoclaved instruments, viscoelastics, irrigation line and BSS solution was used. Intracameral Vancomycin 1mg/0.1 ml was routinely used in all cases.
All the patients were instructed to wear dark goggles after surgery and were discharged on the same day after starting the postoperative medications in the hospital. The post operative medications included Ofloxacin-Dx eyedrop ( micro labs, Bangalore) and nevanac( Alcon , Novartis) eyedrop. Separate postoperative medication kits were provided for each eye . Patients were explained about eye hygiene and were instructed to report back immediately if any ominous signs and symptoms such as decreasing vision, eye pain or redness were experienced. Patients were called for post-operative check up on day 1, 2 weeks , 3 months and annually. At 2 weeks, visual acuity, refraction and dilated fundus examination were performed. The visual acuity was measured using Snellens visual acuity chart at 6 meters, which was later converted to Snellens decimal values for statistical analysis.
RESULTS
A total of 2470 eyes from 1235 patients with a mean age of 68.34 years (range = 32-90 years) were included in the study, out of which 28.9% (n=714) were women and 71.1% (n=1756) were men.The mean axial length was 23.4 +/- 1.76 (21.23 to 26.1 mm) (Table 2)
The various systemic and ocular co-morbities of the participant patients are listed in Table 3. The systemic morbidities of the patients chiefly consisted of Diabetes Mellitus (DM) 27.79% (n=686), hypertension 35.41 % (n=874), cardiac problems 2.86 %(n=70), parkinsonism 0.08% (n=2) and arthritis 0.85% (n=21), whereas, the noteworthy ocular co-morbidities were Dry Age Related Macular Degeneration -ARMD 23.32% (n=576), Diabetic Retinopathy 6.5%(n=160), wet ARMD 1.0%(n=24), Pseudoexfoliation 0.41%(n=10) and Epi-Retinal Membrane 0.25%(n=6).
76 eyes (3%) underwent ISBCS with FLACS (Femtosecond laser Assisted Cataract Surgery) and 46 eyes (1.86%) underwent FLACS with MFIOL implantation, while the rest 97 % underwent routine phacoemulsification surgery. One patient with Down’s syndrome underwent bilateral cataract surgery under IV Sedation. Multifocal IOLs were implanted in 575 (23.2 %) of the patients. Pediatric cases were 4 eyes (0.16%).
VISUAL AND REFRACTIVE OUTCOMES
The mean preoperative best corrected visual acuity in Logmar was 0.40 ± 0.16 . At 2 weeks post-operative follow up, the best corrected visual acuity had improved significantly to 0.08 ± 0.1 (p-value=0.000), with a mean uncorrected visual acuity of 0.04 ± 0.13 Logmar.
A statistically significant reduction in the spherical equivalent (SE) was observed , where the SE reduced from a pre-op value of -1.35 ± 4.4 D to 0.15 ± 0.57 D at 2 weeks post-operatively(p=0.001). 92.05% patients achieved a targeted post- operative spherical equivalent(SE) refraction within ±0.5D, while all eyes were within ± 1.5 D at the end of 2 weeks .(Table 4).
INTRA AND POST-OPERATIVE COMPLICATIONS
The chief intra operative complication encountered in the series was posterior capsular tears, which occurred in 11(0.45%) eyes . It is noteworthy to mention that this complication occurred in the second eyes of these patients , whose first eye surgery was uneventful. Of these 11 eyes, 4 eyes required anterior vitrectomy with placement of 3 piece foldable IOL in the sulcus. Among the 4 viterectomised eyes, 3 eyes achieved a best corrected visual acuity of 6/6 and one eye with myopic degeneration achieved a best corrected vision of 6/12.
Postoperative complications in the decreasing order of frequency were- rise in Intraocular pressure (IOP), prolonged post operative inflammation and cystoid macular edema (CME). Intermediate rise in IOP (21 to 30mmHg) was seen in 1.94% (n=48) eyes out of which 0.57% (n=14) eyes needed antiglaucoma medications in the post-operative period. The post-operative inflammation was seen in 1.3% (n=31) of the patients, out of which 0.68 % (n=17) were diabetic individuals. CME was seen in 2 eyes (0.08%), both being unilateral. No sight threating complications such as endophthalmitis, retinal detachment, corneal decompensation and intraocular hemorrhages were observed in any of the eyes operated in the series. (Table 5)
The incidence of PCR in our study was 11 eyes (0.446%) which were comparable to the other studies by Dr Kotkaren 4(0.14%) and Dr Arshinoff 30 (1.47%) which are other similar studies having comparable total number of eye. TABLE-6
Discussion:
Previously some studies have reported that the major concerns in performing an Immediate Sequential Bilateral Cataract Surgery(ISBCS) are the risks of certain vision threatening complications like endophthalmitis, RD, CME, corneal edema and refractive surprises.32,33
Our literature review revealed that the actual incidence of these dreaded bilateral complications was not more than the unilateral scenario. Regarding bilateral endophthalmitis, so far 4 cases of bilateral endophthalmitis have been reported since 1952. 5,39-41 .However, it was noticed that all these cases in the ISBCS case series had occurred before the use of intracameral antibiotic prophylaxis in preventing postoperative endophthalmitis as also highlighted by the ESCRS study.36 This shows that the chances of endophthalmitis can be reduced to nearly nil, if the guidelines laid by International Society of Bilateral Cataract Surgeons37 and the United Kingdom Royal College of Ophthalmologists38 are strictly followed .
