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Abstract
Purpose To study the pattern of compliance to follow-up of children less than 5 years of age undergoing surgery for congenital and developmental cataract over a period of 5 years.
Methods It is a retrospective study of children less than 5 years of age undergoing cataract surgery between January and December 2010 for congenital or developmental cataract and followed up until 31 December 2015. Age, sex, distance from hospital and urban or rural habitat, delay in presentation, socioeconomic status, laterality, morphology and type of cataract, implantation of intraocular lens and interventions done were noted. Compliance to follow-up at postoperative 1 week, 1 month, 3 months, 6 months, 1 year and then once a year until 5 years were recorded.
Results 169 patients were included in the study. The median follow-up was 22 months. Median age at surgery was 10 months and had a negative correlation with total follow-up. Male-to-female ratio was 1.82. Logarithmic curve of follow-up was noticed with 85%, 61%, 55%, 52%, 39% and 28% patients attending 1 month, 3 months, 6 months, 1 year, 3 years and 5 years of follow-up, respectively. Low socioeconomic group had poor follow-up compared with higher socioeconomic group (P=0.009), but the curve of follow-up was similar in both groups; multiple interventions group had better follow-up (P<0.0001).
Conclusion Curve of loss to follow-up is logarithmic in children undergoing paediatric cataract surgery. Age at surgery and low economic status are the most important factors associated with poor follow-up.
- lens and zonules
- treatment surgery
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Introduction
Cataract is now considered as one of the most common causes of preventable childhood blindness and is included among the priority eye diseases by the World Health Organization (WHO).1 Prevention of visual loss should be a continuous effort in critical age period, when the visual system is immature. Early recognition and surgical removal of cataract and supportive measures like postoperative care, amblyopia therapy and refractive correction are important.2–5 Patients with congenital cataracts have higher chances of visual axis opacification, development of glaucoma and other adverse events after cataract surgery.6–10 Regular follow-up plays a crucial role in early detection of complications and its management.11
Follow-up of children undergoing cataract surgery has been known to be poor, especially in the developing world.3 12 This is a matter of serious concern, particularly in younger children who are at greater risk of permanent visual loss. Several studies from the developing world have focused on the predictive factors for good follow-up in paediatric cataract surgeries,13–15 and included children below 18 years of age who underwent cataract surgery, including traumatic cataract. None of these studies have discussed the predictive factors and pattern of follow-up for children below 5 years of age.
The purpose of the present study is to evaluate the pattern of compliance to follow-up of children less than 5 years of age undergoing surgery for congenital and developmental cataract and to study the various demographic, clinical and surgical factors that are associated with the follow-up.
Methods
This is a retrospective study conducted at L V Prasad Eye Institute (LVPEI), Hyderabad, India. The study was approved by the Institutional Ethics Committee and adhered to the tenets of the Declaration of Helsinki. All children below 5 years of age who underwent cataract surgery between 1 January 2010 and 31 December 2010 were included. Their postoperative follow-up visits until 31 December 2015 were studied. Patients with preoperative ocular comorbidities like congenital glaucoma, retinopathy of prematurity, corneal opacity, retinoblastoma and surgical indications like post-traumatic cataract or secondary cataract following an intraocular surgery, which would change or require additional follow-up visits, were excluded from the study. The demographic data collected included age at the time of surgery, gender and place of residence. Patients were divided into ‘high’ and ‘low’ socioeconomic class based on their ability or inability to pay for the hospital services, respectively. Based on the address provided by the patient, the distance from the place of residence to the base hospital was calculated using Google maps (https://www.google.co.in/maps).16 It was noted whether the patient came from a rural or urban community.
Based on history, duration between the age of child at which parents first noticed the ‘visual complaint’ and the cataract surgery was calculated and was termed ‘time delay for surgery’. On examination, visual acuity was measured using age-appropriate measures. A detailed anterior and posterior segment examination was performed with appropriate investigations whenever needed. The laterality and morphology of cataract was noted. Patients were diagnosed clinically to have congenital or developmental cataract based on the onset of symptoms and the morphology of cataract. Systemic abnormalities if any were noted. All patients underwent a standard surgical procedure of lens aspiration, primary posterior capsulorhexis and anterior vitrectomy with or without implantation of an intraocular lens (IOL) as described in our earlier studies.17 The decision to implant an IOL was made intraoperatively by the operating surgeon depending on the horizontal and vertical corneal diameter (>10.50 mm), the adequacy of capsular support and the absence of anterior segment dysgenesis. The postoperative regimen followed for all patients was uniform with follow-up visits at day 1, 1 week, 1 month, 3 months, 6 months, 1 year and yearly thereafter until 5 years. In case of bilateral cataract, the duration between the surgeries for each eye was 1 week and the postoperative visits were scheduled after the second eye surgery. If the patient underwent any surgical or laser intervention, then the nature and the follow-up visit at which it was performed was noted. Visual acuity at the last follow-up visit was recorded for all the patients using Teller acuity charts, fixing and following light or brightly coloured objects for non-verbal children and matching Lea symbols, Kay pictures and LogMAR visual acuity charts for verbal children.
