Faculty Bibliography

PURPOSE/OBJECTIVE:Corneal collagen cross-linking by UVA/riboflavin (X-linking) represents a new method for the treatment of progressive keratoconus and currently is under clinical study. To avoid UVA irradiation damage to the corneal endothelium, the parameters for X-linking are set in a way that effective treatment occurs only in the first 300 microm of the corneal stroma. Here, X-linking not only strengthens the biomechanical properties of the cornea but also induces keratocyte apoptosis. To date, the effectiveness of treatment could be monitored only indirectly by postoperative follow-up corneal topographies or using corneal confocal microscopy. Here we describe a corneal stromal demarcation line indicating the transition zone between cross-linked anterior corneal stroma and untreated posterior corneal stroma. The demarcation line is biomicroscopically detectable in slit-lamp examination as early as 2 weeks after treatment. METHODS:X-linking was performed in 16 cases of progressive keratoconus, and corneas were examined biomicroscopically and by means of corneal topography and pachymetry before and after treatment. RESULTS:In 14 of 16 cases, a thin stromal demarcation line was visible at a depth of approximately 300 microm over the whole cornea after X-linking treatment. CONCLUSION/CONCLUSIONS:This newly observed demarcation line may result from differences in the refractive index and/or reflection properties of untreated versus X-linked corneal stroma and represents an effective tool to biomicroscopically easily monitor the depth of effective X-linking treatment in keratoconus.

In a review of the recent literature, liposuction and tumescent fluid injection are accompanied by hazards of ischemia, flap necrosis, and wound dehiscence at the time of abdominoplasty. The problems that generate complaints from patients and dissatisfaction with tummy tuck surgery are: fullness of flanks and epigastric areas, lack of a posterior lumbar curve, hanging skin over the incision line, and visible scars over the flanks and beyond underwear or swimming suit coverage. The purpose of this article is to introduce modalities to perform liposuctioning of the whole abdomen without confronting the danger of ischemia or flap necrosis. Wide lipoaspiration at the time of abdominoplasty and removing the flanks and epigastric fullness result in a shorter incision line and more natural-looking abdomen. In this article, the authors explain their experience using a new method to omit the complications of classic abdominoplasty surgery in 56 cases performed over a 3-year period (2000-2003).

A bulky nose is a challenging issue to manage, and surgeons have not found the ultimate solution to this problem in the evolution of rhinoplastic surgery. Because of the multiplicity of techniques and controversies published in the literature, it has become confusing for the operating surgeon to find the most appropriate and effective way of solving this frustrating dilemma. The subcutaneous fat is the thickest in the supratip area, and the soft tissue thickness over the tip of the nose varies considerably from patient to patient. The focus of this study was to find a method for reducing the overlying soft tissue of the tip for better re-draping of skin over the nasal skeleton. The hallmark of this technique is to undermine the nasal skin in two layers. We believe that soft tissue trimming in biplane dissection can minimize the thickness of the tip skin in a relatively safe and homogeneous way. With this report we introduce a new method of dissection of nasal soft tissue and of trimming it in different areas of the nose for different purposes. In the authors' opinion, this approach is one of the most effective ways of handling unpliable, thick nasal skin.

BACKGROUND:Repeat operations after refractive surgery have increased in frequency during the past 10 years. The spectrum of the indications for repeat LASIK may have changed. METHODS:All cases of repeat operations after refractive surgery performed between May 1, 2004 and April 30, 2005 at the Institute of Refractive and Ophthalmic Surgery (IROC) were retrospectively investigated regarding indication for repeat surgery and visual and refractive results. The 1-month results were used to estimate the refractive and visual success rate. RESULTS:Of the 76 reoperations, 69 were performed as re-lifts, 3 eyes had new lamellae cut, and 3 cases needed keratoplasties. The reoperations took place 7.5 +/- 13 months after the primary operation (range 0.5 to 60 months). The most frequent indication was residual astigmatism of 0.5 D and more. Visual loss of more than 1 decimal line did not occur and unaided visual acuity increased from 0.64 to 1.05. No complications were reported, however, 3 eyes needed additional enhancement. CONCLUSIONS:Reoperations after LASIK performed as re-lifts appear to be effective and reasonably safe when using the technique described and respecting a residual stromal thickness of 280 microns.

