Stereoacuity and Aniseikonia: Evaluation Before and After Bilateral Implantation of Three Types of Presbyopia-Correcting Intraocular Lenses in Uncomplicated Phacoemulsification with Due Consideration of Interocular Differences in Higher Order Aberrations, Axial Lengths, Refractive Errors, and Acuities.

Purpose: To determine if the changes in stereoacuity and aniseikonia, following bilateral implantation of presbyopia correcting intraocular lenses could be predicted from preoperative measurements of higher order aberrations (HOAs), axial lengths (AL), refractive errors (RE) and corrected visual acuities (CVAs). Patients and Methods: Stereoacuity (Randot tests, @6m & 40cm, in steps of 20 arcsecs") vertical and horizontal aniseikonia (Awaya test @6m, in steps of 1%) with best correction and HOAs (Shack-Hartmann aberrometer) were measured before, 3 and 6 months after uncomplicated bilateral phacoemulsification. Twenty patients (I) underwent a mix-and-match procedure (Tecnis MF, ZKB00 in one eye and ZLB00 in the other), 17 (II) were implanted with a trifocal (AT LISA 839 triMP) and 18 (III) with a one-piece diffractive (Synergy OU) intraocular lens. The resultant aniseikonia (AR) of vertical and horizontal pairs of aniseikonia measurements was calculated using the Pythagorean theorem. Twenty untreated age/gender matched cases were recruited as controls (IV). Results: The key results (p < 0.001) were a) stereoacuity at distance (SAD) and near (SAN) improved, AR reduced in groups I, II & III remaining unchanged in group IV; b) some significant intergroup differences in SAD, SAN & AR were detected at postop; c) at 6 months postop, changes (Δ=pre- minus postoperative value) correlated with preoperative values (x). Linear regression revealed, I ΔSAD=0.66x-57.47 [0.832, ±66.4], ΔSAN=0.96x-34.59 [0.821, ±16.9], ΔAR=0.93AR-2.12 [0.795, ±1.4] II ΔSAD=0.79x-62.91 [0.916, ±38.1], ΔSAN=0.96x-31.49 [0.892, ±8.0], ΔAR=0.91AR-0.91 [0.839, ±1.3] III ΔSAD=0.67x-35.50 [0.991, ±23.7], ΔSAN=0.88x-38.51[0.988, ±10.6], ΔAR=0.86AR-0.96 [0.900, ±1.3]. Figures in parentheses are the corresponding rs and ±limits of agreement between actual and estimated values. Definitive overarching associations connecting interocular differences in HOAs, AL, RE, and CVAs with SAD, SAN and AR were not found. Conclusion: Changes in stereoacuity and aniseikonia can be predicted using preoperative values. ΔSAN can be predicted within ±1, and ΔAR within ±2, scale divisions. In group III ΔSAD can be predicted within ±1, and in group I ±3, scale divisions.

Comparative Analysis of the Clinical Outcomes of Two Toric Presbyopia-Correcting Intraocular Lenses.

INTRODUCTION: To evaluate and compare the clinical outcomes of two toric presbyopia-correcting intraocular lenses (IOLs). METHODS: Non-randomized prospective comparative study including 86 eyes of 51 patients (age 43-83 years) that underwent cataract surgery with implantation of one of the following two IOLs: TECNIS Toric Synergy (Johnson & Johnson Vision) (Synergy group) or AT LISA tri toric 939MP (Carl Zeiss Meditec) (ATLISA group). Visual and refractive outcomes were evaluated during a 6-month follow-up. RESULTS: At 6 months after surgery, all eyes achieved uncorrected distance visual acuity 20/25 or better in both groups, whereas 96.2% and 100% of eyes achieved uncorrected near visual acuity (UNVA) 20/25 or better in the ATLISA and Synergy groups, respectively. All eyes achieved postoperative mesopic UNVA 20/30 or better in both IOL groups; 96.2% and 100% of eyes had a manifest cylinder ≤ 0.50 D at 6 months in ATLISA and Synergy groups, respectively. Mean magnitude of error was 0.04 ± 0.20 and - 0.04 ± 0.09 D in ATLISA and Synergy groups, respectively (p = 0.05). In the defocus curve, significant differences were found between IOL groups for most of distance-corrected visual acuities, except those corresponding to defocus of 0 D (p = 0.268) and - 1 D (p = 0.361). CONCLUSIONS: The two toric presbyopia-correcting IOLs evaluated provide an efficacious astigmatic correction combined with a successful distance, intermediate and near visual rehabilitation. The visual performance seems to be better for most visual demands with the TECNIS Toric Synergy IOL, especially for distances closer than 40 cm.

