If patients notice a decrease in night vision or have frequent headaches, increased eye fatigue, blurred/distorted vision, the diagnosis could be astigmatism.
When diagnosed with astigmatism, patients will occasionally think they have an eye disease, which we reassure them is not the case. Then we explain that it is a very common eye condition, and it means the surface of the cornea is nonspherical, or not completely round. We often communicate it to our patient as: “Your eye is shaped like a football, not a soccer ball.”
Affected by astigmatism
It is important our patients understand how their vision is affected by astigmatism. When a patient has astigmatism, his vision may seem blurred, and objects may seem somewhat misshapen or distorted. It is not uncommon for a patient with an astigmatism to notice frequent headaches, and a usual complaint is night vision seems more compromised than during the day.
We make it clear to patients diagnosed with myopia or hyperopia it is not unusual to have accompanying astigmatism. Continuing the explanation, it is important to help patients understand that astigmatism does not make contact lens wear impossible. The amount of astigmatism will help the eyecare professional identify the most appropriate contact lenses for comfort and visual acuity.
Toric contact lenses
Soft toric contact lenses are manufactured with the same material as spherical contact lenses and are available in daily, weekly, biweekly, and monthly disposable options. Though not used as frequently, soft toric contact lenses that are replaced annually are also available. There are many soft toric contact lens choices for the astigmatic patient; several are available in custom designs, enabling us to encourage a patient with a more complex refractive need to wear contact lenses.
Another option to fit astigmatic patients is a gas permeable (GP) or rigid contact lens, which is beyond the scope of this article.
The all-important first question our patient almost always asks is, “What is the additional cost of toric contact lenses?”
When we speak to our patients about cost, it is important they realize the value of the contact lenses we recommend. The significance of the detailed fitting, the multiple fitting steps needed to ensure the most comfortable fit, and physical difference of the toric contact lenses to provide the most optimum vision will help the patient understand the fitting fees and the additional expense of toric contact lenses.
Patients must understand that a more complex fitting procedure will often accompany toric contact lenses. This includes a longer trial time because numerous parameters must be considered and the possibility of using several trial contact lenses. Any additional charges will be reflected upon the complexity of the initial contact lens fit. The contact lens design and material may also be reflected in the expense.
However, contact lens manufacturers have increased design parameters and reproduction stability in new lens designs, which greatly reduces the amount of chair time needed to achieve a successful toric lens fit.
For our patients to further understand the complexity of the toric contact lenses, it often helps to explain how the toric contact lens differs from the spherical contact lens. The explanation goes like this: Toric contact lenses have two powers, a correction for distance or near, and a cylinder. The cylinder represents the power that corrects the astigmatism, and the axis of the cylinder location.
Remember that complications with toric contact lenses are very similar to those with spherical lenses.
One complication is contact lens intolerance from a patient wearing her contact lenses too long, meaning wearing them longer than the recommended wearing time by the contact lens manufacturer, or sleeping in contact lenses that have not been approved for extended wear. Overwearing contact lenses may cause cornea epithelial microdefects that may develop into serious eye infections.
New contact lens wearers do not plan to create bad habits; it becomes our obligation to advise our patients of possible repercussions. We educate our patients of the importance of compliance with precise instructions, complete with a full explanation of possible consequences (if directions are not followed), to eliminate the chance of unnecessary complications.
Occasionally contact lens solutions are not compatible with our patients’ corneas or our recommended contact lenses; perhaps the current solution is not sufficient for contact lens sterilization. This may lead to blurred vision combined with some discomfort.
We educate our patients on maintaining the care, including the solutions that are compatible with their new contact lenses. We also make ourselves available should patients need to alert us for any questions or obstacles.
A complication that has a notably different outcome and very common among all contact lens wearers is dry eye. It is sometimes caused by simply not blinking as frequently as necessary to maintain the eyes natural moisture. When a toric contact lens patient does not blink enough, this lack of blinking hinders the contact lens’ ability to maintain the axis of the contact lens and creates spectacle blur.