Francisco J. Garcia-Ferrer

Intraocular lens power calculation after laser in situ keratomileusis for myopia and hyperopia: A standardized approach

Purpose. (1) To determine the effect of myopic and hyperopic laser in situ keratomileusis (LASIK) on calculation of intraocular lens (IOL) power. (2) To determine a standard way to approach the IOL power determination after LASIK, and (3) To compare different suggested methods. Methods. Biometric analysis and theoretical calculation of IOL powers for eyes undergoing LASIK for myopia and hyperopia were performed. Results. Manual keratometry after LASIK for myopia resulted in underestimation of IOL power. Manual keratometry after hyperopic LASIK resulted in overestimation of IOL power. The amount of error was directly related to the amount of correction by LASIK. Conclusion. The pre-LASIK refraction can be used theoretically to determine an accurate IOL power.

Surgical monovision and monovision reversal in LASIK.

Purpose: This study was designed to assess the success of surgical monovision in presbyopic patients. Methods: A university refractive surgery center retrospective chart review of 82 patients who elected to undergo surgical monovision with laser in situ keratomileusis (LASIK) between January 2000 and January 2003 was conducted. Specific factors included for analysis included preoperative and postoperative defocus spherical equivalent, whether the patient underwent enhancements, whether the patient underwent a preoperative monovision trial with contact lens, and whether the patient underwent monovision reversal. Results: Eighty-two patients who underwent LASIK for monovision were analyzed. Mean preoperative spherical equivalent in the distance-corrected eye was −4.07 (standard deviation (SD), 2.49); for the eye corrected for near vision, mean preoperative spherical equivalent was −4.10 (SD, 2.56). Postoperative spherical equivalent in the distance eyes was −0.01 (SD, 0.38) and in the near eyes −1.24 (SD, 0.91). There were 6 enhancements in the near eyes (7%) and 17 enhancements in the distance vision eyes (21%). This difference was statistically significant (P = 0.007). Thirty patients underwent a contact lens trial of monovision before LASIK, and none of those patients elected monovision reversal. There were 52 patients who did not undergo a contact lens monovision trial before LASIK monovision, and 2 of these patients underwent monovision reversal. Monovision success in this population was 97.6%. Conclusion: Surgical monovision can help presbyopic patients achieve their goal of reduced dependence on spectacles. A trial of monovision contact lenses or spectacles may be important in helping surgeons select patients for successful surgical monovision.

Analysis of intraocular lens power calculation in post-radial keratotomy eyes

Purpose: To determine whether refractive complications can be prevented by applying the currently most accurate method of intraocular lens (IOL) power calculation in the post‐radial keratotomy (RK) patient. Setting: Department of Ophthalmology, University of California, Davis, Sacramento, and American Eye Institute, Cedars Sinai Medical Center, Los Angeles, California, USA. Methods: Twenty‐four eyes having cataract surgery after RK were studied retrospectively for the final postcataract refraction and for the target refraction used in selecting the IOL. Nine of the eyes were further studied for the keratometry (K) values obtained with different methods and for the theoretical postoperative refraction with an IOL aiming for plano or −1.50 diopters (D) based on the known flatter calculated K, axial length, power of the implanted IOL, and refraction after cataract surgery. Results: Implantation of an IOL aiming for plano in the 24 post‐RK eyes would have resulted in a hyperopic refraction in 83.4% cases. The choice of an IOL targeted at myopia reduced the frequency of hyperopia to 42.0% (24 cases). Selection of an IOL calculated with a flatter calculated K and aiming for plano decreased the frequency of hyperopia to 44.4%; however, aiming for −1.50 D still resulted in hyperopia in 44.4% of eyes (9 cases). Conclusions: Unintentional hyperopia can be significantly decreased but not eliminated as a complication of post‐RK cataract surgery. The accuracy of the IOL power determination can be improved if myopia is targeted as the postcataract surgery refractive error and the flatter calculated K is used in the IOL determination.

Cataract surgery practice patterns in the United States Veterans Health Administration.

&NA; To document current cataract surgery practice patterns of ophthalmologists in the United States Veterans Health Administration, an anonymous online 27‐question survey was emailed to the 132 members of the Association of Veterans Affairs Ophthalmologists. The results were tabulated in a computerized database and analyzed with descriptive statistics. The response rate was 53% (70/132); 89% (62/70) of the respondents performed cataract surgery. Sixty percent (36/60) of the responding cataract surgeons were full‐time employees, and most (85%, 51/60) trained residents. Common practices among them included partial coherence interferometry for biometry (81%, 47/58), topical anesthesia (57%, 33/58), clear corneal incisions (91%, 53/58), and acrylic single‐piece intraocular lens (IOL) implantation (97%, 56/58). Eighty‐three percent (48/58) offered toric IOLs at their facilities. These results will help benchmark cataract surgery practice patterns in teaching hospitals and facilitate comparison with cataract surgery in other settings. Financial Disclosure: No author has a financial or proprietary interest in any material or method mentioned.

SUPERFICIAL HYPERTROPHIC DENDRIFORM EPITHELIOPATHY POST-KERATOPLASTY

Purpose To describe a distinct and unusual superficial dendriform keratopathy that can be seen in postkeratoplasty eyes. Method Three Caucasian women in their sixth decade of life were referred to the Corneal and External Disease Service at the University of California, Davis, and underwent penetrating keratoplasty for different diagnoses. After keratoplasty, hypertrophic dendriform epithelial lesions were observed. These were refractory to debridement as well as topical antibiotic and steroid combinations. Immunofluorescent antibody testing was performed in all cases to rule out herpetic infection, and the patients were treated with nonpreserved lubricants and medications to eliminate medication toxicity as the cause of the lesions. Results All three patients in this series developed raised, hypertrophic epithelial lesions after keratoplasty, which were refractory to therapy. Comfort and mild increase in visual activity were restored with the use of thin, moderate water content therapeutic contact lenses. Conclusions Superficial hypertrophic dendriform epitheliopathy is a distinct syndrome that occurs postkeratoplasty in patients with preexisting chronic ocular inflammation, tear dysfunction, and/or lid disease exacerbated by the toxic effects of postoperative topical medication.

Superficial hypertrophic dendriform epitheliopathy: a follow-up series.

Purpose: To report the interval courses of previously reported cases of superficial hypertrophic dendriform epitheliopathy (SHDE) and to describe 3 new cases of this uncommon entity following penetrating keratoplasty. Method: Retrospective chart review. Results: We report follow-up on 3 previously described cases of SHDE, including discussion of cases and their clinical course. All 3 patients had persistent surface abnormalities complicating graft success resulting in poor visual outcomes. Three new cases of SHDE are discussed with a summary of the ocular findings and treatment. All patients underwent multiple penetrating keratoplasties for recurrent graft failures resulting from chronic postkeratoplasty surface keratopathy. Conclusions: SHDE is a rare complication of penetrating keratoplasty that can lead to delayed healing, chronic derangement of the corneal surface, corneal scarring, and an increased risk of graft rejection. Understanding and recognizing this entity is crucial for maximizing graft outcomes. Further investigation of the pathogenesis is necessary for complete understanding and management of the disorder.