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.

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.

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.

Management of ocular complications of Vogt-Koyanagi-Harada syndrome.

BACKGROUND: Vogt-Koyanagi-Harada syndrome (VKH) is a multisystem disorder, characterized by the T-cell-mediated autoimmune process directed against melanocytic antigens in the ocular, nervous, auditory and integumentary systems. The ocular hallmarks of the disease involve severe bilateral panuveitis associated with exudative retinal detachment. CASE REPORT: We report a pediatric case of probable VKH Syndrome with isolated ocular findings, in which bilateral vitritis, papillitis and serous retinal detachments involving the macula with intra-retinal edema and choroideal thickening were detected. INTERVENTION: Subtenon triamcinolone acetonide injection was performed in addition to systemic corticosteroid and cyclosporine treatments. Evolution Prompt improvement was seen in the ocular manifestations of VKH syndrome, which persisted for at least 4 months. Subtenon corticosteroid injection, together with systemic corticosteroid and cytotoxic treatment, prevented the ocular complications of invasive intraocular treatment modalities, and at the same time reduced the systemic corticosteroid dosage. CONCLUSION: We recommend use of ocular invasive treatment modalities in Vogt-Koyanagi-Harada Syndrome only if the disease progression cannot be controlled. If systemic medications fail to stop the progression of the disease activity, subtenon injections may be considered before intraocular treatment modalities.

Evaluation of the corneal topographic characteristics of keratoconus with orbscan II in patients with and without atopy.

PURPOSE: : To analyze the differences in corneal topography in keratoconus patients with and without atopy. METHODS: : In the Beyoglu Eye Research and Training Hospital Refractive Surgery Department, corneal examination with the Orbscan II device (Bausch & Lomb) was done to all patients between May and June 2004 who were diagnosed as keratoconus with corneal topography findings and who did not have any surgical procedure. The atopy grading was done according to the criteria of the UK Atopy Study Group (1994). Patients were divided into 2 groups according to the presence of atopy. The Orbscan findings of the 2 groups were compared. RESULTS: : Among 70 keratoconus patients, 33 patients had partial or full atopy. Sixty-six eyes of the 33 patients were classified as the atopic group, whereas 74 eyes of the remaining 37 patients were classified as the control group. The mean age of the patients was 27.7 +/- 9.5 years in the atopic group and 26.9 +/- 9.5 years in the control group. The central corneal thickness was 428.5 +/- 37.1 mum in the atopic group and 491.8 +/- 56.3 mum in the control group. There was a statistically significant difference between the mean central and thinnest corneal pachymetric readings, the distance of thinnest point to corneal center, anterior and posterior elevation values, distances of the anterior and posterior elevation to the central cornea, and irregularity indexes in the 2 groups (P < 0.05). CONCLUSIONS: : This study shows that corneal topographic and pachymetric characteristics of keratoconus may be different in atopic eyes from those in nonatopic eyes. Atopic keratoconus patients could possibly be evaluated as a separate entity in keratoconus disease.

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 x 1) and ofloxacine (5 x 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 Pearson's correlation test. RESULTS: The mean central foveal retinal thickness was preoperatively 202.4 +/- 25.9 micro m, postoperatively 200.4 +/- 26.1 micro m at 1st day (p = 0.29), 208.4 +/- 27.6 micro m at 1st week (p = 0.29), 226.2 +/- 54.9 micro m at 1st month, 215.2 +/- 24.0 micro m at 3rd month, 213.5 +/- 29.4 micro m at 6th month (p < 0.001). Perifoveal macular thicknesses at superior, inferior, temporal, and nasal quadrants were 264.9 +/- 28.8 micro m, 266.1 +/- 29.5 micro m, 255.0 +/- 31.3 micro m, 260.3 +/- 34.0 micro m, respectively, preoperatively; 287.9 +/- 28.4 micro m, 288.0 +/- 26.3 micro m, 286.8 +/- 33.1 micro m, 272.0 +/- 32.4 micro 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.

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 Fyodorov's 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.

Congenital keratoglobus with blue sclera in two siblings with overlapping Marshall/Stickler phenotype.

We aimed to describe congenital keratoglobus with blue sclera in two siblings with overlapping Marshall/Stickler phenotype. Two sisters (ages four and six) with bilateral high astigmatism were evaluated by slit-lamp microscopy. Corneal topography and pachymetry maps were also obtained. Slit-lamp examination revealed that both corneas were globular in shape with peripheral corneal thinning. Pachymetry maps showed diffuse corneal thinning. Two siblings had in common the features of keratoglobus, blue sclera, atypical face, hearing loss, and hypermobile joints. We tentatively diagnosed the sisters as having an overlapping Marshall-Stickler phenotype based on clinical and radiological findings. Marshall-Stickler syndrome may exist in the differential diagnosis of keratoglobus with blue sclera.

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.

Corneal wavefront-guided customized laser in situ keratomileusis after penetrating keratoplasty.

PURPOSE: To assess the efficacy and safety of corneal wavefront-guided custom laser in situ keratomileusis (LASIK) to correct refractive errors and higher-order aberrations (HOAs) after penetrating keratoplasty (PKP). SETTING: Beyoglu Eye Training and Research Hospital, Istanbul, Turkey. DESIGN: Noncomparative case series. METHODS: The study comprised consecutive patients who were unable to tolerate spectacles or contact lenses for the correction of anisometropia after PKP and had corneal wavefront-guided custom LASIK. The uncorrected (UDVA) and corrected (CDVA) distance visual acuities, manifest refraction spherical equivalent (MRSE), and corneal HOAs were recorded before and after LASIK. RESULTS: The study evaluated 11 eyes (10 patients). The mean follow-up after LASIK was 24.3 months ± 11.7 (SD) (range 9 to 36 months). The mean MRSE was -2.97 ± 1.66 diopters (D) (range -0.50 to -5.38 D) preoperatively and -0.88 ± 0.96 D (range -2.75 to 0.5 D) postoperatively. The mean total higher-order root mean square (RMS) was 4.65 ± 1.14 µm (range 2.26 to 5.94 µm) preoperatively and 2.71 ± 1.31 µm (range 1.22 to 5.33 µm) postoperatively. Postoperatively, the UDVA improved in 7 eyes and remained unchanged in 4 eyes. The CDVA improved in all eyes postoperatively even cases in which the attempted astigmatic correction was not totally achieved. CONCLUSIONS: Corneal wavefront-guided custom LASIK after PKP did not totally correct both refractive errors and HOAs because of the high volume of laser ablation required and inadequate corneal stromal thickness.

