Comparative analysis of two femtosecond LASIK platforms using iTRAQ quantitative proteomics.

PURPOSE: New femtosecond laser platforms may reduce ocular surface interference and LASIK-associated dry eye. This study investigated tear protein profiles in subjects who underwent LASIK using two femtosecond lasers to assess differences in protein expression. METHODS: This was a randomized interventional clinical trial involving 22 patients who underwent femtosecond laser refractive surgery with a contralateral paired eye design. Corneal flaps of 22 subjects were created by either Visumax or Intralase laser. Tear samples were collected preoperatively, and at 1 week and 3 months postoperatively using Schirmer's strips. Tear protein ratios were calculated relative to preoperative protein levels at baseline. The main outcome measures were the levels of a panel of dry eye protein markers analyzed using isobaric tagging for relative and absolute quantitation (iTRAQ) mass spectrometry. RESULTS: A total of 824 unique proteins were quantifiable. Tear protein ratios were differentially regulated between the eyes treated with different lasers. The secretoglobulins Lipophilin A (1.80-fold) and Lipophilin C (1.77) were significantly upregulated (P < 0.05) at 1 week postoperatively in Visumax but not in Intralase-treated eyes. At 1 week, orosomucoid1 was upregulated (1.78) in Intralase but not Visumax-treated eyes. In the same eyes, lysozyme, cathepsin B, and lipo-oxygenase were downregulated at 0.44-, 0.64-, and 0.64-folds, respectively. Transglutaminase-2 was downregulated in both groups of eyes. CONCLUSIONS: Different laser platforms induce distinct biological responses in the cornea and ocular surface, which manifests as different levels of tear proteins. This study has implications for surgical technology and modulation of wound healing responses. (ClinicalTrials.gov number, NCT01252654.).

Patient and surgeon experience during laser in situ keratomileusis using 2 femtosecond laser systems.

PURPOSE: To describe the subjective experience of patients and surgeons during laser in situ keratomileusis (LASIK) using the Intralase 60 kHz or the Visumax 500 kHz femtosecond laser. SETTING: Singapore National Eye Centre, Singapore. DESIGN: Prospective randomized clinical study. METHODS: In myopic patients, LASIK was performed with the corneal flap created using the 60 kHz laser in 1 eye and the 500 kHz laser in the contralateral eye. Postoperatively, patients completed a standardized validated questionnaire about their subjective intraoperative experiences (eg, light perception, pain, fear). Surgeons reported their intraoperative experiences and preferences. RESULTS: Loss of light perception occurred in 50.0% of 60 kHz laser cases and 0% of 500 kHz laser cases during docking and in 63.0% and 0% of cases, respectively, during laser flap creation (P < .0001). The mean pain score with the 60 kHz laser was significantly higher during docking (P < .0001) but not during laser flap cutting (P = .006). Subconjunctival hemorrhage occurred in 67.4% of eyes with the 60 kHz laser and in 2.2% of eyes with the 500 kHz laser (P < .0001). The 500 kHz laser was preferred by 78.3% of patients, while 21.7% preferred the 60 kHz laser (P < .0001). The surgeons preferred the 60 kHz laser in 50.0% of cases and the 500 kHz laser in 8.7% (P < .0001); 41.3% had no preference. CONCLUSIONS: Patients preferred surgery with the 500 kHz laser with no loss of light perception, less pain, less fear, and less subconjunctival hemorrhage. Surgeons preferred the 60 kHz laser.

Comparison of efficacy and safety of laser in situ keratomileusis using 2 femtosecond laser platforms in contralateral eyes.

PURPOSE: To compare the efficacy, predictability, and refractive outcomes of laser in situ keratomileusis (LASIK) using 2 femtosecond platforms for flap creation. SETTING: Multisurgeon single center. DESIGN: Clinical trial. METHODS: Bilateral femtosecond LASIK was performed using the Wavelight Allegretto Eye-Q 400 Hz excimer laser system. The Visumax femtosecond platform (Group 1) was used to create the LASIK flap in 1 eye, while the Intralase femtosecond platform (Group 2) was used to create the LASIK flap in the contralateral eye. The preoperative, 1-month, and 3-month postoperative visual acuities, refraction, and contrast sensitivity in the 2 groups were compared. RESULTS: The study enrolled 45 patients. Three months after femtosecond LASIK, 79.5% of eyes in Group 1 and 82.1% in Group 2 achieved an uncorrected distance visual acuity of 20/20 (P=.808). The mean efficacy index was 0.97 in Group 1 and 0.98 in Group 2 at 3 months (P=.735); 89.7% of eyes in Group 1 and 84.6% of eyes in Group 2 were within ± 0.50 diopter of emmetropia at 3 months (P=.498). No eye in either group lost more than 2 lines of corrected distance visual acuity. The mean safety index at 3 months was 1.11 in Group 1 and 1.10 in Group 2 (P=.570). CONCLUSION: The results of LASIK with both femtosecond lasers were similar, and both platforms produced efficacious and predictable LASIK outcomes. FINANCIAL DISCLOSURE: No author has a financial or proprietary interest in any material or method mentioned.

