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Ergonomics for the Retinal Physician

Protect your musculoskeletal health with these tips for daily practice.

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The practice of retina is inherently physically demanding. In the clinic, repetitive work at the slit lamp or with the indirect can generate muscle tension through the back, neck, and shoulders. In the operating room, great strain can be placed on the body as well. To ergonomic experts, these “non-neutral” positions that are repeatedly utilized can give rise to the development of musculoskeletal disorders (MSD). Musculoskeletal disorders are soft-tissue injuries resulting from long-term, repeated wear and tear on the body in the form of repetitive motion, force, vibration, and awkward positions. Muscles, tendons, ligaments, nerves, and joints all have the potential to be affected as small traumas accumulate over time.

Although MSD are common occupational injuries across many professions, there has been increased awareness about musculoskeletal disorders in health professions and how to optimize the ergonomics of daily practice. There are numerous publications evaluating ergonomics and MSDs in the dental and laparoscopic surgery fields, and now the field of ophthalmology is starting to address the inherent risk associated with how ophthalmologists practice. A survey published in the American Journal of Ophthalmology in 2005 reported that 30% to 40% of the survey’s respondents had experienced symptoms of MSD (mainly cervical spine and low back problems as well as carpal tunnel syndrome) within the preceding 30 days.1 These findings have been substantiated by additional reports of high rates of MSD symptoms among ophthalmologists.2-5 The ramifications of MSDs can be significant. Beyond physical pain, MSDs can have a financial impact due to temporary or permanent disability, productivity loss, or early retirement. In response to these studies, the American Academy of Ophthalmology commissioned a task force to identify the ergonomic factors that can be modified in everyday practice to reduce the risk of MSD and to educate members about safe practices from a musculoskeletal standpoint.

There are many aspects of both clinic and surgical practice that may predispose ophthalmologists in general and retina specialists in particular to the development of MSD. The National Institute of Occupational Safety and Health have identified categories that influence the development of musculoskeletal disorders.6 Although not all work-related causes of MSD can be modified, understanding the role of ergonomics is important for the practicing ophthalmologist. There are 4 activity-related factors encountered by a retina specialist on a daily basis that can increase the risk of MSDs:

  1. Awkward postures: Flexion/extension of the wrist, back, or neck or positioning of the elbows away from the body.
  2. Environmental factors: Vibration, cold, and emotional stress, some of which a retina surgeon might encounter.
  3. High forces: Tight pincer grip of biomicroscopic lens, cutter, or forceps can place high force in the carpal tunnel.
  4. Repetitive motions.

The musculoskeletal impact of these factors is most likely to be felt by physicians with a high case load. A survey of 697 ophthalmologists in the northeast United States found that age or duration of practice were not risk factors for reporting MSD symptoms. However, seeing more than 100 patients per week, performing ≥4 surgeries and/or ≥6 laser surgeries per week were associated with increased risk of neck, upper extremity, or lower back pain.1 In addition, female ophthalmologists are at greater risk for developing MSDs than male ophthalmologists, in part due to a shorter stature, making it more likely female ophthalmologists will adopt awkward positions when treating patients.

Once a physician is aware of the ergonomic influences that can precipitate MSD, small adjustments can be made in daily practice to help reduce the risk of developing musculoskeletal injuries. These ergonomic interventions do not necessitate a significant investment in physician time. A time-motion study of dentists found that proper patient positioning requires approximately 5 seconds.7 Taking the time to practice good technique can help protect productivity in the long run. Below are some tips for making ergonomic adjustments to daily practice.

EXAM ROOM LAYOUT

As electronic medical records are becoming standard, physicians should pay attention to how computer screens are oriented in relation to the patient chair. Setting up the room to reduce the awkward neck postures, torqueing the back, and sharp edges of desks can reduce the risk of musculoskeletal symptoms. Having as much adjustability in the room is helpful.

The chair should be at a height that allows both feet to be flat on the floor with the knees at 90 to 110 degrees. The keyboard tray should be slightly below elbow height, and the physician’s arms should be on either side. The monitor should be positioned so that the top is at eye level (Figure 1). Physicians should ensure they are sitting on the stool or chair completely in order to reduce stress on the hips and provide lumbar support.

Figure 1. Image A depicts neck twisting, a keyboard that is too high, a seat that is too high for the knees, and undue pressure on the hips and lower back. Image B depicts slouching, a keyboard that is too high, a console that is too low for legs to fit under, and undue pressure on the hips and lower back. Image C depicts a seat that is too high to reach the keyboard tray, no back support, a keyboard that is too high, and undue pressure on the hips and lower back.
REPRINTED WITH PERMISSION FROM THE AMERICAN ACADEMY OF OPHTHALMOLOGY.

SLIT LAMP EXAM

Positioning of the physician and patient is essential to minimize back, hip, and neck strain. To minimize stress on the lumbar spine and hips, the physician’s feet should be positioned flat on the floor with the back against the backrest of the chair (Figure 2). Raise the patient’s examination chair so as to allow the wheels of the doctor’s chair to slide under the foot rest of the patient’s chair; this will help reduce the degree of forward flexion at the hips required by the physician during the slit-lamp exam. Keeping the neck in a neutral position also is critical; adjusting the oculars such that they are slightly below the neutral position of the physician can aid with this. A soft elbow rest can reduce strain on the shoulder and elbow. It is also important to be mindful of the wrist position, as the wrist should be kept in a neutral position without extension or flexion. The physician should always move the exam chair to realign when examining the second eye and not torque the back to examine the left eye after the right eye is completed (Figure 3). Another piece of advice is to grip the condensing lens with the least amount of pressure necessary. Because retinal physicians primarily concentrate on looking through the lens, they can easily forget about the pressure being exerted on the perimeter of the lens.

