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Keywords:

  • 15D;
  • cataract surgery;
  • New Zealand priority criteria;
  • quality of life;
  • VF-14;
  • visual acuity

Abstract.

  1. Top of page
  2. Abstract.
  3. Introduction
  4. Patients and methods
  5. Results
  6. Discussion
  7. Acknowledgments
  8. References

Purpose:  It is necessary to develop tools for patient selection to target cataract surgery to patients with the best expected outcomes. We used visual acuity, visual functioning 14 (VF-14) test, the 15-dimension health-related quality-of-life questionnaire (15D) and the New Zealand priority criteria to evaluate the criteria for cataract surgery in a post hoc setting.

Material and methods:  Ninety-three consecutive patients living in a defined rural area in Finland had cataract surgery as a part of the Pyhäjärvi Cataract Study in 2003. Success of cataract surgery was defined as improvement of visual acuity by at least 2 lines and/or improvement of visual function measured by questionnaires.

Results:  The patients with a visual acuity of 0.30 logMAR (0.5 Snellen decimal) or worse in the better eye and/or 0.52 logMAR (0.3 Snellen decimal) in the worse eye had successful surgery in 59–83% of cases depending on the definition of success. When subjective judgement was added, the success rates varied between 63% and 91%.

Conclusion:  Setting indication criteria, it seems sufficient to use two global questions in addition to visual acuity: one on the subjective view on disability, and one on a more neutral view on visual function, such as the 15D item on vision. The VF-14 did not perform any better than the single item counterparts.


Introduction

  1. Top of page
  2. Abstract.
  3. Introduction
  4. Patients and methods
  5. Results
  6. Discussion
  7. Acknowledgments
  8. References

Cataract is the leading cause of blindness in the world though modern cataract surgery is an elegant tool to restore visual acuity in patients who are disabled by it (WHO 2009).

The rate of cataract surgery varies about 20-fold from country to country depending on resources available. The indication for cataract surgery in many developing countries may be around visual acuity poorer than 1.0 logMAR (0.1 Snellen decimal) while in some industrial countries the indication can be around 0.3 logMAR (0.5 Snellen decimal) (Foster 2001). In Finland, a six-fold increase in the cataract surgery rate took place between the years 1982 and 2000 reaching the rate of 6.3/1000 inhabitants in the year 2000, and the visual acuity of the eye to be operated improved markedly at the same time (Leinonen & Laatikainen 2002). With a high cataract surgery rate, the cost of surgery per quality-adjusted life year gained in Finland has been found to be much higher than previously reported (Räsänen et al. 2006).

It is clear that someone binocularly blind because of cataract benefits the most of surgigal treatment. The benefit of second eye surgery is not as great as that of the first eye, but second eye surgery when there is no ocular co-morbidity has been shown to be helpful and improve stereoacuity especially (Laidlaw et al. 1998). A fourth of patients with coexisting dry age – related macular degeneration (AMD) have been reported to have very good benefit from surgery, while half of the patients without AMD scored equally well (Lundström et al. 2002). Setting the indication for surgery becomes more relative if the second eye cataract is mild, or if even the first eye cataract is little disabling, or if there is severe co-morbidity with not much cataract. There is probably a limit when it is not worth to give the patient a try even in the more well-off societies. It does not seem right to perform surgery if there is hardly a chance to be better off visually after surgery than before.

There is a broadening gap between possibilities of treatment and resources available, and more could be done to the patients than we can afford. As for cataract, there is a need to separate an ageing process of the lens from a condition requiring surgery. As priorities need to be set, it is desirable that the choices were made in such a way that the health status of patients would be maximized with the resources available. Treatments should be offered to those who benefit the most, and spare those who are not expected to gain visually. However, it is often not self-evident which group the patients belong to. To be able to set the indications correctly, it is necessary to have a reliable way to predict visual outcome.

Ophthalmologists seem to agree that visual acuity is not sufficient as the single measurement of disability caused by cataract. For example, the VF-14 test as well as shortened forms of it are aimed to measure preoperative impairment and outcome of surgery of cataract patients and are even in clinical, not only scientific use (Steinberg et al. 1994b; Uusitalo et al. 1999; Pager 2004).

