Management of the preoperative evaluation

Issue: May/June 2011

ByMitchell A. Jackson, MD

Second in a series of the top 10 reasons for poor premium IOL outcomes and how to remedy them.

M. Jackson

Now that you have mastered the fine art of managing patient expectations in a premium IOL patient (see the first of this series in the March/April 2011 issue), the next step paramount in achieving that promised premium outcome is the preoperative evaluation.

The premium preoperative evaluation has both subjective and objective components, divided into the following categories.

Preoperative history

The preoperative history typically begins with a patient questionnaire about previous refractive surgery, systemic medical conditions (immune diseases, diabetes, depression), systemic and/or topical medications (tamsulosin, sumatriptan, antidepressants, antihistamines), and occupational/recreational needs.

When taken carefully, the preoperative history will illicit the visual complaints that are most demanding for that specific patient and aid in proper premium IOL selection. For example, an elderly patient who plays bingo regularly and is afraid to drive at night will most likely benefit from a multifocal upgrade, whereas a younger professional who drives 1 hour roundtrip to work the nightshift daily and relies heavily on computer usage will probably be happier with an accommodating IOL upgrade. Previous refractive surgery will usually result in a change in spherical aberration, induction of higher-order aberrations and even irregular astigmatism (seen commonly in multiple-incision RK), setting up an ugly outcome with multifocal optics; however, the same patient could potentially benefit from an appropriate monofocal selected for spherical aberration effect. Remember, myopic LASIK results in positive spherical aberration and hyperopic LASIK results in negative spherical aberration.

Certain medical conditions and/or medications will increase dry eye risk postoperatively and hinder accurate diagnostic data capture preoperatively. For example, a three-piece multifocal might be the best approach in a Flomax (tamsulosin, Boehringer Ingelheim) patient, who may end up needing a sulcus/optic capture placement due to a higher posterior capsule rupture rate.

Ocular surface

The ocular surface is underrated and must be assessed and treated aggressively to avoid the non-premium outcome. Even with the best intraoperative surgery, a poor ocular surface will lead to vision fluctuation, blurred vision, induced refractive error and even discomfort — and any or all of the above spell disaster for a premium IOL patient.

For instance, William B. Trattler, MD, and colleagues recently presented data on tear breakup time below 5 seconds in up to 62% of patients undergoing cataract surgery and central corneal staining in up to 50% of patients. Poor tear film will lead to inaccurate corneal topography, keratometry and/or biometry for IOL calculations and may even yield a keratoconus-like corneal map that returns to normal shape after appropriate topical therapy. Diagnostic drops such as Fluramene (fluorescein green/lissamine green B solution, EyeSupply) provide rapid simultaneous staining of the conjunctiva and corneal surfaces to be able to grade the severity of the ocular surface with minimal chair time.

Further, ocular surface assessment must be characterized as lid margin or aqueous deficiency, and the appropriate treatments must be tailored. For lid margin disease, consider topical antibiotic/steroid combinations such as Zylet (loteprednol etabonate 0.5% and tobramycin ophthalmic suspension 0.3%, Bausch + Lomb), Tobradex ST (tobramycin 0.3% and dexamethasone ophthalmic suspension 0.05%, Alcon), or AzaSite (azithromycin ophthalmic solution, Inspire) with warm compresses, and/or lipid tear replacement therapies such as Soothe (glycerine 0.6% and propylene glycol 0.6% Bausch + Lomb) or Systane Balance (propylene glycol 0.6%, Alcon) for 1 to 4 weeks preoperatively.

For aqueous-deficient patients, consider Restasis (topical cyclosporine, Allergan), preservative-free lubrication such as Refresh Optive (carboxymethylcellulose sodium 0.5% and glycerin 0.9%, Allergan) or Systane Ultra (polyethylene glycol 400/propylene glycol 0.4%/0.3%, Alcon), punctal plugs, and/or omega-3 fatty acid nutrition such as EyeRelief (Doctor’s Advantage) or Tears Again Hydrate (Cynacon/Ocusoft). TearLab osmolarity measurements yielding hypertonic readings above 306 will benefit from topical Freshkote (polyvinyl pyrrolidone 2.0%, FocusLabs), Blink Tears (polyethylene glycol 400 0.25%, AMO), and/or TheraTears (sodium carboxymethylcellulose 0.25%, Advanced Vision Research).

