Valium is commonly used in Nigeria and a research has been conducted to determine the effect of the drug on healthy Nigerians.
Choosing subjects for the research
For this research, the testing center has decided to choose 20 healthy volunteers (10 from each sex). These volunteers had to be between 35 to 40 years. Their weight should be between 60-68 kg. Also, they should have participated in the optometry outreach that the School of Optometry had organized.
Individual interviews have been conducted with the volunteers and data related to socio-demographic and medical history have been collected. During the interview, the researchers have managed to get a verbal consent from the volunteers. Furthermore they were also screened and tested by optometrist. This was done to ensure that neither refractive errors nor ocular pathologies were present that would corrupt the research.
It has been noticed before the research that all volunteers near point of convergence (NPC) was 8-10 cm. The volunteers’ pupil size were measured. Also their near point of convergence along with their amplitude of accommodation (AA) and Visual acuity (VA) (both near and far) were measured. This was done to initial values before following protocols were started.
The university’s Health Research Ethical Committee has approved of the research. Visual parameters were checked both before and after the drug was administered. According to the Preliminary studies it took a maximum time of 30 minutes for the drugs to take effect. The effect of the drugs lasted over 60 minutes. To measure the diameter of the pupil a pupilometer was used. To measure NPC the meter rule was followed. To measure VA and phoria both Snellen distance and reduced Snellen chart were used respectively. AA assessment was done using a phoropter and its accessories.
The valium used for this research was “Roche 10TM”. This is a light blue scored tablet.
Before the research was started, the researchers made sure that the volunteers understood the instructions properly.
A pupilometer was used measure the pupillary diameter of each of the volunteers. This was done three times and the average of these measurements was determined and expressed in mm. Standard illuminated Snellen optotypes were used to measure Visual acuity. The distance for both near and far where 0.4 m and 6 m respectively.
To measure Near point of convergence, the volunteers were told to focus their eyes on the tip of a pencil. This pencil was placed 40 cm away from the subject. It was slowly moved towards the volunteer till he/she complained about diplopia. Position where the image doubled was also determined.
Amplitude of accommodation was used determined with the help of phoropter.
Phoria was determined by placing vertical letter 0.4 m apart for near and for far Snellen optotype was placed at 6m.
Once these where determined each of the volunteer was given a valium tablet marked Roche 10 TM. To help the volunteers dissolve the tablets each volunteer was given 50ml of water. The measurements were taken first after 20 minutes and 30 minutes respectively.
Analyzing the data
GraphPad Prism version 4.0 was used to analyze the data and show it tabular form.
Findings of the research
One complaint that was received is that volunteers faced drowsiness. However, once ambulatory activity was introduced this problem was solved.
Pupil diameter along with the visual acuity did not change throughout the experiment. Near point of convergence and Amplitude of accommodation changed. Near point of convergence had increased by 51% after the administrating valium while Amplitude of accommodation had increased by 13.4 %.
Before the research the distribution between orthophoric, exophoric, and esophoric were 30%, 30% and 40% respectively. After administrating valium, the exophoric were converted into orthophoric. That means the percentage of orthophoric doubled. Esophoric were not converted and in fact became mor esophoric.
Researchers concluded that since the dosage was low, the Valium did not reach the eyes that is why the diameter was unaffected. VA was not affected as the lack blood flow to the lens prevented Valium from reaching them. Even though AA changed, it can be due to many reasons like the subject’s ocular health. They concluded that long term use must be closely monitored so that the long term effects of the drug on their vision can be prevented.