Clinical Outcomes With a New Continuous Range of Vision Presbyopia-Correcting Intraocular Lens.

PURPOSE: To evaluate the clinical outcomes including patient-reported outcome measures in a sample of eyes undergoing bilateral cataract surgery with implantation of a new model of presbyopia-correcting intraocular lens (IOL). METHODS: This non-randomized prospective case series enrolled 206 eyes of 103 patients undergoing phacoemulsification cataract surgery with bilateral implantation of the TECNIS Synergy IOL (Johnson & Johnson Vision). High and low contrast visual acuity, refractive, defocus curve, and patient-reported visual performance (Catquest-9SF questionnaire) outcomes were evaluated during a 3-month follow-up. RESULTS: A total of 96.1% (99 of 103) and 91.3% (94 of 103) of patients achieved binocular postoperative uncorrected distance (UDVA) and near visual acuity (UNVA) of 0.00 logMAR (20/20), respectively. Mean postoperative mesopic UNVA for both eyes was 0.14 ± 0.03 logMAR. Likewise, mean binocular UDVA and UNVA were 0.00 ± 0.03 and 0.04 ± 0.02 logMAR. An almost flat mean defocus curve was obtained, with visual acuities between 0.00 and 0.10 logMAR for most defocus levels in both eyes. A reduction of contrast led to a limited but statistically significant change in UNVA in both eyes (P < .001). The Rasch calibrated scoring of item 2 and the Rasch calibrated mean score of the Catquest-9SF questionnaire increased significantly with surgery (P < .001). CONCLUSIONS: This new presbyopia-correcting IOL provides a continuous range of functional focus, with a limited deterioration under mesopic conditions, which is perceived as a satisfactory outcome by the patient if proper patient selection is performed. [J Refract Surg. 2021;37(4):256-262.].

First Experiences with Implantation of Phakic Lenses in Correction of Myopia in R. N. Macedonia.

Objective: Analysis of visual acuity parameters in patients with moderate to high myopia and myopic astigmatism 1 year after treatment with phakic intraocular lenses. Material and methods: This was a retrospective study on 35 patients (52 eyes) with moderate to high myopia who were implanted with the Visian V4c phakic implantable Collamer lens (Staar Surgical, Nidau, Switzerland). Examined parameters were: uncorrected distance visual acuity (UDVA) and best corrected visual acuity (CDVA), manifest and cycloplegic refraction, intraocular pressure, and endothelial cell count. The investigated parameters were measured preoperatively, 1, 3, 6 and 12 months postoperatively. Results: In 17 patients, phakic lenses were implanted binocularly and in 18 patients monocularly. Preoperatively 34.62% of patients had CDVA from 0.9 to 1.0. One year after the surgery 48.08% of patients had UDVA from 0.9 to 1.0. Preoperatively 80.77% of patients had diopter range from -6.00 Dsph to -10.00 Dsph. At 1 year postoperatively 78.85% of patients were within 0.00 Dsph to -1.00 Dsph. Preoperatively, in patients with astigmatism -4 Dcyl to -2 Dcyl dominated, as opposed to significant improvement postoperatively when 94.23% had astigmatism ranging from -1.0 Dcyl to 0 Dcyl. Conclusion: The implantation of phakic lenses demonstrated a successful postoperative outcome in the treatment of myopia and myopic astigmatism. Visual acuity and refraction show a gradual and significant improvement in visual function parameters within 1 year of lens implantation.

Changes in Endothelial Cell Count Up to Three Years After Implantation of Toric Implantable Collamer Lenses.

