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The effectiveness and safety of single-use disposable instruments in cataract surgery--a clinical study using a surgeon-based survey.


There is an increasing trend towards using disposable instruments for many surgical procedures, with single use instruments replacing reusable instruments in many procedures such as tonsillectomy and laparoscopic cholecystectomy. The reasons for this include the reduced theoretical risk of transferring prion disease, less likelihood of cross-infection and overall perceived cost effectiveness. Disposable instruments may also facilitate the increased throughput of procedures in some surgical specialities and allow for more cases to be performed on a theatre list.

The National Institute for Health and Clinical Excellence (NICE) has issued online guidance on the reduction of transmission of CJD for interventional procedures on high risk tissues, including guidelines for operations on the retina, vitreous body or optic nerve (NICE 2006). There are no such recommendations currently in place for cataract surgery.

Withington Community Hospital Diagnostic Treatment Centre, Manchester (WDTC), was the first high throughput cataract surgical unit in the UK to adopt the exclusive use of disposable steel instruments for cataract surgery. Surgical lists run on a daily basis with various grades of surgeon operating under consultant supervision.

By comparison, at the Manchester Royal Eye Hospital (MREH), these same surgeons perform cataract surgery with predominantly reusable titanium instruments.

The project was chosen because WDTC had become a bulk provider of cataract procedures (around 2,500 procedures per year). Due to the stand alone nature of this treatment centre with no on-site sterilization services, the cost analysis of using reusable instruments, transportation costs, sterilization costs and turn-around times, showed that switching to disposable instrumentation was more cost-effective. Initially many of the operating clinicians at both senior and junior level were concerned based on anectodal evidence that instrumentation quality of the disposables made the surgery more difficult to carry out and increased the risk of per-operative complications.

The aim of this prospective questionnaire-based study was to compare the ease of use, handling, defects and complication rates between single use and reusable instruments used for phacoemulsification cataract surgery.


Audit methodology was chosen to reduce any potential reporting bias inherent in any retrospective study. The same group of surgeons could assess instrument quality at contemporaneous periods between the two operating sites.

A questionnaire methodology was chosen to assess the surgeons' opinions regarding instrument quality and its impact on their surgery as they carried it out rather than looking at any structural or mechanical properties of the instruments.

Questionnaires were distributed among all ophthalmic surgeons operating at WDTC and MREH during the period January 2006 and January 2007.

The questionnaire was completely anonymous with only the grade of surgeon being asked in order to subsequently analyse responses according to surgeon grade and experience.

A list of all available instruments in both centres was drawn and only matching instruments were included in the survey. The questionnaire sequentially listed these instruments and assessed four aspects relating to any of them used during each cataract operation performed by a particular surgeon:

1. Ease of handling of instrument

2. Ease of use of instrument

3. Any instrument defects

4. Any surgical complications during the procedure

Handling was defined as: how the instrument feels in the hand, resistance to compression, grip etc. Ease of use was defined as: the ability of the instrument to carry out its function.

These two aspects were then graded by surgeons as poor, moderate or good according to a numerical score from 1 to 3 respectively. The presence of defects in an instrument and any complications occurring during a procedure were also assessed by the questionnaire.

Results were analysed using the Chi-squared test.


93 questionnaires were returned from MREH for reusable instrumentation during the period 03/02/2006 to 23/12/2006.

157 questionnaires were returned from WDTC for disposable instrumentation during the period 01/02/2006 to 17/07/2006.

Figure 1 shows the breakdown of grade of surgeon answering the questionnaires from the two centres.

As evidenced in Table 1, the questionnaires showed more 'moderate' and less 'good' responses for ease of use and handling of disposable instruments compared to permanent instruments.


These results were reflected in all surgeon groups but seemed more significant in the responses from trainee surgeons (Table 2).

For all permanent instruments totalled, 95.8% of responses were 'good', 2.6% of responses were 'moderate' and 1.6% 'poor' whereas for all disposables totalled, 67.1% of responses were 'good', 28.2% were 'moderate' and 4.7% 'poor'.

As for pre-existing defects, 3.8% (19/507) of permanent instruments were marked as being defective compared to 7.2% (48/670) of disposables (p = 0.0122).

