In many publically funded health systems cataract surgery is subject to rationing. Delaying time to surgery or neglecting the second eye cataract in elderly patients may result in poorer health. We analyse the degree of visual impairment, visual dysfunction, depression, and rate of falls in patients before and after age-related cataract surgery.
Life expectancy is increasing, and with it the prevalence of age-related cataracts and the number of cataract extractions.1 In the UK cataract surgery is performed in 3,200 people per 100,000 inhabitants per year for those over 65 years old. In view of the ever-increasing demand for cataract surgery, healthcare managers in the UK have questioned whether cataract surgery should be rationed.2
An argument to counterbalance this increasing expenditure is that cataract surgery remains one of the most cost-effective healthcare interventions.3 Good vision also has a significant impact upon cognitive impairment, depression, mobility, falls prevention and independent living in older adults.4,5
There is limited multidisciplinary research into how cataracts contribute to vision-related disability and psychological distress in elderly patients whilst waiting for surgery.6 Equally, there is uncertain and contradictory information about how cataract surgery impacts on visual functioning and mental health in elderly patients.2,4,7,8,9,10
In this longitudinal, prospective, before-and-after study we describe the degree of visual dysfunction, physical impairment and mental distress in elderly patients waiting for cataract surgery. We then evaluate the positive impacts of cataract surgery on each of these health domains. We also examine if distinct areas of vision-related disability and psychological distress are equally impacted by cataract surgery, not only in general, but by first or second eye cataract surgery. Finally, we attempt to provide a visual acuity threshold that no elderly patient should reach without having had cataract surgery, to prevent high rates of falls and also significant detriment in vision, visual dysfunction and depression.
The study recruited 312 patients from two public hospitals in Cadiz (Spain) from October 2013 to February 2014. Eligibility criteria were: age ≥60, clinical diagnosis of cataract, informed consent signed. Exclusion criteria: combined ocular surgery; hospital admission in the last one month; treatment for severe psychiatric disease requiring admission in an acute unit in the twelve months prior to the study (severe cognitive impairment, bipolar disorder, personality disorder, eating disorder, chronic insomnia or schizophrenia); chronic disabling systemic disease (cerebrovascular event with sequeale, severe hearing impairment, cardiac insufficiency grade III or IV NYHA); cancer with a remission period of less than three years.
The study followed the Helsinki Declaration on patient´s safety, and it was approved by The Andalucian Research Ethics Committee.
Routine sociodemographic data (sex and age) and peri-operative variables were gathered by blinded nurse practitioners and ophthalmologists (vision and ocular descriptors), one month before and four months after the surgery.
One month before and four months after surgery, patients completed the self-reported questionnaires for visual dysfunction and depressive status (VF-14 and GDS-15, respectively).
The details of patients´ comorbidity were obtained from their updated primary care e-records: diabetes, hypertension, dyslipidaemia, previous vascular thrombosis or embolism, benign prostate hyperplasia, COPD, chronic pain, depression, anxiety, insomnia and/or psychosis. The number of falls requiring emergency department attendance in the 12 months prior to the study was also recorded.
Visual acuity (VA)
VA was obtained through Snellen optotype in logMAR, with best correction and through pinhole. 0.0 logMAR indicates excellent vision, whereas the higher the score, the worse the vision. For instance, the World Health Organization defines low vision as a VA worse than 0.5 logMAR and blindness as a VA worse than 1.3 logMAR.
Visual dysfunction (VF-14)
The VF-14 (Visual Functioning Index) self-questionnaire measures the capacity to perform 14 activities from everyday life that can be affected by cataracts. The score ranges from 0 (worst level) to 100 points (best level of function).11 By consensus, a score of 0 to 70 points reflects a significant disability to perform activities dependant on vision.11,12,13 The VF-14 has been validated in the Spanish language12 and its use is concise.14 Its validity, reproducibility and use pre and postoperatively has been corroborated in many published studies, making it the most used of its kind internationally.13
Psychological distress (GDS-15)
The GDS-15 (Geriatric Depression Scale Short Form) measures the presence of depressive symptoms with 15 questions. A score of 0-4 suggests no depressive symptoms, 5-9 suggests the presence of depressive symptoms and 10-15 points is suggestive of established depression.15 It has been validated in the Spanish language16 and it’s designed specifically for use with elderly patients.15 It has a high distinctive power to differentiate between depressed and not depressed adults (r=0.84, p<0.001).17
Stratification criteria divided the cohort in two groups: first eye (cataracts in both eyes) and second eye patients (one eye with cataract and the fellow eye already operated).