Figure 2. The casters on a chair contacting the footrest underneath the patient (A). This contact decreases the ability of the physician to get as close to the patient as possible and will cause forward leaning. The chair should be elevated so that the casters can slide underneath and the physician can sit as close as possible to the patient (B).
REPRINTED WITH PERMISSION FROM THE AMERICAN ACADEMY OF OPHTHALMOLOGY.

Figure 3. The physician should not place the elbow on a hard surface or bend sideways in the chair (A, B). It is better to use a soft cushion to decrease the contact stress on the elbow (C). Avoid using the hard lens case as an elbow rest (D). Additionally, it is better to move the chair instead of leaning the torso from side to side while using the slit lamp.
REPRINTED WITH PERMISSION FROM THE AMERICAN ACADEMY OF OPHTHALMOLOGY.

INDIRECT OPHTHALMOSCOPY

Excessive neck flexion and awkward postures commonly are seen during indirect ophthalmoscopy. Properly positioning the indirect on the head, reclining the patient, and raising the chair will significantly decrease neck flexion. Supporting one’s hands on the patient’s forehead and face will reduce shoulder stress. Loosening the pincer grip on the lens will lower carpal tunnel forces.

OPERATING ROOM

There are several potential intervention points to improve ergonomics in the retinal surgery operating room (Figure 4):

Figure 4. In the operating room, adjust the eyepieces to avoid awkward neck postures. Back and neck position while using microscope is critical. In this image, the physician’s neck is in extension. The eyepieces need to be set slightly below sitting eye height.
REPRINTED WITH PERMISSION FROM THE AMERICAN ACADEMY OF OPHTHALMOLOGY.

  • The block: Similar to the indirect examination, positioning the operating chair to reduce neck flexion and awkward postures is critically important.
  • The operating chair: Using operative beds with electric controls rather than manual controls (such as a foot pump and crank) will reduce the risk of injury for the physician and staff. Also, pay attention to the use of the wrist rest. A wrist rests helps reduce stress on the shoulders and trapezius. However, resting the wrists on a hard metal object can increase the risk of mechanical injury. Padded wrist rests can diminish this possibility.
  • Positioning of scope: Oculars should be positioned slightly below neutral position of the surgeon. Scopes with extended oculars will allow the surgeon to utilize the backrest of a chair, which thereby supports the spine. Feet should be on the floor or on pedals at a similar height. If there is a mismatch of pedal height, add towels under the lower profile pedal to equalize height.
  • Pincer grips: Holding instruments firmly is required, but the pressure should be monitored and, if possible, reduced. Taking frequent breaks to reduce carpal tunnel pressure is important.

OTHER CAUSES AND HOW TO COMBAT MSD

While there is significant risk of injury during the practice of ophthalmology, one must also consider the impact of texting (significant neck flexion), multitasking by cradling a cell phone with the neck, bending, lifting and other daily activities. Aerobic and core exercises, healthy weight maintenance, avoidance of smoking, and stress reduction are critically important to physicians’ overall well-being.

For a comprehensive review of the American Academy of Ophthalmology Task Force recommendations, the authors recommend the ergonomics course available through the American Academy of Ophthalmology’s Ophthalmic News and Education Network. RP

REFERENCES

  1. Dhimitri KC, McGwin G Jr, McNeal SF, et al. Symptoms of musculoskeletal disorders in ophthalmologists. Am J Ophthalmol. 2005;139(1):179-181.
  2. Kitzmann AS, Fethke NB, Baratz KH, Zimmerman MB, Hackbarth DJ, Gehrs KM. A survey study of musculoskeletal disorders among eye care physicians compared to family medicine physicians. Ophthalmology. 2012;119(2):213-220.
  3. Chatterjee A, Ryan WG, Rosen ES. Back pain in ophthalmologists. Eye (Lond). 1994;8:473-474.
  4. Sivak-Callcott JA, Diaz SR, Ducatman AM, Rosen CL, Nimbarte AD, Sedgeman JA. A survey study of occupational pain and injury in ophthalmic plastic surgeons. Ophthal Plast Reconstr Surg. 2010;27(1):28-32.
  5. Kaup S, Shivalli S, Kulkarni U, Arunachalam C. Ergonomic practices and musculoskeletal disorders among ophthalmologists in India: An online appraisal. Eur J Ophthalmol. 2018. [Epub ahead of print]
  6. US Department of Health and Human Services National Institute for Occupational Safety and Health. Proposed national strategies for the prevention of leading work-related diseases and injuries. Cincinnati, OH: Association of Schools of Public Health; 1986.
  7. Dougherty M. Ergonomic principles in the dental setting. June 2001. Thomson Healthcare/Dental Products Report. Available at http://www.designbyfeel.com/wp-content/uploads/2010/09/papers_ergonomic_principles_part1.pdf .