Orkun Muftuoglu

Ten-year follow-up of photorefractive keratectomy for myopia of more than -6 diopters.

PURPOSE To evaluate the long-term outcomes of excimer laser myopic photorefractive keratectomy (PRK) for myopia higher than -6 diopters (D). DESIGN A long-term (10-year) follow-up retrospective, interventional case series. METHODS The study included 267 eyes of 191 patients with myopia with spherical equivalent (SE) of more than -6 D treated with myopic PRK at the Instituto Oftalmológico de Alicante, Alicante, Spain, using the VISX 20/20 excimer laser (Santa Clara, California, USA). All patients were evaluated three months, one year, two years, five years, and 10 years after surgery. The main outcome measures were refractive predictability and stability, mean corneal keratometry, topographical cylinder, safety, efficacy, stability of visual acuity, and postoperative complications. RESULTS At 10 years, 156 (58%) of 267 eyes were within +/- 1.00 D and 209 (78%) were within +/- 2.00 D. One hundred and twenty-four eyes (46.4%) underwent retreatments because of overcorrection, regression, or both. The mean SE decreased (myopic regression) in eyes that did not undergo retreatment, with a mean magnitude of -1.33 +/- 2.0 D over 10 years (-1.13 +/- 0.20 D per year). One hundred and twenty-one (48.3%) of 267 eyes demonstrated increase in best spectacle-corrected visual acuity, and only eight eyes lost lines of vision because of cataract and posterior segment-related complications. The mean corneal haze score decreased gradually from 0.48 +/- 0.69 at three months to 0.09 +/- 0.33 at 10 years. CONCLUSIONS PRK for myopia of more than -6 D is a safe and effective procedure in the long-term.

Ten years after Photorefractive Keratectomy (PRK) and Laser In Situ Keratomileusis (LASIK) for Moderate to High Myopia (Control-Matched Study)

Objective: To compare the long-term outcomes of photorefractive keratectomy (PRK) and laser in situ keratomilesis (LASIK) for myopia between −6 and −10 D. Methods: A retrospective, control-matched study including 68 eyes, 34 which underwent PRK and 34 LASIK, with myopia between −6 and −10 D, operated using the VISX 20/20 excimer laser, was performed. Optical zones of 5.5 to 6 mm were used. All PRK-treated eyes were matched with LASIK-treated eyes of the same age, spherical equivalent within ±1.25 D, sphere within ±1.5 D and cylinder within ±2.5 D. All patients were evaluated 3 months, 1 year, 2 years, 5 years and 10 years after surgery. The main outcomes measures were refractive predictability and stability, safety, efficacy and re-treatment rate. Results: At 10 years, 20 (71%) and 23 (88%) were within ±1.00 D after PRK and LASIK respectively. The re-treatment rate was 35% and 18% respectively. No eye lost more than two lines of BSCVA in both groups. The efficacy was 0.90 for PRK and 0.95 for LASIK. Conclusions: Both PRK and LASIK were safe for moderate myopia. LASIK demonstrated slightly better efficacy, predictability, and less rate of re-treatment after 10 years. The technical improvements should be taken into account when comparing these results with those obtained more recently.

Effect of a yellow intraocular lens on scotopic vision, glare disability, and blue color perception

PURPOSE: To compare the photopic and scotopic contrast sensitivity with and without glare as well as blue color perception between eyes with an AcrySof SN60AT Natural intraocular lens (IOL) (Alcon Laboratories Inc.) and eyes with a conventional AcrySof SA60AT IOL. SETTING: Ankara University School of Medicine, Department of Ophthalmology, Ankara, Turkey. METHODS: Right eyes of 38 patients with an AcrySof Natural IOL and right eyes of 38 age‐matched patients with a conventional AcrySof SA60AT IOL were included in a study. Contrast sensitivity was measured with the Functional Acuity Contrast Test under photopic conditions. Scotopic contrast sensitivity in the presence or absence of glare was measured using the Mesotest II (Oculus GmbH). Blue–green color vision was evaluated with the Moreland equation of the HMC Anomaloskop MR (Oculus GmbH). RESULTS: The mean age of patients was 66.6 years ± 8.2 (SD) in the Natural IOL group and 66.4 ± 8.0 years in the conventional IOL group. There was no statistically significant difference in photopic contrast sensitivity, scotopic contrast sensitivity with and without glare, or disability glare between the 2 groups (P>.05). Photopic and scotopic contrast sensitivity with and without glare significantly decreased with age in both groups (P<.01). There was no statistically significant difference in anomaloscope scores between the 2 groups (P>.05). The Moreland middle match point showed a significant shift toward blue with age in both groups (P<.01). CONCLUSIONS: The AcrySof SN60AT Natural IOL provided contrast sensitivity under photopic and scotopic conditions (with and without glare) and blue color perception comparable that obtained with the AcrySof SA60AT IOL. Scotopic vision and blue color discrimination decreased with age with both IOLs.

