Oman Journal of Ophthalmology

ORIGINAL ARTICLE
Year
: 2012  |  Volume : 5  |  Issue : 3  |  Page : 150--156

Visual outcome and impact on quality of life after surgeries differ in children operated for unilateral and bilateral cataract (Pune study 2011)


Mukesh Paryani1, Rajiv B Khandekar2, Kuldeep Dole1, Sheetal Dharmadhikari1, Nikhil Rishikeshi1,  
1 Department of Community Ophthalmology, H V Desai Eye Hospital, Hadapsar, Pune, India
2 Department of Non communicable Diseases Surveillance and Control, Eye and Ear Health Care, Ministry of Health, Muscat, Oman

Correspondence Address:
Rajiv B Khandekar
EHCP, NCD, DGHA, MOH (HQ) POB: 393, Pin: 113, Muscat
Oman

Abstract

Background: We compared vision and quality of life (VQL) of children aged 5-15 years and operated for unilateral and bilateral cataract between 2008 and 2010 in western India. Materials and Methods: In this cohort study, ophthalmologists assessed vision, anterior and posterior segment of eyes with cataract. Children completed a functional vision questionnaire (LVP-FVQ). Follow up at 6 months after surgery included the best corrected visual acuity (BCVA), FVQ and eye assessment. The improvement of BCVA and quality of life were compared in group of unilateral and bilateral cataract. Result: A total of 20 (70%) bilateral and 7 (39%) unilateral cataract were operated within 1 month of detection. All 48 eyes with bilateral cataract were congenital and 12 (67%) unilateral cataract were traumatic. Among bilateral group, 27 eyes [56.2% (95% confidence interval (CI) 44.4-72.2)] and in unilateral group 11 eyes [61.1% (95% CI 38.6-83.6)] had vision ≥ 20/60 at 6 months follow up. The visual gain was significantly higher in children who were operated between 1 month and 1 year of detection (adjusted Odds ratio (OR) = 15.6 P = 0.03). Positive impact on VQL in bilateral group was noted in 50%, 27%, and 13% children for subscale of distant vision, near vision, and field of vision, respectively. There was positive impact in these subscales among children with unilateral cataract. Thirty percent eyes with bilateral cataract and 22% of eyes with unilateral cataract improved their vision. Surgery within 1 month of cataract was significant predictor of improved vision (OR = 16.6 P = 0.02). Conclusion: Vision and VQL improved in children with unilateral and bilateral cataract. However, it was better 6 months following surgery in children with bilateral cataract than in children with unilateral cataract.



How to cite this article:
Paryani M, Khandekar RB, Dole K, Dharmadhikari S, Rishikeshi N. Visual outcome and impact on quality of life after surgeries differ in children operated for unilateral and bilateral cataract (Pune study 2011).Oman J Ophthalmol 2012;5:150-156


How to cite this URL:
Paryani M, Khandekar RB, Dole K, Dharmadhikari S, Rishikeshi N. Visual outcome and impact on quality of life after surgeries differ in children operated for unilateral and bilateral cataract (Pune study 2011). Oman J Ophthalmol [serial online] 2012 [cited 2019 Dec 13 ];5:150-156
Available from: http://www.ojoonline.org/text.asp?2012/5/3/150/106094


Full Text

 Introduction



Visual impairment at an early age has far reaching implications on a child's life. It can hinder education, hamper personality development, and deprive the individual of career opportunities, thus increasing the socioeconomic burden on the family and the community. [1] Blindness costs billions of dollars in the form of lost productivity, caring for the blind, their rehabilitation, and special education. Approximately one-third of which is incurred by childhood blindness. [2] Unfortunately, half of them were blind as they were not operated for cataract, whereas the rest were blind due to amblyopia due to late surgery or due to postoperative complications. Thus, pediatric cataract constitutes an important contributor of visual acuity reduction in childhood and this affects negatively to the growth in developing countries. [3]

Early detection and standard management by qualified ophthalmic surgeon improve visual outcomes of pediatric cataract. Those who do not regain complete vision after surgery could subsequently be trained in low vision rehabilitation. [4] The pediatric cataract surgeon has to be aware of prognosis and prepare parents for possible outcomes in their children before offering cataract surgery. Visual outcome after pediatric cataract surgery depends on the etiology and co-morbidities (systemic and ocular). [5],[6] As vision in the fellow eye is near normal, unilateral cataract are often detected late and are brought for surgery late. In bilateral cataract, parents often neglect fellow eye once vision is regained following surgery in the first eye. Thus different approaches of parents of children with unilateral and bilateral childhood cataract could cause variation in results of surgery. Children with unilateral congenital cataracts also have poor prognosis for obtaining binocular fusion and almost all of them develop strabismus. [4],[7]

The impact of a successful cataract surgery in children can be assessed by comparing vision-related quality of life (VQL) before and after intervention. [8] However, standard instruments give less information about general health of patient and as these instruments are tested in adults. Information on VQL in children with eye problems has been developed but is challenging. [9],[10] It would be interesting to study VQL in children after cataract surgery. We also compared the visual gain and change in VQL after cataract surgery for unilateral and bilateral cataract.

