Influence of a Therapeutic Soft Contact Lens on Epithelial Healing, Visual Recovery, Haze, and Pain After Photorefractive Keratectomy.

OBJECTIVES: To examine the influence of a therapeutic soft contact lens (TSCL) after alcohol-assisted photorefractive keratectomy (PRK) on visual recovery, epithelial closure, pain perception, and haze formation. METHODS: Prospective, randomized, single-center, contralateral eye, patient-masked study. Same surgeon treated 15 patients with bilateral PRK using a Vidaurri Fluid Retention Ring (Katena) with 8.7 mm inner diameter to apply ethanol 18% for 30 sec. Each patient received a TSCL (Balafilcon A, PureVision, Bausch & Lomb) in a randomized fashion in one eye only. RESULTS: Without knowing which eye had a contact lens, four patients preferred the eye with TSCL so much that these patients wanted a TSCL inserted in the second eye as well. Uncorrected distance visual acuity improved postoperatively from day 1 to 3 months from 0.61 to 1.18 with TSCL and from 0.21 to 1.04 without TSCL. Uncorrected distance visual acuity was statistically significantly better on days 1 and 2 with TSCL. Epithelial defect was on average smaller with TSCL. Epithelium was closed at day 4 in all eyes except one without TSCL. Pain perception was significantly lower with TSCL on days 1 and 2. Haze levels after 3 months were significantly lower with TSCL (with 0.09/without 0.45, respectively). One eye without TSCL had haze grade 2 (Fantes). CONCLUSIONS: A TSCL had statistically significantly and clinically meaningful beneficial effects in the first days in visual recovery and pain perception and after 3 months in haze formation. Epithelial healing was slightly quicker with the use of TSCLs (not statistically, but clinically significantly).

Evaluation of epithelial integrity with various transepithelial corneal cross-linking protocols for treatment of keratoconus.

Purpose. Corneal collagen cross-linking (CXL) has been demonstrated to stiffen cornea and halt progression of ectasia. The original protocol requires debridement of central corneal epithelium to facilitate diffusion of a riboflavin solution to stroma. Recently, transepithelial CXL has been proposed to reduce risk of complications associated with epithelial removal. Aim of the study is to evaluate the impact of various transepithelial riboflavin delivery protocols on corneal epithelium in regard to pain and epithelial integrity in the early postoperative period. Methods. One hundred and sixty six eyes of 104 subjects affected by progressive keratoconus underwent transepithelial CXL using 6 different riboflavin application protocols. Postoperatively, epithelial integrity was evaluated at slit lamp and patients were queried regarding their ocular pain level. Results. One eye had a corneal infection associated with an epithelial defect. No other adverse event including endothelial decompensation or endothelial damage was observed, except for epithelial damages. Incidence of epithelial defects varied from 0 to 63%. Incidence of reported pain varied from 0 to 83%. Conclusion. Different transepithelial cross-linking protocols have varying impacts on epithelial integrity. At present, it seems impossible to have sufficient riboflavin penetration without any epithelial disruption. A compromise between efficacy and epithelial integrity has to be found.

Inflammatory response in the anterior chamber after implantation of an angle-supported lens in phakic myopic eyes.

Purpose. To evaluate the inflammatory reaction after implantation of an angle-supported foldable acrylic anterior chamber IOL for myopia correction over time. Methods. Adult individuals seeking vision correction with stable myopia >7.0 D were included. Exclusion criteria are anterior chamber depth <2.8 mm, insufficient endothelial cell density, other preexisting ocular conditions, and prior eye surgery. Laser flare photometry and slitlamp examination were performed before and up to 1 year after implantation of an AcrySof Cachet IOL (Alcon Laboratories, Forth Worth, TX, USA). Postoperative treatment comprised antibiotic eye-drops for 5 days and nonsteroidal anti-inflammatory eye-drops (NSAIDs) for 4 weeks. Results. Average laser flare values of 15 consecutive eyes of 15 patients were 8.3 ± 9.7 preoperatively and 19.0 ± 24.2 (1 day), 24.0 ± 27.5 (1 week), 17.6 ± 13.4 (1 month), 14.9 ± 15.4 (3 months), and 10.0 ± 7.0 (1 year) photon counts/ms after implantation, respectively. Slitlamp examination yielded 0 or 1+ cells (SUN classification) in every one eye throughout the follow-up period. Conclusion. Results indicate a low maximum inflammatory response and a quick recovery to a long-term safe level. The use of NSAIDs seems sufficient in routine cases, thus avoiding potential drawbacks of using corticoids.