Arshinoff and Odorcic (2009) calculated the risk of bilateral endophthalmitis to be 0.005% which was suggested to almost 10 times rarer than the unilateral endophthalmitis (Table 6). They noted that in these cases of bilateral endophthalmitis, there was an obvious breach in aseptic protocols followed during surgery.42
In our series, no eye developed endopthalmitis which we believe was due to meticulous case selection (excluding cases with high risk of infection), thorough intraoperative asepsis protocols followed and skilfully performed surgery. The precautions taken intraoperatively included complete segregation of the two procedures by using separate sets of drapes, gowns, gloves and full cycle autoclaved instruments for both eyes . There is also enough evidence that the intraoperative use of intracameral vancomycin (20mcg/ml) has significantly minimised the incidence of endophthalmitis to 0.001% and that Vancomycin was found to be equally efficacious as cephalosporin and moxifloxicin in preventing endophthalmitis.34 In addition, utmost care was taken to achieve a good wound architecture, minimal tissue injury and ensuring leak proof incision closure.
Bilateral CME is another concern regarding postoperative visual loss in the scenario of ISBCS .In our study, no patient developed bilateral CME, however 2 patients presented with unilateral CME, which resolved in 3 months with treatment. Meticulous case selection to avoid high risk cases, atraumatic surgery and mandatory use of post-operative NSAIDs have been proven to prevent post-operative CME, that may potentially lead to delay in visual rehabilitation.43
In our study, only those diabetic patients (689/27.79%) were included who were well controlled with medical treatment . However, we excluded patients with arthritis and Uveitic patients.
No eye in the series developed irreversible corneal edema leading to endothelial decompensation, as this was well taken care of by good patient selection and meticulously performed surgery. Most of the reported cases of corneal edema were transient (0-2.4%) and unilateral. Wertheim et al reported bilateral corneal edema after ISBCS, which resolved within 3 months with medical management.13One case of bilateral corneal decompensation requiring penetrating keratoplasty has been reported, but there is no mention of any ocular comorbidity.44
We believe high risk cases like collagen vascular disease, active rheumatism, dry eye, corneal thinning, corneal exposure should be contraindicated for ISBCS.(these are risk factors for corneal melting and post op uveitis )
There is no report of bilateral RD following ISBCS till date. In the present study also, no eye in the series had retinal detachment in the post-operative period. All the patients had preoperative dilated 360° fundus examination with indentation to rule out any possible high risk lesion, the presence of which excludes the patient for ISBCS. Also, the maximal axial length operated was 26.1mm. Cases of previous RD, extreme axial length, post trauma, high risk retinal lesions, and combined surgery were excluded from the study (TABLE 1). So far only 4 studies have reported post- operative RD (0.15-0.2%)4,5,10,15 which is comparable to the unilateral cases (0.1-0.7%).45
We had a favorable refractive outcome in our cases with 92.05% eyes having post-operative residual refractive error within ±0.5D and 98.83% within ±1.0D (Table3). Our refractive results were comparable to the previous studies.13,15,24,46The literature review (table7) revealed that refractive surprises following ISBCS were mainly observed in high myope or hyperope which form the extremes of the bell shaped distribution of post cataract surgery refractive outcome.47 We believe our favorable outcome is possible due to strict selection criteria excluding extremes of AL ,corneal astigmatism of more than 1.5D, use of IOL Master for biometry and use of modern formulae(SRK/T).