Steep central island (SCI) formation after photorefractive keratectomy (PRK) and laser in situ keratomileusis (LASIK) represents a major drawback in the visual rehabilitation of patients after refractive laser surgery. Because of the small size of SCIs, current ablation algorithms are unable to properly calculate an ablation pattern for customized retreatment. We present the use of a new ablation algorithm for the treatment of SCIs that occurred after PRK or LASIK surgery. This algorithm uses a smaller zone of approximation and takes into account the spherical shift induced by removal of the SCI. In all 3 eyes treated, best spectacle-corrected visual acuity increased to 20/16 and remained stable at the 1- and 3-month follow-up, with disappearance of the SCI in corneal topography. This new treatment algorithm may be of benefit to patients experiencing visual side effects due to SCI formation after PRK or LASIK surgery.

PURPOSE/OBJECTIVE:To compare the results of the Q-factor customized aspheric ablation profile with the wavefront-guided customized ablation pattern for the correction of myopic astigmatism. SETTING/METHODS:Institute for Refractive and Ophthalmic Surgery, Zurich, Switzerland. METHODS:Thirty-five patients were enrolled in a controlled study in which the nondominant eye was treated with the Q-factor customized profile (custom-Q study group) and the dominant eye was treated with wavefront-guided customized ablation (control group). Preoperative and 1-month postoperative high-contrast visual acuity, low-contrast visual acuity, and glare visual acuity, as well as aberrometry and asphericity of the cornea, were compared between the 2 groups. All eyes received laser in situ keratomileusis surgery, and the laser treatment was accomplished with the Wavelight Eye-Q 400 Hz excimer laser. RESULTS:For corrections up to -9 diopters (D) of myopia, there were no statistically significant differences between the 2 groups regarding any visual or optical parameter except coma-like aberrations (3rd Zernike order), where the wavefront-guided group was significantly better 1 month after surgery (P = .002). For corrections up to -5 D (spherical equivalent), the Q-factor optimized treated eyes had a significantly smaller shift toward oblate cornea: DeltaQ15 = 0.25 in Q-factor customized versus DeltaQ15 = 0.38 in wavefront-guided treatment (P = .04). CONCLUSIONS:Regarding safety and refractive efficacy, custom-Q ablation profiles were clinically equivalent to wavefront-guided profiles in corrections of myopia up to -9 D and astigmatism up to 2.5 D. Corneal asphericity was less impaired by the custom-Q treatment up to -5 D of myopia.

BACKGROUND:Nomograms are efficient tools to improve the predictability of refractive procedures by using statistical methods to analyze pre- and postoperative refractive data. The purpose of this work was to analyze the clinical relevance and limitations of nomograms in a case series. METHODS:Computer simulations based on the known unpredictability for refractive outcomes were performed for three different distribution functions of the preoperative refractions. In addition, the clinical applicability was investigated in three different cohorts that underwent laser in situ keratomileusis (LASIK). RESULTS:The use of individual nomograms significantly improves the predictability of the refractive outcome. However, theoretical investigation demonstrates that a homogeneous data distribution within cohorts is a key factor for predictable nomogram calculations. Outliers within the cohorts are not integrated into the nomogram calculation due to the mathematical model used. CONCLUSIONS:Nomograms are helpful for improving refractive outcomes. However, they are currently limited to approximately 90% within +/-0.5 D.

Although of benign nature and slowly progressive, paranasal sinus mucoceles may, depending on their localization, cause a multitude of ophthalmological symptoms due to compression and displacement of adjacent tissue. Here we report the unusual case of a patient suffering from a progressively growing giant mucocele that developed years after ENT surgery and that was neglected for almost 2 decades despite massive symptoms. This case report demonstrates the importance of including mucoceles of the paranasal sinuses into the differential diagnosis of unilateral or bilateral proptosis.

The predictability and quality of results in corneal refractive laser surgery are determined by a number of factors. Here, the calculation and choice of the ablation profile represent central elements. Our growing knowledge about the physical and optical properties of the eye in recent years has led to the development of different strategies in the generation of ablation profiles. This review describes the currently used ablation profiles with their advantages and disadvantages and provides an outlook on future methods for the calculation of ablation profiles.