A Critical Evaluation of Refractive Outcomes Following LASIK for Moderate to High Astigmatism Using Two Excimer Laser Platforms.

PURPOSE: To calculate the surgically induced astigmatism (SIA) following LASIK and identify any association between SIA and the target induced astigmatism (TIA) at 1 year postoperatively. METHODS: The SIA was calculated using the TIA and residual astigmatism values for [A] myopic astigmatism and [B] mixed astigmatism treated with either the [I] WaveLight Allegretto EyeQ 400-Hz (Alcon Laboratories, Inc. Fort Worth, TX) or [II] Schwind Amaris 750S (Schwind eye-tech-solutions, Kleinostheim, Germany) platforms. The TIA and corresponding SIA results were analyzed using various techniques. RESULTS: Key findings were the negative SIA power (y1) was significantly correlated with negative TIA power (x1) and sine of the TIA axis (x2) as follows: [A] I, y1= 0.829x1-0.403x2-0.325 (F = 87.76, r = 0.804, P < .001, n = 127); II, y1= 0.891x1-0.037x2-0.192 (F = 240.06, r = 0.901, P < .001, n = 119) and [B] I, y1= 1.063x1+0.233x2+0.411 (F = 990.99, r = 0.881, P < .001, n = 61); II, y1= 1.029x1-0.115x2+0.322 (F = 270.12, r = 0.908, P < 0.001, n = 111). The sine of negative SIA axis (y2) was significantly correlated with negative TIA power (x1) and TIA axis (x2) as follows: [A] I, y2 = 0.951x2-0.007x1+0.008 (F = 446.58, r = 0.950, P < .001, n = 127); II, y2 = 0.856x2+0.007x1+0.105 (F = 277.18, r = 0.912, P< .001, n = 119) and [B] I, y2 = 0.953x2+0.009x1+0.075 (F = 362.6, r = 0.963, P < .001, n = 61); II, y2 = 0.977x2-0.004x1+0.002 (F = 2910.9, r = 0.990, P < .001, n = 111). CONCLUSIONS: The predicted SIA power was up to 12% less than expected in cases of -6.00 diopters cylinder treated for myopic astigmatism using the Allegretto platform. The mean predicted angle of error (the angle between the SIA and TIA axes) was less than 4°, increasing to 12° for against-the-rule astigmatism. The Allegretto platform tended toward a clockwise axis rotational error, whereas the Amaris platform tended toward the opposite. [J Refract Surg. 2017;33(2):104-109.].

Comparison of Verisyse and Veriflex Phakic Intraocular Lenses for Treatment of Moderate to High Myopia 36 Months after Surgery.

PURPOSE: To compare refractive stability, endothelial cell count (ECC), incidence of complications, and patients' satisfaction between a rigid Verisyse (group I, n = 198) and foldable Veriflex (group II, n = 212) phakic intraocular lenses (pIOL) over 36 months postop. MATERIALS AND METHODS: This was a retrospective study. Patients' satisfaction and incidence of photic phenomena were evaluated at one month and one year postop. Data were analyzed to determine difference between groups for astigmatism, mean spherical equivalent (MRSE), uncorrected (UDVA) and corrected (CDVA) monocular distance visual acuity, complication rate (acute and chronic), and ECC. Differences were considered statistically significant when p < 0.05. RESULTS: Group II cases had significantly higher UDVA, CDVA, and lower astigmatism during the entire follow-up. There was no significant difference in mean MRSE or mean ECC postoperatively. In both groups, mean ECC reduced significantly at one month postop, followed by a gradual linear decline between 1 and 36 months of 22.4 cells/mm2/annum (group I) and 13.32 cells/mm2/annum (group II). Overall complication rates were ≤ 10% with no significant inter-group differences. Group I patients reported lower incidence of halos at one month but more problems with night vision at one year compared with group II. Overall satisfaction was high and total incidence of reported photic phenomena was low. CONCLUSION: Both Verisyse and Veriflex pIOLs are effective in correcting myopia. The Veriflex lens demonstrated better refractive outcome; however, subclinical inflammation observed in the Veriflex group and potential influence of inflammation on ECC loss require further investigation.

