BY JOHN F. DOANE, MD, FACS; PERRY S. BINDER, MD, MS; PARAG A. MAJMUDAR, MD; LOUIS E. PROBST, MD; STEPHEN G. SLADE, MD, FACS; AND WILLIAM B

Transcription

1 What Is Your Diagnosis? Surgeons discuss their analyses of various topographies of possibly keratoconic cases and converse about their treatment recommendations. BY JOHN F. DOANE, MD, FACS; PERRY S. BINDER, MD, MS; PARAG A. MAJMUDAR, MD; LOUIS E. PROBST, MD; STEPHEN G. SLADE, MD, FACS; AND WILLIAM B. TRATTLER, MD Recently, attention has focused on the importance of properly diagnosing all forms of keratoconus or pellucid marginal degeneration, be it frank or forme fruste, and how to proceed with treatment. The editors of Cataract & Refractive Surgery Today and I therefore decided to give various surgeons the opportunity to make diagnoses and treatment decisions for five topographies of five eyes of five different patients. In terms of this article assignment, I was unfair to each of the responding surgeons in that the data presented were incomplete. From the stated clinical histories and with the objective data that I provided, an exact diagnosis is nearly impossible to achieve. We asked surgeons to participate in this article to (1) demonstrate what details each one may agree or disagree upon in borderline cases of keratoconus, pellucid marginal degeneration, or their forme fruste topographic variants and (2) illustrate that a patient s complete medical and ocular history and data from his clinical examinations (comparisons of and in between eyes) are required to most accurately provide a correct diagnosis. Each of these patients underwent some sort of refractive treatment in Clinical decisions are quite different today than back then. The results of previous treatment choices have hence altered our thought processes about identifying candidates for corneal laser vision correction. All of the responding surgeons in this article, to their credit, wanted more data and a more complete understanding to formulate their best treatment strategy. No additional data were provided. The surgeons devised their treatment actions and diagnoses based up the information given. I thank the surgeons who participated in this article. John F. Doane, MD, FACS AUGUST 2006 I CATARACT & REFRACTIVE SURGERY TODAY I 57

2 CASE NO. 1 A 47-year-old white male patient has worn rigid gas permeable contact lenses for 20 years. He wants to do something more health conscious with his eyes. His manifest refraction is X 174 = 20/20-1 OD and X 031 = 20/20-2 OS. His central pachymetry is 585µm OD and 565µm OS at the 6-mm optical zone along the 270º meridian. Doctor s Name Perry S. Binder, MD, MS Diagnosis Focal inferior steepening. Inferior/superior ratio = 1.30D, with no placido distortion. I see a dry spot focally and distortion of the cornea s shape due to contact lens wear. I would ask how long the patient s contact lenses have been out of his eyes and question whether or not artificial tears modified the topography. Parag A. Majmudar, MD Louis E. Probst, MD There is definite inferior steepening in this eye. Analysis of the fellow eye would be helpful, as would evaluation of the posterior cornea with the Orbscan topographer (Bausch & Lomb, Rochester, NY). This topography is slightly asymmetrical with a pattern that is present in about 20% of refractive patients. This topography is in the 0.50D scale on the Humphrey topographer (Carl Zeiss Meditec Inc., Dublin, CA), so this will magnify any slight asymmetries, making this eye seem worse than it is. If the scale were changed to a 1.00D scale, this topography would be normal. Stephen G. Slade, MD, FACS William B. Trattler, MD I would want to know this patient s clinical history, particularly how long he has not worn the rigid gas permeable contact lenses. The patient s topography is in 0.25D steps; 1.00 or 1.50D steps are more practical. However, there seems to be less than 1.00D of an inferior/superior ratio difference at 3mm, so the patient has some asymmetry. This topography demonstrates mild inferior steepening. Providing the numerical view on the Humphrey topographer s printout allows for careful analysis of the degree of inferior steepening and is the standard printout in my practice. Evaluation with the Orbscan or Pentacam (Oculus, Inc., Lynnwood, WA) would provide important information and be helpful in assessing this patient as a candidate for refractive surgery. John F. Doane, MD, FACS: The management for this case was based upon data from his fellow eye. His left eye s central pachymetry was D in his right eye. The left eye had oblong mires on keratometry. Due to the fact that the left eye was so advanced, I elected to not offer c 58 I CATARACT & REFRACTIVE SURGERY TODAY I AUGUST 2006

