https://orcid.org/0000-0002-3751-7244
ABSTRACT
Purpose
To evaluate the incidence and cost of intraocular lens(IOL) waste during IOL implantation, as well as the reasons for it.
Methods
A retrospective analysis was conducted on the data of 485 patients from the IOL waste registers of a single tertiary eye hospital in China during 2016–2020. The primary outcomes were the incidence, cost, and reasons for different IOL properties. Cases were examined to ascertain IOL material, design, procedural details, and causes of waste.
Results
IOL waste occurred in 485 (6.62‰) of the 73,246 IOL implantations during the study period. The total cost of IOL waste was 429, 850.26 Chinese Yuan (CNY) related to waste with an average cost of 2, 442.33 CNY per procedure during the study period. Comparisons between IOL properties showed that polymethyl methacrylate (PMMA) material (39, 2.05%), three-piece design (142, 1.49%), and secondary IOL implantation (26, 2.16%) were associated with IOL wastage, and the difference was statistically significant. The causes of IOL waste were damage (107, 60.80%), patient reasons (37, 21.26%), aseptic errors (22, 12.50%), IOL quality problems (8, 4.55%), and loss (2, 1.14%).
Conclusions
The incidence of IOL waste is low, but still leads to a significant cost burden due to a large number of cataract surgeries. PMMA material, three-piece design, and secondary implantation were identified as factors increasing IOL waste. Damage emerged as the primary reason for waste, largely attributed to human error. Therefore, the development of strategies to mitigate IOL waste is imperative.
INTRODUCTION
Cataract remains the leading cause of blindness and the primary cause of visual impairment worldwide.Citation1, Citation2 In addition, as the population continues to grow and the aging society accelerates, potential visual disability due to cataracts will be a burgeoning threat. Surgery is currently the only treatment option once the lens becomes clouded and vision decreases.Citation3 Different surgical techniques have been developed to remove the clouded lens, as well as an intraocular lens(IOL) implantation.Citation4–8
IOL is widely used in cataract surgery and is a necessary tool for correcting vision. The price of IOL has become a major component of the cost of cataract surgery, which accounts for more than 40% of the cost and leads to a significant decline in the profitability of the surgeries.Citation9 However, IOL waste is a common problem, including intraoperative and reoperative IOL exchange,Citation10–12 but the expression “IOL waste” has not been explicitly defined or discussed.
This prompted us to conduct a retrospective study for 2016–2020. The primary purpose of this study was to assess the incidence of IOL waste In a large ophthalmic specialty hospital, and we attempted to quantify the cost of IOL wasted in different surgical procedures in five years. On the other hand, we aim to find the causes of waste and explore solutions to reduce IOL waste.
METHODS
This was a retrospective research using the hospital’s electronic medical record system and an IOL waste register. This retrospective study comprised patients who had wasted an IOL at the Eye Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, China, between January 2016 and December 2020. An electronic medical record database was used to record product information for each wasted IOL. These data are routinely collected as part of the IOL waste registers, which record information about the characteristics of patients and the IOL. Surgical procedure type and surgeon were also collected. All cases were reviewed to determine the demographic characteristics of the patient and IOL, including the IOL model, material, design, price, and the cause of waste. Currency conversions were based on rates prevailing from 2016 to 2020, with 1 US$ equal to 6.7 CNY during the survey period.
Data collection all data was obtained through a retrospective chart review and entered into a standardized computerized database for subsequent analysis. This research conformed to the tenets of the Declaration of Helsinki. The Wenzhou Medical University Eye Hospital’s Research Ethics Committee authorized this study (2021-027-K-24-01). Given the retrospective nature of the study and the absence of direct patient involvement, the need for written informed consent was waived.
For this study, an IOL was considered to be wasted when the sterile packaging was opened for use, and also included the IOL that had to be removed and replaced after implantation, but ultimately the IOL was still not implanted in the patient during the surgery and could not be reused in a different patient.
All statistical analyses were performed using SPSS 24.0 (IBM Corp. Armonk, NY, USA). Descriptive statistics were calculated for various clinical characteristics. Normally distributed variables were described with means and standard deviations, while non-normally distributed variables were described with medians and interquartile ranges (IQR). The significant difference between groups in the incidence of IOL waste was analysed by the chi-square test. Statistical comparisons of cost variables were performed using nonparametric methods (Kruskal-Wallis Rank Sum Test). p value＜0.05 was considered significant.