Two surgical complications out of 93 procedures were reported in the permanent instrument group (2.2%) compared to six out of 157 in the disposable instrument group (3.8%). This difference however was not statistically significant (p = 0.4681)


Cataract surgery is the commonest surgical operation performed by ophthalmologists in the UK. There is an increasing demand for higher output and decreased waiting times for this procedure. The establishment of a stand-alone high throughput cataract surgery centre at Withington Community Hospital necessitated a pragmatic approach to instrumentation at this centre. As no decontamination/sterilisation services existed at this site, the use of traditional reusable instruments would have incurred a cost not only for decontamination but also for transportation of instruments to and from the site. Other considerations included turn around times for sterilisation and total number of instruments available on a cataract tray, which would often be in excess to that required by any particular surgeon. For these reasons the decision was made to use disposable instruments available according to surgeons' preference. Another potential advantage of disposable instruments is the reduced theoretical risk of transmission of Creutzfeld Jacob Disease (CJD). Although so far no cases of CJD have been reported after cataract surgery, there is the potential for transmission of prions between patients from reusable surgical instruments.

The disposable steel instruments provided for use in our hospital were designed to closely match the design and feel of their reusable counterparts. However, because they were made from steel rather than titanium they could not match the instruments exactly leading to a concern that they could affect the performance of surgery in an adverse way. In our survey most reusable instruments were deemed to be superior to their disposable counterparts with high statistical significance in many cases. However the difference in number of 'poor' responses was much less between the two groups, indicating a certain degree of 'acceptance' for disposable instruments. This shows that reusable instruments are probably easier to use but disposables are still acceptable to perform an indicated task and, although the study showed a difference in overall instrument defects, the difference in complication rates was not statistically significant.

The issue of safety is essential in contemplating disposable instruments for any type of surgical procedure. The strongest evidence for this comes from the National Tonsillectomy Audit which showed a doubling of complication rates on introduction of disposable instruments but a return to previous levels upon institution of protocols to ensure consistency in the quality of these instruments (Royal College of Surgeons of England 2005).

Other studies have compared reusable versus disposable instruments particularly for tonsillectomy and these also revealed an overall higher complication rate with disposable compared to reusable instruments (Maheshwar et al 2003). The presence of systems to ensure equivalence in quality between disposable and reusable instruments and the ability to report defects or inadequacies in instruments is therefore imperative to preserving a certain standard of patient safety.

To our knowledge there is no published literature which addresses training issues and disposable instruments. Our study did not directly tackle training issues but a significant difference in responses between senior and junior staff was evident in some cases. While it may be beneficial to be able to use both instrument types successfully, the risk of compromising patient safety during training needs to be considered. As already stated however, the difference in complication rates was not statistically significant in our study. We believe that trainees should be made aware of the differences and have the time and opportunity to get used to them before conducting independent lists.

Other important issues regarding the utilisation of disposable instruments are cost analysis and environmental impact of these instruments. In both laparoscopic cholecystectomy and endoscopic gastric/colonic biopsies the cost of reusable instrumentation has been shown to be significantly less than that of disposables (Apelgren et al 1994, Lejeune et al 2001) . Most price quotations for disposable ophthalmic instruments are not cheaper than permanent alternatives even when sterilisation costs are calculated. However the high turnover rates made possible by the independence from sterilisation units and transport when using disposables should theoretically make these instruments economically feasible. The unexplored environmental issues and the impact of disposable refuse is difficult to assess and quantify but may be significant. The search is on for readily available decontamination methods which are effective against prion disease as this would abolish the advantage of disposables instruments in avoiding transmission of spongiform encephalopathies.

To our knowledge WTC was the first ophthalmic department in the UK to use a fully disposable set of instruments for phacoemulsification cataract surgery. As a result of this study feedback has been given to the manufacturers and we are optimistic that newer, finer instruments are emerging, restoring more confidence in surgeons and resulting in less risk to the patient. This audit shows that disposable instruments in cataract surgery are an acceptable alternative despite a significant difference in their 'ease of use and handling' when compared to reusable alternatives.

Disposable instrumentation is a very topical subject at the moment, particularly in ophthalmology. Very few studies have been published concerning this topic despite the widespread use of disposable instruments in all surgical sub-specialities. This survey provides insight into the potential advantages and disadvantages of utilising these instruments and also evidences the need for further studies into issues such as the effects on training, patient safety and cost-effectiveness. We encourage other departments using single use instruments to report their experience.

Provenance and Peer review: Commissioned by the Managing Editor; Peer reviewed.