The Ministry of Social Affairs and Health in Finland (2005) has published legislative amendments to secure access to treatment on equal grounds. The national uniform criteria to cataract surgery in Finland require that the patient’s ability to drive and/or read is threatened because of decreased visual acuity. The patient’s visual problems must be related to cataract, not missing or inappropriate spectacles or other eye diseases. The indication for cataract surgery is one or more of the following: (i) The best-corrected visual acuity of the better eye is 0.5 Snellen or less, (≥0.30 LogMAR), (ii) the best-corrected visual acuity in the worse eye is 0.3 Snellen or less (≥0.52 LogMAR), (iii) cataract disturbs daily activities significantly, (iv) the patient suffers from anisometropy after previous surgery (>2 D), and/or (v) cataract bothers the patient in some other essential way (e.g., prevents laser procedure for diabetic retinopathy).

We aimed to define preoperative criteria for successful cataract surgery based on various predictive factors. This study was conducted before the cataract surgery access criteria came into force in March 2005.

Patients and methods

  1. Top of page
  2. Abstract.
  3. Introduction
  4. Patients and methods
  5. Results
  6. Discussion
  7. Acknowledgments
  8. References

Patients

All 111 patients aged 60–89 who were on the waiting list for cataract surgery at the Department of Ophthalmology, Oulu University Hospital, from five municipalities (Pyhäjärvi, Haapajärvi, Nivala, Haapavesi, Kärsämäki) in January 2003 were eligible for this study and were invited to participate. Ninety-six patients (86%) responded and were examined in January 2003. Two patients did not report any visual problems and cataract surgery was cancelled. One patient had an acute retinal detachment requiring treatment first, and cataract surgery was postponed. Ninety-three patients had their cataract operated by the end of June 2003. There were no cases of postoperative endophthalmitis or other complications with permanent effect on optical or visual outcome. Intra-operative posterior capsule rupture occurred in four cases, and the lens was placed in sulcus in these cases. One patient received an IOL misplaced in the capsular bag with the wrong side out. Four patients died during follow-up for reasons not related to cataract surgery. The median follow-up time was 9 months. All participants gave an informed consent. The study is described in more detail in Falck et al. (2008).

Clinical examination and surgery

The patients were referred to the Department of Ophthalmology by private ophthalmologists or general practitioners. In the case of the latter, the patients had to be examined by an ophthalmologist at the outpatient clinic to be placed on the waiting list. In 2003, the criteria for cataract surgery were based on common loose consensus of the referring ophthalmologists and those operating cataract at the hospital, yet the final decision on surgery was up to the discretion of the operating surgeon.

One author (AF) examined the cataract patients before the operation. The ophthalmic examination included the measurement of the visual acuity with the patient’s current glasses and with best correction, applanation tonometry, slit lamp biomicroscopy and dilated fundus examination. The axial length and keratometry were measured. Cataract was graded using a modified LOCS III classification, i.e., the lens was compared with the LOCS III reference pictures after dilation (Chylack et al. 1993). In addition, the New Zealand priority criteria for cataract (Hadorn & Holmes 1997) were used.

Seven surgeons of the clinic performed the procedures using the phaco-emulsification technique. Before the criteria for access to care were defined, according to the standard practice of the clinic, the patients were recommended to have the postoperative check-up at 1 month at their local private ophthalmologist.

Interviews

A trained nurse interviewed the patients using the VF-14 (Steinberg et al. 1994a) and the 15D health-related quality of life questionnaires (Sintonen 2001) at the clinic before surgery and by phone about a month after the operation. The patients were asked to grade the benefit of surgery using a four-point scale (the operation was definitely worth while, helped somewhat, was worth trying or should not have been done). The nurse also addressed an open question about the patient’s vision after the operation. A second phone interview was carried out in the end of follow-up, 9 months after surgery by the same nurse. The VF-14, the 15D and the New Zealand priority criteria (excluding visual acuity) were administered. The reported results are based on the latter phone interview.