3 Recommendations for Treatment I assume the patient s fellow eye is normal. I suggest that the patient have his contacts out of his eyes longer before a topography is repeated. Assuming the corneal steepening regresses, I would perform monovision LASIK, undercorrecting the nondominant eye by 1.50D using the Intralase laser (Intralase Corp., Irvine, CA). I would attempt a 110-µm flap. Assuming this patient has been out of contact lenses for a sufficient amount of time (ie, 3 weeks or more for a patient who has worn rigid gas permeable contact lenses), his topography has normalized, and Orbscan showed posterior elevation < 50µm, I would perform LASIK. Before making a treatment choice, I would need to see the fellow eye s topography and Orbscan. I would also need to know the results of the clinical eye examination, as a dry eye could cause the current corneal pattern. I am somewhat reassured by the thick pachymetry, the very mild asymmetry on the 0.50D scale, the rigid gas permeable contact lens wear history, and the older age of the patient that this is not forme fruste keratoconus. If the other tests were all completely normal, I would be comfortable with performing customized LASIK in this case. I would need more information before proceeding with any corneal procedure. I would consider him a candidate for LASIK or the Visian Implantable Collamer Lens (ICL; STAAR Surgical Company, Monrovia, CA). If there were any doubt, I would implant a phakic ICL. I would instruct the patient to refrain from wearing his contacts, use artificial tears or Restasis (Allergan, Inc., Irvine, CA) frequently, and then return to my office in 2 weeks for repeat testing to see if the inferior steepening is real or related to warpage or dryness of the cornea from extended contact lens wear. If the irregularity on this topography improves, then the patient is an appropriate candidate for LASIK and/or surface ablation. If the irregularity remains but the Orbscan/Pentacam map is normal, then LASIK can be considered, because of the patient s age and thick corneas and especially because the degree of inferior steepening is less than the 1.40D criterion for forme fruste keratoconus. I would advise LASIK as an excellent option but mention that surface ablation would further reduce the low risk of ectasia. µm and 493µm at the 6-mm optical zone along the 270º meridian. The inferior/superior ratio discrepancy in his left eye was 17.00D compared with orneal laser vision correction to the patient in either eye. The diagnosis was keratoconus for his left eye and forme fruste keratoconus in his right. AUGUST 2006 I CATARACT & REFRACTIVE SURGERY TODAY I 59

4 CASE NO. 2 A 45-year-old white male patient wants to eliminate his use of glasses and contact lenses for distance vision. The manifest refraction in his left eye is X 160 = 20/20+2 visual acuity. The patient s central pachymetry is 531µm. Doctor s Name Perry S. Binder, MD, MS Diagnosis I would ask how long the patient s contact lenses have been out of his eyes. I note semilunar steepening across two quadrants. The inferior/superior ratio equals 0.70D. I see no mire distortion. The patient s nose appears to block some data inferiorly nasally. There is probable contact lens warpage of the cornea. Parag A. Majmudar, MD Louis E. Probst, MD Stephen G. Slade, MD, FACS William B. Trattler, MD I would say that this patient has an inferior elevation of his cornea, which is worrisome for forme fruste keratoconus. The placido images show irregular astigmatism, which could be from contact lens warpage or from forme fruste keratoconus. Orbscan would be helpful, as would knowing the length of time the patient has been out of contact lenses.. This topography is slightly asymmetrical with a pattern that is present in about 20% of refractive patients. This topography is in the 0.50D scale on the Humphrey topographer, so this will magnify any slight asymme tries and make this eye seem worse than it is. If the scale were changed to a 1.00D scale, this topography would be normal. I would require further information on this patient for a more complete clinical picture. The patient s topography is in 0.25D steps. I would want to know how long he has not been wearing contact lenses. Given that he does have some inferior steepening and a flat central area, I would want to rule out pellucid marginal degeneration. My bottom-line diagnosis would be: that I need more information. I would also want to see his other eye. This is the most challenging topography to interpret in this series, and my first question is, how long has the patient not worn contact lenses? Orbscan/Pentacam analysis might be extremely helpful in determining the degree of corneal abnormality. The pattern of irregularity most closely resembles early pellucid marginal degeneration, as there is against-the-rule astigmatism along with a midperipheral area of steepening that sweeps in both directions. John F. Doane, MD, FACS: I decided upon the plan for this case based upon the presentation of the data of patient s fellow eye. The diagnos eye was X 010, which provided 20/25+2 acuity. The inferior/superior ratio discrepancy for his right eye was 6.00D and for his left ey eye, which had an oblong or egg-shaped appearance. Central pachymetry of his right eye was 551µm. No surgical intervention was recomme 60 I CATARACT & REFRACTIVE SURGERY TODAY I AUGUST 2006