 Materials and Methods



The ethical and research committee of our hospital approved and supported our research. It was conducted between October 2008 and March 2010. Our study population comprised of children aged 5-15 years, presenting to the pediatric ophthalmology department. They were either walk-in patients or referred by vision centers, school teachers, pediatricians, or through 'Sarva Shiksha Abhiyaan'; a health-campaign conducted by the Ministry of Education in Maharashtra state to provide a comprehensive education along with health to all children.

This was an unmatched cohort study with a 5:2 proportion of eyes with bilateral and unilateral pediatric cataract. We assumed that 30% of eyes with unilateral cataract will have excellent grade of visual acuity (vision >6/18) and 80% of eyes of children with bilateral cataract will have 'excellent' grade of visual acuity after surgery. [11] We used Open Epi calculator to determine the sample size for our study. [12] To achieve 95% confidence interval (CI) and 80% power of the study, we needed 16 eyes with unilateral cataract and 40 eyes with bilateral cataract. We excluded children with unilateral cataract cases due to trauma in the last 1 week of attending eye clinic. We also excluded verbally or intellectually challenged children who would not be able to respond or comprehend the questionnaire.

The field staff comprised of one pediatric ophthalmologist, one ophthalmologist oriented in pediatric ophthalmology, one pediatric optometrist, and two ophthalmic assistants.

The demographic information regarding age, gender, area of residence, time, and manner of detection of cataract was acquired. The baseline ocular assessment included the best corrected distant visual acuity (BCVA), slit lamp bio-microscopy (Topcon Japan), grading of cataract, other ocular co-morbidity, and status of the fellow eye. The posterior segment when visible, was examined both using +90D fundus lens (Volk - USA) and binocular indirect ophthalmoscope (Keelar, UK),

The BCVA was graded as mild visual impairment (20/30 to 20/60), moderate visual impairment (MVI) (<20/60 to 20/200), severe visual impairment (SVI) (<20/200 to 20/400), and blind (<20/400). [13] The impact of intervention was calculated by comparing BCVA 6 months after surgery and before surgery. If a child did not visit for 6 months follow-up in two unilateral and two bilateral cataract cases due to far distances, we considered 6 week as postoperative BCVA.

To assess quality of life of child due to visual impairment, we adopted the LV Prasad-Functional Vision Questionnaire (FVQ). [14] Our questionnaire was in local Marathi language and it had 19 questions to cover life-related tasks pertaining to near vision, distant vision, color vision, and field of vision [Figure 1]. The field staff asked the questions to each child and noted their responses. The difficulties experienced in the visual function related task were graded as 'no difficulty' and four grades of difficulties from 'little', 'moderate', 'great deal', and 'incapacitating'. If option on visual task was not applicable, it was also mentioned. For no difficulty '0' point was awarded. For different grades of severity of difficulties, 100, 75, 50, and 25 points were given. We summed score of each type of visual function (distant vision, near vision, field of vision, and color vision) for a child. The impact on the quality of vision was determined by subtracting the preintervention score from the score at 6 months after the intervention. For each child, the percentage of impact was calculated depending on denominator. Thus for a child who replied all questions, the denominator for distant and near vision functions was 600 and for the field of vision and color vision functions, the denominator was 500 and 200, respectively. If the question was not applicable for a child, the value of that question was deducted from the denominator value. The impact value was graded as 'excellent', 'good', 'poor', and 'very poor' if score was '>75%', '51-75%', '26-50%', and '<25%', respectively. {Figure 1}

The details of cataract surgery included type of surgery, with or without intraocular implant, intraoperative, and postoperative complications. This was to ensure that impact of intervention in two groups was having minimum influence of differential intervention.