Questionnaires

The VF-14 questionnaire consists of 14 five-point questions regarding visual performance in various daily activities. The calculated final score varies from 0 (unable to do all applicable activities because of vision) to 100 (able to do all applicable items without difficulty). The 15D is a general instrument for measuring health-related quality of life (Sintonen 2001). It consists of 15 five-point questions, one of which is about seeing1 and the rest describe other health-related aspects of life, e.g., hearing, speaking and eating. The total score varies between 0 (dead) and 1 (no problems). The New Zealand criteria for cataract surgery include a section on visual acuity (0–40 points) and questions about symptoms of cataract, ocular and other co-morbidity and visual performance (Hadorn & Holmes 1997). The final score can vary between 0 and 100, higher scores indicating stronger need for surgery.

Post hoc criteria for cataract surgery

For this study, the following requirements were developed to justify cataract surgery: (i) The visual acuity had to be at least 0.30 logMAR (at most 0.5 Snellen) in the better eye and at least 0.52 logMAR (at most 0.3 Snellen) in the worse eye (these are the national criteria). (ii) The patient’s response to the question about vision related problems had to be moderate or severe. (iii) The response to the 15D item on vision (15D Vision) had to be at least 3. This value usually affects statistically significantly also the 15D total score (personal information from Harri Sintonen, the developer of the 15D Quality of Life instrument). (iv) The VF-14 total score had to be less than 80. (v–vii) Visual acuity combined to the above-mentioned disability criteria. Both the visual acuity and the respective disability criteria needed to be fulfilled. (viii) The New Zealand priority criteria score needed to be at least 30.

Post hoc criteria for diagnostic success

In clinical practice, the diagnosis is based on the ophthalmologist’s subjective observation whether the lens is nontransparent enough to be classified as having cataract. The diagnostic accuracy was evaluated using the modified LOCS classification. The operated eye needed to fulfil the criteria for any cataract type: nuclear (≥5), cortical (≥4) or posterior subcapsular (≥3).

Post hoc criteria for treatment success

As there are no published or generally accepted criteria to define successful cataract operation, the following definitions were used: (i) The difference between pre- and postoperative visual acuity of the operated eye had to be at least 0.2 LogMAR, which corresponds to improvement by 2 lines in the logarithmic visual acuity chart. (ii) The patient’s response to surgery was required to be ‘The operation was absolutely worth going through’. (iii) The 15D Vision item was required to improve at least one unit. (iv) The VF-14 score was arbitrarily required to improve at least 14 points, or if the VF-14 score was above 86 before surgery, it had to be 100 after surgery. Because the New Zealand priority criteria has been aimed to be used in selection of patients for cataract surgery only, it was considered inappropriate to try to use it in the measurement of treatment success.

Statistical analyses

The association between categorical variables was tested by χ2-test. Logistic regression was used to evaluate the value of different post hoc criteria for surgery. Multiple regression models were adjusted for age, sex, macular degeneration and other eye disease. Diagnostic accuracy was also measured by sensitivity and specificity.

Results

  1. Top of page
  2. Abstract.
  3. Introduction
  4. Patients and methods
  5. Results
  6. Discussion
  7. Acknowledgments
  8. References

The median age of patients was 77 (range 60–89) years; only 13 (14%) were less than 70 years of age (Table 1). There were 63 women (68%) and 30 men (32%). The education level was low in general. Most patients were previous farmers or self-employed, which is typical to this generation and geographical area. Although only 12 patients (13%) reported no chronic diseases, they were in a relatively good functional condition, 85 (91%) being somewhat independent in their daily activities.

Table 1.   Baseline characteristics of the patients having cataract surgery in the Pyhäjärvi Cataract Study in 2003 (N = 93).
Characteristicn%*
  1. * Percentages may not add up to 100 because of rounding.

