Ana Paula Canto

Diagnosis of Ocular Surface Lesions Using Ultra-High Resolution Optical Coherence Tomography

PURPOSE To assess the use of ultra-high-resolution (UHR) optical coherence tomography (OCT) in the diagnosis of ocular surface lesions. DESIGN Prospective, noncomparative, interventional case series. PARTICIPANTS Fifty-four eyes of 53 consecutive patients with biopsy-proven ocular surface lesions: 8 primary acquired melanosis lesions, 5 amelanotic melanoma lesions, 2 nevi, 19 ocular surface squamous neoplasia lesions, 1 histiocytosis lesion, 6 conjunctival lymphoma lesions, 2 conjunctival amyloidosis lesions, and 11 pterygia lesions. INTERVENTION Ultra-high-resolution OCT imaging of the ocular surface lesions. MAIN OUTCOME MEASURES Clinical course and photographs, UHR OCT image, and histopathologic findings. RESULTS Ultra-high-resolution OCT images of all examined ocular surface lesions showed close correlation with the obtained histopathologic specimens. When clinical differential diagnosis of ocular surface lesions was broad, UHR OCT images provided optical signs indicating a more specific diagnosis and management. In cases of amelanotic melanoma, conjunctival amyloidosis, and primary histiocytosis and in 1 case of ocular surface squamous neoplasia, UHR OCT was instrumental in guiding the diagnosis. In those cases, UHR OCT suggested that the presumed clinical diagnosis was incorrect and favored a diagnosis that later was confirmed by histopathologic examination. CONCLUSIONS Correlations between UHR OCT and histopathologic findings confirm that UHR OCT is an adjunctive diagnostic method that can provide a noninvasive means to help guide diagnosis and management of ocular surface lesions. FINANCIAL DISCLOSURE(S) The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Epithelial ingrowth after LASIK: clinical characteristics, risk factors, and visual outcomes in patients requiring flap lift.

PURPOSE To describe clinical characteristics, risk factors, and visual outcomes in patients requiring flap lift for epithelial ingrowth following LASIK. METHODS Consecutive, noncomparative, retrospective case series of eyes requiring flap lift for epithelial ingrowth following LASIK from June 2003 through July 2011 at a tertiary care, university-based eye hospital. Main outcome measures were uncorrected distance visual acuity (UDVA) and corrected distance visual acuity (CDVA) at 1 and 3 months and recurrence of epithelial ingrowth. RESULTS Forty-five eyes were included. Laser in situ keratomileusis retreatment was the most common etiologic factor for epithelial ingrowth (28/45 eyes [62%]). All patients were treated with flap lift and scraping. Mean logMAR UDVA at presentation was 0.28 (Snellen equivalent 20/38). Mean logMAR UDVA at 3 months was 0.17 (Snellen equivalent 20/30) with 53% of eyes 20/25 or better. Mean logMAR CDVA at 3 months was 0.06 (Snellen equivalent 20/23) with 78% of eyes 20/25 or better. Epithelial ingrowth into the central cornea portended a trend towards UDVA worse than 20/25 or worse at 3-month follow-up (hazard ratio [HR] 5.54, 95% confidence interval [CI]: 0.98-31.3, P=.05) and CDVA worse than 20/25 at 3-month follow-up (HR 4.32, 95% CI: 0.85-21.9, P=.08). Recurrence after treatment was 31% at 3 months and 36% at 1 year. Risk factors for recurrence included: infectious etiology of ingrowth (HR 5.7, 95% CI: 1.11-29.1, P=.04), use of microkeratome for primary LASIK (HR 4.64, 95% CI: 1.07-20.1, P=.04), and hyperopic primary LASIK (HR 2.49, 95% CI: 0.98-6.31, P=.06). CONCLUSIONS Patients undergoing flap lift for the treatment of epithelial ingrowth have a relatively high rate of recurrence but good visual acuity outcomes.

The use of Bowman's layer vertical topographic thickness map in the diagnosis of keratoconus.