5 Recommendations for Treatment I would repeat the topography after the patient has not worn contact lenses for an additional 2 to 4 weeks. If there were no change in the topography (meaning a diagnosis of permanent contact lens warpage), I would not perform surgery. If the topography improves, and assuming the patient has a mesopic pupil of < 6mm in diameter, I would perform LASIK with the Intralase and attempt a 100-µm flap. If the pupil is > 6mm in diameter and/or if wavefront-guided laser surgery is planned, I would perform PRK. If the topography normalized after refraining from contact lenses for an appropriate amount of time, and the posterior elevation by Orbscan was normal, I would perform surface ablation. Before making a treatment choice, I would need to see the fellow eye s topography and Orbscan. I would also need to know the results of the clinical examination as a dry eye could cause the current corneal pattern. I am somewhat reassured by the thick pachymetry, the very mild asymmetry on the 0.50D scale, the rigid gas permeable contact lens wear history, and the older age of the patient, that this is not forme fruste keratoconus. If the other tests were all completely normal, I would be comfortable with customized LASIK in this case. I would need more information before proceeding with any corneal procedure. I recommend that the patient refrain from contact lens wear and then return in 1 month for a repeat topography (plus Orbscan/Pentacam maps). If the corneal irregularity is still present, I would recommend that the patient continue with contact lenses and/or glasses. Additionally, this patient may consider a phakic IOL. On the other hand, if the repeat topography is more normal than the original presentation, the patient may consider LASIK or surface ablation. is was frank pellucid marginal degeneration for his right eye and mild forme fruste pellucid marginal degeneration in his left. The refraction of his right e was 0. Topography of the patient s right eye revealed a classic crab claw appearance. Of note was the significant irregularity of the mires for his right nded. I instructed the patient to switch from soft to rigid contact lenses. AUGUST 2006 I CATARACT & REFRACTIVE SURGERY TODAY I 61

6 CASE NO. 3 A 32-year-old white male seeks refractive surgery to be less dependent on glasses and contact lenses. Manifest refraction for his left eye is X 030 = 20/20 visual acuity. His central pachymetry is 606µm. Doctor s Name Perry S. Binder, MD, MS Diagnosis Asymmetric corneal steepening, nonorthogonal astigmatism. Inferior/superior ratio is 5.30D. Mires are distor ed inferiorly and nasally. Irregular elevation on the topographic map strongly suggests keratoconus in spite o the cornea s thickness. I would question how good the patient s vision was with contact lenses. Parag A. Majmudar, MD Forme fruste keratoconus. Louis E. Probst, MD I would diagnosis this topography as asymmetrical with nonorthogonal astigmatism. Stephen G. Slade, MD, FACS I would require further information on this patient for a more complete clinical picture. The patient s topography is in 0.50D steps, which is better than 0.25D steps. I would diagnose this case as forme fruste keratoconus until proven otherwise. I would repeat the topography, look at the fellow eye, etc. William B. Trattler, MD This patient s topography represents an early case of pellucid marginal degeneration, and therefore he is an inappropriate candidate for LASIK. Despite the patient s normal corneal thickness, the patient is young and has astigmatism at the 30º axis. Evaluation of his topography reveals an area of inferior steepening that is a few diopters steeper than other parts of his cornea. Although a classic claw shape is not noticeable, a partial claw shape is visible. Orbscan/Pentacam analysis may provide further documentation for this case of pellucid marginal degeneration. John F. Doane, MD, FACS: This patient s initial topographic diagnosis was aysmmetric astigmatism, and he did undergo LASIK. The data for his left eye and 1 year after original surgery in his right eye for residual astigmatism. Five years after the original surgery, the patient underwent unaided vision 6 years after enhancement surgery of his left eye and 2 years after enhancement of his right eye. The patient has not exhibited which may have resulted from his history of significant allergy-associated eye rubbing). The patient would have likely done well if the original 64 I CATARACT & REFRACTIVE SURGERY TODAY I AUGUST 2006