Apparent Corneal Ectasia After Bilateral Intrastromal Femtosecond Laser Treatment for Presbyopia.

PURPOSE: To report a case of apparent corneal ectasia after intrastromal femtosecond laser treatment for presbyopia (INTRACOR). METHODS: A healthy 56-year-old male with low hyperopia underwent an unremarkable bilateral INTRACOR procedure in March/April 2011. The patient was discharged after follow-up and returned 5 years later. RESULTS: Before discharge, the monocular logarithm of the minimal angle of resolution uncorrected distance visual acuity (UDVA) values were R, 0.0 and L, 0.10. In both eyes near (UNVA) visual acuities were 0.0. There were signs of slight posterior central corneal steepening without loss of corneal stability. Five years postop, monocular UDVA and UNVA values were 0.4 and 0.0, respectively. Ectasia was observed in both eyes, and the centrally placed 5 concentric rings after the INTRACOR procedure were visible under slit-lamp biomicroscopy. CONCLUSIONS: There is no clear reason to explain why the patient developed bilateral corneal steepening. It could be that the patient's corneal stromal fibers gradually weakened over this 5-year period.

Vector analysis of astigmatism before and after LASIK: a comparison of two different platforms for treatment of high astigmatism.

PURPOSE: To compare the outcomes of astigmatic laser in-situ keratomileusis (LASIK) procedures between two different platforms using J0 and J45 vector analysis. METHODS: Patients were divided into four groups, depending on the type of astigmatism and laser platform on which they were treated. Astigmatism was between 2 and 7 diopters (D). One hundred and thirty-five patients with myopic astigmatism (246 eyes) and 102 patients with mixed astigmatism (172 eyes) underwent unremarkable LASIK correction on Wavelight Allegretto Eye-Q 400Hz and Schwind Amaris 750S laser platform. The preoperative and postoperative sphere, negative cylinder [C] and axis (ø) of manifest refractions were subjected to vector analysis by calculations of the standard J0 (cos [4π(ø-90)/360]xC/2) and J45 (sin[4π(ø-90)/360]xC/2). RESULTS: Reporting the key results, we found J0 significantly reduced after LASIK in both groups (p < 0.001) but not J45. There was no significant association between individual pairs of pre and postoperative J0 & J45 values. There was no significant difference between the outcomes of the two platforms. CONCLUSIONS: Wavelight Allegretto 400Hz and Schwind Amaris 750S showed excellent results for treating patients with astigmatism, regardless whether it is mixed or myopic astigmatism. The J45 did not reduce significantly possibly because of the low number of eyes with oblique astigmatism. There was no genuine difference post-operatively between groups treated on two different laser platforms according to the vector analyses.

Comparison of Wavelight Allegretto Eye-Q and Schwind Amaris 750S excimer laser in treatment of high astigmatism.

PURPOSE: To compare functional outcomes of Wavelight Allegretto Eye-Q 400Hz and Schwind Amaris 750S excimer laser for astigmatism between 2 and 7 diopters(D). METHODS: Prospective comparative non-randomized case series of 480 eyes assigned in two laser groups and further divided into myopic and mixed astigmatism subgroups. All treatments were centered on corneal vertex. One-year results were compared between the groups. Statistical analysis was performed using z-test. RESULTS: Both Allegretto and Amaris postoperative uncorrected distance visual acuity (UDVA) improved in comparison to preoperative corrected distance visual acuity (CDVA). The difference was significant in the Allegretto group for myopic astigmatism (p = 0.017). There was no difference in postoperative UDVA between lasers. Average sphere decreased in all groups for both lasers (p < 0.001) without difference in effectiveness of spherical correction between lasers for both groups. In Allegretto, average cylinder decreased from -3.30D to -0.55D in myopic astigmatism (p < 0.001) and from -3.84D to -0.85D in mixed astigmatism (p < 0.001). In Amaris average cylinder decreased from -3.21D to -0.43D in myopic astigmatism (p < 0.001) and from -3.66D to -0.58D in mixed astigmatism (p < 0.001). Amaris group had less residual astigmatism (myopic astigmatism p = 0.023, mixed astigmatism p < 0.001). Mean spherical aberration shifted from positive to negative in mixed astigmatism for both lasers. CONCLUSION: Both lasers are effective in terms of UDVA, CDVA, spherical correction, and preservation of high-order aberrations. However, Amaris was more effective in cylinder correction.