Corneal topography

As an adjunct to corneal slit lamp evaluation, corneal topography will reveal conditions such as forme fruste keratoconus, frank keratoconus, pellucid marginal degeneration and irregular astigmatism (map-dot-fingerprint epithelial dystrophy, post-RK). Corneal topography is also necessary to decipher whether a patient is a candidate for premium IOL placement in the first place, or if another procedure, such as laser vision correction, piggyback IOLs, limbal relaxing incisions or collagen cross-linking, when readily available, is the best enhancement option for residual refractive error.

IOL calculations

Pristine IOL calculations will result from keratometry and biometry measurements with a pristine ocular surface. A-scan devices such as IOLMaster (Carl Zeiss Meditec), Lenstar (Haag-Streit) or immersion will typically give the most accurate biometry readings, including the anterior chamber depth and lens thickness measurements needed in certain formulas such as Holiday II or Haigis-L (the latter useful in post-LASIK cases). Emmetropia is the most important objective goal in the premium IOL patient, and selecting the correct formulas and priming the ocular surface preoperatively to perfection to achieve such is critical.

Macular assessment

Macular disease, if not diagnosed preoperatively in the premium patient, will potentially lead to less-than-expected outcomes, dissatisfied patients, increased chair time, probable IOL exchange, and little to no profitability in the end. Despite the obvious dilated retinal evaluation of the posterior pole, OCT assessment of the macula for the anterior segment surgeon is quick, easy and educational for proper IOL selection.

Epiretinal membranes, macular pucker, macular holes/pseudoholes, and subclinical macular degenerative changes often go undetected by routine retinal examination and are discovered far too late after a multifocal optic is in place. Although accommodating IOLs may have a better place with such patients, caution is recommended as postoperative subjective visual function typically does not match postoperative quantitative Snellen acuity or preoperative patient expectations. OCT technology also provides an excellent means for gauging postoperative topical nonsteroidal/steroid tapering in terms of macular edema and/or detecting subclinical macular edema in the first place.

Patient discussion

Lastly, the surgeon’s final discussion with the premium IOL patient is the driving force behind the patient’s ultimate decision on whether to upgrade. As mentioned in part 1 of this series, minimizing the patient’s choice to only one upgraded IOL option and avoiding brands is recommended. Patients really do not understand the difference between a diffractive, an apodized or an aspheric surface. The patient’s ultimate goal is to see without glasses, and he or she could care less about J1 vs. J2 vs. J3. Each patient has different visual demands, and J1 in one patient may just not be good enough but J5 to another patient may be the lead testimonial on your practice website. That final preoperative discussion with your patient will set the tone for the entire patient experience. It is our responsibility, as premium surgeons, to choose the appropriate premium IOL for the patient to obtain the premium outcome, premium word-of-mouth and, ultimately, premium surgical volume.

References:
Benelli U, Nardi M, Posarelli C, Albert TG. Tear osmolarity measurement using the TearLab Osmolarity System in the assessment of dry eye treatment effectiveness. Cont Lens Anterior Eye. 2010;33(2):61-67.

Chang DF, Braga-Mele R, Mamalis N, et al; ASCRS Cataract Clinical Committee. Clinical experience with intraoperative floppy-iris syndrome. Results of the 2008 ASCRS member survey. J Cataract Refract Surg. 2008;34(7):1201-1209.

Luchs J. Efficacy of topical azithromycin ophthalmic solution 1% in the treatment of posterior blepharitis. Adv Ther. 2008;25(9):858-870.

Trattler WB, Goldberg D, Reilly C. Incidence of concomitant cataract and dry eye prospective health assessment of cataract patients. Presented at: World Cornea Congress; April 8, 2010; Boston.

Mitchell A. Jackson, MD, can be reached at Jacksoneye, 300 N. Milwaukee Ave., Suite L, Lake Villa, IL 60046; 847-356-0700; fax: 847-589-0609; email: mjlaserdoc@msn.com.

Disclosure: Dr. Jackson is on the speakers bureau for Allergan, Abbott/AMO, Bausch + Lomb, Ista, Inspire, Alcon and Technolas PV. He is a consultant for Hoya and Cynacon/Ocusoft and is on the advisory board for Noble Vision Group.