Influence of corneal cross-linking for keratoconus on several objective parameters of dry eye.

PURPOSE: To evaluate the potential influence of corneal cross-linking (CXL) with ultraviolet-A light and riboflavin in keratoconic eyes on several objective parameters of dry eye syndrome. METHODS: This prospective single center study included 30 consecutive eyes of 16 patients that underwent CXL with riboflavin and ultraviolet-A treatment (epithelial removal, 30 minutes soaking with riboflavin, 30 minutes of illumination with 365 nm, 3 mW/cm(2), 5 cm distance). Several dry eye syndrome parameters were evaluated preoperatively and 3 and 6 months after the procedure: intra-individual comparison of fluorescein and Rose bengal staining, height of tear film meniscus, and tear film break-up time. RESULTS: Pathologic staining (more than 10 point-shaped areas or diffuse staining) with fluorescein was evident before CXL in 1 eye, 3 months after CXL in 1 eye, and 6 months after CXL in 1 eye. Rose bengal staining 3 and 6 months postoperatively was comparable to preoperative staining. Tear film height was reduced in 2 eyes before CXL and in 4 eyes 3 months postoperatively, and was normal in all eyes after 6 months. The number of eyes with reduced tear film break-up time was not significantly changed. CONCLUSIONS: CXL had no significant impact on several parameters of dry eye syndrome 3 and 6 months postoperatively.

Keratectasia after treating presbyopia with INTRACOR followed by SUPRACOR enhancement.

PURPOSE: To report a case of unilateral keratectasia after INTRACOR, which was followed by an additional excimer LASIK enhancement with a new presbyopia-correcting ablation profile. METHODS: The non-dominant eye of a 49-year-old man with emmetropia was treated with the INTRACOR procedure using the Technolas femtosecond laser (Technolas Perfect Vision GmbH, Munich, Germany) for presbyopia. Neither eye had risk factors for keratectasia. Two years later, a presbyopia-correcting LASIK (SUPRACOR LASIK; Technolas Perfect Vision GmbH) enhancement was performed in the same eye because of deteriorated distance and near visual acuity. RESULTS: The eye treated with INTRACOR followed by SUPRACOR LASIK developed marked keratectasia topographically limited to the area altered by INTRACOR, whereas the fellow eye remained stable and still has no signs of keratoconus. CONCLUSIONS: This case emphasizes the incomplete knowledge of the risk factors for keratectasia following INTRACOR alone and in combination with a SUPRACOR LASIK enhancement. It also suggests that the combined weakening effect of both procedures on corneal mechanical stability may be too strong even in the absence of established risk factors for LASIK surgery.

Aspheric wavefront-guided versus wavefront-guided LASIK for myopic astigmatism with the Technolas 217z100 excimer laser.

PURPOSE: To compare clinical outcomes of wavefront-guided LASIK with and without aspheric compensation in myopic eyes. METHODS: In this observational, single-center study, 134 eyes were treated using an aspheric module in combination with wavefront-guided profiles (PTA-algorithm) and compared to 146 eyes treated with the predecessor wavefront-guided software (APT) that has no aspheric compensation. All treatment plans included the Rochester nomogram that accounts for the preoperative manifest refraction and interaction of higher order aberrations. Active eye-tracking (including cyclorotational movements) was utilized during photoablation. RESULTS: Results at the 3-month follow-up: 67 % of PTA-treated eyes and 39 % of APT-treated eyes achieved an uncorrected distance visual acuity (UDVA) of 20/20 or better. Change in mean higher order aberration root-mean-square (HOA RMS) after PTA treatments was not statistically significant (p = 0.18). The increase in HOA RMS after APT treatments was statistically significant (p = 0.003). Change in mean postop spherical aberration (SA) after PTA treatments was not statistically significant (p = 0.27). The change in SA after APT treatments was statistically significant (p = 0.001). In both cohorts, mean uncorrected low-contrast visual acuity was statistically not different to preoperative corrected values. CONCLUSIONS: Adding an aspheric compensation to wavefront-guided myopic LASIK statistically improved clinical results in terms of visual acuity and refractive outcomes. Low-contrast visual acuity was not negatively affected in either group. While in APT-treated eyes mean HOA RMS and mean SA were significantly increased postoperatively, PTA-treated eyes showed neither induced HOA RMS nor induced SA.

Hypermotility of an iris-fixated anterior chamber phakic intraocular lens due to nontraumatic iris laxity.