We used bivariate analysis, factorial analysis and multiple regression to determine the variables associated with the benefit of the surgery upon the level of visual functioning and depressive symptoms.
For the bivariate analysis, we used Kolmogorov-Smirnov and Shapiro-Wilks tests for quantitative variables. For variables following normal distribution, we used Pearson coefficient correlation and/or lineal regression, student’s t-test and ANOVA. For variables not following a normal distribution, we used parametric techniques: Spearman correlation, Mann-Whitney U test, Wilcoxon, Kruskall-Wallis, X2, Fisher and McNemar. For the multivariate analysis, we used linear regression or multivariate logistics.
Results were considered significant at the p<0.05 level. The statistical analysis was done using SPSS v19 (IBM SPSS).
|VF measured on VF-14 scores and DS measured on GDS-15 scores. CF = Counting Fingers at 30 cm. HM = Hand Motions at 30 cm. PL = Perception of Light at 30 cm.|
|VA logMAR||VA Snellen (metric)||VA Snellen (imperial)||VA decimal||VF||DS||Falls <12 meses|
Ages ranged from 60 to 91 years old. 24.20% were aged 60-69, 45.18% were aged 70-79 and 30.62% were 80 years old and over. The majority of the participants were married (62.4%) and 26.8% had been widowed. 73.8% lived with their partners and/or another family member, 25.9% lived on their own and only 0.3% lived in a residential home. 62.7% were women. 93% of men had retired and 90.2% of women had been and still were housewives.
193 patients had first eye and 119 had second eye surgery. They all had the same surgical technique: phacoemulsification with implant of monofocal acrylic lens under topical anaesthesia. The percentage of patients with baseline ocular, physical and psychiatric comorbidity was similar for both groups (around 20%, 69% and 45%, respectively), suggesting the participants were homogeneous except for the cataracts. However, those on waiting list for the first eye reported a higher rate of falls (19.8%) than the second eye group (13.7%).
Benefits of cataract surgery in visual acuity
The median VA before surgery was 0.69 logMAR and the median VA after surgery was 0.15 logMAR, with no significant difference between first and second eye surgery patients. This reflects a visual benefit of 6 Snellen lines.
After surgery for the first eye, the major improvement on VA was for the sexagenarians (0.78 ± 0.15 logMAR). The differences in VA benefit between age groups was clinically significant (p<0.005), showing diminished benefit as the patients’ age increased (0.74 ± 0.17 for septuagenarians and 0.61 ± 0.10 for over 80s).
Benefits of cataract surgery in visual functioning
The VF-14 scores prior to surgery were 47.73 (±23.8) for first eye patients and 68.51 (±22.4) points for second eye patients (p<0.001). As the scores were below 70 points, this suggests significant visual dysfunction in both groups.
The benefit in visual functioning was 25.54 VF-14 points for patients undergoing first eye surgery and 15.38 points for patients undergoing second eye surgery. Patients having had cataract surgery for the first eye had a significant gain (≥ 1 out of 4 points) in 10 items (Figure 1A): reading small print such as a telephone book, reading a book, reading large print on newspapers, recognising nearby people, doing fine work such as sewing or carpentry, writing forms, playing board games such as bingo, taking part in sports like bowling, watching television and daytime driving. However, patients having had cataract surgery for the second eye only had a significant improvement in three items (Figure 1B): doing fine work, day and night driving.
The benefit in visual functioning was greater in those who underwent first eye compared to second eye surgery for all age groups. The sexagenarians improved 27.70 ± 11.7 VF-14 points after first eye surgery, in contrast with the 19.94 ± 6.3 VF-14 points after second eye for the same age group. The benefit on VF-14 was less noticeable in the over 80s that had second eye surgery (14.08 ± 4.46 VF-14 points).
Benefits of cataract surgery in depressive symptoms
GDS-15 scores before surgery were 5.45 (±3.5) for first eye patients and 4.56 (±3.2) points for second eye surgeries. For both groups the score is close to or greater than 5 points, suggesting significant depressive symptoms.
