When filling out the lab form, always include the patient's PCP so he can receive a copy of the lab results. I will personally call the PCP when ordering labs in addition to sending a letter documenting what was ordered and why.
Now you are ready to order labs. Here are a few examples of commonly used labs and reminders of what the labs are looking for courtesy of Patricia Fulmer, OD, from NewGradOptometry.com.
• CBC c diff: complete blood count with differential; full panel describing blood makeup (erythrocyte, leukocyte, neutrophil, plasma count, etc.)
• BMP (or Chem-8): basic metabolic panel; measures non-fasting glucose, electrolytes, and kidney function
• ESR: erythrocyte sedimentation rate; test measuring the rate at which red blood cells settle within one hour; general inflammation marker
• CRP: C-reactive protein; general inflammation marker
• HLA-B27: Human leukocyte antigen B27; presence of this antigen is indicative of the patient being at risk for or having an autoimmune disorder; the test is non-specific for which autoimmune disorder the patient may be affected
Related: The changing dry eye dynamic
• FTA-ABS: Fluorescent treponemal antibody absorption; evaluates whether or not the patient has ever had syphilis; once the patient has been infected, this test will always be positive, even after the active infection is cleared
• RPR: Rapid plasma regain; test for active syphilis; less specific than FTA-ABS, but more indicative of an active infection
• Thyroid panel (free T4, free T3, and TSH): T4=thyroxine; TSH=thyroid stimulating hormone; measures the amount of free T4 in the patient’s blood, indicative of overproduction of the main hormone produced by the thyroid gland (hyperthyroidism); measures the amount of TSH in the blood, indicative of lack of production of appropriate hormones by the thyroid gland, resulting in excess stimulating hormone (hypothyroidism)
• HbA1C: Glycosylated or glycated hemoglobin test; measurement of average glucose level over the last three months
• ANA: Antinuclear antibody; autoimmune disorder marker; non-specific
• ACE: Angiotensin-converting enzyme; elevated levels indicate likely sarcoidosis
• Lipid Panel: measures overall cholesterol, HDL, LDL, and triglyceride levels in the patient’s blood
Ordering labs may improve patient care
A 50-year-old Caucasian male presented for a routine exam with the chief complaint of decreased near vision. A dilated exam finds an isolated retinal microaneurysm OD.
He has not routinely been seen by a primary-care physician. His blood pressure was 130/70 mm Hg. In this case, initiation of labs would aid in a possible underlying systemic cause for the retinal findings. It would be recommended to order the following:
• CBC w/differential,
• Fasting blood sugar (FBS)
• Lipid panel
A 45-year-old female presented with a chief complaint of one eye appearing larger than the other. The exam revealed normal extraocular muscle (EOM) function, no evidence of proptosis, and normal pupil function—however, eyelid retraction was noted OD.
No other ocular pathology was noted upon dilation. For this patient, TSH, free T4, free T3, and CBC w/diff would be recommended. It would also be recommended to image the patient with a CT of the orbits.
As we continue to grow as a profession, remember we are treating the whole patient, not just the eye alone. Incorporating lab work and imaging into your comprehensive eye care will improve patient outcomes and continue to grow your practice.