PURPOSE: Permanent immovability of phakic intraocular lenses (pIOLs) for the correction of high myopia is crucial in avoiding injury to the corneal endothelium and maintaining visual acuity. Unstable position of iris-fixated pIOLs due to traumatic or nontraumatic disenclavation of the haptic has been described previously. METHODS AND RESULTS: We report a different mechanism of repeated excessive implant motility in both eyes of a young woman who developed late nontraumatic elongation of the iris fibers to which an iris-claw pIOL was fixated. This led to increased motility of the pIOLs with blinking causing mild iritis. Subsequent bilateral successful re-enclavation to other iris fibers ameliorated these symptoms. After 2.5 years, these iris fibers, too, were elongated, causing excessive movements of the pIOLs and consecutive endothelial cell loss necessitating removal of the pIOLs. The etiology of this iris fiber laxity remains unclear. CONCLUSIONS: Surgeons should be aware of this rare potential complication.

Effect of repositioning or discarding the epithelial flap in laser-assisted subepithelial keratectomy and epithelial laser in situ keratomileusis.

PURPOSE: To evaluate the influence of the epithelial flap after epithelial laser in situ keratomileusis (epi-LASIK) and laser-assisted subepithelial keratectomy (LASEK) to correct low to moderate ametropia on visual recovery, epithelial closure, pain, and haze formation. SETTING: Zentrum für Refraktive Chirurgie, Augenabteilung am St. Franziskus Hospital, Münster, Germany. DESIGN: Comparative case series. METHODS: Patients having bilateral epi-LASIK or bilateral LASEK had 1 treatment with a repositioned epithelial flap and 1 treatment with a discarded flap. Patients were masked to the epithelial replacement. Primary outcomes were visual acuity (decimal scale), diameter of epithelial defect, pain score (subjective visual analog scale 0 to 10), and haze formation (Fantes scale). Postoperative visits were at 1, 2, and 4 days and after 3 months. RESULTS: Twenty patients had epi-LASIK and 20 patients had LASEK. The mean increase in uncorrected distance visual acuity from 1 day to 3 months was 0.32 to 0.99 (epi-LASIK flap-on), from 0.41 to 0.98 (epi-LASIK flap-off), from 0.26 to 0.96 (LASEK flap-on), and from 0.37 to 0.92 (LASEK flap-off), respectively. At 4 days, epithelial closure was complete in 79 of 80 eyes. Postoperative pain levels decreased comparably in all groups. Haze levels after 3 months were 0.45, 0.43, 0.35, and 0.35 (epi-LASIK flap-on, epi-LASIK flap-off, LASEK flap-on, LASEK flap-off, respectively). Efficacy indices after 3 months were 1.07, 1.09, 1.11, 1.07, respectively. CONCLUSION: No clinically significant differences in terms of visual recovery, epithelial closure time, pain perception, and haze formation between LASEK and epi-LASIK were detected regardless of epithelial flap retention. FINANCIAL DISCLOSURE: No author has a financial or proprietary interest in any material or method mentioned. Additional disclosures are found in the footnotes.

Influence of mydriatic eye drops on wavefront sensing with the Zywave aberrometer.

PURPOSE: To investigate a potential influence of mydriatic eye drops on wavefront sensing with the Zywave aberrometer (Technolas Perfect Vision) in terms of predicted phoropter refraction (PPR) and higher order aberrations (HOA). METHODS: In this prospective study, 200 myopic eyes were measured in miosis and pharmacologically induced mydriasis with an aberrometer and automated refraction. One hundred eyes were dilated with tropicamide 0.5%+phenylephrine 2.5% eye drops (tropicamide/phenylephrine group), and the remaining 100 eyes with tropicamide 0.5% (tropicamide only group). The PPR values for a pupil diameter of 3.5 mm in miosis and mydriasis, respectively, were compared and correlated to the corresponding values of automated refraction. Changes in HOAs up to the 4th order were recorded. RESULTS: Predicted phoropter refraction values obtained in mydriasis were less myopic than in miosis. The spherical equivalent refraction of PPR differed by an average of 0.36 ± 0.36 diopters (D) in the tropicamide/phenylephrine group. In the tropicamide only group, the difference was 0.24 ± 0.43 D. Sphere of PPR differed by an average of 0.33 ± 0.36 D in the tropicamide/phenylephrine group and by an average of 0.24 ± 0.35 D in the tropicamide only group. Patient age had no major influence on the level of difference. Automated refraction yielded a smaller difference in spherical equivalent refraction. Changes in HOA root-mean-square were statistically significant. CONCLUSIONS: The cycloplegic effect of mydriatic eye drops should be taken into account when interpreting aberration measurements and planning a wavefront-guided ablation. Ideally, the use of mydriatic eye drops should be avoided to minimize refractive surprises.