The benefit in depressive symptomatology was 1.92 GDS-15 points for the first eye and 1.07 points for the second eye group. The first eye group improved significantly (≥10%) in nine items against the second eye group that improved in four items (Figure 1C). After four months those patients who had had cataract surgery for the first time had recovered part of their interest in previous hobbies, were less bored or moody, were less afraid of life events, felt happier and less helpless, manifested less sadness and worthlessness, and had recovered part of their energy. For those who had had cataract surgery on the second eye, they felt less feelings of emptiness, were less afraid of life events, felt less helpless and reported less sadness.
The benefit in depressive symptoms was greater in those who underwent first eye surgery compared to second eye surgery for all age groups. The sexagenarians interviewed following first eye surgery improved 1.91 ± 1.3 GDS-15 points after surgery compared to the 0.73 ± 0.62 GDS-15 points after second eye for the same age group. The benefit on GDS-15 was less noticeable in the over 80s that had second eye surgery (0.28 ± 0.28 GDS-15 points).
|TABLE 2. A) Scores on visual function VF-14 questionnaire in the pre and postoperative periods.
Benefit of cataract surgery =postoperative-preoperative scores. A score of ≤ 70 points or less on the VF-14 indicates disabling visual function for everyday activities. Physical comorbidity for: diabetes, hypertension, dyslipidaemia, previous vascular event on antiplatelets and/or anticoagulants, benign prostate hyperplasia on medication, COPD on bronchodilators, chronic pain on analgesics.
|Preoperative visual function||p||Postoperative visual function||p||Benefit in visual function||p|
Correlation between rate of falls and preoperative visual acuity, visual functioning and depressive symptoms
Table 1 shows the average VF-14 and GDS-15 scores preoperatively, along with the rate of falls, in correlation with the visual acuities while on the waiting list. The critical VA is 1.00 logMAR or worse, as the average VF-14 score at this point is reduced by half, the average GDS-15 score reaches the 5 points and the rate of falls increases at 10%.
Impact of cataracts and its surgery on pre-existing physical and psychiatric comorbidity
No significant differences between patients with physical comorbidity and those without it on visual functioning were detected, neither while on the waiting list nor four months after cataract surgery (Table 2). However, those patients with psychiatric comorbidity had worse preoperative depression while on the waiting list and reported greater benefit after cataract surgery on the GDS-15 test than those free of mental illness.
|TABLE 2. B) Scores on depressive symptoms GDS-15 questionnaire in the pre and postoperative periods.
Benefit of cataract surgery =postoperative-preoperative scores. A score of ≥ 5 points indicates high suspicion of depression. Psychiatric comorbidity for: current treatment includes antidepressants, anxiolytics, hypnotics and/or antipsychotics.
|Preoperative depression||p||Postoperative depression||p||Benefit in depression||p|
The entire population studied found a significant benefit from cataract surgery in visual acuity (6 Snellen lines), in visual functioning (22.06 points on VF-14) and on depressive symptoms (1.20 point on the GDS-15). These benefits were higher in patients aged between 60 and 70 years old, compared to older age at presentation. This may reflect the fact that cataracts develop gradually over a period of time. Therefore, delays in surgical extraction may contribute to a further irreversible decline in visual, physical, and mental health.18
Furthermore, we noticed in our study that the rate of complications was higher in patients over the age of 80, at 9.2% (compared to 7.4% on sexagenarians and 4.3% on septuagenarians). Our patients who had complications had worse resulting vision after surgery, with an average VA of 0.52 (0.46-0.58) logMAR.
Foss et al found no association with an increase in patients’ physical activity after cataract surgery.19 In our study, we proved a gain in visual functioning, but we believe that older patients have other factors besides poor vision, ie. poor motility, to account responsible for a non-increase in physical activity after cataract surgery. However, cataract surgery would enable them to carry on performing activities dependant on vision such as reading and writing even if they have poor motility, preventing loss of autonomy and delaying dependency. Furthermore, a randomised controlled trial showed that cataract surgery reduces the rate of falls (0.66, CI 0.45-0.96)20 not only because it increases vision but also patient confidence.10
Our results have demonstrated that cataract surgery has a positive impact on depression, contrary to many other studies.4,5,19,21,22 Our whole population study showed a beneficial impact on depressive symptoms after cataract surgery, both for the first eye and the second eye group, with a reduction of 1.92 and 1.07 points, respectively, on the GDS-15. Both groups went from a depressive status to a suspect-free status, even at four months after their intervention. Surgery has shown to contribute positively to reduce the feeling of emptiness, anticipatory fear, helplessness and sadness (more that 10% improvement in both groups studied).