RESULTS
A total of 73 246 eyes underwent IOL implantation surgery during the study period, and 485 eyes (6.62‰) of 485 patients experienced IOL waste, translating to an incidence of IOL waste of 7 per 1000 surgeries (95% confidence interval [CI] 6 to 7), with 485 IOL from 16 manufacturers and 33 different types. In this study, the median age of 485 procedures at the time of IOL implantation was 66.99 years (range 4–98). Of these, 231 (47.63%) were left eyes and 272 (56.08%) were females. The average cost of lens waste was CNY 3 316.53 (US$ 595.00). The mean IOL power was 21.05 D (range 0–29.5).
shows the details of the incidence of wasted IOL in different IOL materials, designs, and surgical procedures, and the results show that PMMA materials and 3-piece design IOL have a higher risk of IOL waste, in comparison, secondary intraocular lens implantation(SIOL) have a higher risk across all surgical procedures. IOL waste occurred in 485 of 73,246 procedures (6.62‰) during the study period. In the comparison of the IOL material, IOL waste occurs in 252 eyes (33,289 cases [0.76%] in the Hydrophobic group, 194 eyes (38056 cases [0.51%]) in the Hydrophilic group, and 39 eyes (1901 cases [2.05%]) in the PMMA group. The risk of IOL waste was significantly higher in the 3-piece design than in the 1-piece design, plate-haptic design, and quadripode design. The highest proportion of IOL waste was found in SIOL, while the lowest was found in phacoemulsification(Phaco), which had an incidence of IOL waste of 2.16% and 0.55%, with 26 and 316 eyes occurring. There were significant differences in the incidence among IOL materials, designs, and surgical procedures (P＜0.001).
Table 1. Incidence of wasted IOL in the different properties.
Overall, the total cost of IOL waste was CNY 1 608 515.75 (about US$ 240 077.13) related to waste, with an average cost of CNY 3 316.75 (US＄ 495.00) per procedure during the study period (). The range in cost of IOL waste was CNY 80–12 299.8 (about US$ 11.94–1 835.79) per procedure. In addition, higher cost IOL waste is associated with more frequent use resulting in more waste, but at a lower incidence. Conversely, less frequent use resulted in a higher incidence.
Table 2. Number and cost of wasted IOL at our hospital in 2016–2020.
Hydrophobic material had the highest waste of IOL among IOL materials, and more than half of the costs of IOL waste came from the 1-piece design among four IOL designs. Phaco had the highest total cost and average cost among the seven surgical procedures. The average cost of each procedure was over US＄300, except for Microincision cataract surgery(MSICS).
shows that the causes of IOL waste are diverse, mainly including damage, breaches in sterility, getting stuck, reasons of patients, quality problems of IOL, and loss. All causes of IOL waste were recorded in the IOL waste register. The most reason for waste of all 485 IOL in this study was IOL damage, occurring in 314 cases (64.74%), of which haptics damage (217 cases) was more than two times as common as optical damage(97 cases). The incidence of quality problems or loss of IOL occurred in smaller percentages.
Table 3. Reasons for wasted IOL in different properties.
DISCUSSION
In this study, we reported an incidence of IOL damage of 6.62 per 1000. To our knowledge, this is the first study that has addressed the cost and the reason for IOL waste at a Chinese institution. Previous studies usually focus on IOL exchange but rarely mention IOL waste.Citation13–15 These procedures can lead to IOL waste. In the assessment of intraocular lens (IOL) characteristics and their impact on waste generation, our study unequivocally demonstrates that hydrophilic IOLs, quadripode IOLs, and Phaco procedures are associated with a lower likelihood of IOL waste generation, whereas PMMA lenses, 3-piece IOL designs, and SIOLs pose a heightened risk of IOL waste. In addition, hydrophilic IOL has higher water content, which makes them more flexible and soft than hydrophobic IOL, and can be implanted through smaller incisions.Citation16,Citation17 3-piece acrylic IOL with lower water content may be more vulnerable to surface damage during folding, which plays an important role in the waste of IOL.Citation18
OL waste is an unavoidable condition in IOL implantation, which impacts patient injury and the cost of health care. This increases the operation time and procedure, and it might also increase the rate of surgical complications.Citation19–21 In our present study, we investigated we quantified the magnitude of the problem of intraoperative IOL waste in cataract surgery, as well as its causes. The mean wasted component cost was US$ 490.00 per procedure (range, 11.94–1835.79), with a total wasted IOL value for the study period of US$ 240 077.13. There is not much difference between the IOL of Hydrophobic and Hydrophilic materials in the amount and cost of IOL waste. The IOL waste cost for each procedure was more than US＄300.00, except for MSICS. The lowest cost was US$ 11.94, and the highest was US$ 1835.79. The cost of IOL is 120–1100 Indian Rupees (about US$ 1.6–14.8) for cataract surgery in India. Another study showed that £150 could be spent on six IOL during cataract surgery (about $27.7 per IOL) at a global ophthalmology charity.Citation22 The National Bureau of Statistics reported that China’s per capita medical and health consumption expenditure in 2020 was CNY 1843.00 (US$ 275.07). In short, an average of US$ 300 for IOL waste is a considerable cost to developing countries, and IOL waste will persist in the future. The results showed that intraoperative IOL waste occurred in 485 cases (0.66%) during 5 years, which may impose a greater cost burden on hospitals and become a potential target for cost control measures of IOL implantation. In addition, as the population ages and lives are extended, cataract surgery is expected to increase year by year,Citation23 and the total cost of IOL waste is likely to rise at an equally high rate. Therefore, it is necessary to further increase the proportion of medical expenditure in total fiscal expenditure and take preventive measures to reduce the risk of intraocular lens pollution.
