If your pachymeter gathers dust between glaucoma patients, take a look at other uses for it. These include refractive surgery comanagement, assessing contact lens fittings and monitoring corneal dystrophies.
Surgical Comanagement
After glaucoma, the second most important use for a pachymeter is refractive surgical comanagement. Pachymetry is a standard procedure for any patient undergoing refractive corneal surgery, says optometrist Jeffery Augustine, of Brecksville, Ohio. First, pachymetry can help you determine whether patients are refractive surgery candidates. Before referring potential LASIK patients to a surgeon, O.D.s should check patients corneal thickness to determine if their measurements are sufficient for refractive surgery, says optometrist Greg Black, of Fort Lauderdale, Fla. If O.D.s determine that patients are candidates based on their corneal thickness measurements, O.D.s can do a more thorough pre-operative consultation, Dr. Black says.
What corneal thickness measurement is sufficient for refractive surgery? Five-hundred microns is the general rule, says optometrist Joseph Shovlin, of Scranton, Pa. However, whether corneal thickness is sufficient for refractive surgery really depends on the patients prescription and ablation size, he says. For example, if the patient needs a -2.00D correction, a 500m cornea might be fine. But if the patient needs a -10.00D correction, a 500m cornea might be too thin, Dr. Shovlin says.
Pachymeters can also be used during surgery. In my practice, we use a pachymeter intraoperatively to check the flap thickness and residual amount of stromal bed, Dr. Augustine says. This is important for patients who have higher degrees of myopia or hyperopia because we need to ensure that they have enough tissue to laser, he says.
A normal flap thickness is 110m with the IntraLase laser (IntraLase Corp.) and 120m with a standard microkeratome, Dr. Augustine says. If the residual bed is less than 250m, LASIK should not be performed, Dr. Shovlin says. However, Ive seen patients who have residual beds over 250m who get ectasia. And, I have seen patients who have corneas thicker than 500m who end up with ectasia because their correction was so high and required a multi-zone configuration, he says. To avoid this, take careful pachymetry readings before and during surgery, and avoid correcting most refractive errors higher than 8.00D.
If the patients flap would be too thin for LASIK, pachymetry can help O.D.s determine if another type of refractive procedure would suit a patient. For example, depending on their corneal thickness, some patients may be candidates for PRK or epithelial LASIK, but not for traditional LASIK with a flap, says optometrist James Fanelli, of Wilmington, N.C.
Contact Lens Fittings
Pachymetry can also be used to determine whether contact lenses are causing corneal edema, says Dr. Black. Although silicone hydrogel lenses typically do not cause much swelling, you cant be certain of this until youve checked the cornea, says optometrist Robert Cole, of Bridgeton, N.J.
If you are fitting a patient for a 30-day lens, use your pachymeter to check the patients corneal thickness before beginning lens wear, Dr. Cole says. Then, check the corneal thickness again 30 days later, he says. You must take a pachymetry measurement before patients begin wearing contact lenses to be able to determine if the cornea is swollen after wearing lenses, Dr. Cole says. Also, if your patient has problems with his or her lenses, pachymetry measurements can help you compare the effects of different lenses, he says.
Corneal Dystrophies
Pachymetry plays two roles in patients who have corneal dystrophies, especially endothelial dystrophies such as Fuchs, Dr. Fanelli says. First, pachymetry measures overall corneal stability. Pachymetry tells me if the cornea is getting thicker over time or remaining the same, he says. Second, pachymetry allows you to determine therapeutic benefit. For example, a patient with Fuchs can benefit from IOP reduction or hypertonic therapy, and pachymetry is an excellent way to measure the effect of these therapies, Dr. Fanelli says.
To Buy or Not to Buy?
In addition to its variety of uses, pachymeters are relatively inexpensive and can help your bottom line. There arent many other pieces of diagnostic equipment available in the $2,000 to $3,000 price range, says optometrist and practice-building consultant Gary Gerber, of Franklin Lakes, N.J.