The data on the impact on visual acuity for distance and visual functions for eyes with unilateral and bilateral cataract were compared. The information was computed using Microsoft Excel® . The data was analyzed with the help of Statistical Package for Social Studies (SPSS version 12) (IBM Boston). Univariate analysis was carried out using parametric method to calculate frequencies and percentage proportions. For quantitative variables, we calculated the mean and standard deviation. For statistical validation and comparison of results of group of children/eyes with unilateral and bilateral cataract, we used Open Epi (Rollin school of Pubic health. Emory University, Atlanta, USA) software. [12] For qualitative variables we estimated difference in percentage proportion and their 95% CI. For quantitative variables, we used difference of means and their 95% CI.

We conducted binominal regression analysis to predict factors affecting good visual outcomes of pediatric cataract surgery. Outcome variable was eyes with normal vision (20/20 to 20/60) and eyes without normal vision at 6 months after surgery. Age, sex, mode of recruitment, unilateral and bilateral involvement, the eye involved, preoperative blindness status, and interval between detection and surgery were the dependent variables.

Children that improved vision after surgery were given spectacles for distance and for near. The children suspected to have amblyopia were provided amblyopia therapy also. Those having residual vision were trained and given low vision devices free of cost. The outcomes of this study were shared with parents and colleagues in a state ophthalmology conference.

 Results



In our study, 24 children and their 48 eyes were in bilateral cataract group and 18 eyes of 18 children were in unilateral cataract group. Average time taken by child to complete the questionnaire was 15-20 minutes. The mean age of children with bilateral cataract and unilateral cataract was 8.8 years (± 2.6 years) and 10.2 years (± 2.9 years), respectively. The difference in age was not significant [difference of mean -1.7 years (-3.5 to +0.06), P = 0.06]. Further comparison of the participants of the two groups is shown in [Table 1]. Two-third of eyes with unilateral cataract was of traumatic etiology. The time interval between detection and surgery was less than 1 month in 4/5 of eyes with bilateral cataract, whereas 40% of eyes with unilateral cataract underwent surgery 1 year after detection. {Table 1}

The visual gain was calculated by comparing BCVA of eye at 6 months after cataract surgery to the preoperative BCVA [Figure 2]. The grades of visual acuity at 6 months and before surgery were compared for unilateral and bilateral group [Table 2]. No significant difference was noted in attaining 'normal vision' 6 months after cataract surgery among unilateral and bilateral cataract group. Seven of 14 (29.2%) eyes with vision <20/400 before surgery, had improved vision 6 months after surgery and could use residual vision with the help of low vision aids. Amblyopia and retinal changes associated with trauma or birth defects were main reasons for poor vision following cataract surgeries in most of the children with both unilateral and bilateral cataract.{Figure 2}{Table 2}

We carried out stratified analysis for visual gain among '5- to 10-' (n=27) and '11- to 15-'year-old children (n=15) to compare unilateral (n=18 eyes) and bilateral (n= 48 eyes) cataract groups. In the former age group, eight bilateral group and nine unilateral group had vision <6/60 6 months after surgery [RR = 0.47 (95% CI 0.28-0.78)]. In the latter age group, eight bilateral group and nine unilateral group had vision <6/60 [RR = 0.38 (95% CI 0.11- 1.19)]. Thus age was confounder in the association of poor vision and unilateral/bilateral cataract group.

The results of regression analysis are given in [Table 3]. Interval between the detection of cataract and surgical intervention was crucial as it influenced significantly in visual outcome of eye operated for pediatric cataract in our study. Those operated for cataract after more than 1 year of detection, had lesser chances of regaining normal vision. {Table 3}

We compared impact of cataract surgery on VQL among children with bilateral cataract and unilateral cataract. The number and percentage of grade of impact for distant vision, near vision, field of vision, and color vision-related function is given in [Table 4]. 'Excellent + good' grade of quality of life related to distant vision after surgery was significantly better in bilateral compared with unilateral group (P = 0.0006). There was no difference in near vision function (P = 0.05), field of vision (P = 0.33), and color vision (P = 0.33) related quality of life among children operated for unilateral and bilateral cataract. The children with unilateral cataract had significantly lesser impact of intervention than in children with bilateral cataract.{Table 4}

 Discussion



This is the first study in India to compare visual gain and impact on VQL following surgeries in children with unilateral and bilateral cataract. Although nearly 60% of children regained vision >20/60 6 months after cataract surgery with lens implantation, there was no significant difference in vision gain among children of unilateral and bilateral cataract groups. The improvement in VQL was significant in children operated for bilateral cataract compared those operated for unilateral cataract. This difference was marked in visual functions for distant vision. The interval between detection and surgery and traumatic etiology were confounders in association of visual gain at 6 months in children with unilateral/bilateral cataract. Our cohort was of children aged 5-15 years. Other researchers have reviewed visual gain and VQL also include children of less than 5 years of age. [15],[16] Therefore comparison of our study results with such studies should be done with a caution.

