Vedat Kaya

Evaluation of Macular Changes After Uncomplicated Phacoemulsification Surgery by Optical Coherence Tomography

Purpose: To evaluate the effect of uncomplicated phacoemulsification surgery on macula by optical coherence tomography (OCT). Methods: A total of 110 eyes of 102 patients who underwent uncomplicated phacoemulsification and foldable intraocular lens implantation at Beyoglu Eye Research and Training Hospital between February and March 2005 and who were without any systemic disease, fundus or other ocular pathology were included. Postoperatively, topical prednisolone acetate (6× 1) and ofloxacine (5× 1) was started, and by decreasing the dosage progressively, treatment was continued for 6 weeks. Full ophthalmologic and OCT examinations were done preoperatively and at the postoperative 1st day, 1st week, 1st, 3rd, and 6th months. Mean retinal thicknesses, volumetric analyses at central fovea, superior, inferior, temporal, and nasal macular quadrants, and thinnest foveal retinal thicknesses were recorded. Preoperative and postoperative measurements were analyzed statistically by using ANOVA test, paired samples t-test with Bonferroni correction, and Pearsons correlation test. Results: The mean central foveal retinal thickness was preoperatively 202.4 ± 25.9 μ m, postoperatively 200.4 ± 26.1 μ m at 1st day (p = 0.29), 208.4 ± 27.6 μ m at 1st week (p = 0.29), 226.2 ± 54.9 μ m at 1st month, 215.2 ± 24.0 μ m at 3rd month, 213.5 ± 29.4 μ m at 6th month (p < 0.001). Perifoveal macular thicknesses at superior, inferior, temporal, and nasal quadrants were 264.9 ± 28.8 μ m, 266.1 ± 29.5 μ m, 255.0 ± 31.3 μ m, 260.3 ± 34.0 μ m, respectively, preoperatively; 287.9 ± 28.4 μ m, 288.0 ± 26.3 μ m, 286.8 ± 33.1 μ m, 272.0 ± 32.4 μ m, respectively, at postoperative 1st month (p < 0.001). The change in mean central foveal thickness, foveal thinnest retinal thickness, mean perifoveal retinal thickness and volumetric analyses was insignificant at postoperative 1st day (p > 0.05), and significant at 1st week, 1st, 3rd, and 6th months (p < 0.05 for all measurements). Conclusions: Statistically significant increase in macular thickness was detected at postoperative early periods, after the 1st week after uncomplicated cataract operation. The increase in macular thickness starts from parafoveal regions. Longer follow-up of patients is required for the macular consequences, and different treatment protocols should be studied in a randomized controlled fashion.

Central corneal thickness, anterior chamber depth, and pupil diameter measurements using Visante OCT, Orbscan, and Pentacam.

PURPOSE To evaluate the agreement among three different optical methods in measuring anterior chamber depth (ACD), central corneal thickness (CCT), and pupil diameter. METHODS One hundred eyes of 50 healthy patients (25 men, 25 women) were enrolled in the study. Mean patient age was 25 years (range: 21 to 32 years). Exclusion criteria were history of any intraocular or corneal surgery, contact lens wear, corneal anomalies, and spherical refraction >5.00 diopters (D) or cylindrical refraction >2.00 D. All measurements were done by the same operator under mesopic light conditions and repeated using three different optical methods: Visante optical coherence tomography (OCT) (Carl Zeiss Meditec), Orbscan (Bausch & Lomb), and Pentacam (Oculus Optikgeräte GmbH). RESULTS Mean CCT as measured by Visante OCT, Orbscan, and Pentacam was 529+/-30.5 microm, 554+/-32.7 microm, and 552+/-29.3 microm, respectively. Mean ACD values were 2.94+/-0.34 mm, 2.84+/-0.33 mm, and 2.98+/-0.33 mm, respectively. Mean pupil diameter measurements were 4.87+/-1.09 mm, 4.0+/-0.67 mm, and 3.05+/-0.59 mm, respectively. The Visante OCT measured CCT thinner and Orbscan measured ACD shallower than the other two methods. All three methods measured pupil diameters significantly different. CONCLUSIONS This study found some statistically significant but clinically insignificant differences among the optical methods assessed. The differences are small and do not influence decisions for refractive surgery in clinical practice.