Reimbursement for pachymetry is typically low, Dr. Gerber says. (see Billing and Coding for Pachymetry.) However, owning one allows you to provide a higher level of care for your patients and enables you to comanage more refractive surgery patients, so it typically pays for itself very quickly, he says. Also, you will likely start detecting more glaucoma patients with a pachymeter, and in turn, you will be administering and charging for other tests, Dr. Gerber says.
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Billing and Coding for Pachymetry How to Code How to Bill and Get Reimbursed Patients who receive a corneal graft. Pachymetry can monitor the metabolic function of the donor tissue, so carriers will pay for annual CCT measurements. Aphakic patients who wear contact lenses. Pachymetry can be used to monitor corneal swelling caused by the typical extended wear schedule of the high-plus lenses. Keratoconic patients. These patient should have their corneal thickness monitored every year, even if there are no visible complications. Carriers will reimburse for pachymetry more than once a year in only two situations: Corneal graft patients who show signs of graft rejection. Many independent O.D.s will not encounter this situation because corneal surgeons typically monitor most graft patients. Corneal edema. Pachymetry should be performed in the initial diagnosis of edema and thereafter to evaluate the efficacy of treatment. However, provide the carrier with supporting documentation to justify the frequency of extra pachymetric measurements. Case Example: Billing for a Patient with Late-stage Fuchs Corneal Dystrophy On the first visit, the patient is diagnosed with: The carrier is billed for: Note that some carriers may require the -59 modifier (distinct procedural service) if pachymetry is performed the same day as the initial exam. The next visit occurs within a week after the hyperosmotic agent is prescribed. The same diagnoses are used. The billed procedures are: If your patient has corneal edema due to low Dk contact lenses, the code (371.24 Contact lens-induced corneal edema) does not allow for pachymetry reimbursement because this condition is iatrogenic, or doctor caused. However, the advent of silicone hydrogel technology will likely extinguish this condition in the near future. Note the following billing and coding pearls: Corneal pachymetry can only be paid once per lifetime per provider. If you are seeing a glaucoma suspect patient for the first time, bill for pachymetry this one time only. Once a patients corneal thickness is a matter of record, there is no reason to duplicate the measurement for monitoring subsequent IOPs. If only one eye is being measured, append modifier -52 to the pachymetry code on the CMS-1500 form. This will result in a whopping $6.06 reimbursement for the procedure. If you do not charge your patients who pay cash for pachymetry, do not bill the medical carrier. Most vision plans do not reimburse for medical procedures or diagnostic testing. Im not aware of any vision plan that pays for pachymetry. The Million Dollar Question |
| A Guide to Pachymeters |
| Pachymeter | Manufacturer | Features | For more information |
|
AccuPach V |
Accutome |
65 MHz probe sampling. |
www.accutome.com |
| Pachette 3 | DGH Technology |
Measures and stores up to 25 bilateral measurements. |
www.dghkoi.com
|
| OLCR Pachymeter | Haag Streit |
20Hz measurement rate. |
www.haag-streit.com Phone: 800-787-5426 |
| Corneo-Gage Plus | Sonogage |
50MHz transducer. |
www.sonogage.com |
| PacScan 300 | Sonomed | 20MHz probe. Provides average and standard deviation for each reading. Multiple corneal maps. Measurement review capability. Automatic calibration test and probe sensitivity test. |
www.sonomedinc.com Phone: 800-227-1285 |
| SP-3000 | Tomey |
20MHz frequency. |
www.tomey.com |
| Handheld Pachymeter | Manufacturer | Features | For more information |
| PachPen | Accutome |
65MHz sampling probe. |
www.accutome.com Phone: 800-979-2020 |
| PachMate DGH 55 | DGH Technology |
Weighs 3.6oz. |
www.dghkoi.com |
| Pocket II Precision Pachymeter | Quantel Medical |
Weighs 16oz. |
www.quantelmedical.com Phone: 888-660-6726 |
| SP-100 Handy Pachymeter | Tomey |
20MHz frequency. |
www.tomey.com |
