Ramin Khoramnia

Anterior chamber measurements using Pentacam rotating Scheimpflug camera.

PURPOSE: To investigate the mean values and standard deviations according to age, reliability, and correlation between different parameters of anterior chamber measurements using the Pentacam rotating Scheimpflug camera. SETTING: Heidelberg IOL and Refractive Surgery Research Group, Department of Ophthalmology, University of Heidelberg, Heidelberg, Germany. METHODS: This prospective clinical study comprised 76 healthy volunteers (mean age 46.6 years ± 16.8 [SD]). Three consecutive measurements were made of only 1 eye and anterior chamber depth (ACD), mean and minimum anterior chamber angle (ACA), and anterior chamber volume (ACV) were evaluated. RESULTS: Mean ACD was 2.93 ± 0.36 mm, mean ACA was 34.81 ± 5.05 degrees, minimum ACA was 29.99 ± 5.53 degrees, and mean ACV was 160.3 ± 36.81 mm3. Increasing age was associated with reduced ACD and ACV; however, mean and minimum ACAs were lowest in patients aged 40 to 59 years. Excellent correlation was found between ACD and ACV (R = 0.92). Anterior chamber depth and mean ACA correlated only moderately (R = 0.65). The correlation coefficient between ACD and minimum ACA was smaller (R = 0.58). There was no correlation between ACV and ACA (R = 0.37). Minor standard deviations were noted (ACD 0.02 ± 0.02 mm, mean ACA 1.12 ± 0.94 degrees, minimum ACA 2.04 ± 2.67 degrees, and ACV 2.48 ± 1.65 mm3). CONCLUSIONS: Using the Pentacam, it was possible to examine different parameters of the anterior chamber within a short period and with good reliability. The evaluation of the ACA in different positions can help to classify the potential risk for angle‐closure glaucoma.

Central and peripheral pachymetry measurements according to age using the Pentacam rotating Scheimpflug camera.

PURPOSE: To investigate the mean values and standard deviations as well as the reliability of consecutive examinations of central and peripheral corneal thickness measurements according to age using the Pentacam rotating Scheimpflug camera (Oculus, Inc.). SETTING: Department of Ophthalmology, University of Heidelberg, Heidelberg, Germany. METHODS: Seventy‐six healthy volunteers were enrolled in a clinical prospective study. Three consecutive Pentacam measurements of 1 eye per subject were taken. Evaluated were the central corneal thickness (CCT), corneal thickness at 4 peripheral points (3.0 mm superior, inferior, nasal, and temporal), and the thinnest point of the cornea. The volunteers were then assigned to 3 groups to assess the influence of increasing age on the study parameters. RESULTS: The mean age of the subjects was 46.6 years ± 16.8 (SD). The mean CCT was 539.62 ± 31.87 μm. Peripherally, the corneal thickness was between 11% and 19% higher than centrally, with the superior cornea being the thickest followed by the nasal, the inferior, and the temporal cornea. The thinnest point was located in the inferotemporal quadrant in 92% of eyes and in the superotemporal quadrant in 8%. There was no correlation between age and corneal thickness. Minor mean standard deviations of consecutive measurements were noted in the corneal center (4.33 μm), increasing significantly toward the periphery (mean 8.31 μm). Increasing age was not associated with decreasing reliability. CONCLUSIONS: Using the Pentacam, it was possible to acquire information about corneal thickness across the entire cornea. No correlation was found between increasing age and change in peripheral or CCT. Good reliability was noted for pachymetry measurements decreasing slightly toward the periphery, which was independent of age.

Corneal Collagen Crosslinking in post-LASIK keratectasia

Background/aims To evaluate the effect of corneal collagen crosslinking with riboflavin and UV-A as a treatment option for postlaser in situ keratomileusis keratectasia. Methods Crosslinking was carried out in 22 eyes of 15 patients with iatrogenic keratectasia. Follow-up, according to a standardised protocol (uncorrected visual acuity (UCVA), best-corrected visual acuity (BCVA), slit-lamp examination, pachymetry and topography), was performed preoperatively 1, 3, 6 and 12 months after crosslinking. Results The mean BCVA was 0.19 (SD±0.21) logMAR preoperatively, 0.25 (SD±0.17) 1 month, 0.20 (SD±0.20) 3 months, 0.18 (SD±0.21) 6 months and 0.15 (SD±0.14) 12 months postoperatively (statistically significant postop1–postop6, p=0.0335). The maximum k-readings were 44.12 (SD±3.97) preoperatively, 46.23 (SD±4.14) 1 month, 43.88 (SD±4.25) 3 months, 45.06 (SD±5.07) 6 months and 44.43 (SD±4.06) 12 months postoperatively (statistically significant preop–postop1, p=0.0281). Conclusion Crosslinking in patients with iatrogenic keratectasia stabilised the UCVA and BCVA as well as the maximum k-readings in our cohort. It seems to be a safe and promising procedure to stabilise the refraction and the corneal topography, and thus to stop the progression of visual loss, thereby avoiding or delaying disease progression and keratoplasty.