Recent studies provide an updated clinical perspective on blue light-filtering IOLs

BackgroundRecent reviews of blue light-filtering intraocular lenses (IOLs) have stated their potential risks for scotopic vision and circadian photoentrainment. Some authors have challenged the rationale for retinal photoprotection that these IOLs might provide. Our objective is to address these issues by providing an updated clinical perspective based on the results of the most recent studies.MethodsThis article evaluates the currently available published papers assessing the potential risks and benefits of blue light-filtering IOLs. It summarizes the results of seven clinical and two computational studies on photoreception, and several studies related to retinal photoprotection, all of which were not available in the previous reviews. These results provide a clinical risk/benefit analysis for an updated review for these IOLs.ResultsMost clinical studies comparing IOLs with and without the blue light-filtering feature have found no difference in clinical performance for; visual acuity, contrast sensitivity, color vision, or glare. For blue light-filtering IOLs, three comparative clinical studies have shown improved contrast sensitivity and glare reduction; but one study, while it showed satisfactory overall color perception, demonstrated some compromise in mesopic comparative blue color discrimination. Comparative results of two recent clinical studies have also shown improved performance for simulated driving under glare conditions and reduced glare disability, better heterochromatic contrast threshold, and faster recovery from photostress for blue light-filtering IOLs. Two computational and five clinical studies found no difference in performance between IOLs with or without blue light-filtration for scotopic vision performance and photo entrainment of the circadian rhythm. The rationale for protection of the pseudophakic retina against phototoxicity is discussed with supporting results of the most recent computational, in-vitro, animal, clinical, and epidemiological investigations.ConclusionsThis analysis provides an updated clinical perspective which suggests the selection of blue light-filtering IOLs for patients of any age, but especially for pediatric and presbyopic lens exchange patients with a longer pseudophakic life. Without clinically substantiated potential risks, these patients should experience the benefit of overall better quality of vision, reduced glare disability at least in some conditions, and better protection against retinal phototoxicity and its associated potential risk for AMD.

Evaluation of Internal Refraction with the Optical Path Difference Scan

PURPOSE To evaluate internal refraction and its relation to other optical properties of the eye across a large range of refractive errors, which can provide useful information for the assessment and design of intraocular lenses and corneal ablation patterns. DESIGN Cohort study. PARTICIPANTS Three hundred ninety-four eyes of 197 healthy subjects with a mean age of 27+/-7 years (range, 18-42). METHODS All eyes underwent optical path difference scans to evaluate corneal topography, whole and internal ocular refraction (determined by the subtraction of corneal refraction from whole ocular refraction), and total and higher-order aberrations (HOAs) were assessed. After the conversion of any spherocylindrical refractive errors to vectorial data (sphere equivalent, blurring strength; cylinder, J(0) [power of Jackson cross cylinder at 90 degrees and 180 degrees] and J45 [power of Jackson cross cylinder at 45 degrees and 135 degrees]), the distribution of internal refraction among refraction groups (high myopes, low to moderate myopes, hyperopes, mixed astigmats, and emmetropes) and relationships between internal refraction, corneal refraction, and wavefront aberrations were analyzed. The compensation relation and its rate between corneal and internal astigmatism was assessed by the compensation factor (CF). MAIN OUTCOME MEASURES Whole ocular power and astigmatism, corneal power and astigmatism, internal power and astigmatism, CF for astigmatic data, location of the highest internal refraction zone, and wavefront aberrations. RESULTS The highest refraction zone was mostly (90%) located in the center in myopes, whereas it was located at the nasal side (71%) in hyperopes. There was a significant correlation between whole ocular and internal powers (P<0.01), but no correlation was observed between corneal and internal powers (P>0.05). Internal astigmatism was mostly against the rule. The mean CF J(0) was 0.63+/-3.78 and CF J(45) was 0.57+/-2.47. The magnitude of the internal astigmatism under the 3-mm zone was correlated with the magnitude of corneal astigmatism (P<0.05). The distribution of astigmatic CF differed among refraction groups. There were significant correlations between internal power and spherical aberration (P<0.05) and internal cylinder under the 5-mm zone and HOAs (P<0.001). CONCLUSION There is a remarkable tilt in internal refraction in hyperopes. Although there is a tendency of undercompensation of the corneal astigmatism by internal astigmatism in the entire group of eyes, the compensation differs among refraction groups.