We do not perform ISBCS in AL length less than 21 mm and more than 26. 5mm. IOL master is used for biometry and in cases of dense cataract A scan is done where 3 consecutive reading with standard deviation (SD) of 0.03mm is taken. We have optimized our lens constants for all the IOLs used in our hospital. In addition to this, the surgical technique, type of IOL and in the bag placement of IOL also have a considerable impact on the final refractive and visual outcome. 22.1% of our patients had bilateral multifocal IOL (MFIOL) implantation with excellent visual outcome. Bilateral implantation of MFIOL has been proven to give better contrast sensitivity, stereopsis and faster neuro-adaptation compared to unilateral implantation.48
Our hospital has maintained a Lean Six Sigma score (National Demonstration Project conducted by Quality council of India) .This project looks at optimizing post-operative refractive outcomes after cataract surgery by analysing the various causes leading to suboptimal refractive outcomes such as errors in biometery .Nethradhama was the first eye hospital in the country to be accredited by NABH in 2008 . National Accreditation Board for Hospitals & Healthcare Providers (NABH) is a constituent board of Quality Council of India, set up to establish and operate accreditation programme for healthcare organisations. The hospital abides by the benchmarks prescribed by NABH for eye health standards and continues to improve the quality of eye care.50
The most common intraoperative complications seen in all the case series were posterior capsular rent (PCR) and vitreous loss (10.7 to 0.05%) (TABLE8). PCR with or without vitreous loss are known to be associated with an increased risk of more than six-fold for acute endophthalmitis.37 In our hospital if there is a posterior capsular rent with or without vitreous loss in first eye, we usually defer second eye surgery. Joseph and Benzera reported cases of bilateral PCR with vitreous loss, but were not associated with endophthalmitis.6,7 None of the cases of bilateral endophthalmitis have stated if there was any posterior capsule rent or vitreous loss.
4 pediatric eyes- (2 Patients) underwent ISBCS under GA which was uneventful.
Our study did not calculate the economic benefits but there have been studies that have proven beyond doubts that ISBCS has a tremendous impact on cutting down health care cost to almost half.49 In our country , where there is a long waiting list for cataract surgery and the health care providers are mostly concentrated in the urban areas, ISBCS may be considered on a routine basis provided that strict protocols are followed. More convenient to patients – better compliance with post-op medications, reduced hospital visits , faster visual rehabilitation and shorter period of restrictions after surgery. However, we do not recommend performing bilateral cataract surgeries in camp conditions or set ups where high standards of asepsis cannot be ensured.
CONCLUSION
Bilateral cataract surgery can be a preferred practice, but only if the surgeon has the competence to do it. An experienced surgeon with minimal complication rate, proven accuracy of their biometry measurement, strict operation room sterilization protocol and good well trained support staff are the few criteria’s to perform IBSCS to achieve its proven advantages. With proper precautions, IBSCS can be taken up as a preferred practice in eligible cases which can benefit the patient and the health care provider in terms of early visual rehabilitation, cost effectiveness and time saving. In cases of pediatric cataract requiring general anesthesia and in special situations like debilitated and Down‘s patient’s it is the ideal procedure.
Table -1 Exclusion Criteria
| INCREASED RISK OF CORNEAL DECOMPENSATION | Endothelial dystrophies