PURPOSE: To determine the temporal effect of toric implantable collamer lens (TICL) implantation and location on corneal endothelial cell density (ECD) over a period of 36 months after surgery. METHODS: ECD [number of cells per square millimeter estimated using the Specular Microscope SP-1P (Topcon Europe Medical B.V., Netherlands)] data were collected from cases deemed suitable for the TICL (VTICMO, VTICM5; STAAR Surgical, Nidau, Switzerland). The preoperative refractive error (sphere and cylinder) ranged from -1.00 to -22.25 diopter sphere and from -0.50 to -5.50 diopter cylinder. ECD was evaluated at preoperative and all postoperative sessions. RESULTS: Key findings were as follows: the mean ECD (±SD, 95% confidence interval) was 2720 cells/mm (±272, 2620-2820 cells/mm) preoperatively, which was reduced to 2372 cells/mm (±325, 2250-2490 cells/mm) at 36 months postoperatively (P < 0.001). Linear regression revealed the following significant correlations between the (1) log of the change in ECD (y1) and log of preoperative ECD (x1) at 2 years postoperatively, y1 = 2.513x1-6.2816 (n = 62, r= 0.3503, P = 0.005); (2) mean ECD (y2) and log time (in months, x2), y2= 2543.7-36.997x2-38.99x2 (r=-0.9654, n = 7, P = 0.0004); and (3) mean axial distance between the front surface of the crystalline lens and the TICL back surface (y3) and time postoperatively (in months, x3), y3 = 0.1035x3-5.2808x3 +473.18 (r = 0.8512, n = 7, P = 0.015). CONCLUSIONS: Expected ECD loss after TICL implantation by 2 years postoperatively is predictable. On average, over 3 years after implantation, there is (1) an initial rapid decline in ECD, followed by a gradual fall in the rate of cell loss, and (2) a gradual fall in the distance between the TICL and the crystalline lens by 2 years postoperatively, followed by a reversal by the third year.

Unwanted Astigmatism and High-order Aberrations One Year after Excimer and Femtosecond Corneal Surgery.

SIGNIFICANCE: Small incision lenticule extraction (SMILE) is advanced as the most minimally invasive and least traumatic corneal procedure for correcting refractive errors using a single laser. Although SMILE obtains similar results to femtosecond laser in situ keratomileusis (LASIK) with spherical myopia, it has deficiencies in astigmatism correction. PURPOSE: The purpose of this study was to compare refractive outcomes and high-order aberrations (HOAs) between SMILE and femtosecond LASIK corneal procedures at 1 year post-operative. METHODS: Ninety-two patients (181 eyes) with myopia/myopic astigmatism underwent either SMILE (group 1) or femtosecond LASIK (group 2). The refractive target was to achieve emmetropia in all cases. Data were analyzed to determine significance of change in refraction and HOAs. Furthermore, astigmatism was subjected to vector analysis using the Thibos (calculation of change, Δ, in J0 and J45 values) and Alpins (calculation of difference, ΔC, between target-induced astigmatism [TIA] and surgically induced astigmatism) methods. RESULTS: Forty-five patients (89 eyes) from group 1 and 47 patients (92 eyes) from group 2 completed the study. The main significant (P ≤ .001) findings were as follows: (a) residual astigmatism was greater in group 1; (b) group 1, ΔJ0 = 1.015J0 + 0.040 (R = 0.861), ΔJ45 = 1.082J45 + 0.019 (R = 0.792), ΔC = 0.401TIA + 0.323 (R = 0.489), and mean spherical aberration increased from -0.003 (SD, ±0.059; 95% confidence interval [CI], -0.015 to 0.009) to 0.028 µm (SD, ±0.041; 95% CI, -0.037 to -0.020); and (c) group 2, ΔJ0 = 0.952J0 - 0.005 (R = 0.921), ΔJ45 = 0.962J45 - 0.002 (R = 0.923), ΔC = 0.187TIA + 0.101 (R = 0.272), mean coma reduced from 0.114 (SD, ±0.087; 95% CI, 0.096 to 0.132) to 0.077 µm (SD, ±0.059; 95% CI, 0.065 to 0.089), and trefoil from 0.089 (SD, ±0.049; 95% CI, 0.079 to 0.0990) to 0.056 µm (SD, ±0.047; 95% CI, 0.046 to 0.066). CONCLUSIONS: In comparison with SMILE, femtosecond LASIK offered better precision in the overall control of astigmatism and HOAs.

Incidence and Clinical Characteristics of Post LASIK Ectasia: A Review of over 30,000 LASIK Cases.