Drug-induced intraocular lens movement and near visual acuity after AcrySof intraocular lens implantation

Purpose: To evaluate the factors influencing AcrySof intraocular lens (IOL) (Alcon Laboratories) movement and near visual acuity after cyclopentolate 1% and pilocarpine 2%. Setting: Department of Ophthalmology, University of Ankara, Ankara, Turkey. Methods: Thirty eyes of 22 patients with AcrySof IOL implantation were included in this prospective study. Near visual acuity (Jaeger) at 35 cm through best distance correction without an add and pupil diameter were measured and correlated with anterior chamber depth (ACD) measured with ultrasound biomicroscopy (UBM) after application of cyclopentolate 1% and pilocarpine 2%, respectively. The magnitude of the change in the ACD was correlated with the accommodation amplitude, patient age, time interval between surgery and imaging, preoperative axial length, capsulorhexis diameter, ACD during cycloplegia, IOL diameter, and presence of posterior capsule opacification (PCO). Results: Near visual acuity significantly decreased after application of cyclopentolate 1% and increased after application of pilocarpine 2% (P<.001) in all eyes. The IOL moved anteriorly in 8 (26%) eyes and posteriorly in 22 (74%) eyes after pilocarpine 2%. There was no correlation between the ACD and near visual acuity under cyclopentolate 1% (r = 0.06, P>.05) or pilocarpine 2% (r = 0.04, P>.05). There was a moderate correlation between the anterior IOL movement and accommodation amplitude (P<.05, r = 0.42). There was no correlation between the magnitude of the IOL movement and patient age, time interval between surgery and imaging, the preoperative axial length, capsulorhexis diameter, ACD during cycloplegia, IOL diameter, and the presence of PCO (P>.05). Conclusions: There was better near visual acuity in all eyes with the AcrySof MAIOL, although most IOLs move slightly backward after of pilocarpine 2%. This points out pseudoaccommodation rather than pseudophakic accommodation. Ultrasound biomicroscopy is useful in determining the ACD and the relation between the IOL and the surrounding tissues after cataract surgery.

Changes in pupil size and centroid shift in eyes with uncomplicated in-the-bag IOL implantation.

PURPOSE To determine changes in entrance pupil size and pupil center shift under low mesopic and photopic conditions of illumination in eyes with in-the-bag intraocular lens (IOL) implantation. METHODS Entrance pupil size and pupil center shift were measured under low mesopic (0.06 lux) and photopic (60 lux) conditions of illumination in 55 patients with unilateral pseudophakia (study group) and 55 age- and sex-matched patients with bilateral cataracts (control group) using the NIDEK OPD-Scan. Pseudophakic eyes had an uncomplicated intraoperative and postoperative course and best spectacle-corrected visual acuity of 20/20. Cataractous eyes had no additional ocular or systemic problems affecting the pupil. Both groups were analyzed with respect to pupil size and shift in both conditions of illumination. RESULTS Mean patient age was 64.2 +/- 6.8 and 63.6 +/- 4.3 years in the study and control groups, respectively (P = .45). In the study group, differences in pupil size under low mesopic (5.12 +/- 1.02 and 5.13 +/- 0.96 mm for pseudophakic and phakic eyes, respectively) and photopic (3.44 +/- 0.39 and 3.45 +/- 0.39 mm for pseudophakic and phakic eyes, respectively) conditions of illumination were not statistically significant (P = 1.00 and P = .95 for pseudophakic and phakic eyes, respectively). Differences in pupil shift between pseudophakic (0.11 +/- 0.08 mm) and phakic (0.12 +/- 0.10 mm) eyes were not statistically significant (P = .83) in the study group. In the control group, differences in pupil size under low mesopic (P = .59) and photopic conditions of illumination (P = .60) in the right and left eyes as well as pupil shift (P = .71) were not statistically significant. CONCLUSIONS Uncomplicated in-the-bag IOL implantation has no influence on pupil size and shift.

Optical factors in increased best spectacle-corrected visual acuity after LASIK.