Descriptive statistics included mean and standard deviation (SD) and median and inter-quartile range (IQR) for continuous variables. Spearman’s correlation was used to determine the correlation between two continuous variables. Mann-Whitney test was used to determine the difference between two groups and Kruskal-Wallis test for more than two groups. A P value of less than 0.05 was considered statistically significant. Statistical analysis was performed using commercial software (Stata V.11.2; StataCorp, College Station, Texas, USA).
Results
A total of 262 patients below 5 years of age underwent cataract surgery during the study period out of which only 169 patients were included. The median follow-up of patients was 22 months (IQR 4–59 months) and the median age at the time of surgery was 10 months (IQR 4–27 months). Male-to-female ratio was 1.8:1 (109 boys and 60 girls). There was no significant difference (P=0.49) in the total follow-up between boys (median 23 months, IQR 4–59 months) and girls (median 19 months, IQR 3–51 months). There was a significant correlation between the age at surgery and the follow-up duration (rho=−0.32, P<0.0001), and higher age at surgery was associated with poorer follow-up (figure 1). A total of 137 patients presented with bilateral cataract and 32 presented with unilateral cataract. Three bilateral cases had one eye operated outside the study period and one bilateral case was lost to follow-up after the first eye surgery and did not undergo the other eye surgery; the other eye of these four cases were excluded from the analysis. One hundred thirty eyes had total cataract, 33 eyes had nuclear, 39 had lamellar, 19 had other miscellaneous types and in 81 eyes, the morphology of cataract was not documented.
Follow-up patterns after paediatric cataract surgery: scatter plot showing negative correlation between age at surgery with the total follow-up in months. It shows that patients operated on at a younger age had better follow-up compared with those operated late.
Fifteen per cent of patients were lost to follow-up at 1 month and dropped rapidly to 61% at 3 months, but slowed thereafter to 55%, 52%, 39% and 28% attending 6 months, 1 year, 3 years and 5 years of follow-up, respectively (figure 2A). The follow-up of patients belonging to higher socioeconomic status (median 35 months, IQR 8–60 months) was significantly longer (P=0.009) than those belonging to lower socioeconomic status (median 14 months, IQR 2–54 months) (figure 2B). The trend in the curve of drop-out for the two groups was similar but was steeper in the low socioeconomic group (figure 2C). There was no significant difference in the follow-up between rural and urban habitat (P=0.71). There was no relationship between distance from the patients’ residence to the base hospital and the duration of follow-up (P=0.12). Clinical features like congenital or developmental cataract (P=0.64), unilateral or bilateral cataract (P=0.31) or cataract morphology like partial or total cataract (P=0.42) did not show any relationship with the total follow-up duration. The median time delay for surgery was 2.5 months (IQR 0.5–6 months). There was no significant correlation between the duration of symptoms and the total follow-up duration (P=0.48). The implantation of IOL at the time of primary surgery had no effet on the duration of the final follow-up (P=0.37). In case of bilateral cataracts, IOL was implanted either in both eyes or both eyes were left aphakic. Patients who underwent secondary intervention (median 59 months, IQR 37–64 months) had a significantly longer follow-up than those who did not undergo any secondary intervention (median 13 months, IQR 2–51 months) (P<0.0001) (table 1).
(A) Follow-up patterns after paediatric cataract surgery: a line diagram showing the percentage of patients attending various follow-ups. The line denotes the slope of the curve, which is similar to that of an exponential decay (a logarithmic curve). (B) Box plot showing significant difference in the final follow-up between high and low socioeconomic groups. (C) Similar logarithmic curve of drop-outs (left) from follow-up seen in both the high as well as low socioeconomic group; however, the slope in the low socioeconomic group is steeper.
Details of each factor and its association with follow-up of the patient
We compared the follow-up between patients who underwent cataract surgery with primary IOL implantation (median 13.5 months, IQR 2.75–41 months; excluding patients who underwent additional intervention) with those who underwent multiple interventions in the form of secondary IOL or any other procedure (median follow-up 59 months, IQR 37–64 months) and found that there was a significant difference between these two groups (P<0.0001, Mann-Whitney U test). However, we did not find any significant difference in follow-up in children undergoing additional interventions between primary IOL (median 60, IQR 42–64) and no IOL group (median 38, IQR 32–56) (P=0.25, Mann-Whitney U test). Similarly, we found that the follow-up was not significantly different in children not undergoing any additional interventions between the primary IOL implantation (median 13.5, IQR 2.75–41) and no IOL group (median 12, IQR 2–55.5) (P=0.97, Mann-Whitney U test).