PURPOSE: To report the incidence of postoperative ectasia after laser in situ keratomileusis (LASIK). METHODS: A retrospective case review of 30,167 eyes (16,732 patients) was conducted following LASIK between August 2007 and August 2015. The follow-up was between 2 and 8 years. Tomography was performed after 2 years postop. After identifying cases of ectasia, the charts of these patients were examined to identify any common factors that may have predisposed them to develop ectasia. RESULTS: Ten eyes of seven patients developed post-LASIK ectasia. Eight eyes had been treated for myopia and myopic astigmatism, two eyes for mixed astigmatism. There were no cases of ectasia after LASIK for hyperopia. All 10 cases of ectasia had a flap that was created using the Moria M2 mechanical microkeratome (average flap thickness 118.15 ± 12.88 µm) and refractive error corrected using the Wavelight Allegretto excimer laser. Retrospectively, most prevalent risk factors were thin cornea (≤ 500 µm, 50% of cases), anterior topographic map irregularities (e.g., asymmetric bow tie, 40% of cases), Ectasia Risk Score > 3 (40% of cases), percent tissue thickness alteration ≥ 40% (20% of cases) and low residual stromal bed (≤ 300 µm, 30% of cases). One eye had no identifiable risk factors. In the retrospective chart review 14.97% (4,506) of all the eyes had similar risk factors to the cases that went on to develop ectasia. CONCLUSION: The incidence of ectasia was 0.033% over 8 years. The incidence could be higher as some cases may destabilize beyond this period and some patients were lost to follow-up asymptomatic of any clinical signs. Other intrinsic factors may trigger the development of post LASIK ectasia. The current widely accepted risk factors are not sufficiently rigorous for screening out potential ectasia from developing after LASIK. There is a need to augment accuracy with higher sensitivity and specificity.

Autologous Neurosensory Retinal Free Flap Treatment for a Large Macular Hole.

A patient presented with a large chronic macular hole (MH) of 700 µm. Best-corrected visual acuity (BCVA) was 20/200. Since the MHs edges were attached and stiff, an autologous neurosensory retinal flap was harvested and placed into the MH to close it. Perfluoro-n-octane heavy liquid (PFC) was instilled over the flap and exchanged with silicone oil (1,000 cs). Seven days postoperatively, the MH was closed, with a BCVA of 20/80 that improved to 20/60 at months 1 and 3. Optical coherence tomography and angiography showed patch incorporation with fovea formation and normal circulation. [Ophthalmic Surg Lasers Imaging Retina. 2018;49:e89-e92.].

Postoperative Late-Onset Endophthalmitis Caused by Leishmania donovani: A Case Report.

Leishmania donovani is a human blood parasite that belongs to the genus Leishmania. We would like to present a case of late Leishmania donovani endophthalmitis in one eye of a patient that underwent simultaneous bilateral grade 3 cataract surgery.

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.].

The clinical depth of field achievable with trifocal and monofocal intraocular lenses: theoretical considerations and proof of concept clinical results.

BACKGROUND: To estimate the depth of field (DOF) achievable with multi-and monofocal intraocular lenses (IOLs) and compare with actual measurements of DOF in cases implanted with a trifocal IOL and biconvex monofocal IOL METHODS: I) Computer simulations were produced to describe the relationship between DOF, pupil size, preoperative ametropia, and retinal blur tolerance limit for a model eye implanted with either multi- or monofocal IOLs. II) Monocular DOF and pupil size were measured under distance viewing conditions between 3 and 6 months postoperative following uneventful cataract surgery. Cases were implanted with either i) trifocal aspheric IOL (n = 36), or ii) biconvex aspheric monofocal IOL (n = 26). DOF was also measured at 0.33 m in cases implanted with i). RESULTS: Simulations revealed significant associations between DOF, pupil size, and retinal blur tolerance limit. The mean (±SD) DOF & pupil sizes were at distance for i)  above 2.59D (0.68) & 3.54 mm (0.377), and for ii) above 1.67D (0.51) & 2.90 mm (0.351), and for i) above 3.16D (0.46) at near. The difference between groups were significant for DOF and pupil size at distance (p < 0.001). DOF was significantly greater at near compared with distance in i) above (p < 0.001). For a pupil size of 3 mm, the simulations produce similar DOF values when the tolerance limit of retinal blur is 10 µ. CONCLUSIONS: The DOF was significantly better after implanting the trifocal IOL compared with the monofocal IOL, and DOF is increased under near viewing conditions. The clinical results are similar to calculated DOF values when the tolerance limit of retinal blur is 10 µ.

