Simultaneous Bilateral Cataract Surgery in Outreach Surgical Camps

Abstract

OBJECTIVES

The aim of this study was to evaluate the safety and visual outcomes of simultaneous bilateral cataract surgery (SBCS) with intraocular lens implantation performed in outreach surgical eye camps.

METHODS

The medical records of 47 consecutive patients who underwent simultaneous bilateral small-incision cataract surgery between January 2010 and December 2015 in outreach surgical camps in rural Cameroon were reviewed. The measures included postoperative visual outcomes and intraoperative and postoperative complications.

RESULTS

Data from 94 eyes of 47 participants (30 men, 17 women; mean age: 60.93 ± 13.58 years, range: 45–80 years) were included in this study. The presented best visual acuity (VA) was less than 3/60 in 100% of the eyes. At the 4-week follow-up, 84.04% of the eyes showed increased VA of 1 line or more (P = .001). Of these, 71 (75.53%) achieved good VA (greater than 6/18). Intraoperative or postoperative complications occurred in 19 (20.21%) eyes. The most serious intraoperative complication was a posterior capsule rupture and vitreous loss (2 patients, 2 eyes). The postoperative complications included a transient elevation in the intraocular pressure (6 eyes), chronic corneal oedema (5 eyes), iris capture (3 eyes), lens decentration (2 eyes), and hyphema (1 eye). No cases of postoperative endophthalmitis were recorded.

CONCLUSIONS

Under the strict observation of endophthalmitis prophylaxis, SBCS is an option to reduce the cataract blindness backlog in rural areas of developing countries.

Introduction

Cataracts are the leading treatable cause of blindness in the world.¹ In sub-Saharan countries, many barriers contribute to low rates of cataract surgical coverage, including lack of financial resources, difficult access to eye care services, ignorance, and fear of surgery.² To overcome some of these barriers, we organized free eye camp surgery in rural areas in which simultaneous bilateral cataract surgery (SBCS) was performed in select patients. Simultaneous bilateral cataract surgery has become an increasingly debated issue, despite improvements in cataract surgical techniques. The primary issue is related to the risk of bilateral postoperative endophthalmitis.³ However, most agree that SBCS should be used for bilateral paediatric cataracts to mitigate deprivation amblyopia and to prevent children from undergoing general anaesthesia more than once.^4,5 Performing a massive SBCS in locations other than hospitals remains a challenge. Therefore, the aim of this study was to assess the immediate visual outcomes and complications of patients undergoing SBCS in eye camps in Cameroon.

Materials and Methods

Patients

All patients who underwent SBCS in the outreach surgical camps in rural Cameroon between January 2010 and December 2015 were consecutively included in this study. Informed written consent was obtained from all participants before surgery, and the protocol was approved by the local ethics committee. The inclusion criteria were bilateral mature cataracts (Figure 1), a prompt pupillary reaction and compliance for local anaesthesia. The exclusion criteria were a high intraocular pressure (IOP; greater than 21 mm Hg), pinkeye (increased risk of infection), active uveitis, corneal decompensation, uncontrolled hypertension, and diabetes. Moreover, those patients who did not have anyone to take care of them after the surgery were not eligible for SBCS. Preoperatively, the patients underwent complete ophthalmologic evaluations, including uncorrected visual acuity (UCVA) and pinhole visual acuity (PHVA) assessments using the Snellen vision chart at a distance of 6 m. In addition, the IOP was tested using a Schiøtz tonometer, slit lamp examination (before and after pupillary dilatation), and pupillary reflex. A fundus examination was conducted using indirect ophthalmoscopy.

Figure 1.

Bilateral mature cataract.

Procedure

Each eye operation was performed as a separate and individual surgery, with separate sterilization cycles, routines, and instrument trays. Prior to the surgery, the patient’s face was cleaned with 5% povidone-iodine for 3 minutes (Figure 2), and 5% povidone-iodine was dropped in the fornix. The second eye was cleaned again with 5% povidone-iodine before it was operated. Local anaesthesia consisted of a mixture of 3 mL bupivacaine and 3 mL xylocaine with parabulbar or retrobulbar injection. The operation technique was a modified small-incision cataract surgery (mSICS).⁶ Polymethylmethacrylate intraocular lenses (IOLs) were implanted, and only standard IOLs (20 or 21 dioptres) were used. Sine biometry was not available. At the end of the procedure, 1 mg/0.1 mL of cefuroxime was injected in the anterior chamber, and a mixture of triamcinolone and gentamicin was given subconjunctivally. The postoperative medication consisted of a topical mixture of steroid/antibiotics drops that were used every hour with gradual tapering. Each patient was discharged with eye sheets on postoperative day 3 (Figure 3), and clear explanations were provided regarding the postoperative care and 4-week follow-up visit. The follow-up visit was conducted at the same campsite. The uncorrected UCVA and PHVA were tested and classified according to the World Health Organization (WHO) recommendations.⁷ In addition, slit lamp and dilated fundus examinations were performed to identify the reasons for no amelioration in visual acuity (VA). The diagnosis of postoperative refractive error was made on the basis of a UCVA, which improved by at least 2 lines with a pinhole.