Prospective, paired comparison of laser in situ keratomileusis and laser epithelial keratomileusis for myopia less than -6.00 diopters.

PURPOSE To compare visual and refractive results, contrast sensitivity, and tear stability after laser in situ keratomileusis (LASIK) in one eye and laser epithelial keratomileusis (LASEK) in the fellow eye for low myopia. METHODS Patients diagnosed with low myopia, with a maximum difference of 1 D between their two eyes, were randomly assigned to receive LASEK on one eye and LASIK on the other eye. A total of 64 eyes of 32 patients with a mean age of 26.83 +/- 5.33 years were included in the study. Preoperative myopia ranged from -1.00 to -6.00 D. Follow-up was 6 to 12 months. Uncorrected (UCVA) and best spectacle-corrected visual acuity (BSCVA), Schirmer test results, tear break-up time, corneal asphericity, corneal uniformity index, predicted corneal acuity, and contrast sensitivity values were compared with preoperative values. A Wilcoxon test was used for statistical comparisons and a P-value less than .05 was considered significant. RESULTS At 6 months after surgery, there was no statistically significant difference in UCVA, BSCVA, spherical and cylindrical refractive error, Schirmer test, or tear break-up time between groups. Contrast sensitivity values in the LASIK eyes were lower in comparison to preoperative values, but there was no change in the LASEK group. CONCLUSIONS Based on 6-month results, LASEK for low myopia was safe and effective with predictable results, offered early refractive stability, and may be considered an alternative for LASIK.

Efficacy of corneal collagen cross-linking using a custom epithelial debridement technique in thin corneas: a confocal microscopy study.

PURPOSE To examine the corneal collagen cross-linking (CXL) effect with a customized epithelial debridement technique in thin corneas using anterior segment optical coherence tomography (OCT) and confocal microscopy. METHODS Two patients with keratoconus who underwent a customized epithelial debridement technique (preserving the epithelium in thinner corneal regions where the deepithelialized corneal thickness was <400 μm) and subsequent CXL were examined by anterior segment OCT and in vivo confocal microscopy 1 month postoperatively. RESULTS Anterior segment OCT showed the demarcation line in the peripheral deepithelialized corneal areas, but it was not detectable in the central corneal regions corresponding to the cone where the epithelium was preserved. In vivo confocal microscopy analysis revealed total loss of keratocytes together with the intense honeycomb-like stromal edema in the anterior ∼320 μm of the cornea in the deepithelialized areas. This effect was mild under the intact epithelium with preservation of keratocytes and only a mild increase in stromal reflectivity. CONCLUSIONS In this confocal microscopy study, the corneal stroma under the intact epithelium seemed to be spared from the collagen CXL effect by the customized epithelial debridement technique.

Evaluation of corneal topography with Orbscan II in first-degree relatives of patients with keratoconus.

Purpose: To evaluate the corneal topographic characteristics of first-degree relatives of patients with keratoconus with corneal topography to determine the incidence of clinical keratoconus and topographic abnormalities. Methods: Between February and August 2006, Orbscan II analysis was done in 144 eyes of 72 cases who were first-degree relatives of patients diagnosed with clinical keratoconus. The findings were compared with preoperative Orbscan analyses of 52 clinically normal individuals who underwent laser in situ keratomileusis surgery and did not develop corneal ectasia in 3 years of follow-up. Results: In 8 of the 72 first-degree relatives of patients with keratoconus, clinical keratoconus was diagnosed by the topographic pattern in Orbscan and clinical examination (group 1). The remaining 64 subjects (group 2) were compared with the control group (group 3). The central corneal thickness was 523.7 ± 40.4 μm in group 2, whereas it was 546.3 ± 33.1 μm in group 3 (P < 0.05). The central corneal thickness, thinnest pachymetric reading, posterior elevation value, distance between the greatest anterior/posterior elevation points, and corneal center, posterior best fit sphere (BFS) values, posterior BFS:anterior BFS ratio, and irregularity values were significantly different between group 2 and group 3 (P < 0.05). Conclusions: The keratoconus incidence was found to be 11% in first-degree relatives of patients with keratoconus as opposed to a reported incidence of keratoconus of 0.05% in the general population. In first-degree relatives of patients with keratoconus who did not have a topographic keratoconus pattern, abnormal corneal topographic values were detected. The asymptomatic relatives of patients with keratoconus should undergo a thorough preoperative analysis for subtle topographic abnormalities before any keratorefractive surgery.

