A More Accurate Estimate
In his article “ Steep Competition: LRI vs Toric IOLs” (March 2012), Dr. Bronner states, “Discuss toric IOLs with all patients who have refractive astigmatism. In most cases, this is a fair indication if there will be residual cylinder after [cataract] surgery.”

However, more accurately, residual cylinder after cataract surgery is directly related to preoperative corneal cylinder, location of incision and the amount of surgically induced astigmatism (SIA). Postoperative corneal cylinder goes straight to the post-op refractive outcome. Preoperative refractive astigmatism has little bearing. It is those individuals who have little preoperative refractive cylinder in the face of significant corneal cylinder and/or those in which the incision location and SIA result in significant corneal cylinder who truly need counseling.

Here is a good rule of thumb on deciding whether your patient will have significant post-op refractive astigmatism: Begin with the pre-op keratometry readings. Factor in the SIA. If the incision is going to be placed at 12:00, this will flatten the vertical K reading by approximately 0.50D. If the patient has 1.00D of with-the-rule (WTR) astigmatism or less, their post-op corneal cylinder should be 0.50D or less. However, if this patient has pre-op corneal cylinder of 0.50D against-the-rule (ATR) astigmatism, they would be expected to have 1.00D ATR post-op. If the surgical incision is temporal, the math is similar––the meridan of the incision flattens the K reading by about 0.50D. In this case, WTR is increased by surgery and ATR is reduced.

Sight Gags by Scott Lee, O.D.

If the referring O.D. wants to more accurately calculate post-op residual astigmatism, he or she may do so with the help of online calculators. Values for pre-op Ks, incision location and SIA are required. The latter two measurements may be obtained from the surgeon who is anticipated to manage the case. Note that it is unnecessary to know the spherical power of the IOL to be implanted in order to calculate the need for a toric IOL. For simplicity, use 20.00D. The online toric calculator will tell you if a toric IOL is indicated and, if so, which power toric to implant. It also calculates residual astigmatism. The online LRI calculator also requires patient age for calculations.

Using the tools outlined above, concerned O.D.s can more accurately counsel their patients on whether they might benefit from an LRI or toric IOL.

––Howell M. Findley, O.D.
Lexington, Ky.

Dr. Bronner responds:
Dr Findley’s points are all well made and the article was inappropriately vague in its wording on this topic. The point that I attempted to make is that, in the absence of keratometric or topographic data (which is required to predict postoperative cylinder, as stated in the preceding paragraph of the article), refractive cylinder could be used to guide general discussion––knowing that it may change after acquisition of the aforementioned metrics at the surgery center. The process of estimating postoperative astigmatism was beyond the scope of the article; however, the more information a referring O.D. can gather, the greater his or her role in the targeted outcome will be.

––Aaron Bronner, O.D.
Boise, Idaho

Time for More Shared-Equity Partnerships
Thank you to Derek Cunningham, O.D., and Walt Whitley, O.D., for defining the different forms of “integrated eye care” (“ What is ‘Integrated Eye Care?’” March 2012). Prior to this article, the eye care world has only heard ophthalmology’s definition. All models position optometrists to care for their patients to the full extent of the optometrists’ license. Well done.

What is never mentioned in our ophthalmology colleagues’ versions of integrated eye care is ownership.

Optometrists have been employed by ophthalmologists for years. The ophthalmologist determines income formulas, hiring and firing, work schedules, staffing, equipment purchases and, most importantly, retirement equity in the business. In other words, the ophthalmologist(s) ultimately controls the practice.

Shared-equity partnerships solve this problem. If they really want to “integrate” the practice, then offer the optometrist(s) equity ownership with equity-based managerial authority. They provide this incentive to new “partner ophthalmologists,” so they should also offer this to the “partner optometrists.” Then, we’ll truly experience comprehensive, integrated eye care.

––Randall N. Reichle, O.D.
Bellaire, Texas

Drs. Cunningham and Whitley respond:
Thank you for comments, and we could not agree with you more. Much of the historical hierarchy of the O.D./M.D. business relationship is an unnecessary reflection of scope of practice––or more likely gross earning potential. Just as you mentioned, shared-equity partnerships have rarely been introduced or addressed in regards to integrated eye care.

Nonetheless, there are many examples, such as your practice, where this model has been very successful. Optometrists are continuing to demonstrate their increased worth on both the business and clinical side. With the future changes in both the supply and demand of eye care services, we may see many more examples like Eye Centers of Texas integrating eye care.

––Derek N. Cunningham, O.D.
Austin, Texas

Walter O. Whitley, O.D., M.B.A.
Virginia Beach, Va.