Children who presented with congenital cataract were divided into three subgroups based on their age at the time of surgery into early (0 to 6 months), mid (7 to 24 months) and late presenters (≥25 months). On further subgroup analysis, it was found that the early presenters had a longer median follow-up (median 58 months, IQR 12–64 months) compared with those of mid (median 20 months, IQR 6–56 months) and late presenters (median 8 months, IQR 1–22 months) (figure 3). There was a significant difference between the follow-up of patients below 6 months of age and those more than 24 months of age (P=0.0007). There were no significant differences in the follow-up between the early and mid or mid and late presenters group (figure 3). Patients who underwent additional intervention were divided into two subgroups: one with secondary IOL implantation and the other group with any other procedures. There was no significant difference in the follow-up between these two groups (P=0.44). Patients undergoing ≥2 secondary interventions did not show any significant difference in the follow-up from those undergoing single secondary intervention (P=0.12). The visual outcomes at the final visit are shown in table 2.
Follow-up patterns after surgery in congenital cataract subgroup: box plot shows comparison of total follow-up between early (0 to 6 months), mid (7 to 24 months) and late presenters (>24 months) in children with congenital cataract. The total follow-up of early presenters is better than mid and late presenters, but statistical significance was reached only between the follow-ups of early and late presenters.
Visual acuity at the final visit*
Discussion
Follow-up in children after cataract surgery has been a major concern in the developing world due to lack of awareness, means of transport and poverty. The follow-up rates are variable in different parts of the globe ranging from a mean follow-up of 3.5 months in Mexico13 to 98.3% of patients attending at least one follow-up, 66.9% patients attending 2 weeks of follow-up and 42.9% attending 10 weeks of follow-up in Tanzania.14 Gogate et al reported only 20.6% patients followed up regularly.15 These studies included children up to late teens undergoing surgery for all types of cataract including traumatic cataract whereas we focused particularly on children less than 5 years of age operated for either congenital or developmental cataract, which are more prone to permanent visual loss.
We noted an exponential rate of drop-outs in the follow-up with close to 40% being lost by 3 months and then slowing down to 50% by 1 year and further down to 72% drop-outs at the end of 5 years (figure 2A). It is known that the myopic shift is greater in younger children and follows a logarithmic curve,18 which implies that the maximum refractive changes occur within the first year of surgery. Hence, a good follow-up in the initial postoperative period is necessary for optimal refractive correction.
Figure 2A highlights two points; one being that the maximum efforts to create awareness for a good follow-up needs to be done in the perioperative period, as the parents are more receptive then, and once again after 1 month, so that we can reach out to the maximum number of patients before they drop out. Second, if a patient is coming for follow-up until 1 year or more, then he/she is likely to continue follow-up for a longer time. There could be multiple explanations to this trend such as parents assuming that their responsibility is completed once the surgery gets over, or that once the child sees well, there is no necessity for further visits, or that they were not aware about the need for follow-up.15 These reasons can be easily tackled with the help of a good counselling team in the perioperative period. Frequent visits initially may be taxing to the parents considering the direct and indirect financial burden with respect to travelling, accommodation and per-diem expenses. Many of the parents live on daily wages, especially in the low socioeconomic group. Travelling from long distance means additional expenditure on travel and accommodation, and also loss of livelihood for a few days, which may make a huge impact on the financial aspects of these families. Frequent and regular visits in the initial period may be a huge discouraging factor for them to continue the follow-up; however, they should be informed about the prospects of fewer postoperative visits later.
Gogate et al found that children less than 5 years of age had better follow-up compared with older children.15 However, the follow-up pattern of children less than 5 years has been poorly understood. We found a significant correlation between age at surgery and total follow-up. In patients with congenital cataract, those operated before 6 months of age (early presenters) had better follow-up compared with the late presenters. This could be attributed to the fact that if the parents were not vigilant enough to bring the child to the hospital early, they may not be so sincere with the follow-up either. This finding has been in consistence with the study by Eriksen et al. 14 Nine patients (21.95%) in the early presenter group (≤6 months at surgery) in congenital cataract did not follow up for more than 1 year with a median follow-up of 1 month.
We did not find any significant difference in the follow-up between boys and girls. However, the number of girls seeking medical services was only half to that of boys. Other studies have also found that the number of girls getting operated on and following up regularly for visual rehabilitation is poor compared with boys.13–15 This could be attributed to the male centric societies in these geographical areas. Many girls may still be deprived of necessary medical care and efficient strategies need to be designed to increase the number of girls being operated on and followed up by creating awareness in the society. Pleasantly though, we noted that if the parents of a girl are willing to visit a hospital for surgical treatment, then they are likely to follow up just as regularly as that of boys.