7 Recommendations for Treatment - f I would have the patient continue with contact lenses if his vision is good. Otherwise, he could receive Intacs (Addition Technology, Inc., Des Planes, IL), a phakic IOL, or surface laser ablation. I would recommend surgery on one eye at a time, with careful informed consent about the risks of ectasia after laser surface ablation treatment. Although there is mounting evidence that PRK might be successful in forme fruste keratoconus, I would not perform surgery but would fit the patient with rigid gas permeable contact lenses. Prior to making any treatment decision, I would need to see the fellow eye s topography and Orbscan map. An asymmetrical pattern like this makes me much more cautious. If the other tests were normal, other than this change, I would perform customized PRK with a detailed consent form signed by the patient. If there were other abnormalities found on the Orbscan map, I would not perform surgery. I would offer no surgical treatment for this patient. However, if something had to be performed, I would implant an ICL. Obviously, soft or hard contact lenses are appropriate first-line options for this patient. I may consider a phakic IOL, although addressing the residual astigmatism is significantly challenging. is right eye was essentially identical to that of his left eye. The patient underwent a lifting LASIK enhancement 4 months after the original surgery in a customized PRK enhancement of his right eye for residual asymmetric astigmatism only. The patient has been completely stable and happy with any signs of ectasia to date. In hindsight, this case represented early forme fruste keratoconus (note the mild oblong mires on photokeratoscopy, surgery had been a customized PRK procedure, which was not available at the time. AUGUST 2006 I CATARACT & REFRACTIVE SURGERY TODAY I 65

8 CASE NO. 4 A 34-year-old white male wants to eliminate spectacles for distance vision. His manifest refraction is X 080 = 20/20+2 visual acuity. His central pachymetry is 520µm. Doctor s Name Perry S. Binder, MD, MS Diagnosis There is no history of contact lens wear. I see asymmetric inferior steepening with an inferior/superior ratio that equals 2.10D, distorted mires inferiorly, and an abnormal elevation map. I would say this eye has keratoconus. Parag A. Majmudar, MD There is very prominent inferior steepening. If contact lens warpage is ruled out, the diagnosis is forme fruste keratoconus. Louis E. Probst, MD Based on the topography alone, my diagnosis is forme fruste keratoconus; however, I would require the fello eyes topography, a clinical examination, and an Orbscan for a complete diagnosis. Stephen G. Slade, MD, FACS William B. Trattler, MD I would require further information on this patient for a more complete clinical picture. The patient s ocular topography is in 0.50D steps, which is better than 0.25D steps. This is forme fruste keratoconus until proven otherwise. This case could be keratoconus, but, again, I cannot make that diagnosis without the clinical examination. The patient s topography reveals more than 2.50D of inferior steepening. Despite a BCVA of better than 20/20, this patient has a moderate degree of forme fruste keratoconus. Orbscan/Pentacam analysis would allow for an enhanced understanding of the degree of forme fruste keratoconus. John F. Doane, MD, FACS: This patient has forme fruste keratoconus. His eyes were essentially symmetric with identical appearances on topo tive error in each eye within the first year postoperatively. To date, he has done well, is quite happy with his unaided vision, and uses no additi 66 I CATARACT & REFRACTIVE SURGERY TODAY I AUGUST 2006

