Correction of pseudophakic presbyopia using Lasik with aspheric ablation profiles and a micro-monovision protocol.

PURPOSE: To evaluate the outcomes of Lasik with aspheric ablation profiles and a micro-monovision protocol for correction of presbyopia in pseudophakic patients. PATIENTS AND METHODS: This study included 50 pseudophakic eyes of 25 patients. Full ophthalmic examination, dominant eye tests and tests for tolerance of anisometropia (1 or 2 diopters) were done preoperatively. All cases were treated by Lasik with laser-blended vision technique. The dominant eye corrected to plano, and the nondominant eye corrected with near add in the range from 1.50 to 2.00 diopters. Excimer laser ablation was done using the MEL90 with a 250-Hz pulse rate (Carl Zeiss Meditec, Jena, Germany, Triple-A profile, Lasik mode). The follow-up period was 6 months with visits at 1, 3 and 6 months postoperatively. RESULTS: The mean postoperative uncorrected distant visual acuity at 1 month (0.74 ± 0.11) was significantly lower than the preoperative level (0.84 ± 0.14) (p < 0.001). But it improved at the 3rd (0.80 ± 0.09) and 6th months (0.82 ± 0.10) with no significant difference with the preoperative level (p = 0.344). The mean uncorrected near visual acuity was significantly higher at the 1st (2.94 ± 1.63 J), 3rd (2.95 ± 1.82 J) and 6th (2.92 ± 1.83 J) postoperative months than the preoperative level (2.26 ± 1.48 J) (p < 0.001). Insignificant change in stereopsis was found after surgery (p = 0.849). The micro-monovision was well tolerated (95.8%). CONCLUSION: Lasik with aspheric ablation profiles and a micro-monovision protocol is an effective option for presbyopia correction in pseudophakic patients.

Tear Martix Metalloproteinase-9 and Tissue Inhibitor of Metalloproteinase-1 in Post-Lasik Ectasia.

PURPOSE: To estimate the concentrations of matrix metalloproteinase-9 (MMP-9) and tissue inhibitors of metalloproteinase-1 (TIMP-1) in the tear film of cases with post-Lasik ectasia (PLE) to spot any role of these mediators. SETTINGS: Ophthalmology department, Benha University hospitals, Egypt. METHODS: Twelve eyes of 12 patients with PLE, 30 eyes of 30 patients with KC, 25 eyes of 25 subjects with uncomplicated Lasik and finally 25 eyes of 25 healthy subjects as a control group were studied. Subjects with ocular surface diseases, previous ocular surgeries except for Lasik in PLE group and Lasik group, were excluded. All subjects had full ophthalmic examination and Pentacam imaging. The concentration of tear MMP-9 and TIMP-1 was measured by ELISA. RESULTS: Our results showed a significant elevation in the level of MMP-9 and a significant reduction in the level of TIMP-1 in tear samples from PLE cases (MMP-9 was 59.17 ± 28.15 ng/ml, and TIMP-1 was 110.3 ± 50.6 ng/ml) and also in KC cases (MMP-9 was 53.12 ± 17.35 ng/ml, and TIMP-1 was 105.8 ± 56.3 ng/ml) when compared to post-Lasik group (MMP-9 was 35.65 ± 17.32 ng/ml, and TIMP-1 was 155.2 ± 39.4 ng/ml) and control group (MMP-9 was 31.92 ± 20.78 ng/ml, and TIMP-1 was 162.5 ± 48.2 ng/ml). CONCLUSION: The results pointed to potential role of MMP-9 in the pathogenesis of PLE and also referred to a biochemical similarity between PLE and KC. More studies are needed in the future to investigate larger number of tear mediators.

Preoperative intravitreal bevacizumab use as an adjuvant to diabetic vitrectomy: histopathologic findings and clinical implications.

PURPOSE: To evaluate the effects of intervals between preoperative intravitreal injection of bevacizumab (IVB) and surgery on the components of removed diabetic fibrovascular proliferative membranes. DESIGN: Interventional, consecutive, prospective, comparative case series. PARTICIPANTS: A total of 52 eyes of 49 patients with active diabetic fibrovascular proliferation with complications necessitating vitrectomy. METHODS: Participant eyes that had IVB were divided into 8 groups in which vitreoretinal surgery was performed at days 1, 3, 5, 7, 10, 15, 20, and 30 postinjection. A group of eyes with the same diagnosis and surgical intervention without IVB injection was used for comparison. In all eyes, proliferative membrane specimens obtained during vitrectomy were sent for histopathologic examination using hematoxylin-eosin stain, immunohistochemistry (CD34 and smooth muscle actin), and Masson's trichrome stain. MAIN OUTCOME MEASURES: Comparative analysis of different components of the fibrovascular proliferation (CD34, smooth muscle actin, and collagen) among the study groups. RESULTS: Pan-endothelial marker CD34 expression levels starting from day 5 postinjection were significantly less than in the control group (P < 0.001), with minimum expression (1+) in all specimens removed at or after day 30 postinjection. Positive staining for smooth muscle actin was barely detected in the control eyes at day 1, and consistently intense at day 15 and beyond (P < 0.001). The expression level of trichrome staining was significantly high at day 10, compared with control eyes (P < 0.001), and continued to increase at subsequent surgical time points. CONCLUSIONS: A profibrotic switch was observed in diabetic fibrovascular proliferation after IVB, and our results suggest that at approximately 10 days post-IVB the vascular component of proliferation is markedly reduced, whereas the contractile components (smooth muscle actin and collagen) are not yet abundant.