  2. Categories are not mutually exclusive.

Gender
 Female6368
 Male3032
Age
 60–691314
 70–794649
 80–893437
Education
 Primary6674
 Secondary1011
 Lower vocational1112
 Higher vocational22
 Missing4
Prior occupation
 Higher office worker33
 Lower office worker44
 Self-employed44
 Farmer3639
 Skilled manual worker2224
 Unskilled manual worker910
 Missing4
Living
 Independent8591
 Assisted89
Living situation
 Alone3841
 With someone5559
Chronic disease
 None1213
 Diabetes1213
 Hypertension4649
 Coronary heart disease3437
 Cerebrovascular disease1516
 Other3639

Baseline visual acuity, function and cataract type

The visual acuity of the eye to be operated was ≤0.3 LogMAR (better than 0.5 Snellen) in 41 patients (44%) (Table 2). Thirty-six patients (39%) had previously had a cataract operation in the other eye, and 28 (30%) had some degree of age-related macular degeneration. Additionally, 21 patients (23%) had other eye disease potentially affecting vision, such as glaucoma or diabetic retinopathy. According to the modified LOCS criteria, 69 patients (74%) had one or more cataract types in the eye to be operated: 41 (44%) had nuclear, 20 (22%) had cortical and 24 (26%) had posterior subcapsular cataract. Visual acuity was but cataract type was not associated with perceived trouble attributed to vision, 15D vision, VF-14 index and NZ score at baseline (Table 3).

Table 2.   Visual characteristics of the patients having cataract surgery at baseline in the Pyhäjärvi Cataract Study in 2003 (N = 93).
Characteristicn%*
  1. mLOCS = LOCS III classification (Chylack et al. 1993) modified for this study.

  2. * Percentages may not add up to 100 because of rounding.

  3. The study eye was selected randomly if the patient was operated bilaterally (n = 14).

Visual acuity in the better eye (LogMAR)
 <0.38086
 0.3–0.511011
 ≥0.5233
Visual acuity in the worse eye (LogMAR)
 <0.33639
 0.3–0.512830
 ≥0.522830
Missing1
Visual acuity in the operated eye (LogMAR)
 <0.34144
 0.3–0.512729
 ≥0.522527
Visual function (median, range)
 VF-1479.527.3–100
 15D Vision21–4
 New Zealand score238–67
Macular degeneration
 None6368
 Mild2729
 Moderate22
 Missing1
Other eye disease
 No7277
 Yes2123
Cataract operations
 No prior operations5761
 Prior operation3639
Nuclear cataract (mLOCS ≥5) in the operated eye
 Yes4144
 No5256
Cortical cataract (mLOCS ≥4) in the operated eye
 Yes2022
 No7075
 Missing3
Posterior subcapsular cataract (mLOCS ≥3) in the operated eye
 Yes2426
 No6469
 Missing5
Any cataract type (mLOCS as above) in the operated eye
 Yes6974
 No2426
Table 3.   Visual acuity and cataract type by dazzle, perception on visual problems, VF-14, 15D vision item, and New Zealand score at baseline in the Pyhäjärvi Cataract Study in 2003 (N = 93).
CharacteristicnPerceived trouble attributed to vision (moderate to severe)15D Vision (≥3)VF-14 (≤80)NZ score (≥30)
a%a%a%a%
  1. Cataract classified using a modified version of LOCS III (Chylack et al. 1993): cataract considered present if mLOCS ≥5 for nuclear, mLOCS ≥4 for cortical or mLOCS ≥3 for posterior subcapsular type.

  2. a = Number of patients with the problem.

  3. p-Values from χ2−test with 5 or 3 degrees of freedom.

  4. * The study eye was selected randomly if the patient was operated bilaterally (n = 14).

Visual acuity in the better and worse eye (LogMAR)
 Both < 0.3201552563000
 <0.3 and 0.3–0.512662383193500
 <0.3 and ≥0.522662315581662623
 Both 0.3–0.51658346761006100
 0.3–0.51 and ≥0.5210660880770880
 Both ≥ 0.5254803603605100
 Total932830434647512527
 p-value <0.0010.020.01<0.001
Cataract type in the operated eye*
 None2472913541146729
 Any692130304336521826
 Total932830434647512527
 Nuclear only31113515481652929
 Cortical only13323646862431
 Posterior  subcapsular only10330330660110
 None24729135411 46729
 p-value 0.870.640.780.64

Diagnostic and treatment success by criteria for cataract surgery

The distributions for the different criteria for surgery and those for diagnostic and treatment success are given in Table 4.