The distant vision improved at 6 months in 59% of eyes of children operated for cataract with lens implantation in our cohort. However, the proportion of eyes with '20/20 to 20/40' vision after surgery was not different in eyes with bilateral (58.3%) and unilateral cataract (61.1%). Cassidy et al. found that at least 1 year after surgery, the vision was 20/40 or better in 73.5% of eyes with bilateral cataract and in 45.5% of eyes with unilateral cataract in children of younger than 5 years of age. [15] Casaer et al. documented that 46.2% and 40% eyes had vision 20/40 or better in bilateral ad unilateral cataract in children (6 years and younger) at least 1 year after surgery. [16] Hussain et al. suggested that the mean visual acuity was 0.57 logMAR in eyes operated for bilateral cataract and 0.91 logMAR in eyes operated for unilateral cataract. [17] Agervi et al. studied 3- to 15-year-old children with cataract. They noted that 40% of children with bilateral cataract and 44% of children with unilateral cataract gained vision ≥ 0.5 6 months after surgery. [11] On studying visual outcome of children with cataract undergoing surgical rehabilitation, Haitt noted that 40% of eyes with unilateral cataract and 44% of eyes with bilateral cataract had vision ≥0.5. Less than half of 160 eyes with cataract were operated with lens implantation in this study. [18] While comparing these results, one should note that our cohort comprised of children aged 5-15 years while few other studies had younger children.

VQL improved markedly in children that were managed for bilateral cataract compared with the children with unilateral cataract. This is natural as before surgery the VQL in children with unilateral cataract was of high grade as they use the fellow eye with good vision for their daily activities. Birch et al. noted that children with bilateral cataract have significantly worse competence subscales than those with unilateral cataract. [10] Lopes et al. studied VQL in children with bilateral congenital cataract and they also noted low score on competence subscale. [19] Although Ye et al. had noted that visual acuity is the single most important parameter that influence vision-related quality of life, we had included subscales for distant, near, field, and color vision. [20] It was interesting to note that although impact of cataract surgery in children with cataract was positive for distant vision, near vision, and field of vision subgroups, there was minimum change in color vision function. This observation should be further confirmed through studies with larger sample and detailed color vision tests.

The time interval between the detection of cataract and cataract surgery was an important factor to predict visual gain following cataract surgery in our study. Bronsard et al. also noted that long delay is a major deterrent to improved visual outcome in pediatric cataract surgeries. [21]

Although all eyes with cataract did not regain vision ≥ 20/40 in our study, 30% of eyes with bilateral cataract and 22% of eyes with unilateral cataract improved their vision. Such children can be trained to use their residual vision with the help of low vision aids. [22] This will certainly improve their vision-related quality of life. Amblyopia could be one of the complications in unilateral cataract with long interval between detection and surgery in our study and that could be the reason for less vision and less impact on VQL.

There are a few limitations in our study. All cases of bilateral cataract were of congenital/developmental etiology, whereas two-third of unilateral cataracts were due to ocular trauma. Thus difference in outcomes of unilateral and bilateral cataract could also be due to variation in causes of cataract. Information on systemic diseases in children with cataract was missing. Presence of systemic co-morbidities, myopic shift, and postoperative complications have been documented to be responsible for differential visual gains and change in quality of life following unilateral and bilateral cataract surgeries in children. [9],[17],[23] Two children with bilateral cataract could not visit our institution at 6 months, hence, their vision at 6 weeks was taken as reference. If vision had altered between these two scheduled follow-up visits, our result could have been different.

 Conclusion



Vision and VQL of life improved in children with unilateral and bilateral cataract. However, it was better 6 months following surgery in children with bilateral cataract than in children with unilateral cataract. While noting such association, etiology of cataract and time of surgery should also be noted before judging the impact of intervention.

 Acknowledgments



The authors thank the Ethical and Research Committee of HV Desai eye hospital for their approval and support in this survey. Dr. Andurkar's encouragement and help in logistics was enormous. The authors are thankful to Dr. Parikshit Gogate, Dr. Sucheta Kulkarni, Dr. Sudhir Taras and the entire pediatric ophthalmology and community ophthalmology department.