PURPOSE To study the factors that correlate with improved best spectacle-corrected visual acuity (BSCVA) after LASIK. METHODS This was a nonrandomized, prospective clinical trial of 850 eyes from 480 patients undergoing LASIK for myopia, hyperopia, and mixed astigmatism. The mean preoperative spherical equivalent refraction was -3.75+/-4.82 diopters (D) (range: -13.88 to 6.00 D). From this population, 72 eyes (including 22 amblyopic eyes) from 43 patients were found to have improved BSCVA 6 months after LASIK. All patients underwent LASIK with the NAVEX platform. These eyes were analyzed to evaluate factors that correlated with improved BSCVA. Pre- and postoperative BSCVA, refraction, pupil diameter, corneal topography, asphericity (Q value), total aberrations, and higher order wavefront aberrations were analyzed. All wavefront aberrations were measured using the NIDEK Optical Path Difference Scan aberrometer (OPD-Scan) preoperatively and at 6 months postoperatively. RESULTS Postoperatively, the mean sphere was -0.44 1.30 D (range: -4.50 to +2.50 D). The mean increase in BSCVA was 0.15+/-0.09 logMAR. A statistically significant negative correlation was observed between the increase in BSCVA and the preoperative BSCVA (P<.01). Mixed astigmatic and highly myopic eyes are more likely to gain BSCVA after LASIK than moderately myopic (P<.05) and hyperopic eyes (P<.001). In patients with myopia, the amount of BSCVA improvement correlated with the magnitude of the correction (P<.05). The induction of spherical aberration negatively correlated with the increase in BSCVA (P<.05). There were no significant differences between normal eyes and amblyopic eyes with respect to postoperative improvement in BSCVA (P>.05). CONCLUSIONS Decreased preoperative BSCVA, lower total spherical aberration induction, and preoperative mixed astigmatism and high myopia correlate with an increase in BSCVA after LASIK.

In vivo confocal microscopy findings in a patient with posterior amorphous corneal dystrophy

A 21‐year‐old man, with bilateral posterior amorphous corneal dystrophy, was studied by biomicroscopy, corneal topography and in vivo confocal microscopy. The best‐corrected visual acuity was 6/21 in the right eye and 6/6.9 in the left eye. Biomicroscopy revealed bilateral, asymmetric, sheet‐like opacification at the deep posterior stromal layer. The corneal topography displayed asymmetric against‐the‐rule astigmatism in the right eye and prominent steepening at the inferior paracentral cornea in both eyes. In vivo confocal microscopy of the corneas demonstrated microfolds and hyper‐reflective layer at the posterior stroma just adjacent to the endothelial layer. The epithelium, Bowman’s membrane, anterior stroma and the endothelial layer were normal. In vivo confocal microscopy is useful in evaluating the corneal dystrophies.

Comparison of Macular Thickness Measured by Optical Coherence Tomography After Deep Anterior Lamellar Keratoplasty and Penetrating Keratoplasty

PURPOSE To compare the postoperative macular thickness changes using optical coherence tomography (OCT) in eyes that underwent deep anterior lamellar keratoplasty (DALK) and penetrating keratoplasty (PKP). DESIGN Prospective, nonrandomized clinical trial. METHODS Sixty eyes of 60 patients (32 male, 28 female) with keratoconus who underwent corneal transplant surgery in an institutional setting were included in the study. Thirty eyes underwent DALK and 30 eyes underwent PKP. All eyes underwent corrected visual acuity (CVA) measurement and macular thickness measurement using spectral-domain OCT preoperatively, and 1 week, 1 month, 3 months, and 6 months postoperatively. The main outcome measures were CVA and macular thickness. RESULTS The DALK group had significantly better mean CVA than that of the PKP group at 1-month (P < .001), 3-month (P = .002), and 6-month (P = .040) follow-ups. The mean macular thickness significantly increased at 1 week after PKP surgery, remained stable at 1-month follow-up, and decreased at 3- and 6-month follow-ups. On the other hand, the mean macular thickness remained stable during 6 months after DALK. Although there was no significant difference between groups preoperatively (P = .970) and at 6-month follow-up (P = .339), the PKP group had significantly higher mean macular thickness than that of the DALK group at 1-week (P < .001), 1-month (P < .001), and 3-month (P = .005) follow-ups. CONCLUSION Although mean macular thickness increases and peaks around 1 month and returns back to normal levels at 6 months after PKP surgery, it does not change after DALK.