Table 4. Post hoc criteria for cataract surgery, treatment success and treatment failure in the Pyhäjärvi Cataract Study in 2003 (N = 93).
CriteriaCut-pointPatients who met the criteria
n%
  1. mLOCS = LOCS III classification (Chylack et al. 1993) modified for this study.

  2. * The study eye was selected randomly if the patient was operated bilaterally (n = 14).

  3. Number of patients with missing values ranged from 0 to 18.

Criteria for cataract surgery
 Visual acuity (LogMAR)*≥0.30 in the better eye or ≥0.52 in the worse eye4447
 Perceived trouble attributed to visionModerate to severe2830
 15D Vision≥34346
 Perceived trouble attributed to vision or 15D VisionEither of above5155
 VF-14 Index≤804751
 Visual acuity* and perceived trouble attributed to visionAs above2123
 Visual acuity* and 15D VisionAs above3032
 Visual acuity* and VF-14 IndexAs above3234
 New Zealand priority criteria≥302527
Criteria for diagnostic success
 mLOCS in the operated eye*Nuclear (≥5), cortical (≥4) or posterior subcapsular (≥3)6974
Criteria for treatment success
 Visual acuity in the operated eye*Improved ≥2 log units5370
 Opinion on surgeryOperation was absolutely worthwhile7284
 15D VisionBetter6177
 VF-14 IndexImproved ≥14 points3949

The diagnostic sensitivity of the preoperative criteria varied from 23 to 52% and the specificity from 46 to 79% (Table 5). In multiple logistic regression, visual acuity and visual acuity combined with 15D vision or VF-14 index were associated positively (odds ratio, OR, 1.98, 1.88 and 1.75, respectively) but 15D vision and NZ score negatively (OR 0.47 and 0.60, respectively) with cataract.

Table 5.   Results on diagnostic success by criteria for surgery in the Pyhäjärvi Cataract Study in 2003 (N = 93).
Criteria for surgeryDiagnostic success*
a/n%OR (95% CI)Se %Sp %
  1. Cut-points for criteria for surgery and diagnostic success are given in Table 4.

  2. a = Number patients diagnosed successfully among those who met the criteria for surgery; n = Number of patients who met the criteria for surgery; OR = Odds ratio; CI = Confidence interval; Se = Sensitivity; Sp = Specificity.

  3. * Any cataract type in the operated eye: LOCS III classification (Chylack et al. 1993) modified for this study, nuclear (≥5), cortical (≥4) and posterior subcapsular (≥3).

  4. Adjusted for age, sex, macular degeneration and other eye disease.

  5. The study eye was selected randomly if the patient was operated bilaterally.

All69/9374
Visual acuity36/44821.98 (0.72–5.42)5267
Perceived trouble attributed to vision21/28750.93 (0.32–2.693071
15D Vision30/43700.47 (0.16–1.34)4346
VF-1436/47771.28 (0.48–3.38)5254
Visual acuity and Perceived trouble attributed to vision16/21760.92 (0.28–3.02)2379
 15D Vision25/30831.88 (0.59–5.98)3679
 VF-1426/32811.75 (0.59–5.20)3875
New Zealand score18/25720.60 (0.19–1.86)2671

All preoperative criteria but 15D vision, VF-14 index and NZ score predicted improved visual acuity (Table 6). Only perceived trouble attributed to vision positively predicted postoperative opinion on surgery. On the other hand, all preoperative criteria predicted improvement in VF-14 index, and all of them except NZ score that of 15D vision.

