Suphi Taneri

Safety, efficacy, and stability indices of LASEK correction in moderate myopia and astigmatism☆☆☆

Purpose: To evaluate the visual outcomes and complications in low to moderate levels of myopia and astigmatism treated with laser‐assisted subepithelial keratectomy (LASEK) with a focus on postoperative recovery. Setting: Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, Massachusetts, USA. Methods: A retrospective analysis of a case series of eyes treated with LASEK from 1996 to July 2002 with a follow‐up of 2 years was performed. The LASEK technique involved creating an epithelial flap with 25 to 45 seconds of exposure to 20% alcohol, ablating the corneal surface using 3 different excimer lasers and nomogram adjustment, and repositioning the flap and applying a bandage contact lens. The main outcome measures were uncorrected visual acuity (UCVA), efficacy index, manifest refraction, best spectacle‐corrected visual acuity (BSCVA), safety index, retreatment rate, and complications. Results: One hundred seventy‐one eyes (85 right eyes and 86 left eyes) of 105 patients were studied. Preoperatively, the mean spherical equivalent was −2.99 diopters (D) ± 1.43 (SD) (range −0.38 to −7.75 D) and the mean cylinder, −0.78 ± 0.73 D. The UCVA ranged from 20/800 to 20/32, and the BSCVA ranged from 20/63 to 20/16; the median was 20/20. One week postoperatively, 96% of eyes had a UCVA of 20/40 or better but definitive visual recovery took more than 4 weeks in some eyes. Approximately 95% of eyes were within ±1.0 D of emmetropia after 4 to 52 weeks; the remaining 5% did not show major deviations. At 4 to 52 weeks, only 1 eye was overcorrected by more than 1.0 D of manifest refraction. The safety index remained close to 1.0 for the follow‐up after 4 weeks. The efficacy index displayed a plateau at 0.9 from 1 month to 1 year. No serious complication (including recurrent erosion syndrome) was encountered. The mean follow‐up was 31 weeks, and the retreatment rate was 2.9% up to 2 years of follow‐up. Conclusions: The long‐term safety and effectiveness of LASEK for the correction of low to moderate myopia and astigmatism were demonstrated. The treatment effect stabilized after 4 weeks.

Surface ablation techniques

The ongoing quest for a safe, simple, effective, minimally invasive, and stable refractive surgical procedure to correct refractive errors has stimulated the development of surface ablation techniques and laser in situ keratomileusis. In this review, we describe the history, patient assessment, techniques, outcomes, and complications of surface ablation (photorefractive keratectomy, laser-assisted sub-epithelial keratectomy, epithelial laser-assisted in situ keratomileusis) and compare the results of various surface techniques. Surface ablation procedures will continue to evolve, with potential improvements in outcomes accompanying future sophisticated ablation profiles and laser technology.

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.

Laser in situ keratomileusis flap thickness using the Hansatome microkeratome with zero compression heads

PURPOSE: To evaluate predictability and possible factors affecting flap thickness in laser in situ keratomileusis (LASIK) using the Hansatome microkeratome (Bausch & Lomb Surgical) with zero compression heads. SETTING: Zentrum für Refraktive Chirurgie Münster, Münster, Germany. METHODS: A prospective nonrandomized comparative (self‐controlled) trial analyzing flap thickness in 153 consecutive patients having LASIK using the Hansatome microkeratome with zero compression was conducted. Two hundred thirty‐eight eyes that had uncomplicated primary LASIK (n = 237) or secondary LASIK (n = 1) by the same surgeon and same technique using 4 different microkeratomes of the same model were evaluated. Each keratome cut was performed with a new Accuglide (Bausch & Lomb) blade in a 160 μm (n = 89), 180 μm (n = 128), or 200 μm (n = 21) Hansatome zero compression head coupled to a 8.5 mm (n = 106) or 9.5 mm (n = 131) suction ring. Only Hansatome elements with the same serial numbers were combined. Ultrasound subtraction pachymetry was routinely used to determine intraoperative flap thickness. Flap thickness was correlated with microkeratome head dimension, suction ring size, preoperative keratometry obtained by Orbscan IIz (Bausch & Lomb), preoperative corneal thickness as obtained by ultrasound pachymetry, refractive error, and age. RESULTS: Measured intraoperative flap thickness was significantly different (P<.01) from predicted flap thickness. The mean flap thickness was 97 μm ± 18 (SD) (range 65 to 163 μm), 111 ± 20 μm (range 61 to 177 μm), and 131 ± 20 μm (range 89 to 162 μm) for the 160 μm, the 180 μm, and 200 μm heads, respectively. There was a good correlation between microkeratome head and corneal flap thickness. However, there was a variability between devices. There was a low correlation between baseline ultrasound pachymetry at the time of surgery and corneal flap thickness (r = .26) and a small effect of ring size. There was no correlation with keratometry, refractive error, or age. CONCLUSIONS: There was a remarkable difference in the flap thickness of microkeratomes of the same make and model. This emphasizes the need to measure intraoperative flap thickness and to evaluate every microkeratome separately. Factors affecting flap thickness seem to be more device dependent than patient related; obtaining flap thickness in the first eye did not enable predictions of the flap thickness in the fellow eye.

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

PurposeTo compare clinical outcomes of wavefront-guided LASIK with and without aspheric compensation in myopic eyes.MethodsIn 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.ResultsResults at the 3-month follow-up: 67 % of PTA-treated eyes and 39xa0% 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 (pu2009=u20090.18). The increase in HOA RMS after APT treatments was statistically significant (pu2009=u20090.003). Change in mean postop spherical aberration (SA) after PTA treatments was not statistically significant (pu2009=u20090.27). The change in SA after APT treatments was statistically significant (pu2009=u20090.001). In both cohorts, mean uncorrected low-contrast visual acuity was statistically not different to preoperative corrected values.ConclusionsAdding 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.

Influence of Mydriatic Eye Drops on Wavefront Sensing With the Zywave Aberrometer

PURPOSEnTo 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).nnnMETHODSnIn 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.nnnRESULTSnPredicted 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.nnnCONCLUSIONSnThe 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.

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.

Influence of Corneal Cross-linking for Keratoconus on Several Objective Parameters of Dry Eye

PURPOSEnTo 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.nnnMETHODSnThis 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.nnnRESULTSnPathologic 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.nnnCONCLUSIONSnCXL 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.

PURPOSEnTo report a case of unilateral keratectasia after INTRACOR, which was followed by an additional excimer LASIK enhancement with a new presbyopia-correcting ablation profile.nnnMETHODSnThe 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.nnnRESULTSnThe 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.nnnCONCLUSIONSnThis 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.

Retinal detachment and phthisis bulbi after implantation of an iris prosthetic system

We report 2 eyes of 2 patients who developed persistent inflammation, hypotony, and total retinal detachment after secondary implantation of an iris prosthetic system (IPS) in association with cataract surgery. The first patient had an uneventful history of 16 years despite a retained intraocular glass foreign body and the second patient, of 38 years after sustaining penetrating corneoscleral injury with iris tissue loss. Both patients were thoroughly assessed clinically, and the enucleated globe in the first patient was examined by light microscopy. Both eyes had chronic inflammation with retrocorneal and cyclitic membrane formation around the artificial iris-lens diaphragm. These cases suggest that implantation of an IPS combined with cataract surgery can trigger decompensation of posttraumatic eyes that had been stable over a long period.