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Comparison of Contrast Sensitivity between Spherical and Aspheric Intraocular Lenses

Nida Amin, Aamir Ali Chaudhary, Fatima Iqbal, Komal Atta.

Purpose: To determine whether the implantation of aspheric intraocular lens (IOLs) provided better contrast sensitivity as compared to spherical intraocular lenses.

Methods: Analytical study (Cross Sectional Design) was conducted at Ophthalmology department of Madina Teaching Hospital, Faisalabad. 50 subjects aged between 50 to 80 years, male and female, implanted with spherical and aspheric intraocular lens were included in study. Contrast sensitivity was tested by Pelli-Robson chart at 1m. After 1-3 months of cataract surgery contrast sensitivity was assessed.

Results: There were 50 participants with Mean±SD age 60±3.2 including 18 females. Mean±SD contrast sensitivity was 0.7440±0.12610 in spherical group and 1.6680±0.11715 this in aspheric group. (p=0.01)

Conclusion: By this study, better-quality intraocular lens with good contrast sensitivity were ruled out. The use of aspheric intraocular lens provided better contrast sensitivity than spherical intraocular lens (IOLs).

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Blink Rate and Basal Tear Secretion Rate in Computer Users.
 Hina Nasir, Fatima Iqbal, Syeda Iqra.
Purpose: To determine blink rate and detect dry eye conditions among excessive computer users. Methodology: 52 subjects of either gender were included among which 32 were bankers and 20 were working in accounts and human resources department. Blink rates of the study participants were determined by asking the individuals to read a text as the way they used to read on computer screen at a distance of 50 cm and number of blinks per minute was counted. For basal tear secretion rate schirmer’s testII was performed. Convenient sampling technique was used and data was analyzed by SPSS (Statistical Package for Social Sciences) software version 20. Results: Parameters which effect both blink rate and basal tear secretion rate were age, gender, duration of computer use and eye gaze while reading. A correlation was established between blink rate and variables as mentioned using Pearson’s chi-square and Fisher’s Exact Test. There was a significant relationship between blink rate and age (p < 0.02, 0.03 respectively) while other variables had insignificant relationship (p>0.05). Conclusion: Increase in blink rate with increase in duration of computer use is a result of eyes’ defensive mechanism against atmosphere. However, blink rate decreases with age.
Comparison of Axial length calculations in supine and upright positions.
Hina Akhter, Rabia Murtaza, Momina Mushtaq, Hajra Sohail, Qamar Aslam.

Purpose: To compare axial length in emmetropes, myopes and hypermetropes in upright and supine position Methods: It was descriptive cross-sectional study, conducted at ophthalmology department of Madina Teaching Hospital Faisalabad from November 2017 till May 2018. Patients were selected through non-probability convenient sampling.180 eyes were included with equal division of emmetropes, myopes and hypermetropes with ages ranging between 20-50 years. Axial length was measured in both upright and supine positions by contact A-scan method. Results: In emmetropic eyes, mean AL in supine position was 23.22mm and 22.98 in upright position (P<.005). While mean AL in supine and upright position was 22.07 and 23.95mm (p=0.068) in myopic eyes and 22.50 and 22.43 mm (p=0.21) in hypermetropic eyes. On average, there was an underestimation of AL measurements in upright position by 0.24mm, 0.12mm and 0.07mm in emmetropic, myopic and hyperopic eyes respectively. Conclusion: Axial length values obtained in supine position were longer than obtained in upright position. In supine position there was less corneal compression and better target fixation compared to upright position. 
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Changes in Tear Film Stability After Recovery from Acute Conjunctivitis

Batool A, Kashif M, Kouser S, Haider N.

Abstract

Purpose: 

To evaluate changes in tear film after recovery from acute conjunctivitis and to compare it with normal healthy eyes.

Methods: 

This case- control study involved a total of 60 subjects’ eyes: 45 were those who had recovered from acute conjunctivitis and 15 were subjects of control group. Total duration of study was six months from March 2016 to august 2016 conducted in Madina Teaching Hospital Faisalabad with age range from 20 to 40 years. Tear break up time (TBUT) was measured on both recovered from disease, one month after recovery, and healthy eyes. Non- probability convenient sampling technique was used to determine the sample size. Statistical independent samples t- test was applied to analyze the data at a level of significance 5% by using SPSS version 20.