However, one of the limitations of our research is that it can´t stablish the sequential cause-effect relationship between cataract and depression, as we don´t know for how long the patient had had significant cataract until extraction. Despite this, our study supports Freeman et al6 results in that patients whose cataract surgery is delayed present with worse VA and are at higher risk of developing depression. Freeman et al shows that when patients are listed with a VA of worse than 0.5 logMAR, 36% of them present depression (≥5 points on the GDS-15).6 In our study, these percentages were 51.4% in first eye surgery, and 45.1% in second eye surgery. As 0.5 logMAR is the minimal VA to read at standard print, we suspect that losing this ability predisposes patients with cataracts to depression.
A novelty result in our study is that even those patients with pre-existing psychiatric pathology (depression, anxiety, insomnia and mild psychosis), an improvement in VA after cataract surgery can contribute to a global improvement in their depressive symptoms (1.42 ±0.71 GDS-15 points, p=0.03). In our cohort, 6.3% of males and 17.2% of females had criteria of established depression while on the waiting list for cataract surgery (GDS-15 ≥ 10 points). We also noticed that 20% of our patients were on antidepressants. However, four months after cataract surgery, only 2.3% of males and 8.4% of females had criteria of established depression. We have proved that the beneficial impact of cataract surgery was clearly superior (0.40 points less on the GDS-15) in patients with previous psychological diagnosis than on those without it. Based on this, it may be interesting to reassess patients with diagnosed depression after cataract surgery, and maybe readjust their antidepressants accordingly.
Finally, we should avoid our elderly population from suffering from advanced cataracts. For patients whose cataracts cause a VA of 1.00 logMAR or worse, there is a peak increment in dysfunction in everyday activities dependant on vision and also in depressive symptoms. Furthermore, when patients reach 1.00 logMAR on VA, the rate of falls increases to 31.7%.
In summary, our results have led us to believe that expedited cataract surgery is an effective intervention to improve vision in the elderly. It is important in reducing visual-related dysfunction, psychological distress and rate of falls. Despite financial pressure, neglecting second eye cataract surgery in elderly patients may reduce their ability to achieve the full benefits of cataract surgery.
Leticia Royo-Dujardin, Department of Ophthalmology, The Newcastle Hospitals
Robert W Philpott, Department of Elderly Care, Royal Cornwall Hospitals
Annika S Quinn, Department of Ophthalmology, Torbay and South Devon
Eduardo Alcalde-Vilchez, Department of Ophthalmology, Hospital Universitario Puerta del Mar, Cadiz, Spain
Kathy Y Liu, Division of Psychiatry, University College London,
Enrique Rodriguez-de la Rua, Department of Ophthalmology, Hospitales Universitarios Virgen Macarena y Virgen del Rocio, Sevilla, Spain
Jose P Novalbos-Ruiz, Department of Biomedicine, Biotechnology and Public Health, Universidad de Cadiz, Cadiz, Spain
Conflict of interest: none declared
8. Meuleners LB, Hendrie D, Fraser ML, et al. The impact of first eye cataract surgery on mental health contacts for depression and/or anxiety: a population-based study using linked data. Acta Ophthalmol 2013; 91: e445–9
9. Walker JG, Anstey KJ, Hennessy MP, et al. The impact of cataract surgery on visual functioning, vision-related disability and psychological distress: a randomized controlled trial. Clin Experiment Ophthalmol 2006; 34: 734–42
13. Valderas JM, Alonso J, Prieto L, et al. Content-based interpretation aids for health-related quality of life measures in clinical practice. An example for the visual function index (VF-14). Qual Life Res 2004; 13: 35–44
16. Martínez de la Iglesia J, Onís Vilches MC, Dueñas Herrero R, et al. Versión española del cuestionario de Yesavage abreviado (GDS) para el despistaje de depresión en mayores de 65 años: adaptación y validación. Medifam 2002;12.
18. Gray CS, Karimova G, Hildreth AJ, et al. Recovery of visual and functional disability following cataract surgery in older people: Sunderland Cataract Study. J Cataract Refract Surg 2006; 32: 60–66