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.

Efficacy and safety of iris-supported phakic lenses (Verisyse) for treating moderately high myopia.

AIM: To evaluate efficacy and safety of iris-supported phakic lenses (Verisyse) for treating moderately high myopia. METHODS: This prospective clinical study included 40 eyes from 29 patients, who underwent implantation of Verisyse for correction of myopia from -6.00 to -14.50 diopters (D) in the Eye Clinic ''Svjetlost'', Sarajevo, from January 2011 to January 2014. Uncorrected distance visual acuity (UDVA), manifest residual spherical equivalent(MRSE), postoperative astigmatism, intraocular pressure(IOP), endothelial cell (EC) density were evaluated at one, three, six and twelve months. Corrected visual acuity (CDVA), index of safety and efficacy were evaluated after 12 months. RESULTS: Out of 29 patients 15 were males and 14 females, with mean age of 27.9 ± 5.0. After 12 months 77.5% eyes had UDVA ≥ 0.5 and 32.5% had UDVA ≥ 0.8. Mean MRSE was 0.55D ±0.57D and mean postoperative astigmatism -0.86D ± 0.47D. Efficacy index was 1.09 ± 0.19 and safety index 1.18 ± 0.21. One eye(2.5%) lost two Snellen lines and three eyes (7.5%) one line, 11 eyes (27.5%) gained one line, and five eyes (15.5%) gained two lines. EC loss after 12 months was 7.59 ± 3.05%. There was no significant change of IOP after one year follow up. CONCLUSION: Implantation of iris-supported phakic lenses (Verisyse) for treating moderately high myopia is an efficient and safe procedure.

Bowman strip complications during routine LASIK: Two cases demonstrating the clinical advantage of using Mitomicyn C in such cases / Complicaciones a nivel de una porción de la membrana de Bowman durante la rutina del procedimiento LASIK: dos casos que demuestran la ventaja clínica del uso de Mitomicina C en tales casos

No disponible

Three-year corneal graft survival rate in high-risk cases treated with subconjunctival and topical bevacizumab.

PURPOSE: To evaluate the effect of combined subconjunctival and topical bevacizumab treatment on corneal graft survival rate in high-risk eyes. METHODS: Prospective, consecutive, interventional case series. Fifty eyes of 50 high-risk patients scheduled for penetrating keratoplasty (PK) were included in the study; two Stevens-Johnson syndromes (SJS), five corneal combustions due to chemical burn, seven post-traumatic vascularised leucomas, 11 post-infectious vascularised leucomas, 19 rejected grafts and six corneal ulcers. Additional surgeries such as autologous limbal stem cell and/or amniotic membrane transplantation were performed together with PK in ten cases. All eyes received subconjunctival injection of 0.5 ml bevacizumab (25 mg/ml) after PK. Eyes with more than two quadrants of neovascularisation (NV) received bevacizumab drops (25 mg/ml) postoperatively for up to 12 weeks. Donor grafts were followed up for best-corrected visual acuity, graft clarity, change in NV, endothelial cell density loss (ECD), and adverse events. Mean follow-up was 36.5 months (range 32-61). RESULTS: Best-corrected visual acuity increase was statistically significant in 82 % (41/50) of eyes 3 years after PK (paired t-test, p = 0.02). Thirty-five (70 %) high-risk grafts remained clear throughout the 3-year follow-up period. Decrease of corneal NV was observed in 84 % (42/50) of eyes treated with bevacizumab. ECD changed from preoperative 2,864 ± 301 down to 1,905 ± 187 cells/mm(2) at 3 postoperative years. A non-healing epithelial defect was recorded in one patient with SJS after 12 weeks of topical bevacizumab. CONCLUSION: Combined subconjunctival and topical bevacizumab treatment may improve corneal graft survival rate in the majority of high-risk cases.

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.