ThinOptX vs AcrySof: comparison of visual and refractive results, contrast sensitivity, and the incidence of posterior capsule opacification.

Purpose. To evaluate the visual and refractive results, the changes in contrast sensitivity, and the incidence of posterior capsule opacification (PCO) after the implantation of UltraChoice 1.0 ThinOptX (ThinOptX Inc.) intraocular lens (IOL) and conventional acrylic foldable IOL (AcrySof MA30AC). Methods. Twenty-five patients were randomized into two groups prospectively. In Group 1, microincisional phacoemulsification and the ThinOptX IOL implantation were applied in one eye, and in Group 2, conventional phacoemulsification and the AcrySof IOL implantation were applied in the fellow eye. Uncorrected visual acuity (UCVA) and best-corrected visual acuity (BCVA), surgically induced astigmatism (SIA), contrast sensitivity, and the incidence of PCO were observed in the two groups and comparisons were made. Results. Mean follow-up period was 12.8±1.5 months (range 11 to 14 months). In the last follow-up examination, UCVA and BCVA were significantly lower and the PCO scores were significantly higher in Group 1 (p<0.05). Although SIA was lower in Group 1, the difference was not statistically significant. Contrast sensitivity in higher spatial frequencies was significantly lower in Group 1 in the 6th month and 12th month visits. Capsular contraction was seen in 3 eyes (12%) in Group 1 whereas there was no capsular contraction or phimosis in Group 2. Conclusions. Long-term evaluation of the ThinOptX IOL concludes with an increased rate of PCO, a diminished resistance to the capsular contraction vs the AcrySof IOL, and a decrease in visual performance. The poor after cataract performance of this rollable lens shows that microphacoemulsification and ThinOptX IOL implantation is not as effective as conventional phacoemulsification and AcrySof IOL implantation in the long term.

REFRACTIVE AND VISUAL OUTCOMES AFTER INTACS VS FERRARA INTRASTROMAL CORNEAL RING SEGMENT IMPLANTATION FOR KERATOCONUS: A COMPARATIVE STUDY

PURPOSE To evaluate the refractive, topographic, optical, visual acuity, and quality outcomes of two types of intrastromal corneal ring segments (ICRS) in the treatment of keratoconus. METHODS In this retrospective study, 16 eyes that had been implanted with Intacs ICRS (Addition Technology Inc) (Intacs group) and 17 eyes implanted with Ferrara ICRS (Ferrara Ophthalmics Ltda) (Ferrara group) were evaluated. Pre- and postoperative examinations included uncorrected and corrected distance visual acuities (UDVA and CDVA, respectively), manifest refraction, slit-lamp examination, topography, and ocular wavefront analysis. Contrast sensitivity measurements under photopic, scotopic, and scotopic with glare conditions were performed 1 year postoperatively. RESULTS One year postoperatively, a significant decrease was noted in spherical equivalent refractive error of 3.76 ± 0.39 diopters (D) and 3.42 ± 0.88 D and keratometry of 3.43 ± 0.24 D and 3.28 ± 0.78 D in the Intacs and Ferrara groups, respectively; and increase in mean UDVA and CDVA in Snellen lines of 0.18 ± 0.04 and 0.21 ± 0.05, respectively, in the Intacs group and 0.21 ± 0.09 and 0.26 ± 0.08, respectively, in the Ferrara group (P<.01 for all). The postoperative increase in UDVA and CDVA and decrease in keratometry readings were not significantly different between groups (P>.05 for all). Mean higher order aberrations decreased in the Intacs group and increased in the Ferrara group (P>.05 for both). Postoperatively, a significant decrease was noted in scotopic contrast sensitivity when glare was introduced in the Ferrara group, which was positively correlated with pupil diameter (r(15)=0.50, P=.04). CONCLUSIONS Both ICRS types provided comparable refractive, topographic, and optical quality outcomes. Eyes with Ferrara ICRS experienced greater decrease in scotopic contrast sensitivity under glare, which was significantly correlated with pupil diameter.

Phakic posterior chamber plate intraocular lenses for high myopia.