9 Recommendations for Treatment I would recommend that this patient not undergo refractive surgery. He should wear rigid gas permeable contact lenses. I would not perform surgery but would fit the patient with rigid gas permeable contact lenses. I would need the results of the other tests before making a treatment decision; however, the topography pattern is quite clear. Although customized PRK is a medicolegally safe option, I would opt to perform no surgery, as the pattern is so dramatic. I always ask myself, could a lawyer show this topography to a jury and make me look like I was negligent? If the answer is yes, then I do not do it. I would offer nothing, or else if surgery had to be done, I would implant an ICL. In this case, I do not consider LASIK an appropriate option. Soft or hard contacts may provide excellent quality of vision. Some doctors may offer surface ablation for this type of patient with extensive informed consent. However, for this case, I recommend Intacs, which can significantly reduce the refractive error and also help stabilize the cornea. graphy prior to bilateral LASIK, which was performed in early The patient underwent a relifting enhancement for very small amounts of refraconal visual aids. AUGUST 2006 I CATARACT & REFRACTIVE SURGERY TODAY I 67

10 CASE NO. 5 A 32-year-old while female wants to be less dependent on glasses and contact lenses. Her manifest refraction is X 175 = 20/20+ visual acuity. Her central pachymetry is 561µm. Doctor s Name Perry S. Binder, MD, MS Diagnosis I would ask for medical/clinical history. I see circumferential steepening with a flat central area and a flat periphery that suggests previous refractive surgery. I would investigate whether or not the eye underwent an type of trauma or if it had undergone orthokeratology. Parag A. Majmudar, MD There is atypical against-the-rule cylinder with wraparound to the inferior cornea that makes the diagnosis pellucid marginal degeneration or forme fruste keratoconus. Louis E. Probst, MD My diagnosis would be pellucid marginal degeneration; however, I would need to see the results of the clinic examination, topography in her other eye, and the Orbscan to make the definitive diagnosis. Stephen G. Slade, MD, FACS William B. Trattler, MD I would require further information on this patient for a more complete clinical picture. The patient s ocular topography is in 0.50D steps, which is better than 0.25D steps, but this is an abnormal topography in that th eye could have pellucid marginal degeneration. To make that diagnosis, one would need to document ectas with the clinical examination. This patient has pellucid marginal degeneration. Despite her BCVA of better than 20/20, she has against-therule astigmatism, and a claw shape is visible on her topography. An Orbscan/Pentacam analysis would be helpful to further determine the severity of her pellucid marginal degeneration. John F. Doane, MD, FACS: This patient had normal-thickness corneas, a normal central corneal power, and essentially symmetric topograph metric, and there was no irregularity in the keratometry mires. In hindsight, this patient did have moderate forme fruste keratoconus. After u tact lenses, which provide excellent acuity. 70 I CATARACT & REFRACTIVE SURGERY TODAY I AUGUST 2006

11 Recommendations for Treatment y I would instruct the patient to remove all contact lenses for 2 months and then I would recheck her eye. I would await more patient history and evaluate the status of her fellow eye. I would not perform surgery but would fit the patient with rigid gas permeable contact lenses. al I would not perform surgery in this case unless there was improvement in the cornea s appearance with time. Customized PRK would be a medicolegally safe option with a detailed informed consent form signed by the patient. However, the appearance based on the topography alone coupled with the young age of the patient concern me regarding a greater chance of a problem in the future. e ia I would offer nothing. If surgery had to be performed, I would implant an ICL. I recommend that this patient continue to use glasses or soft contacts, because her BCVA with refraction is better than 20/20. She is not an appropriate candidate for LASIK. c patterns and refractions as well as excellent BCVA. The overall color pattern of her axial map showed an against-the-rule pattern that appeared symdergoing bilateral LASIK, the patient progressed to have irregular mires and a loss of BSCVA. The patient has been successfully fitted with rigid con- AUGUST 2006 I CATARACT & REFRACTIVE SURGERY TODAY I 71