First results of Intracor procedure in Croatia.

This study reports early outcomes of a cohort of presbyopic patients treated with Intracor. The study took place from December 2010 to May 2011 and was conducted in University Eye Hospital "Svjetlost", Zagreb, Croatia. 95 eyes were enrolled in this prospective clinical trial (49 patients with non dominant eye and 23 with bilateral treatment). All patients gave informed consent prior to enrollment. Follow up consisted of uncorrected and corrected distant and near visual acuity, record of topographic changes, visual disturbances and patient satisfaction at 1 week, 1 and 3 months after the surgery. In this study Intracor procedure presented as both safe and effective with all eyes gaining several lines of uncorrected near visual acuity (UNVA), and achieving good uncorrected distant visual acuity(UDVA) as well. UDVA was affected by a mild myopic shift, which was effective in reducing mild preexisting hyperopia in some patients but led to a mild myopic outcome in previously emmetropic patients. Statistically significant improvement in UDVA and UNVA was observed in all time points. At 3 months of postoperative follow up all patients gained several lines of UNVA with monocular UNVA Jaeger system 1.67 +/- 0.28. UDVA showed slight improvement over time and initial myopic shift showed tendency of slight decrease with all patients achieving 1.0. Overall patients satisfaction was very high (98%) with only a few (3 patients, 5 eyes) reporting mild halo and glare at 3 months postop.Intracor procedure has proven its short-term safety and efficacy in treating presbyopia. However, longer follow up period is needed.

Penetrating keratoplasty and Verisyse iris-claw lens--is it safe for corneal graft?

The loss of the corneal endothelial cells, especially in a first postoperative year, has been observed in patients who underwent penetrating keratoplasty (PK). The implantation of new generation of "iris claw" phakic IOL (Verisyse) in refractive cases has been shown to cause clinicaly insignificant endothelial cell loss. In our prospective case series we investigated the endothelial cell loss and clinical outcome in patients that either underwent PK and implantation of PCIOL or PK and implantation of Verisyse IOL. In the first group of 9 patients scheduled for PK, implantation of Verisyse was performed due to the absence of the posterior capsule support. 2 of these patients had angle supported ACIOL, 4 patients were aphakic and 3 had posttraumatic cataract with ruptured posterior capsule. The second group of 12 patients had standard "triple" procedure (PK + ECCE + PCIOL). BCVA of both groups of patients prior the operation was hand movement in 12 patients, light perception in 7 patients and 0.05 in 3 patients. The preoperative endothelial cell count of the donor grafts obtained from the eye bank was 2800 cells/mm2 on average. The follow up was 6-10 months. Six months after the operation all "Verysise" patients maintained transparent graft. Postoperative visual acuity improvement was recorded in 18 out of 21 eyes (85.7%). Best spectacle corrected visual acuity of > or = 0.3 was achived in 55.5% in the Verisyse group and in 50.0% of "triple procedure" group. The endothelial cell count and morphology were estimated on the specular microscope on a monthly basis. Mean endothelial cells loss in patients with PK and Verysise was 40 +/- 8% and in patients with "triple" procedure was 42 +/- 12% at 10 postoperative months. There was no significant difference in the endothelial cell loss and clinical outcome between the group of patients who had PK and Verysise as compared to those with implanted PCIOL.