Wiping microkeratome blades with sterile 100% alcohol to prevent diffuse lamellar keratitis after laser in situ keratomileusis

Incidence of diffuse lamellar keratitis after LASIK with 15 KHz, 30 KHz, and 60 KHz femtosecond laser flap creation

PURPOSE

To compare the incidence of diffuse lamellar keratitis (DLK) after laser in situ keratomileusis (LASIK) with flap creation using the 15 kHz (FS15), 30 kHz (FS30), or 60 kHz (FS60) femtosecond laser.

SETTING

University-based academic practice, Ann Arbor, Michigan, USA.

DESIGN

Retrospective comparative case series.

METHODS

Consecutive myopic LASIK cases performed between January 1, 2005, and June 1, 2007, using the IntraLase FS15, FS30, or FS60 femtosecond laser for flap creation were reviewed. Preoperative clinical characteristics, treatment parameters, and intraoperative and postoperative complications were recorded. Statistical comparisons were made using repeated measures analysis, analysis of variance, chi-square, and Fisher exact tests.

RESULTS

Five hundred twenty eyes of 274 patients were included in the study. One hundred seventy-six eyes (93 patients) were treated with the FS15 laser, 180 eyes (93 patients) with the FS30 laser, and 164 eyes (89 patients) with the FS60 laser. Seventeen eyes (10%) in the FS15 laser group, 24 eyes (13%) in the FS30 laser group, and 23 eyes (14%) in the FS60 laser group developed DLK. There was no statistically significant difference in the incidence of DLK between the 3 groups (P = .68).

CONCLUSION

There was no significant difference in the incidence of DLK between the FS15, FS30, and FS60 groups.

The effect of diffuse lamellar keratitis on visual acuity and contrast sensitivity following LASIK

Purpose

To evaluate visual outcome and the changes of contrast sensitivity (CS) after diffuse lamellar keratitis (DLK).

Methods

Using retrospective chart review, 48 eyes of 25 patients who underwent laser in situ keratomileusis (LASIK) with Visx S4 (VISX Inc., Santa Clara, CA) and M2 (Moria, France) and who were followed for at least six months were included. They were divided into two groups: DLK and non-DLK, by diagnosis of DLK or its absence after LASIK. Postoperative logMAR visual acuities and logCS measured using the VCTS® 6500 (Vistech Consultants, Inc., Dayton, OH) were compared with preoperative values in the DLK and non-DLK groups at three and six months after LASIK.

Results

There was no difference in logMAR visual acuity between the DLK and non-DLK groups until the sixth postoperative month. However, CS was significantly decreased at 12 and 18 cycle/degree compared with preoperative values (p=0.043 and p=0.045, respectively) in the DLK group, whereas CS was significantly increased at 12 cycle/degree in the non-DLK group (p=0.042) at six months.

Conclusions

DLK seemed to be strongly associated with a postoperative decrease of CS.

Matched Population Comparison of the Visian Implantable Collamer Lens and Standard LASIK for Myopia of -3.00 to -7.88 Diopters

PURPOSE

To compare matched populations of LASIK and Visian Implantable Collamer Lens (ICL) cases in the correction of myopia between -3.00 and -7.88 diopters (D).

METHODS

One hundred sixty-four LASIK eyes with prospective data collected from a single center and 164 ICL eyes from the multicenter US ICL Clinical Trial were compared in this observational non-randomized study. The LASIK and ICL groups were well matched for age, gender, and mean level of preoperative spherical equivalent refraction.

RESULTS

At 6 months, best spectacle-corrected visual acuity (BSCVA) > or = 20/20 was 85% with LASIK and 95% with ICL (P = .003) compared to preoperative values of 93% and 88%, respectively (P = .292). Loss of > or = 2 lines of BSCVA was significantly lower with the ICL at 1 week (0.6% vs 10%, P < .001) and 1 month (7% vs 0%, P = .001) with comparable outcomes at 6 months (0% vs 1%). At 6 months postoperatively, uncorrected visual acuity (UCVA) > or = 20/15 (11% vs 25%, P = .001) and > or = 20/20 (49% vs 63%, P = .001) was better in the ICL cases. Predictability within 0.50 D at 6 months for ICL cases was 85% (67% LASIK, P < .001); 97% of ICL cases were within 1.00 D (88% LASIK, P = .002). Refractive stability (+/- 0.50 D) between 1 and 6 months was 93% with ICL compared to only 82% with LASIK (P = .006).

CONCLUSIONS

The ICL performed better than LASIK in almost all measures of safety, efficacy, predictability, and stability in this matched population comparison, supporting the ICL as an effective alternative to existing refractive laser surgical treatments for the range of myopia studied.

Observation of the corneal flap interface with metal particles in a rabbit model

PURPOSE

To observe changes, such as diffuse lamellar keratitis, at the corneal interface when metal particles from microkeratome blades were left in rabbit eyes.

SETTING

Department of Ophthalmology, Tokyo Dental College, Suidobashi Hospital, Tokyo, Japan.

METHODS

Following the creation of a corneal flap with microkeratome, metal particles from a microkeratome blade were placed at the corneal interface in 14 rabbit eyes. Microscopic and histopathologic changes were compared with those in the control eyes (n = 4), which did not receive any metal particles. Each examination was conducted at 3 days, 2 weeks, and 1 and 3 months postoperatively. The change in the depth of the metal particles was also measured.

RESULTS

Slitlamp examination did not show an inflammatory reaction or corneal opacification in any eye (100%) with metal particles at the flap interfaces. Histopathologic examinations showed no obvious changes at the flap interfaces or around the metal particles in any eye.

CONCLUSION

Inflammatory reactions, such as diffuse lamellar keratitis, do not appear to be induced by metal particles from the microkeratome blade itself.