Prevalence Refractive Errors among Medical Students of Qassim University, Saudi Arabia: Cross-Sectional Descriptive Study.

OBJECTIVE: To study the prevalence of various errors of refraction among the medical students studying at the college of medicine, Qassim University, Saudi Arabia.
METHODS: This is a cross-sectional descriptive study conducted at Qassim University clinics over a period of two months. The study population comprised 162 male and female students from different academic years. The students were selected randomly so that around 35-40 students were taken from each academic class. The selected study population was explained the objectives of the study and a written consent form that stated the purpose, methods, risks, benefits, and the assurance of the confidentiality of the data was obtained from each student. After giving the consent, each subject was examined by auto refractometer. The examination was carried out by an optometrist without using cycloplegia. Both right and left eyes were thoroughly examined by auto refractometer and on the average three readings of the refraction measurements were taken. The readings were recorded on a data sheet of every individual, and the Statistical analysis was performed using Statistical Package for Social Sciences (SPSS).
RESULTS: One hundred and sixty-two (162) students with a mean age of 22.44 years, Std 1.661 and a range of 8 (19-27) were included in the study. Of the total number, 111 (68.51%) were males and remaining 51 (31.48%) were females. Of the total sample, only 1 (0.617%) student had diabetes mellitus, and 6 (3.70%) students gave a history of previous ocular surgery. Myopia was found to be the commonest error of refraction 53.7% with hyperopia next to it.
CONCLUSION: Myopia is found to be a common error of refraction in young adults. A regular checkup is essential to timely correct the error and to prevent deterioration of the vision.

Introduction

Eyes have been defined as the ‘windows of the soul’. The International Agency for the Prevention of Blindness and World Health Organization have been declared this by starting the global initiative known as ‘VISION 2020’ for reducing of preventable blindness [1] [2]. Errors of refraction particularly myopia, have now become common and are continuously on rising globally [2]. Poor vision is a major limitation for a sound and enlighteningly supporting school/college condition for understudies in various areas of the world. Visual impedance because of uncorrected refractive errors is exceptionally common among youthful grown-ups and is the second most common reason behind treatable visual hindrance [4]. The world’s driving and most easily cured solution for poor vision among youthful grown-ups are refractive errors [5]. Pascolini D, [6] mentioned that visual weakness is a noteworthy medical issue and 80% of the reasons for this infirmity are viably preventable. Refractive errors now are turning into a huge issue in numerous countries globally. The incidence rate of myopia is beginning to increment particularly in Asian nations achieving pestilence levels [7]. Bourne RR et al., [8] claim uncorrected errors of refraction to be among the most common causes of visual disability all over the world. Refractive errors can be a weight on nations’ economy particularly the developing ones. In any case, it can be remedied by utilising a contact lens or power glasses. Many investigations have demonstrated a solid connection between the level of intelligence with years of school participation and the seriousness of myopia [9] [10] [11] [12]. A larger population is seemingly unaware of the problem, and this leads to a progressive visual inadequacy which seriously affects their potential. This applies very clearly to the young adults who are studying in their schools, colleges, and universities and suffer because of poor vision due to common errors of refraction [4] [5] [6] [7] [8] [9] [10] [11] [12].

Therefore, the present study was designed to study the prevalence of various errors of refraction among the medical students studying at the college of medicine, Qassim University, Saudi Arabia. The data collected from this study help to increase the awareness of refractive errors and to enhance vision associated promotions to reduce the refractive errors not only among medical students but also students from other colleges.

Methods

It’s a cross-sectional study conducted over two months in a sample of 162 students from the college of medicine, Qassim University, KSA. The induction of the study population was by random selection from different academic years. The selected study population was explained the objectives of the study and a written consent form that stated the purpose, methods, risks, benefits, and the assurance of the confidentiality of the data was obtained from each student. After obtaining consent from the participants, each participant was examined by an auto refractometer (Auto Refractometer ARK-510A, NIDEK, Aichi, Japan) as described previously [13] [14]. Briefly, three measurements were taken of each participant’s refractive status for their both eye with an auto refractometer. Refractive error measurements were recorded in sphere, negative cylinder, and cylinder axis format.

The readings were recorded on a data sheet of every individual, and the Statistical analysis was performed using Statistical Package for Social Sciences (SPSS). Also, a detailed history was taken about co-morbidities and history of previous surgery for the correction of the errors if any. All calculations of refractive error status were based on the non- cycloplegic auto refractometer readings. Spherical equivalent (SE) was calculated as sphere plus half cylinder. Myopia was defined as SE of at least -0.75 diopters (D) in either eye. Myopes were divided into three refractive error sub-groups based on their refractions (SE): low myopia (SE between -0.75 and -2.99 D), moderate myopia (SE between -3.00 and -5.99 D), and high myopia (SE equal to or more myopia than -6.00 D). Hyperopia was defined as SE+1.00 D or positive and emmetropia as a spherical equivalent value between SE -0.75 D and SE+1.00 D in either eye. Astigmatism was defined as -1 Cylinder or more.

Results

This study comprises exclusively 162 students from different academic years of college of medicine, Qassim University. Among them, 111 (68.5%) were males, and the rest 51 (31.5%) were females. Only 2.65% students had diabetes mellitus, and 3.7% were reported to have previous ocular surgery. The demographic details of all studied subjects are given in Table 1.