Table 6.   Results on treatment success by criteria for surgery in the Pyhäjärvi Cataract Study in 2003 (N = 76-86).
Criteria for surgeryVisual acuityOpinion on surgery
a/n%OR (95% CI)*a/n%OR (95% CI)*
All53/767072/8684
LOCS43/58743.07 (0.90–10.4)55/64861.47 (0.39–5.49)
Visual acuity28/34823.68 (1.12–12.1)33/40830.68 (0.20–2.34)
Perceived trouble attributed to vision18/24751.78 (0.56–5.70)23/26881.74 (0.41–7.43)
15D Vision25/35711.12 (0.38–3.35)32/40800.28 (0.07–1.22)
VF-1424/35690.91 (0.32–2.62)33/42790.27 (0.07–1.04)
Visual acuity and Perceived trouble attributed to vision13/18721.31 (0.37–4.68)16/19840.82 (0.18–3.73)
 15D Vision17/22771.94 (0.56–6.75)22/27810.49 (0.13–1.92)
 VF-1419/24792.09 (0.62–7.01)22/28790.48 (0.14–1.70)
New Zealand score11/17650.87 (0.25–3.08)17/21810.56 (0.13–2.42)
Criteria for surgery15D VisionVF-14
a/n%OR (95% CI)*a/n%OR (95% CI)*
  1. Cut-points for criteria for surgery and diagnostic success are given in Table 4.

  2. Postoperative visual acuity and opinion on surgery values were missing in 17 and 7 patients, respectively.

  3. a = Number of patients treated successfully among those who met the criteria for surgery; n = Number of patients who met the criteria for surgery; OR = Odds ratio; CI = Confidence interval.

  4. * Adjusted for age, sex, macular degeneration and other eye disease.

  5. Any cataract type in the operated eye: LOCS III classification (Chylack et al. 1993) modified for this study, nuclear (≥5), cortical (≥4) and posterior subcapsular (≥3).

  6. The study eye was selected randomly if the patient was operated bilaterally.

All61/797739/7949
LOCS47/61771.04 (0.26–4.12)32/61532.32 (0.73–7.45)
Visual acuity29/37781.32 (0.41–4.25)22/37593.02 (1.07–8.51)
Perceived trouble attributed to vision20/23872.95 (0.70–12.5)19/238311.9 (2.93–48.3)
15D Vision33/359415.2 (2.55–90.4)24/35697.54 (2.30–24.7)
VF-1435/39904.79 (1.31–17.5)34/3987153 (18.1–1297)
Visual acuity and perceived trouble attributed to vision14/17821.75 (0.39–7.85)14/178212.6 (2.42–66.1)
15D Vision21/23916.15 (1.06–35.5)18/237811.5 (2.81–46.8)
VF-1422/25883.74 (0.83–16.9)21/258427.6 (5.00–152)
New Zealand score14/19741.03 (0.26–4.00)13/19685.83 (1.45–23.5)

Discussion

  1. Top of page
  2. Abstract.
  3. Introduction
  4. Patients and methods
  5. Results
  6. Discussion
  7. Acknowledgments
  8. References

According to the findings of this study, the need for cataract surgery ranged from 20% to 51% depending on the preoperative criteria, and only 74% had true cataract in the practice pattern of the everyday clinics in 2003. Currently, LOCS is used only in research and may be too cumbersome for clinical practise, nor does it include a definition or cut-point for clinically significant cataract. Neither visual acuity nor visual function seem to be good surrogates for cataract; they are affected by cataract, but are not cataract-specific. However, there is clearly a need for a diagnostic tool more standardized than a clinician’s subjective evaluation.

Treatment success for cataract has to do with a positive visual outcome and could hardly be defined as a technically uneventful surgical procedure. Improvement of visual acuity by 2 or more lines has been used as criterium before (Tobacman et al. 2003). We ended up expecting and requiring improvement of at least 2 log lines as the visual acuity of our patients` unoperated fellow eyes varied within 2 log lines (Falck et al. 2006). Improvement in questionnaires indicates treatment success in line with improvement of visual acuity. The patient’s opinion on surgery did not seem to be a good measure on treatment success because it was obviously affected also by other factors than the changes in visual ability.