References

1Taylor HR. Refractive errors - Magnitude of the Need. J Community Eye Health 2000;13:1-2.
2World Health Organization Preventing Blindness in children. A Report of WHO/IAPB scientific meeting, Hyderabad; WHO Publication number WHO/PBL/00.77,1.
3Wilson ME, Pandey SK, Thakur J. Paediatric cataract blindness in the developing world: Surgical techniques and intraocular lenses in the new millennium. Br J Ophthalmol 2003;87:14-9.
4Beller R, Hoyt CS, Marg E, Odom JV. Good visual function after neonatal surgery for congenital monocular cataracts. Am J Ophthalmol 1981;91:559-65.
5Tomkins O, Ben-Zion I, Moore DB, Helveston EE. Outcomes of pediatric cataract surgery at a tertiary care center in rural southern Ethiopia. Arch Ophthalmol 2011;129:1293-7.
6Ledoux DM, Trivedi RH, Wilson ME Jr, Payne JF. Pediatric cataract extraction with intraocular lens implantation: Visual acuity outcome when measured at age four years and older. J AAPOS 2007;11:218-24.
7Cheng KP, Hiles DA, Biglan AW, Pettapiece MC. Visual results after early surgical treatment of unilateral congenital cataract. Ophthalmology 1991;98:903-10.
8Brémond-Gignac D, Tixier J, Missotten T, Laroche L, Beresniak A. Evaluation of the quality of life in ophthalmology. Presse Med 2002;31:1607-12.
9Chak M, Rahi JS. British Congenital Cataract Interest Group. The health-related quality of life of children with congenital cataract: Findings of the British Congenital Cataract Study. Br J Ophthalmol 2007;91:922-6.
10Birch EE, Cheng CS, Felius J. Validity and reliability of the Children′s Visual Function Questionnaire (CVFQ). J AAPOS 2007;11:473-9.
11Agervi P, Kugelberg U, Kugelberg M, Zetterström C. Refractive and visual outcome of paediatric cataract surgery in the Ukraine. Acta Ophthalmol Scand 2006;84:674-8.
12Dean AG, Sullivan KM, Soe MM. OpenEpi: Open Source Epidemiologic Statistics for Public Health, Version 2.3.1. www.OpenEpi.com, [Last accessed on 2012 June 23].
13World Health Organization International Statistical Classification of Diseases and Related Health Problems 10th revision Current version for 2003 Chapter VII H54 Blindness and low vision. Available from: http://www.who.int/classifications/icd/en/. [Last accessed on 2011 June 02].
14Gothwal VK, Lovie-Kitchin JE, Nutheti R. The development of the LV Prasad-Functional Vision Questionnaire: A measure of functional vision performance of visually impaired children. Invest Ophthalmol Vis Sci 2003;44:4131-9.
15Cassidy L, Rahi J, Nischal K, Russell-Eggitt I, Taylor D. Outcome of lens aspiration and intraocular lens implantation in children aged 5 years and under. Br J Ophthalmol 2001;85:540-2.
16Casaer P, Casteels I, Foets B. Surgical treatment outcomes of congenital and juvenile cataracts. Bull Soc Belge Ophtalmol 2005;297:45-57.
17Hussin HM, Markham R. Long-term visual function outcomes of congenital cataract surgery with intraocular lens implantation in children under 5 years of age. Eur J Ophthalmol 2009;19:754-61.
18Hiatt RL. Rehabilitation of children with cataracts. Trans Am Ophthalmol Soc 1998;96:475-515.
19Lopes MC, Salomão SR, Berezovsky A, Tartarella MB. Assessing vision-related quality of life in children with bilateral congenital cataracts. Arq Bras Oftalmol 2009;72:467-80.
20Ye HH, Chen WR, Deng DM, Lin Z, Yang WH. Quality of life assessment in children with congenital bilateral cataract. Zhonghua Yan Ke Za Zhi 2007;43:996-9.
21Bronsard A, Geneau R, Shirima S, Courtright P, Mwende J. Why are children brought late for cataract surgery? Qualitative findings from Tanzania. Ophthalmic Epidemiol 2008;15:383-8.
22Gogate P, Khandekar R, Shrishrimal M, Dole K, Taras S, Kulkarni S, et al. Delayed presentation of cataracts in children: Are they worth operating upon? Ophthalmic Epidemiol 2010;17:25-33.
23Abadi RV, Forster JE, Lloyd IC. Ocular motor outcomes after bilateral and unilateral infantile cataracts. Vision Res 2006;46:940-52.