PURPOSE To evaluate the use of Bowmans layer (BL) vertical topographic thickness maps in diagnosing keratoconus (KC). DESIGN Prospective, case control, interventional case series. PARTICIPANTS A total of 42 eyes: 22 eyes of 15 normal subjects and 20 eyes of 15 patients with KC. INTERVENTION Bowmans layer 2-dimensional 9-mm vertical topographic thickness maps were created using custom-made ultra high-resolution optical coherence tomography. MAIN OUTCOME MEASURES Bowmans layer average and minimum thicknesses of the inferior half of the cornea, Bowmans ectasia index (BEI; defined as BL minimum thickness of the inferior half of the cornea divided by BL average thickness of the superior half of the cornea multiplied by 100), BEI-Max (defined as BL minimum thickness of the inferior half of the cornea divided by BL maximum thickness of the superior half of the cornea multiplied by 100), keratometric astigmatism (Ast-K) of patients with KC, and average keratometric (Avg-K) readings. RESULTS In patients with KC, BL vertical thickness maps disclosed localized relative inferior thinning of the BL. Inferior BL average thickness (normal = 15±2, KC = 12±3 μm), inferior BL minimum thickness (normal = 13±2, KC = 7±3 μm), BEI (normal = 91±7, KC = 48±14), and BEI-Max (normal = 75±8; KC = 40±13) all showed highly significant differences in KC compared with normal subjects (P< 0.001). Receiver operating characteristic (ROC) curve analysis showed excellent predictive accuracy for BEI and BEI-Max with 100% sensitivity and specificity (area under the curve [AUC] of 1) with cutoff values of 80 and 60, respectively. The AUC of inferior BL average thickness and minimum thickness were 0.87 and 0.96 with a sensitivity of 80% and 93%, respectively, and a specificity of 93% and 93%, respectively. Inferior BL average thickness, inferior BL minimum thickness, BEI, and BEI-Max correlated highly to Ast-K (R = -0.72, -0.82, -0.84, and -0.82, respectively; P< 0.001) and to Avg-K (R = -0.62, P< 0.001; R = -0.59, P = 0.001; R = -0.60, P< 0.001; and R = -0.59, P = 0.001, respectively). CONCLUSIONS Bowmans layer vertical topographic thickness maps of patients with KC disclose characteristic localized relative inferior thinning. Inferior BL average thickness, inferior BL minimum thickness, BEI, and BEI-Max are qualitative and quantitative indices for the diagnosis of KC that accurately correlate with the severity of KC. In our pilot study, BEI and BEI-Max showed excellent accuracy, sensitivity, and specificity in the diagnosis of KC.

Comparison of IOL power calculation methods and intraoperative wavefront aberrometer in eyes after refractive surgery.

PURPOSE To compare preoperative methods for calculating intraocular lens (IOL) power versus the intraoperative wavefront aberrometer in eyes with a history of refractive surgery. METHODS A retrospective study of 46 eyes (33 patients) with previous refractive surgery that underwent subsequent cataract surgery was conducted. Suggested IOL power predicted by ORange intraoperative wavefront aberrometer (WaveTec Vision Systems, Inc., Aliso Viejo, CA) was compared to power predicted by the (1) SRK-T formula using keratometry and axial length measurements from the IOLMaster (Carl Zeiss Meditec, Dublin, CA), (2) average central keratometry (Avg K) from corneal topography, and (3) average IOL power predicted by the American Society of Cataract and Refractive Surgery (ASCRS) web site. No historical information was used for the calculations. IOL power required for emmetropia was back-calculated using manifest refraction and implanted IOL power after cataract surgery. RESULTS Mean age was 60 ± 7.9 years. Fifteen percent had a history of myopic photorefractive keratectomy (n = 7), 57% myopic LASIK (n = 26), 13% hyperopic LASIK (n = 6), and 22% radial keratectomy (RK) (n = 10). In 37% of cases, ORange predicted IOL power to within ±0.50 diopters (D) of emmetropia, compared to 30% for IOLMaster keratometry, 26% for Avg K, and 17% for ASCRS web site. In eyes after myopic treatment, ORange, IOLMaster, Avg K, and ASCRS web site predicted within ±0.50 D of emmetropia in 39%, 27%, 24%, and 18%, respectively, and within ±1.0 D in 60%, 39%, 39%, and 51%, respectively. In eyes after RK, ORange, Avg K, and ASCRS web site predicted to within ±0.50 D of emmetropia in 14% and the IOLMaster in 43% cases. CONCLUSIONS Although the ORange most often predicted to within ±0.5 D of emmetropia, no method was able to achieve this accuracy more than 50% of the time. Predictions for eyes after RK were worse than for other types of refractive procedures.

Femtosecond laser–assisted technique for performing bag-in-the-lens intraocular lens implantation

&NA; We describe a technique for femtosecond laser–assisted bag‐in‐the‐lens (BIL) intraocular lens (IOL) implantation. Anterior capsulotomy and lens division into small pieces are performed by the laser. A fluid‐filled interface makes it possible to re‐dock the laser to the eye for posterior capsulotomy after the eye has been opened for lens aspiration without complications. The integrated optical coherence tomography also visualizes the posterior capsule, allowing a centered central posterior capsulotomy for uncomplicated IOL positioning. In 31 patients, no complications were observed within a 1‐month follow‐up. Femtosecond laser–assisted cataract surgery facilitated the BIL technique. Financial Disclosure Drs. Dick and Culbertson are members of the medical advisory board of Optimedica Corp. No other author has a financial or proprietary interest in any material or method mentioned.