Evaluation of femtosecond laser in flap and cap creation in corneal refractive surgery for myopia: a 3-year follow-up.

PURPOSE: To evaluate femtosecond laser in flap and cap creation, detect some corneal biomechanical changes, and evaluate dry eye after laser in situ keratomileusis (LASIK), Femto-LASIK, and small incision lenticule extraction (SMILE) with 3-year follow-up. PATIENTS AND METHODS: Preoperative evaluation taken: full ophthalmic examination, Pentacam, ocular response analyzer, ocular surface disease index (OSDI), and tear breakup time (TBUT). LASIK flap was created using Moria microkeratome in 30 eyes (LASIK group) and using VisuMax femtosecond laser in 38 eyes (FS-LASIK group) and SMILE was done by VisuMax in 35 eyes (SMILE group). Postoperative evaluation: anterior segment optical coherence tomography to measure flap and cap thickness, ocular response analyzer to measure corneal hysteresis (CH) and corneal resistance factor (CRF), OSDI, and TBUT at 1, 3, 6, 12, 24, and 36 months after surgery. RESULTS: This study included 103 eyes of 103 patients. The mean deviation of central cap or flap thickness from intended was statistically higher in the LASIK group (P<0.001). Both CH and CRF showed significant reduction postoperatively but were significantly higher in the SMILE group during follow up (P<0.05). The mean OSDI scores were significantly elevated in all groups postoperatively (P<0.01) but were significantly lower in the SMILE group 3 months postoperatively (P<0.05). The mean TBUT was significantly decreased in all groups postoperatively (P<0.01) but was significantly higher in the SMILE group 6 months postoperatively (P<0.05). CONCLUSION: Femtosecond laser is more accurate than microkeratomes. CH and CRF changes were least after SMILE. The three procedures led to significant dryness but for shorter duration with SMILE.

Anterior Chamber Changes After Implantable Collamer Lens Implantation in High Myopia Using Pentacam: A Prospective Study.

INTRODUCTION: The objective of this study was to evaluate the changes of the anterior chamber (AC) of the eye after implantable Collamer lens (ICL) implantation in high myopia by using the Pentacam. METHODS: The prospective study included 34 high myopic patients (34 eyes). All patients were treated with Visian implantable Collamer lens (ICL) (Staar Surgical Co.) implantation. The Pentacam (Oculus) was used for all cases preoperatively and 1, 3 and 6 months postoperatively. AC angle (ACA), AC volume (ACV), central AC depth (CACD), ICL vault, central corneal thickness (CCT), pupil diameter (PD), K readings and intraocular pressure (IOP) were recorded. RESULTS: Our study included 34 eyes of 34 patients, 20 females (59%) and 14 males (41%). Mean ACA was 36.93° ± 4.75° preoperatively, 25.17° ± 5.64° and 25.23° ± 6.05° 1 and 3 months postoperatively (p < 0.001). Mean ACV was 191.24 ± 11.18 mm3 preoperatively, 141.53 ± 16.77 and 142.11 ± 15.89 mm3 1 and 3 months postoperatively (p < 0.001). Mean CACD was 3.59 ± 0.17 mm preoperatively, 2.83 ± 0.24 mm and 2.96 ± 0.25 mm 1 and 3 months postoperatively (p < 0.001). The ICL vault decreased from 0.556 ± 0.033 mm 1 month postoperatively to 0.431 ± 0.056 mm 3 months postoperatively (p < 0.001). There were no statistically significant differences for any of the AC parameters among measurements taken 3, 6 and 12 months postoperatively. There were no statistically significant differences between preoperative and any postoperative measurements of CCT, PD and K readings. CONCLUSIONS: ICL implantation for correction of high myopia leads to significant changes in the anterior chamber angle, volume and depth and insignificant changes in the pupil diameter, CCT and K readings.