Figure 2.

Face cleaning with 5% povidone-iodine.

Figure 3.

Simultaneous bilateral cataract surgery patient at discharge.

Statistical analysis

The data were analysed using the Epi Info 3.5.1 software (US Centers for Disease Control and Prevention, Atlanta, GA, USA), and the quantitative variables were reported as mean ± SD. The qualitative variables were presented in percentages. A Student paired t test was conducted to compare the postoperative and preoperative VAs. A P value of less than .05 was considered to be statistically significant.

Results

Forty-seven patients (94 eyes) who met our inclusion criteria underwent bilateral surgery (30 men [78.72%], 17 women [21.28%]; mean age: 60.93 ± 13.58 years, range: 45–80 years). The mean distance between each patient’s home and the nearest eye clinic was 178 km, and each patient needed 1 or more caretakers. An mSICS and posterior IOL implantation were performed in all cases (100%). Preoperatively, 94 (100%) of the eyes were blind, presenting with VAs of less than 3/60. Table 1 summarizes the preoperative and postoperative VAs at the 4-week follow-up. There was a significant reduction in blindness among this population at the 4-week follow-up, and 84.04% of the eyes showed an increased VA of 1 line or more (P = .001). Pinhole visual acuity was classified according to the WHO recommendations (Table 2). There was a significant increase in VA. Good VA scores of greater than 6/18 were achieved in 71 (75.53%) eyes (P = .001). The causes of VAs of less than 3/60 (no amelioration with the pinhole) are recorded in Table 3. Of the 12 eyes with acuities of less than 6/60 at the 4-week follow-up, 7 (58.33%; 7.44% of all eyes) had pre-existing ocular pathologies. Five (41.67%; 5.31% of all eyes) had poor outcomes due to intraoperative complications.

Table 1.

Pre- and postoperative VAs.

Table 2.

PHVA classification according to the WHO recommendations.

Table 3.

Causes of visual acuities of less than 3/60 (no amelioration with pinhole).

In this study, 19 (20.21%) cases with complications were recorded (Table 4). Intraoperatively, the most serious adverse event was posterior capsule rupture and vitreous loss (2 eyes). The postoperative complications included transient IOP elevations (6 eyes), chronic corneal oedema (5 eyes), iris capture (3 eyes), lens decentration (2 eyes), and hyphema (1 eye). No cases of postoperative endophthalmitis and bilateral complications were recorded.

Table 4.

Intra- and postoperative complications among 94 eyes.

Discussion

Surgical eye camps are one of the several strategies for increasing the number of cataract surgeries performed in developing countries. These camps provide inexpensive surgery in areas close to where most of the people live. Simultaneous bilateral cataract surgery remains controversial, and this procedure is rarely performed in adults in developed countries due to the potential risk of bilateral endophthalmitis. According to the guidelines for cataract surgery published by the Royal College of Ophthalmologists, SBCS should only be used in exceptional circumstances.⁸ In addition, performing an SBCS negates the ability to adjust the surgery in the second eye according to the outcome of the first surgery.^9,10 The mean age of the patients was 63.93 ± 13.58 years in this study, and the use of SBCS is justified in elderly people with severe visual impairment. There was no explanation for the sex difference in this study; the service was offered free of charge, which should have eliminated sex differences. However, Mganga et al¹¹ reported that in developing countries, ‘females may have less access to money and the perceived need lower for improved vision due to their roles in the household and community’.