Financial constraints have been another major reason for poor follow-up in most parts of the world.13–15 We found that patients from the low socioeconomic group had a significantly poor follow-up compared with the high socioeconomic group (figure 2B). Although the trend of drop-outs from follow-up was similar in both groups, it was steeper in the low socioeconomic group (figure 2C).
We did not find any significant relationship between the distance of the patient’s residence to the hospital and total follow-up, which was surprising. Many studies have mentioned that greater distance from the base hospital is associated with poor compliance to follow-up.13–15 There was no difference in the follow-up pattern of patients coming from a rural or urban community. Rural communities usually have poor means of transport and infrastructure, which can be a hindrance to follow-up. These observations were alarming, as we found that one-fifth (19.11%) of patients having less than 1 year of follow-up came from Hyderabad or Secunderabad, the twin cities in which the study hospital is based.
Type and laterality of cataract or the time delay in cataract surgery did not have any correlation with the follow-up. Implantation of IOL at the time of surgery did not affect the final follow-up duration. All patients who were left aphakic were informed about the need for a second procedure for IOL implantation later, but it did not encourage them to follow up regularly. We found that the final follow-up was greater in patients undergoing secondary procedure. This could be because the parents are more concerned with the second procedure or may be the second procedure was an effect of better follow-up as patients coming for review have a better chance of being diagnosed and managed for any ocular adverse event. We found a significantly lower follow-up in patients who underwent cataract surgery with primary IOL implantation (excluding patients who underwent additional intervention) compared with those who underwent multiple interventions in the form of secondary IOL or any other procedure. So implanting an IOL in the primary surgery could be one of the confounding factors for the poor follow-up. However, we did not find any significant difference in follow-up in children undergoing additional interventions between primary IOL and no IOL group and in children not undergoing any additional interventions between the two groups.
Various strategies have been developed and implemented to improve the total postoperative follow-up following paediatric cataract. Various monetary support schemes like sponsored surgery, accommodation and even travelling allowances have been advocated. Appointment of a patient follow-up coordinator has shown improved compliance with follow-up,19–21 so did short message service reminders.22 At LVPEI, we have an additional advantage of having developed a pyramidal model of eye care system comprising 158 vision centres, 16 secondary centres, 9 partner centres and 3 tertiary centres with 1 centre of excellence extending over four states in India. About 73.52% of patients who had a follow-up of less than 1 year belong to districts in which LVPEI has its secondary or a partner centre situated. Other patients come from districts neighbouring these centres. By decentralising the follow-up services to secondary centre, the cost of transport, accommodation and loss of pay at work can be reduced significantly for the patient. This would be a great way of improving the follow-up without putting any extra burden over the family.
There are a few limitations in this study. One of them is its retrospective design. The delay in presentation and the onset of cataract were determined on the basis of history given by parents and the clinical clues. We are not aware whether these children followed up in their locality with an ophthalmologist. However, this is highly unlikely as one-fifth of the children lost to follow-up within 1 year were from the same city where the hospital is located and majority of patients were from areas with no tertiary eye care centres in their vicinity. The distribution of samples was not equivocal in multiple groups like urban and rural, congenital and developmental cataract, intervention and no intervention group, and IOL and no IOL group.
The visual system is not mature in children less than 5 years of age. If timely intervention is not done in these young kids, their vision can deteriorate with permanent vision loss. These interventions may be as simple as prescribing glasses or patching therapy. Our study particularly focused on the children in the age group of less than 5 years. It showed that more than half of the children are lost to the follow-up within 1 year when they need maximum care. Age at surgery had a negative correlation with the total follow-up, higher age being associated with poor follow-up. Moreover, children from the low socioeconomic group had a poorer follow-up compared with the high socioeconomic group. Therefore, strategies should be designed and tested for earlier detection of paediatric cataract and reduce the economic burden associated with frequent follow-up visits in order to improve the follow-up. The time frame to implement these strategies is from the perioperative period up to 1 month postoperatively, in order to reach out to the maximum number of patients.
References
Footnotes
Contributors Design and conduct of the study: RK, PC, SM. Collection, management, analysis and interpretation of the data: PC, RK, SM, AM. Preparation, review or approval of the manuscript: PC, AM, RK.
Funding This work was supported by Hyderabad Eye Research Foundation (HERF).
Competing interests None declared.
Patient consent Detail has been removed from this case description/these case descriptions to ensure anonymity. The editors and reviewers have seen the detailed information available and are satisfied that the information backs up the case the authors are making.
Ethics approval LVPEI Ethics Bureau.
Provenance and peer review Not commissioned; externally peer reviewed.
Presented at Presented at the 4th World Congress of Paediatric Ophthalmology & Strabismus (WCPOS) 2017, Hyderabad, Indiaand APAO 2017, Hongkong.
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