Results: 

Out of total 60 patients, 37 (61.67%) were males and 23 (38.33%) were females. Compared with healthy eyes mean[SD] tear film breakup time in cases were 11.46 [7.12] seconds and in controls

14.31 [6.69] seconds respectively. The mean [SD] tear film breakup of recovered eyes(n=45) were found to be 10.31 [6.78] in age 20 to 30 and 31 to 40 years 11.3[6.21] seconds. However, mean [SD] tear film break up time in healthy eyes (n=15) were 14.01[5.78] and 14.13[6.05] in age group 20-30 and 30 to 40 years respectively. The p- value was less than 0.0001 showing significant results.

Conclusions: 

There was a significant difference in the tear film stability in eyes one month after recovery from acute conjunctivitis as compared to normal healthy eyes. Tear break up time was significantly decreased in recovered (case group) as compare to control group (healthy eyes).


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Problems in Uptake of Low Vision Services in Pakistan.

Ilyas B, Saleem A, Mobeen R.

Abstract:

Purpose. 

The main purposes of this study were to determine the barriers in uptake of low vision services; identify improvement needed for low vision rehabilitation services; to aware the people about low vision rehabilitation services and to evaluate the availability of low vision services in Hospital.

Methods. 

It was a cross sectional study. Fifty low vision patients from both genders, ages ranging between 5 to 60 years, were selected through. A self-designed questionnaire was used to collect data. Mentally retarded, non-cooperative patients, patients of arthritis and poor motor control were excluded from the study. The study was conducted from March 2012 to December 2012. Statistical Package for Social Science (SPSS) version 20 (SPSS, Inc., IBM Corporation, Chicago, IL, USA) was used for statistical analysis.

Results. 48% patients were satisfied with the information provided by practitioner about low vision devices. 64% patients disagreed and 26% strongly disagreed with that low vision devices are affordable. 92% patients disagreed and 2% strongly disagreed with that low vision devices are accessible. 70% patients agreed that low vision devices lead to the improvement in daily activities. 40% agreed and 60% were uncertain about the satisfaction with the low vision rehabilitation services.

Conclusions. Low vision specialists recommend appropriate low vision devices and counsel patients on how better to deal with their reduced vision in general. The main barriers in the uptake of low vision services are non-affordability and problem in the access to devices.


Comparison of Contrast Sensitivity between Low and High Myopes.

Aslam S, Mobeen R.

Abstract:

Purpose. To compare the contrast sensitivity in low and high myopes.

Methods.  It was a descriptive cross sectional study conducted at College of Ophthalmology and Allied vision sciences. Subjects were selected through non-probability convenient sampling technique. A self-designed proforma was filled at time of examination. 106 patients with myopia, ages ranging between 15-30 years were included. Visual acuity was recorded. The type and degree of myopia was evaluated using both subjective and objective method. Fundus was also evaluated. Contrast sensitivity was measured by pelli robson contrast sensitivity chart.

Results. Of 106 subjects , 8.5% had visual acuities between 1.6-1.3  log MAR units, 44.3% had 1.00-0.80, 22.2% had 0.70-0.50, 24.5% had 0.4-0.2 and only 0.5% patients had 0.1-0.10 log units visual acuities. Percentage of myopic patients having -0.50 to -1.50DS, -1.75 to -2.75DS, -3 to -4DS, -4.25 to -5.25DS, -5.50 to -6.50DS, -6.75 to -7.75DS, -11.75 to -12.75DS, -13.00 to -14.00DS and -15.50 to -16.50DS were  21.7%, 21.7%, 4.7%, 1.9%, 38.7%, 6.6%, 0.9%,2.8% and 0.9% respectively. Half of the subjects had low myopia while remaining had high myopia. Patients with low myopia had a better contrast sensitivity compared to high myopia. (P=0.00) Those with high myopia demonstrated better contrast sensitivity while wearing there correction. (P=0.00)

Conclusion. Low myopes had good contrast with and without spectacles. Without optical correction, high myopes had poor contrast sensitivity which was improved by using their optical correction. However, low myopes had better contrast as compared to high myopes both with and without correction.