The presenting VA was less than 3/60 in 100% of the eyes. At the 4-week follow-up, 84.04% of the eyes showed an increased VA of 1 line or more; of these, 75.53% achieved a PHVA of 6/18 or better. However, our results are lower than the 82% reported by Beatty et al.¹² The significant difference between the UCVA and PHVA suggested that the postoperative refractive errors were the cause of the borderline VA. This can be explained by using the available standard IOL in our series. A transient IOP elevation (greater than 21 mm Hg) was observed in 6.38% of the eyes. Beatty et al¹² reported 2 cases of bilateral transient IOP elevations after SBCS. The insufficient removal of viscoelastic substances from the anterior chamber at the end of the surgery was likely the cause of this event in our series. The greatest fear of SBCS has been due to possible simultaneous bilateral endophthalmitis, which is a major cause of blindness after cataract surgery. The incidence of postoperative endophthalmitis varies largely in the literature, ranging between 0.02% and 0.8%.¹³ The absence of endophthalmitis in our series could be attributed to many factors. The patient selection criteria were rigorously respected, as were our operation technique and perioperative care. Preoperatively, all patients underwent periocular skin disinfection and conjunctival irrigation with 5% povidone-iodine for 3 minutes. This protocol of endophthalmitis prophylaxis is strongly supported in the literature.^13,14 In addition, 1 mg/0.1 mL of intracameral cefuroxime was given to all patients in our series. The use of intracameral antibiotics has been proven to reduce the incidence of postoperative endophthalmitis. In a large series, Arshinoff and Bastianelli¹⁵ reported a significant reduction in the rate of postoperative endophthalmitis after SBCS (from 1 in 5759 to 1 in 14 352 cases) with intracameral antibiotics.¹⁶ However, a case of toxic anterior segment syndrome after uncomplicated cataract surgery possibly associated with intra-cameral use of cefuroxime has been reported.¹⁷ Considering that all bacteria cannot be eliminated, Shimada et al¹⁸ recommended the intraoperative irrigation of the surgical field with 0.25% povidone-iodine. Reports from the literature indicate that bilateral endophthalmitis following SBCS is a rare event. One case of bilateral vision loss due to bilateral endophthalmitis after SBCS was reported in a patient who underwent simultaneous bilateral intracapsular cataract surgery. The patient had septicaemia and dysentery, and the same surgical instruments were used for both eyes.¹⁹ In our study, capsule rupture with vitreous loss was found in 2 (2.12%) cases, which was higher than the 0.9% reported in a series of 240 patients by Bhatta et al.²⁰ Ramsay et al²¹ reported a case of bilateral vitreous loss among 453 cases of SBCS. Intraoperative complications, such as vitreous loss, should have automatically disqualified the second eye for the same-day surgery.²² Fortunately, the 2 posterior capsule ruptures in our study occurred when operating on the second eye. Chronic corneal oedema was observed in 5 (5.31%) eyes in this series. This was attributed to corneal endothelial damages caused by instruments in the anterior chamber while extracting a hard lens through the small corneoscleral tunnel. A large tunnel should be considered if a hard lens is suspected.

This study revealed that pre-existing ocular pathologies of the posterior segment were responsible for 58.33% of the cases with poor visual outcomes (VA less than 6/60) at the 4-week follow-up. Despite our rigorous patient selection, we could not diagnose these pathologies preoperatively because of the density of the cataract.

Performing SBCSs in an outreach eye camp presents economic, social, and medical advantages in developing countries. For example, the surgery is performed within the community and near the patient’s home; therefore, the transportation and accommodation fees (for the patient and at least 1 caretaker) required for a visit to the hospital were reduced. A great social benefit following SBCS is freedom for the patient’s guide, who is usually a schoolboy and must miss school to accompany the patient. Leivo et al²³ conducted an economic analysis comparing simultaneous and sequential bilateral cataract surgeries in Finland and concluded that SBCS provided comparable clinical outcomes with substantial savings for health care and non–health care related costs.

The small sample size and short follow-up represent potential limitations to this study. Endophthalmitis following an SBCS is a rare event; thus, a large series is recommended in our setting to confirm and generalize our findings. Furthermore, although the visual outcome was good at the 4-week follow-up, we cannot make statements on later complications, such as posterior capsular opacity. In a previous study, this complication occurred in 2.9% of the eyes at 3 months after surgery.²⁴

Conclusions

The results of our study suggest that SBCS is a viable and safe option to reduce the prevalence of cataract blindness in rural areas in developing countries. Maximal perioperative endophthalmitis prophylaxis should be strictly observed, including periocular skin disinfection via 5% povidone-iodine for 3 minutes, conjunctival irrigation with 5% povidone-iodine, intraoperative irrigation of the surgical field with 0.25% povidone-iodine, and intracameral administration of broad-spectrum antibiotics.