Endothelial count less than 2000cells/mm2 |
| INCREASED RISK OF RD High myopia | Presence of high risk retinal lesions like retinal hole, tear, multiple lattice degenerations.
Post trauma H/O vitreoretinal surgery |
| RISK OF CME | Uncontrolled DM
Active uveitis Intraoperative vitreous loss (in first eye) Combined trabeculectomy /VR surgery |
| INCREASED RISK OF VITREOUS LOSS | Post traumatic
Subluxated lens Phacodonesis Posterior polar cataract |
| NCREASED RISK OD RAISED IOP Glaucoma | Trabeculectomy
Uveitis with sequelae VR surgery |
| INCREASED RISK OF INACCURATE BIOMETRY | AL < 21, >26. 50mm
Corneal astigmatism more than 1. 5D Post Refractive Surgery
|
TABLE 2 – BASELINE CHARACTERISTICS
| MEAN AGE | 68.34 years |
| MINIMUM AGE | 32 years |
| MAXIMUM AGE | 90 years |
| MALE | 71.1% (n=1756) |
| FEMALE | 28.9% (n=714)) |
| AXIAL LENGTH | 23.4 +/- 1.764 (21.23 to 26.1 mm) |
| VISUAL ACUITY | 0.40 +/- 0.17 |
TYPE OF CATARACT
| NUCLEAR | 956 (38.78) |
| CORTICAL | 23 (0.96) |
| POSTERIOR SUBCAPSULAR CATARACT | 43 (1.75) |
| MIXED | 1444(58.49) |
MATURITY OF CATARCT
| MATURE | 319(12.9) |
| IMMATURE | 2150 (87.07) |
TABLE 3- Systemic and Ocular Disease
| SYSTEMIC DISEASES | n(%) |
| Diabetes | 686 ( 27.79) |
| Hypertension | 874 ( 35.41) |
| Heart problems | 70 (2.86) |
TABLE 4 – Deviation from target refraction
| Residual subjective refractive error( S.E) | N (%) |
| ≤±0. 50 | 2284(92.05) |
| ±0.75 | 84 (3.41) |
| ±1.0 | 83(3.37) |
| ±1.25 | 10 (0.41) |
| ±1. 50 | 18 (0.73) |
TABLE 5- Complications
| COMPLICATION | N(%) |
| PCR | 11(0. 44) |
| Vitreous loss | 4(0.16) |
| CME | 2 (0.08) |
| Prolonged iritis | 31(1.3) |
| Post op rise in IOP | 14 (0.58) |
TABLE 6- Comparison with other studies
| Sl no | AUTHORS | YEAR | B/l ENDOPHTHALMITIS | U/L ENDOPHTHALMITIS | Post capsular rent (PCR) | RD | NO. OF EYES |
| 1 | JOSHEP | 1977 | 0 | 3 (0.22%) | 130(9.6%) | 2(0.15%) | 1352 |
| 2 | BENEZERA | 1978 | 2(0.2%) | 1(0.1%) | 14(2.0%) | 2(0.2%) | 448 |
| 3 | FENTON | 1982 | 0 | 0 | NA | 0 | 500 |
| 4 | BEATTY | 1995 | 0 | 1 (0.15%) | 5 (0.8%) | 0 | 638 |
| 5 | BOLGER | 1998 | 0 | 2(0.28%) | 10(1.9%) | 0 | 700 |
| 6 | ARSHINOFF | 1998 | 0 | 0 | 2 (0.69%) | 0 | 600 |
| 7 | RAMSAY | 1999 | 0 | 1(0.19%) | 0 | 1(0.2%) | 518 |
| 8 | Totan | 2000 | 0 | 0 | NA | 0 | 82 |
| 9 | TARUN | 2001 | 0 | 0 | 3 (0.15%) | 0 | 288 |
| 10 | WERTHEIM | 2002 | 0 | 0 | 3 (0.7%) | 0 | 218 |
| 11 | KOTKAREN | 2002 | 0 | 2 (0.07%) | 4(0.14%) | 0 | 2715 |
| 12 | ARSHINOFF | 2003 | 0 | 0 | 30 (1.47%) | 4 (0.2%) | 2040 |
| 13 | JOHANSSON | 2003 | 0 | 2(0.45%) | 1(0.7) | 0 | 440 |
| 14 | SARIKKOLA | 2004 | 0 | 0 | 0 | 0 | 637 |
| 15 | BJORN | – | – | – | 0 | 0 | 330 |
| 16 | LUNDSTROM | 2006 | 0 | 0 | 0 | 0 | 100 |
| 17 | TIEN-ENHUANG | 2007 | 0 | 0 | NA | 0 | 54 |
| 18 | NASSIRI | 2009 | 0 | 0 | NA | 0 | 140 |
| 19 | CHUNG | 2009 | 0 | 0 | NA | 0 | 168 |
| 20 | PETROS | 2011 | 0 | 0 | NA | 0 | 2129 |
| 21 | SARIKKOLA | 2011 | 0 | 0 | NA | 0 | 493 |
| 22 | PEDRO | 2012 | 0 | 0 | NA | 0 | 834 |
| 23 | SOWBHAGYA | 2013 | 0 | 0 | NA | 0 | 166 |
| 24 | JOHANSSON | 2004 | 0 | 0 | 3(0.7) | 0 | 328 |
| 25 | PRESENT STUDY | 2016 | 0 | 0 | 11(0.446%) | 0 | 2470 |
TABLE 7- Post OP REFRACTIVE ERROR
| STUDY | REFRACTIVE ERROR (SE) | |||
| >0. 5-1 | >1.0-1. 5 | >1. 5-2.0 | > 2.0 | |
| JOHANSSON | 43% | 28% | 24% | 5% |
| SARRIKOLA | 83.2% | 14.8% | 1.2% | 0.8% |
| WERTHEIM | – | – | – | 6.9% |
| ARSHINOFF | – | – | – | 0.24% |
| PRESENT STUDY | 98.77% | 1.14% | 0.9% | 0% |
TABLES – LEGEND
TABLE 1- EXCLUSION CRITERIA
TABLE 2- BASELINE CHARACTERISTICS
TABLE 3- SYSTEMIC AND OCULAR DISEASE
TABLE 4- DEVIATION FROM TARGET REFRACTION
TABLE 5 – COMPLICATIONS
TABLE 6 – COMPARISION WITH OTHER SIMILAR STUDIES
TABLE 7 – POST OP REFRACTIVE ERROR
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