Patient satisfaction is a subjective view of the surgical outcome and is affected by patient education. Therefore, providing the patient with realistic expectations before surgery is suggested (Mönestam & Wachtmeister 1999; Mozaffarieh et al. 2005). Patient satisfaction is likely to mirror the outcome with the preoperative expectations and wishes in addition to the amount of improved visual performance. For prioritization purposes, the aim of cataract treatment has to be more concrete than satisfaction, e.g. improvement in visual tasks or visual acuity.

Preoperative data (for example age, poorer questionnaire score, type of cataract, absence of other ocular disease) have been found to identify patients likely to improve in their visual function after cataract surgery in previous studies (Mangione et al. 1995; Tobacman et al. 2003; Quintana et al. 2009). In this study, both the visual acuity and the visual function criteria except NZ score predicted well improvement in visual acuity, 15D vision and VF-14 index in this study. The VF-14 did not perform any better than the single questions.

It seems sufficient to use only two global items, one on the subjective perception of visual problems and one on a more neutral view on visual function such as the 15D vision question; a battery of 14 questions is cumbersome in routine use and follow-up. The VF-14 is not necessarily sensitive for minor visual complaints of cataract patients (Bellan 2005), and the validity of the test concerning patients with not advanced cataract has been questioned (Black et al. 2009). In this study, too, there were subjects scoring 100 in the VF-14 before surgery (6/93 subjects).

Even if patients with perfect scores feel better off postoperatively, those with no measurable visual problems preoperatively cannot be placed high or at all on the priority list. The societies may not be able to fund treatments for all, and those very mildly affected and functionally almost perfectly well-off persons are the ones who should not be let block treatment opportunity from the more severe cases of cataract or other diseases.

As stated in the Finnish national criteria for access to cataract surgery (Ministry of Social Affairs and Health 2005), patients should have distinct cataract with decreased visual acuity and everyday vision related problems which threaten their ability to drive and read. In fact, since the new legislation, the number of patients on the waiting list for cataract surgery has dropped from 24 000 in year 2000 to 12 000 in year 2007 (Tuulonen et al. 2009), indicating that the criteria in clinical practice have been tightened and queues for surgery have shortened. The ethics of setting the limit at visual acuity of 0.3 logMAR for the better eye and 0.52 logMAR for the worse eye for cataract surgery within the publicly funded health care in Finland can be questioned, especially in the otherwise healthy eyes. Problems expressed by the patient (for example glare disturbing driving) is an indication for operating with better visual acuity, however. Eyes with AMD fulfil the visual acuity criteria easily without marked cataract, and putting resources for treatment of eyes with little potential of visual improvement may not be correct prioritizing.

The size of the population was rather small, the criteria were defined post hoc and the cut-points used were determined based on expert opinion and common sense. Several types of possible bias may have been introduced in the study as the patients had one interview at the clinic and two phone interviews with altogether lots of questions even if the same trained nurse conducted the interviews. These biases are, however, typical to all interview studies e.g. on health-related quality of life. Therefore, our results may be considered preliminary even though they do emphasize the importance to investigate and develop practical tools for targeting cataract surgery on those patients that are most likely to benefit from it. The prioritization can be ethical only when justified also scientifically.

Footnotes
  • 1

    Question 2 Vision (1) I see normally, ie I can read newspapers and TV text without difficulty (with or without glasses). (2) I can read papers and/or TV text with slight difficulty (with or without glasses). (3) I can read papers and/or TV text with considerable difficulty (with or without glasses). (4) I cannot read papers or TV text either with glasses or without, but I can see enough to walk about without guidance. (5) I cannot see enough to walk about without a guide, ie I am almost or completely blind.

Acknowledgments

  1. Top of page
  2. Abstract.
  3. Introduction
  4. Patients and methods
  5. Results
  6. Discussion
  7. Acknowledgments
  8. References

This research was supported by the Finnish Office for Health Technology Assessment (FinOHTA).

References

  1. Top of page
  2. Abstract.
  3. Introduction
  4. Patients and methods
  5. Results
  6. Discussion
  7. Acknowledgments
  8. References