Table 1

Demographics details of studied subjects

Subjects	Data
Age, years	22.4 ± 1.661
Mean ± SD; (range)	(19–27)
Gender:
Males	111 (68.5%)
Females	51 (31.5 %)
Co-Morbidities: Diabetes Mellitus
Diabetes Mellitus	01 (2.65%)
Previous ocular surgery	06(3.70%)

In this study, we have taken all five academic year medical students and the breakups of students selected from each academic year are summarised in Table 2.

Table 2

Academic year of MBBS students

Academic Year	Number	Percentage(%)
First year	31	19.35
Second year	40	24.69
Third year	36	22.22
Fourth year	25	15.43
Fifth year	30	18.51
Total	162

Various errors of refractions detected in the study population regarding their frequency are shown in Table 3.

Table 3

Frequency of errors of refraction

Error	Frequency	Percentage (%)
Myopia	87	53.7
Hyperopia Astigmatism	06 02	3.7 1.2
Emmetropia	67	41.3
Total	162

The most successive error of refraction was observed to be nearsightedness which was found in 87 (53.7%) examine subjects in our sample followed by Hypermetropia in 6 (3.7%) and Astigmatism in residual 2 (1.2%) subjects. The remaining 67 (41.3%) study subjects were emmetropes. We further characterised myopic participants into three different categories based upon the severity of myopia. Our results show that mild myopic condition was the highest among all the myopic participants with the frequency of 58 (66.7%), followed by the moderate myopic conditions, which was found with the frequency of 22 (25.3%). However, the severe myopic condition was found in only in 7 myopic participants with the percentage of 8.0%. The results of all studied 87 myopic patients are summarised in Table 4.

Table 4

Degree of the myopic condition in among the medical students

Degree of myopia	Frequency	Percentage (%)
Mild Myopia (SE between -0.75 and -2.99D)	58	66.66
Moderate Myopia (SE between -3.00 and -5.99D)	22	25.28
Severe Myopia (SE equal or more than -6.00D)	07	8.04
Total	87

Discussion

Refractive errors can be perceived through normal examination of patients who present to ophthalmologic centres, or through vision screening of the majority allowed to move around voluntarily. The previous approach may work exquisitely in developed nations with wellbeing cognizant individuals. Vision screening programs are a vital necessity in underprivileged communities all around the world. Vision screening is generally normally done on schoolchildren, which is a valuable methodology for perceiving potentially treatable visual assortments from the standard, incorporating visual need in light of refractive goof and related amblyopia.

Ghaderi et al., [9]. Also mention in their study about rising incidence of errors of refraction in younger age children. It is now well reported that myopia is the most common error of refraction worldwide and it continues on the rise, and now it becomes a major social and economic burden of the affected individuals globally [15].

The prevalence of myopia in the United States appears to be significantly increased in 1999-2004 as compared with 30 years before, whereas Indian population was reported to have myopic condition approximately 20% [16] [17]. As far as the incidences of myopia in the specific cities are a concern, the reports from the cities like Singapore, Hong Kong Taiwan, etc. showed myopia is more common and on the rise [18]. Recently, Pan et al., [19] performed a meta-analysis on age-specific prevalence of myopia among Asian population and was found to be increasing with age [19].

This study was conducted on 162 medical students from all five academic years of Qassim University, Saudi Arabia and the data showed an increased incidence of errors of refraction among them. The majority of them were affected by myopia followed by hyperopia, astigmatism and emmetropia. Our results are fully supported by the previous study conducted in Singapore medical students, which showed the occurrence rate of the myopic condition more than 82% as compared to the frequency of other errors of refraction [20]. Not only have these, but our study is also supported by another study conducted on medical students of Malaysia, where myopia was also found to be higher as compared with other errors of refraction [7].

Furthermore, our findings in medical students are also supported by another study performed among medical students of Norway, where myopia was again reported to be higher [21]. Interestingly, it is also important to the point that not only medical students are affected by myopia, but the reports showed that students at school levels were also affected by myopia [10] [11] [12], these findings further strengthen our results. An investigation of Sydney schoolchildren indicated ethnic contrasts in myopia prevalence; kids of East Asian ethnicity had a higher rate of myopia than European Caucasian kids [22].

Increasing levels of myopia increment the danger of vision hindrance and specifically, high nearsightedness is related to the danger of genuine and perpetual visual inability due to related sight-undermining problems. This study highlights the various degrees of myopia with high myopia being the most dangerous for vision as progression can have deleterious effects on visual acuity. Erdinest et al., [23] have recently proposed various treatment options for controlling the progression of myopia in the young population. Many other similar studies have postulated dangers of progressive myopia to cause various vision-threatening complications like retinal detachment, choroid atrophy, glaucoma etc. [24] [25] [26] [27] [28].

Another cross-sectional survey conducted in KSA included 21 primary schools with of 5176 children (mean age 9.5 ± 1.8 years) [29]. A study involved 504 medical students selected from hail university Saudi Arabia also show results in line with our study [30].

All these related studies have screened for myopia among younger children who may reduce the attribute ability of myopia occurrence. The various errors are correctable visual disorders that can cause blindness and there is a deep concern about the rising incidence of these problems all over the world.

In conclusion, the errors of refraction are the most common correctable causes of blindness all over the world. An action towards screening programs is suggested to pick the population affected to take timely measures to correct the error before it can lead to vision-threatening complications.