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DRY EYE DX AND TX

LOOK BEYOND THE EYES FOR CONTRIBUTORS TO DRY EYE

In a recent Contact Lenses Today column, we explored the impact of improper head posture (forward head posture) at the work desk and how this contributes to headaches and visual discomfort (Mostoff and Mastrota, 2019). We continue that discussion here.

Occipital neuralgia (ON; pain in one or more nerves caused by compression and/or irritation of peripheral nerve structures) is a headache syndrome that can be either primary or secondary. It involves the occipital nerves: two pairs of nerves that originate near the second and third vertebrae of the neck. The pain typically starts at the base of the skull by the nape of the neck and may spread to the area behind the eyes and to the back, front, and side of the head. Cervicogenic headache (CEH) is a secondary unilateral headache with symptoms and signs of neck involvement; it is often worsened by neck movement, sustained awkward head position, or external pressure over the upper cervical or occipital region on the symptomatic side (International Headache Society, 1988). The critical differential point is that ON is neuralgia from the occipital nerve, whereas CEH is nociceptive referred pain from cervical structures.

Physical therapies (Racicki et al, 2013), including engaging McKenzie-based exercises (Al-khamis, 2014), can improve forward head posture and associated digital-use-driven muscular discomfort and headaches. Chin tuck exercises are an effective and accessible antidote to help reverse some of the effects of forward head posture precipitated by prolonged desk/computer work. Proactive modification of the work environment to minimize exposure to harmful postures is key.

An Ergonomic Review

Monitor, keyboard, mouse, and other device orientation and placement will influence neck and shoulder posture. For example, if the keyboard is more than a foot in front of the body, the natural compensation is to reach forward, rounding the shoulders and moving the chin forward. Simply bringing the keyboard closer to body, so that the elbows are at a 90º angle, will preclude detrimental compensatory body posture (www.osha.gov/SLTC/etools/computerworkstations/positions.html ).

In addition to keeping the keyboard close to the body, it should be at an ideal height (at about the height of the elbows). When having to reach up to access the keyboard, the upper trapezius muscles will react with a heightened state of tonic contraction, which could result in “knots” in the upper shoulder muscles. Arm rests can also reduce stress on the neck and upper back.

Appropriate eyewear is instrumental in preventing forward head posture. Difficulty with reading generally induces squinting and leaning forward, precipitating neck and eye strain.

Computer monitors should be positioned about an arms’ length away. Monitor height is critical to proper workstation ergonomics. A monitor that is too high causes upward head tilt, creating a “kink” or local fault/stress in the neck.

Furthermore, improper viewing angle contributes to computer vision syndrome (CVS) (Loh and Redd, 2008). The screen should be placed 10º to 20° below the eye level (Anshel, 2005). Higher viewing angles expose a greater area of conjunctiva and cornea to the air and increase the chances of irritant-like symptoms (Cole, 2003). Depending on what eyewear patients wear, the monitor position may need to be adjusted even lower. Other CVS considerations include blink rate changes, accommodation or binocular vision challenges, and ambient and screen illumination.

Make It Personal

A collaborative effort between physical therapists and eyecare providers can be helpful in devising personalized recommendations on the appropriate eyewear and workplace ergonomics for each patient’s body type, posture, and visual acuity. CLS

For references, please visit www.clspectrum.com/references and click on document #286.