12 CONCLUSION The cases presented in this article illustrate several points for ophthalmologists to consider. It is clear that treatment practices have changed significantly over the past 7 years based upon longer-term patient outcomes. Our current knowledge and high threshold for diagnosing conditions unsuitable for corneal refractive surgery cannot be applied to surgery performed in the past. As always, surgeons will migrate to the procedures with the best outcomes and fewest side effects, and they will abandon treatment options that have too significant a potential for a less-than-desirable outcome. It is also apparent that the advent of phakic IOLs means that the cornea can be completely avoided as the target tissue for refractive correction. The one shortcoming of refractive IOLs at present relates to astigmatic treatment, but time is sure to bring innovations in this area. [What is the risk of ectasia] if patients undergo a lamellar corneal procedure despite a forme fruste topographic pattern? John F. Doane, MD, FACS Also worth noting is that, with enhanced diagnostic tools such as the Pentacam and Visante OCT (Carl Zeiss Meditec, Inc., Dublin, CA), practice patterns may change or be confirmed compared to utilizing surface topography alone. One lingering question is what the risk of ectasia will be if patients undergo a lamellar corneal procedure despite a forme fruste topographic pattern. One statistic I have seen is a 3% chance of progression (D. Hardten, MD, oral communication, October 2003). Some, but not all, patients will develop the condition. A continued analysis of these rates for either LASIK or PRK will be of value. Finally, it is important to compare the two eyes of each patient. Ophthalmologists must also utilize the complete medical, ocular, and family history as well as the results of a comprehensive ocular clinical examination for every decision they make regarding a patient undergoing excimer laser refractive corneal surgery. It is also imperative to note that experienced ophthalmologists can differ in opinions based on topography and that topographic patterns themselves do not make a diagnosis. Perry S. Binder, MS, MD, is Associate Clinical Professor, nonsalaried, for the Department of Ophthalmology, University of California, San Diego, and practices at the Gordon Binder Vision Institute in San Diego. He is a paid consultant for Intralase Corp. but stated that he holds no financial interest in the products mentioned herein. Dr. Binder may be reached at (858) ; garrett23@aol.com. John F. Doane, MD, FACS, is in private practice with Discover Vision Centers in Kansas City, Missouri, and is Clinical Assistant Professor for the Department of Ophthalmology, Kansas University Medical Center. He acknowledged no financial interest in the products or companies mentioned herein. Dr. Doane may be reached at (816) ; jdoane@discovervision.com. Parag A. Majmudar, MD, is Associate Professor, Cornea Service, Rush University Medical Center, and partner at Chicago Cornea Consultants, Ltd. Dr. Majmudar is a consultant to AMO/VISX, Allergan, Inc., and Inspire Pharmaceutical, Inc., but stated that he holds no financial interest in the products mentioned herein. Dr. Majmudar may be reached at (847) ; pamajmudar@chicagocornea.com. Louis E. Probst, MD, serves as Medical Director, TLC The Laser Eye Centers in Chicago, Madison, Wisconsin, and Greenville, South Carolina. He is a consultant for Advanced Medical Optics, Inc., and TLCVision. Dr. Probst may be reached at (708) Stephen G. Slade, MD, FACS, is in private practice in Houston. He is a consultant for STAAR Surgical Company and Intralase Corp. but stated that he holds no financial interest in the products or companies mentioned herein. Dr. Slade may be reached at (713) ; sgs@visiontexas.com. William B. Trattler, MD, is a corneal specialist at the Center for Excellence in Eye Care in Miami and a volunteer assistant professor of ophthalmology at the Bascom Palmer Eye Institute in Miami. Dr. Trattler is a paid consultant to Allergan, Inc., Inspire Pharmaceuticals, Inc., and Norwood Eyecare, Inc. He has received research funding from Allergan, Inc., Alimera Sciences Inc., and Ista Pharmaceuticals, Inc. Dr. Trattler may be reached at (305) ; wtrattler@earthlink.net. SHARE YOUR FEEDBACK Please us at letters@bmctoday.com with any thoughts, feelings, or questions you have regarding this publication. 72 I CATARACT & REFRACTIVE SURGERY TODAY I AUGUST 2006