Femtosecond laser-assisted retreatment for residual refractive errors after laser in situ keratomileusis

Purpose To study the utility of creating an additional side cut within the old laser in situ keratomileusis (LASIK) flap using a femtosecond laser to reduce the incidence of epithelial ingrowth in patients having retreatments for residual refractive errors after LASIK. Setting Bascom Palmer Eye Institute, Miller School of Medicine, Miami, Florida, USA. Design Comparative case series. Methods On a chart review of all cases that had retreatment between January 2004 and April 2011, eyes in which an additional side cut with the femtosecond laser within the old LASIK flap margin was created were classified as Group 1. All eyes having retreatment using traditional flap‐relifting techniques between January 2008 and April 2011 were classified as Group 2. Results Twenty‐four eyes of 18 patients had femtosecond laser–assisted retreatment with side cut only (Group 1), while 103 eyes of 80 patients had a flap‐lift LASIK enhancement (Group 2). Twenty‐seven cases of epithelial ingrowth were identified in the 2 groups, 4 cases (17%) in the side‐cut group and 23 cases (22%) in the flap‐lift group. There was a statistically significant difference between the 2 groups in the incidence of epithelial ingrowth in patients in which the microkeratome was used as the initial method of flap creation (P<.05). Conclusion Femtosecond laser–assisted side‐cut LASIK resulted in a statistically significant lower incidence of epithelial ingrowth after stratification because of the higher risk for epithelial ingrowth in patients who had primary LASIK with microkeratome flaps. Financial Disclosure No author has a financial or proprietary interest in any material or method mentioned.

Factors affecting DSAEK graft lenticle adhesion: An in vitro experimental study

Purpose: The aim of this study was to evaluate different factors that affect Descemet stripping automated endothelial keratoplasty (DSAEK) donor graft lenticle adhesion to the recipient cornea. Methods: This experimental study included 10 eye bank recipient corneas and 10 donor DSAEK lenticles. Recipient corneas were mounted on an artificial anterior chamber (AC), whereas donor lenticles were placed beneath the host cornea. Using optical coherence tomography and imaging software, the interface gap (IG) between the donor and recipient cornea was quantified to evaluate the effect of variations in AC air fill pressure, AC air fill duration, corneal massage, and corneal venting incisions on DSAEK donor graft lenticle adhesion. Results: Different intraocular pressures (IOP) under air for the same time intervals, do not significantly correlate with the IG; nevertheless, it was noticed that the IG decreases as the IOP increases. With respect to the magnitude of AC IOP, there was no statistically significant difference when comparing 10 mm Hg with 30 mm Hg and assessing IG (P = 0.4). Complete air–fluid exchange resulted in significantly higher IG when compared with AC air bubble of 10 and 30 mm Hg that was sustained for 1 hour (P < 0.05). Furthermore, corneal surface massage did not facilitate DSAEK graft adhesion (P = 0.59). Finally, paracentral venting incisions followed by interface fluid aspiration seemed to significantly decrease the IG (P = 0.014). Conclusions: Corneal venting incisions and higher AC IOP values seem to facilitate DSAEK donor graft lenticle adhesion to the recipient cornea.

Complications of Femtosecond Laser-Assisted Re-treatment for Residual Refractive Errors After LASIK

PURPOSE To report complications of femtosecond laser-assisted re-treatment by the creation of side cuts within the old flaps for residual refractive error after primary LASIK in two patients. METHODS Case report. RESULTS Three eyes of two patients had complications with a circumferential sliver of stromal tissue displaced during surgery due to overlap of old and new side cuts. The displaced tissue was repositioned and corneal anatomy was restored. Two of three eyes demonstrated improvement in the uncorrected visual acuity, whereas one eye lost two lines of corrected visual acuity due to loss of tissue at side cut resulting from flap manipulation, which was done at 1 week. CONCLUSIONS These cases demonstrate a complication of femtosecond laser-enabled side-cut for LASIK enhancement and factors that may lead to this complication and precautions to avoid it.

Atypical presentation of Salzmann nodular degeneration diagnosed with ultra-high-resolution optical coherence tomography.

A 59-year-old woman presented with bilateral, peripheral, circular corneal infiltrates. There was a clear zone separating the outer margin of the degeneration from the limbus in both eyes. The inner margins were indistinct. Ultra-high-resolution optical coherence tomography (UHR-OCT) imaging demonstrated subepithelial infiltrations with epithelial thinning and corneal surface elevation. The infiltrate was accompanied by significant stromal scarring, which reached deep layers of the corneal stroma. UHR-OCT findings were consistent with Salzmann nodular degeneration. UHR-OCT can be used as an optical biopsy to diagnose atypical corneal degenerations without tissue sampling.

Relaxing Incisions for Astigmatism Correction in ReLACS

Cataract surgery in the last decade has undergone significant changes, with the primary focus shifting from reducing complications to improving refractive outcomes. Refractive cataract surgery refers to the uncomplicated removal of a cataract with a major objective of minimizing postoperative spectacle dependence. The reduction of refractive astigmatism is an important component of minimizing postoperative spectacle dependence and is facilitated by the availability of femtosecond (FS) laser technology.