Approximately two-thirds of the wasted IOL were attributed to the surgeon or operating room staff due to damage caused by installation and loss of sterility, with the remaining approximately one-third attributed to the vendor representative and disease risk. Possible explanations for these human errors include damage during injection and installation, sterility failure and loss due to misoperation, etc. The reason is that there are only two models of 3-piece IOL and 13 models of 1-piece IOL in this study. Currently, Polymethylmethacrylate (PMMA) is an IOL widely used in MSICS. In our retrospective study, their numbers were low because of the low number of MSICS, which was gradually replaced by Phaco, which would increase the risk of IOL waste.
The incidence of intraocular lens waste is low but usually leads to increased costs and IOL replacement. The occurrence of IOL waste depends on various factors, including IOL materials, design, and surgical procedures. The identification and better understanding of possible risk factors could be helpful for future research as well as for clinical practice.
IOL damage is the most common cause of IOL waste, and the material and design of the IOL may be a significant factor in damage. Other studiesCitation19,Citation24,Citation25 have shown that the IOL injector is an essential factor in accidental damage during IOL implantation, which increases the cost of the procedure. These studies focused on IOL syringes and did not focus on IOL materials or design. Nanavaty MA et al.Citation25 proved that IOL damage may be related to the design, model, and brand of the Injector, but our study did not provide evidence to prove this. However, Of the identified causes, IOL damage was the most common cause of IOL waste, followed by patient conditions and errors in aseptic practices.
Our study also has limitations: Although our study was from a single center, this may limit generality. However, the center is a large tertiary ophthalmic center, receiving many referrals from the surrounding areas and within the province, with an annual volume of over 30,000 ophthalmic surgeries. Therefore, it has very heterogeneous research objects and various materials and designed IOL for clinical use. A second limitation stems from the retrospective design, which limits inferences about causality. However, we compiled a large sample of all consecutive cases over five years to mitigate bias.
CONCLUSION
In conclusion, this is an essential and highly relevant analysis that can pave the way for future research on preventing IOL damage. Our study is a pilot study designed to describe the costs and causes of IOL waste and propose corrective and preventive measures. These actions could include raising team awareness of the issue, improving traceable protocols, and promoting the clever use of following good practices.
ETHICAL APPROVAL AND DECLARATION OF PATIENT CONSENT
The study was conducted according to the guidelines of the Declaration of Helsinki and approved by the Ethics and Research Committees of Wenzhou Medical University Eye Hospital(NO.2021-027-K-24-01). The board waived the need for informed consent for a retrospective study such as this study.
FINANCIAL SUPPORT AND SPONSORSHIP
The Medical Health Science and Technology Project of Zhejiang Province and the Wenzhou Science and Technology Bureau Project.
CONTRIBUTION OF AUTHORS
Involved in design of study (Junjie Cai, Peihua Zhang); Conduct of study (Junjie Cai, Peihua Zhang); Collection of data (Junjie Cai, Yamin Li, Dongdong Pan, Xiaomeng Li); Management (Junjie Cai, Yamin Li, Dongdong Pan), analysis (Junjie Cai, Xiaomeng Li), and interpretation (Junjie Cai, Yamin Li, Dongdong Pan, Xiaomeng Li, Peihua Zhang) of the data; preparation of the manuscript (Nived Moonasar, Junjie Cai, Peihua Zhang, Zhong Lin, Yinghui Shi, Jianxia Lin); and review and approval of the manuscript (Junjie Cai, Yamin Li, Dongdong Pan, Peihua Zhang).
Additional information
Funding
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