PURPOSE Refractive correction of high myopia with phakic minus power intraocular lenses (IOLs) may give dramatic visual results. Various types of lenses developed for this purpose have not gained widespread use due to complications. Long-term results and complications of phakic posterior chamber lenses are yet unknown. The purpose of this study was to evaluate long-term refractive results and complications of early design phakic posterior chamber lenses. METHODS Thirty-four high myopic eyes implanted with phakic posterior chamber IOLs designed by Fyodorov were evaluated retrospectively. Follow-up time ranged from 36 to 62 months. Corneal endothelial cell counts were made at the central cornea preoperatively and in the sixth month in 18 eyes and in the twelfth month in 14 eyes. RESULTS Preoperative refractions were between -7.75 and -21.00 D; refractions at the end of the follow-up period were between -5.75 and +3.00 D. Sixty-three percent of eyes were in the +/-2.00-D range. Endothelial cell loss was 9% at 6 months and 10.22% at 12 month. The difference in endothelial cell counts at 6 and 12 months was not statistically significant. CONCLUSIONS Early design phakic posterior chamber IOLs implanted in this study were developed by Fyodorov and are not used currently. These IOLs provided a stable and reversible refractive correction without leading to cataract formation. Endothelial loss was limited to surgical trauma. Moderate predictability of refractive correction and frequent decentrations with these lenses were linked to the early design of these IOLs.

The use of a supplemental sulcus fixated IOL (HumanOptics Add-On IOL) to correct pseudophakic refractive errors:

Purpose. To evaluate the safety and efficacy of piggybacking with the HumanOptics Add-On intraocular lens (IOL) to correct pseudophakic refractive errors. Materials and Methods. Ten eyes of 10 patients with pseudophakic refractive errors were included in this study. All patients were targeted for a range of refraction −0.50 to +0.50 D. Uncorrected and corrected distance visual acuities (UDVA and CDVA, respectively), endothelial cell count (ECC), anterior chamber depth (ACD), the distance between intraocular lenses, and contrast sensitivity measurements under mesopic, scotopic, and scotopic with glare conditions were evaluated preoperatively and postoperatively. Results. The mean age of the patients was 54±27 years (range 4-78). Mean follow-up time was 10.5±1.36 months (range 6-15 months). Mean diopters of implanted Add-On IOLs were −1.4±6.9 (range −12 to +9 D). Mean preoperative and postoperative UDVA was 0.133±0.12 and 0.73±0.27, respectively (p=0.0001); mean preoperative and postoperative CDVA were 0.77±0.26 and 0.79±0.27, respectively (p=0.066). Mean preoperative and postoperative ACD were 3.87±0.91 mm vs 3.58±1.05 mm, respectively (p=0.343); mean inter-IOL distance was 0.53±0.08 mm. Mean preoperative and postoperative ECC were 2455±302 and 2426±294, respectively (p=0.55). All patients were within the targeted refractive range of −0.50 D to +0.50 D. No complications were observed during the operations or postoperative follow-up period. Conclusions Piggybacking with the Add-On IOL is a safe, efficient, and reliable technique to correct pseudophakic refractive errors.

ZB5M Anterior Chamber and Fyodorov's Posterior Chamber Phakic Intraocular Lenses: Long-term Follow-up

PURPOSE To compare the long-term complications of two outdated phakic intraocular lenses (PIOL) implanted in eyes with high myopia to aid development of better PIOL designs. METHODS Sixty-two eyes of 37 patients implanted with the ZB5M anterior chamber PIOL (anterior chamber group) and 22 eyes of 14 patients implanted with Fyodorovs posterior chamber PIOL (posterior chamber group) were examined. Complications were compared after a mean follow-up of 71.15 +/- 32.17 months (range: 24 to 145 months) in the anterior chamber group and 84.14 +/- 26.43 months (range: 24 to 132 months) in the posterior chamber group (P = .07). RESULTS At last follow-up, pupil ovalization was present in 32 (51.6%) eyes in the anterior chamber group and 1 (4.5%) eye in the posterior chamber group (P < .001), and cataract in 5 (8.1%) eyes in the anterior chamber group and 7 (31.8%) eyes in the posterior chamber group (P = .007). Phakic intraocular lens decentration, glaucoma, retinal detachment, corneal decomposition, and monocular diplopia were additional complications encountered in both groups, with no statistically significant difference. CONCLUSIONS Proper understanding of these outdated PIOLs may be helpful in developing better PIOL designs.