Original Articles
 

By Mr. Shrikant D Pawar , Dr. Tejas Gosavi , Dr. Manohar Dole , Dr. Sanjeev Dole
Corresponding Author Mr. Shrikant D Pawar
The University of Iowa, 143 Biology Building - United States of America 52242-1324
Submitting Author Mr. Shrikant D Pawar
Other Authors Dr. Tejas Gosavi
Pune University, - India

Dr. Manohar Dole
Pune University, - India

Dr. Sanjeev Dole
Pune University, - India

OPHTHALMOLOGY

Intra Ocular Len's, Cataract, and Parametric T-Test.

Pawar SD, Gosavi T, Dole M, Dole S. Investigating Emerging Trends of Intraocular Lens (IOL's) Implantation in Rural India for Cataract. WebmedCentral OPHTHALMOLOGY 2013;4(4):WMC004197
doi: 10.9754/journal.wmc.2013.004197

This is an open-access article distributed under the terms of the Creative Commons Attribution License(CC-BY), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
No
Submitted on: 13 Apr 2013 05:05:57 PM GMT
Published on: 15 Apr 2013 05:49:25 AM GMT

Abstract


Purpose: Investigating emerging trends of intraocular lens (IOL's) implantation in Dr. Manohar Dole Medical Foundation, Narayangaon, India, for Cataract from April 2003 till March 2011.

Materials and Methods: Survey was conducted at Dr. Manohar Dole Medical Foundation, Narayangaon, India, where patients were categorized by Intraocular lens (IOL's) implantations and conservative methods of treatment. The Parametric T test was calculated between number of patients operated for cataract with IOL and the conservative method of treatment to find if there is any significant difference between these two groups.

Result: The significant Parametric P value of 3.60833076940971E-36 was obtained stating that the occurrence of observed difference just by chance is very much unlikely.

Conclusion: We found a significant increase in IOL implantation compared to conservative treatment in the patients at Dr. Manohar Dole Medical Foundation, Narayangaon, India, for 9 subsequent years stating an emerging trend of operative procedures in rural parts of India.

Introduction


According to World Health Organization (WHO), causes of visual impairment in 2002 were glaucoma, age-related macular degeneration, corneal opacities, diabetic retinopathy, childhood blindness, trachoma, and onchocerciasis. The cataract being leading cause of visual impairment in all areas of the world during the last ten years [9]. Cataract is the largest single cause of blindness in the world [1, 2]. In India approximately 9 million people are blind from cataract every year [1, 3]. The surgery for the cataract has been increased in past few years growing from 1.2 million surgeries in year 1992 to 4.8 million surgeries in year 2006 with use of intraocular lens implantations of 90 % of patients [4]. The survey done by the Indian Council of Medical Research (ICMR) in the year 1974 indicated a prevalence rate of 1.38 % in the general population (visual acuity <6/60 in the better eye). A survey (year’s 1999–2001) in 15 districts of the country indicated that 8.5% of the population aged 50 years or more is blind [5]. The proportion of cataract surgeries with IOL implantation was increased from less than 5% in year 1994 to 90% in year’s 2005–2006 [6]. This article highlights the emerging trends of intraocular surgeries in rural parts of India from year 2003 till present date.

Methods


Survey was conducted at Dr. Manohar Dole Medical Foundation, Narayangaon, India, where patients were categorized by Intraocular lens (IOL's) implantations and conservative methods of treatment. The IOL's patients were selected from cataract patients who were further selected from total examined patients. The numbers for the patients were collected from April 2003 till March 2011. Table 1 shows the number of patients observed during this survey.

Results


A comparison of number of patients with Intraocular Lens Implantation with the conservative treatment was plotted in R environment [8] shown in Figure no 1. As observed there was a steady rise of patients with IOL from April through June for year’s 2003 till 2011, followed by a drop through September and a sharp increase from October through December. The IOL's were done free of charge for maximum number of patients with a small number of patients being charged for complicated surgeries requiring visiting surgeons.

Having observed this difference in number of patients for 9 years between different treatment groups shown in Table no 3, we were interested to see whether this difference is statistically significant. We found a Gaussian distribution for values and since we analyzed two independent groups with different sample size, a parametric unpaired T-test was used for seeing the significant difference [7]. The P value was calculated between number of patients operated for cataract with IOL and the conservative method of treatment through year’s 2003 to 2011 for 12 months. The significant P value of 3.60833076940971E-36 was obtained stating that the occurrence of observed difference just by chance would be unlikely and so we rejected the null hypothesis which assumed that the observed difference simply occurred by chance.

We followed the details of paid patients for IOL from the year’s 2002 to 2005 which can be found in Table no 2. The IOL patients were also compared with the Phaco emulsification and foldable Phaco emulsification operated patients for cataract. As seen in Table and Figure no 2, the number of paid IOL operated patients were greater than Phaco but less than paid foldable Phaco emulsification operated patients stating an average increase and subsequent decrease in number of patients through year’s 2002 to 2005.

Conclusions


We found a significant increase in IOL's implantation compared to conservative treatment in the patients at Dr. Manohar Dole Medical Foundation, Narayangaon, India, for 9 subsequent years. The possible causes for such rise could be due to the increased production of IOL’s, sophisticated equipment’s for cataract surgery, infrastructure development and efforts by Government of India and the international non-governmental organizations (NGOs) for spreading awareness and treatment facilities for cataract patients.

Acknowledgements


We are thankful to physicians, visiting surgeons, nurses and administrative staff of Dr. Manohar Dole Medical Foundation, Narayangaon, India, for their kind support in conducting this survey.

References


1. World Health Organization, International Agency for the Prevention of Blindness. Report on the World Vision 2002: Seeing is Believing, Vision 2020. Uxbridge: The Right to Sight; 2002.
2. Resnikoff  S, Pascolini D, Etya’ale D. Global data on visual impairment in the year 2002. Bull World Health Organ 2004; 82:844–851.
3. Venkatesh R, Muralikrihnan R, Civerchia Balent L. Outcomes of high volume cataract surgeries in a developing country. Br J Ophthalmol 2005; 89:1079–1083.
4. Government of India. Vision 2020. www.vision2020india.org. New Delhi: Government of India.
5. Tewari HK, Jose R, Bachani D. Vision 2020 - The Right to Sight, CME series no. 9. New Delhi: All India Opthalmological Society, Syntho Pharmaceuticals Pvt. pp. 8–9.
6. Anon. Performance at a glance 2002–2003. Quarterly Newsletter of National Program of Control of Blindness and Vision 2020: The Right to Sight Initiative 2003; 2:3.
7. Morten W Fagerland. T-tests, non-parametric tests, and large studies--a paradox of statistical practice?. BMC Medical Research Methodology 2012; 12(78); doi: 10.1186/1471-2288-12-78.
8. R Development Core Team (2008). R: A language and environment for statistical computing. R Foundation for Statistical Computing, Vienna, Austria. ISBN 3-900051-07-0, URL http://www.R-project.org.
9. World Health Organization Prevention of Blindness and Deafness. (2012). Causes of blindness and visual impairment. Retrieved from http://www.who.int/blindness/causes/en/.

Source(s) of Funding


None

Competing Interests


None

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Operations became more available ? Posted by Prof. Sergey A Shukolyukov on 15 Apr 2013 08:30:08 AM GMT

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