Intraoperative corneal thickness measurements during corneal collagen cross-linking with hypoosmolar riboflavin solution in thin corneas.

PURPOSE: To monitor corneal thickness during the corneal collagen cross-linking procedure in corneal ectatic diseases, by using isoosmolar riboflavin solution with 20% dextran and hypoosmolar riboflavin solution without dextran. METHODS: The corneal thickness measurements were obtained at 5 different time points: after epithelial removal, after isotonic riboflavin solution application for 30 minutes, after hypotonic riboflavin solution application for 10 minutes, and after 10 and 30 minutes of isotonic riboflavin solution application. RESULTS: A total of 9 eyes of 9 patients with progressive keratoconus (n = 8) and pellucid marginal degeneration (n = 1) were included in this study. After epithelial debridement, the thinnest pachymetric readings were between 331 and 399 µm (average, 376.11 ± 19.88 µm). The thinnest pachymetric measurements decreased significantly after the application of isoosmolar riboflavin solution for 30 minutes (by 55.22 ± 13.40 µm) and increased significantly after hypoosmolar riboflavin application for 10 minutes (by 59.56 ± 29.71 µm) (P < 0.01 for both). This artificial swelling effect was transient, and the thinnest pachymetric readings decreased significantly after 10 and 30 minutes of isoosmolar riboflavin application compared with thickness at the end of hypoosmolar riboflavin application (by 50.22 ± 29.68 µm and 65.11 ± 27.94 µm, respectively) (P < 0.01 for both). CONCLUSIONS: The iatrogenic swelling effect of the hypoosmolar riboflavin solution might be short acting and not durable throughout the UVA application in collagen cross-linking procedure.

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.

Comparison of 3 pupillometers for determining scotopic pupil diameter.

PURPOSE: The pupil diameter under low ambient illumination is diagnostically valuable for refractive surgery. The aim of study was to compare the NeurOptics® Pupillometer, Sirius®, and Ocular Wavefront Analyser® in determining scotopic pupil diameter. MATERIALS AND METHODS: A total of 96 eyes of 48 subjects were included. The scotopic pupil size was measured with 3 instruments and the measurements repeated following instillations of 1% cyclopentolate. Agreement between the instruments was assessed. RESULTS: The mean measurement obtained by Sirius was significantly larger than Ocular Wavefront Analyser and NeurOptics. The Ocular Wavefront Analyser measured significantly smaller than the others. The mean cycloplegic pupillary diameters (7.73±0.70 mm with NeurOptics, 7.42±0.45 mm with Ocular Wavefront Analyser, and 8.06±0.76 mm with Sirius) were significantly different obtained by 3 instruments (p<0.001, for each; one-way analysis of variance and paired t tests). CONCLUSIONS: The differences between measured pupil diameters with or without cycloplegia obtained by the NeurOptics, Sirius, and Ocular Wavefront Analyser were significant and have unacceptable levels of disagreement. These results may not be related to illumination and accommodation only, but also to measurement algorithms and technical differences of the devices.

Unilateral superior pellucid marginal degeneration in a case with ichthyosis.

A 47-year-old man with ichthyosis vulgaris presented to our hospital complaining of reduced visual acuity and ocular discomfort in the left eye. Slit-lamp biomicroscopy revealed a thinning about 2mm from the superior limbus and superficial punctate corneal lesions in the left eyes. Corneal topography was 'butterfly-like' in an area of increased elevation in the left eye. Although ichthyosis vulgaris and unilateral superior pellucid marginal degeneration are both uncommon conditions, this is first report about these two conditions in studied together.

Phacoemulsification in high myopia.

OBJECTIVE: To analyze the visual results of phacoemulsification in highly myopic eyes, to investigate the risk factors for poor postoperative visual acuity and to assess postoperative complications. METHODS: This retrospective study reviewed the records of 209 eyes of 150 patients with high myopia who underwent phacoemulsification and foldable intraocular lens (IOL) implantation between January 1998 and July 2008 at Beyoglu Education and Research Eye Hospital, Istanbul, Turkey. RESULTS: Postoperative best-corrected visual acuity (BCVA) was 0.5 or better in 63.2% of eyes. One hundred forty-seven (70.3%) eyes were within ±1.0 diopter (D) of the intended target refraction. In multiple regressions, only pre-existing myopic chorioretinal macular degeneration was found to be associated with poor BCVA (p=0.000). Nor patient age nor axial length (AL) had any correlation with postoperative BCVA. Retinal detachment (RD) occurred in one eye (0.5%) during mean follow-up (18.7+/-8.9 months). CONCLUSION: Most of the eyes with high myopia achieved satisfactory improvement in BCVA with few complications. Myopic retinal degenerative changes were the single independent factor limiting visual potential. Our lower incidence of postoperative RD could be attributed partially to our lower neodymium:yttrium-aluminum-garnet (Nd:YAG) laser capsulotomy rates and our surgical modification involving the implementation of primary posterior capsulorhexis in all patients younger than 40.