Apelgren KN, Blank ML, Slomski CA, Hadjis NS 1994 Reusable instruments are more cost-effective than disposable instruments for laparoscopic cholecystectomy Surgical Endoscopy 8 (1) 32-34

Lejeune C, Prost P, Michiels C et al 2001 Disposable versus reusable biopsy forceps: A prospective cost analysis in the gastrointestinal endoscopy unit of the Dijon University Hospital Gastroenterology Clinique et Biologique 25 (6-7) 669-673

Maheshwar A, De M, Browning ST 2003 Reusable versus disposable instruments in tonsillectomy: a comparative study of outcomes International Journal of Clinical Practice 57 (7) 579-583

NICE 2006 Patient safety and reduction of risk of transmission of Creutzfeldt-Jakob disease (CJD) via interventional procedures Available from: [Accessed September 2008]

Royal College of Surgeons of England 2005 National Prospective Tonsillectomy Audit Final Report of an Audit Carried out in England and Northern Ireland between July 2003 and September 2004 Available from auditreport_pdf [Accessed 5 February 2009]

Miss Abha Gupta MBChB, BSc(Hons), MRCOphth

Specialist Registrar, Calderdale Royal Infirmary, Halifax

Mr Karl Mercieca MD, MRCOphth

Specialist Registrar in Ophthalmology, Manchester Royal Eye Hospital

Miss Badia Fahad MBChB, MD, DO, FRCS, FRCOphth

Consultant in Ophthalmology, Care of Patients, Training Juniors and Continued Professional Development, The Royal Wolverhampton Hospital NHS Trust, Eye Infirmary.

Mr S Biswas FRCOphth

Consultant Paediatric Ophthalmic Surgeon, Manchester Royal Eye Hospital

The authors have no proprietary interests in any of the work or instruments mentioned. No grants or funds were required to support this study. Data from this paper was recently presented as a poster at the Royal College of Ophthalmologists Annual Congress in Liverpool (May 2008) and as an oral presentation at the Annual Congress of the Association for Perioperative Practice (AfPP) (October 2008).

Correspondence address: Mr Karl Mercieca, Manchester Royal Eye Hospital, Oxford Road, Manchester, M13 9WH. Email:
Table 1: Results from questionnaire and statistical significance

Instrument                 Disposable (n=157)   Permanent (n=94)

                           Good   Mod   Poor    Good   Mod   Poor

Dissecting Scissors         59    33     7       82     1     0
Vannas Scissors              4     5     0        2     0     0
Westcott Scissors            3    19     0       11     0     0

'Y' Nucleus Rotator         13     6     0       42     0     0
Spring Wire Speculum        84    32     9       65     8     6
Curved Needle Holder         5     2     1        5     0     0

45 Degree Tying Forceps     44     4     1       33     0     0
Straight Toothed Forceps     6     5     1       12     0     0
Colibri Toothed Forceps     92    23     3       65     0     0

Straight Tying Forceps      17     1     1       23     0     0
Curved Toothed Forceps       1     1     1        5     1     0
Capsulorrhexis Forceps      74    39     7       75     1     0

Ambidextrous Chopper        26    27     0       41     0     2
Koch Chopper                21     3     1        7     2     0

Instrument                  p Values

Dissecting Scissors        p < 0.0001
Vannas Scissors            p = 0.1535
Westcott Scissors          p < 0.0001

'Y' Nucleus Rotator        p = 0.0001
Spring Wire Speculum       p = 0.0244
Curved Needle Holder       p = 0.2956

45 Degree Tying Forceps    p = 0.0583
Straight Toothed Forceps   p = 0.0183
Colibri Toothed Forceps    p = 0.0002

Straight Tying Forceps     p = 0.2805
Curved Toothed Forceps     p = 0.2231
Capsulorrhexis Forceps     p < 0.0001

Ambidextrous Chopper       p < 0.0001
Koch Chopper               p = 0.6501

Table 2: Sample of results comparing senior with junior grade
responses for disposable instruments only and their statistical

Instrument                   Consultants           Trainees

                          Good   Mod    Poor   Good   Mod    Poor

Dissecting Scissors        43     10     1      16     14     5
Spring Wire Speculum       47      8     5      32     10     3
Colibri Toothed Forceps    49      8     1      30      8     2
Capsulorrhexis Forceps     38     14     5      24     13     3
Ambidextrous Chopper       25      0     0      16     16     0

Instrument                p Values

Dissecting Scissors       p < 0.0009
Spring Wire Speculum      p = 0.3962
Colibri Toothed Forceps   p = 0.2432
Capsulorrhexis Forceps    p < 0.5009
Ambidextrous Chopper      p < 0.0001
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Article Details
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Author:Gupta, Abha; Mercieca, Karl; Fahad, Badia; Biswas, S.
Publication:Journal of Perioperative Practice
Article Type:Report
Geographic Code:4EUUK
Date:Apr 1, 2009
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