Treatment of anti-vascular endothelial growth factor-resistant diabetic macular edema with dexamethasone intravitreal implant.

PURPOSE: To investigate the efficiency of intravitreal dexamethasone implant in patients with chronic diabetic macular edema nonresponsive to three consecutive monthly intravitreal injections of anti-vascular endothelial growth factor administered previously. METHODS: Fifteen patients (16 eyes) were included in this 4-month prospective clinical trial. Main observed outcomes were the changes between initial and monthly visits in best-corrected visual acuity, central foveal thickness, and intraocular pressure (IOP). Patients included had central foveal thickness of >225 µm (measured by optical coherence tomography) and were nonresponsive to previously administered 3 consecutive monthly intravitreal injections of 1.25-mg bevacizumab. Administration of intravitreal dexamethasone implant was performed at baseline, and patients were followed-up monthly. RESULTS: Statistically significant changes from baseline were observed in best-corrected visual acuity (at 2 months), central foveal thickness (at 1, 2, and 3 months), and IOP (at Months 1, 2, and 3) as follows: mean best-corrected visual acuity significantly increased from 0.29 Snellen lines at baseline to 0.39 lines after 2 months (P = 0.0381). At Months 1, 2, and 3, the mean central foveal thickness significantly decreased, from 462 µm at baseline, to 366 µm (P = 0.0343), 346 µm (P = 0.0288), and 355 µm (P = 0.0370), respectively. When compared with baseline IOP of 15.38 mmHg (12-19 mmHg), IOP increased significantly at Months 1, 2, and 3: 18.93 mmHg (range, 16-24 mmHg; P = 0.0003), 19.5 mmHg (range, 16-27 mmHg; P = 0.0003), and 17.5 mmHg (range, 15-21 mmHg; P = 0.0048), respectively. CONCLUSION: Dexamethasone intravitreal implant may present an alternative option in the treatment of chronic diabetic macular edema nonresponsive to three consecutive monthly bevacizumab injections administered previously. However, IOP measures were only slightly increased. It seems that the effect of dexamethasone may last till 4 months after initial injection.

Positive pressure during penetrating keratoplasty can be solved with a modified graft-over-host technique.

PURPOSE: To describe a modified graft-over-host (MGOH) surgical technique which was used to prevent serious complications in cases of positive vitreal pressure during penetrating keratoplasty (PKP) and to compare the endothelial cell density (ECD) loss and clinical outcome between eyes undergoing MGOH or standard PKP. METHODS: In the proposed MGOH technique, the donor graft is sutured over the recipient cornea as soon as signs of positive pressure are noticed, even before cutting the recipient cornea, and the surgery is continued by consecutive cutting of the recipient and continuous suturing of the donor cornea, quadrant by quadrant. Donor grafts were prospectively followed up for the graft clarity, ECD loss and the amount of astigmatism. RESULTS: Of 220 cases scheduled for standard PKP in years 2009-2011, eight were operated by MGOH technique. Despite the fact that the donor cornea is situated over the recipient almost throughout the whole MGOH procedure, the ECD loss is equal between eyes operated on by MGOH technique and standard PKP, and none of the grafts had primary graft failure. The only disadvantage was an increased amount of astigmatism that was not as significant once the sutures were taken out. CONCLUSION: Modified graft-over-host technique seems to be a safe and effective method to prevent complications during PKP complicated by positive vitreal pressure.

Curvature analyses of the corneal front and back surface.

In 25 eyes, age range 60-80 years, in purpose of preoperative treatment prior to cataract surgery, measurements of the radius of curvature as well as main meridians of the anterior and posterior corneal surfaces were performed. Average value of the curvature of the anterior corneal surface (R1) was R1 = 7.84 mm, while posterior radius (R2) was 6.4 mm. Main meridian of the anterior corneal surface was in 70% in plus value (+), while postrerior main meridian was always in minus value. It is very important to highlight that main corneal meridians R1 and R2 always cross outside the 90 degrees angle. That is why the combination of the calculation based on the two main meridians superposition (overrefraction) as a form of crossed cylinders has to be calculated (Astigmatismus directus seu obliquus decusatus) using special formula. One of that kind of formulas is Thompson's. Authors want to emphasise the importance of the optical calculation of the posterior corneal surface in the refractive surgery.