Laser in situ keratomileusis flap measurements: Comparison between observers and between spectral-domain and time-domain anterior segment optical coherence tomography.

PURPOSE: To evaluate the between-observer (interobserver) and between-instrument (intraobserver) variability in flap thickness measurements after laser in situ keratomileusis (LASIK) using spectral-domain and time-domain anterior segment optical coherence tomography (AS-OCT). SETTING: Singapore National Eye Centre. DESIGN: Evaluation of diagnostic test or technology. METHODS: Two independent masked observers measured flap thickness 1 month after LASIK using spectral-domain (RTVue) or time-domain (Visante) AS-OCT. The measurements were taken at central (0.0 mm), -1.5 mm, and +1.5 mm locations. Measurements were repeated to assess between-instrument variability. RESULTS: There was no statistically significant difference in mean flap thickness between the 2 observers at -1.5 mm, 0.0 mm, and +1.5 mm on spectral-domain AS-OCT and at -1.5 mm and +1.5 mm on time-domain AS-OCT (P < .01). There was a statistically significant difference between the 2 observers in the central (0.0 mm) values on time-domain AS-OCT (P=.0008). There was stronger interobserver correlation for spectral-domain AS-OCT at -1.5 mm (r = 0.82), 0.0 mm (r = 0.88), and +1.5 mm (r = 0.88) than for time-domain AS-OCT (r = 0.73, r = 0.62, and r = 0.79, respectively). There was no statistically significant difference in between-instrument measurements. There was stronger between-instrument correlation with spectral-domain AS-OCT than with time-domain AS-OCT at all locations. The mean standard deviation (measure of instrument repeatability) for spectral-domain AS-OCT was 4.19 µm. CONCLUSION: Spectral-domain AS-OCT had closer agreement in between-observer and between-instrument measurements than time-domain AS-OCT and provided more consistent measurements of post-LASIK flap thickness.

Photodynamic Therapy with Verteporfin for Corneal Neovascularisation.

Corneal neovascularization can be a difficult problem to treat. The authors describe a patient with lipid keratopathy secondary to corneal neovascularization treated with photodynamic therapy. Six months following treatment the neovascularization has not returned and the lipid keratopathy has not increased in size. No significant side effects from the treatment occurred. Photodynamic therapy with Verteporfin was a useful treatment modality in this case of corneal neovascularization with associated lipid keratopathy.

Comparison of fibrin glue with sutures for pterygium excision surgery with conjunctival autografts.

PURPOSE: To compare pterygium excision conjunctival autograft surgery using Tisseel fibrin glue versus Vicryl sutures. METHOD: Prospective randomized clinical trial. Fifty patients were randomized into either sutured graft or glued graft groups. Twenty-five received standard conjunctival autograft sutured with Vicryl and 25 received surgery with the autograft placed with Tisseel fibrin glue. Outcome measures include surgical time, patient discomfort, pathology, complications and recurrence rates at 3, 6 and 12 months. Patients were followed up at days 1, 7, 14, 30, 90, 180 and 365. RESULTS: The mean surgical time for the glue group was significantly shorter at 12 min compared with the suture group at 26 min (P < 0.001). Postoperative pain was significantly less at day 1 (P < 0.001) and day 2 (P < 0.05) but was not significantly different following these visits. Complications in the glue group included one patient with an absent graft at week 1 that required revision of the graft. At 3 months there were no recurrences in the glue group and two recurrences in the suture group. The 6- and 12-month recurrence rate was unchanged and not significantly different between the glue and suture groups (both 0/24 and 2/23, respectively). CONCLUSION: Both glued and sutured conjunctival autografting procedures are safe and effective methods for pterygium surgery. The glued autograft recurrence rate at 12 months was similar to that of sutured grafts. Conjunctival autograft with fibrin glue in pterygium surgery decreased surgical time and resulted in less postoperative pain in the first 48 hours but had a higher complication rate.