Implantation of a multifocal toric intraocular lens with a surface-embedded near segment after repeated LASIK treatments.

UNLABELLED We report a 66-year-old patient who presented with increasing hyperopia, astigmatism, and presbyopia in both eyes 8 years after bilateral laser in situ keratomileusis (LASIK) and LASIK enhancement in the left eye aiming for spectacle independence. Bilateral multifocal toric Lentis Mplus intraocular lenses (IOLs) with an embedded near segment and individually customized cylinder correction were implanted uneventfully following phacoemulsification. The Haigis-L formula after previous hyperopia correction was chosen for IOL power calculation and provided reliable results. Emmetropia was targeted and achieved. Three months postoperatively, the uncorrected distance visual acuity had increased from 0.40 logMAR to 0.10 logMAR in the right eye and from 0.20 logMAR to 0.00 logMAR in the left eye. The patient gained 6 lines of uncorrected near visual acuity: 0.20 logMAR in the right eye and 0.10 logMAR in the left eye. This case shows that customized premium IOL implantation can provide accurate results even in challenging cases. FINANCIAL DISCLOSURE The International Vision Correction Research Centre, Department of Ophthalmology, University of Heidelberg, Heidelberg, Germany, has received research grants, lecture fees, and travel reimbursement from Oculentis GmbH.

Optical and material analysis of opacified hydrophilic intraocular lenses after explantation: a laboratory study

BackgroundThe opacification of hydrophilic intraocular lenses (IOLs) is a very rare complication in terms of absolute numbers. We report on the analyses of opacified Euromaxx ALI313Y and ALI313 IOLs (Argonoptics, Germany) using light and scanning electron microscopy, X-ray spectroscopy and optical bench analysis.MethodsOpacified Euromaxx ALI313Y and ALI313 IOLs were explanted after patients presented with a decrease in visual acuity. The explants were sent to our laboratory and examined using light and scanning electron microscopy. The composition of the deposits was analysed using X-ray spectroscopy. The optical quality of the intraocular lens (IOL) was assessed using the OptiSpheric IOL PRO optical bench (Trioptics GmbH Wedel, Germany). Modulation transfer function (MTF) was measured at all spatial frequencies and United States Air Force (USAF) 1951 resolution target pictures were documented.ResultsMacroscopically, the entire optic was opacified in all IOLs. Light and scanning electron microscopy revealed numerous fine, granular, crystalline-like deposits, which were always distributed in a line parallel to the anterior and posterior surfaces of the IOLs. X-ray spectroscopy could prove the deposits consisted of Calcium and Phosphate. Measurements in the optical bench showed deterioration of MTF values at all spatial frequencies and the USAF target pictures demonstrated a significant reduction of brightness as well as resolution with the opacified IOLs.ConclusionsThe calcification of hydrophilic IOLs only occurs rarely. The exact chemical composition of the deposits can be assessed by means of X-ray spectroscopy. Optical quality analysis of the explanted Euromaxx ALI313Y and ALI313 IOLs showed significant reduction of MTF values, which was confirmed by USAF target pictures.

Precision, morphology, and histology of corneal flap cuts using a 200-kHz femtosecond laser

Purpose Laser-assisted in situ keratomileusis (LASIK) requires precise corneal flap cutting. Especially the creation of thin flaps has recently gained importance for thin-flap LASIK. Currently, there is a trend towards faster femtosecond lasers that can produce flaps in a short period of time. We analyzed flaps created with a 200-kHz femtosecond laser concerning their cut precision, morphology, and histology. Methods Femtosecond laser flap cutting was performed on 36 porcine cadaver eyes using the prototype 200-kHz femtosecond laser UltraFlap (WaveLight GmbH, Erlangen, Germany). The eyes were assigned to 3 thickness groups, with a cut depth of 100 µm, 130 µm, or 180 µm, respectively. Additionally, flap diameters were varied, ranging from 8.0 mm to 9.5 mm. Flap thicknesses were determined with a micrometer gauge. Flap diameters were measured with a sliding caliper. Furthermore, flaps were created for histologic examination. Results There were no complications during flap creation. The mean flap thickness and standard deviation was (in micrometers) 96.33±7.45 (intended thickness: 100), 134.67±4.96 (intended thickness: 130), and 174.59±9.35 (intended thickness: 180), respectively. The flap diameter revealed a mean (in mm) of 8.03±0.15 (intended diameter: 8.0), 8.56±0.10 (intended diameter: 8.5), 9.09±0.10 (intended diameter: 9.0), and 9.54±0.15 (intended diameter: 9.5), respectively. Histologic examination showed very little to almost no changes in the structure of the corneal stroma. Conclusions Flap creation could be performed easily without any complications. The morphology and accuracy of the cuts were very reliable and precise. Histology showed a smooth cut.

Safety, efficacy, predictability and stability of laser in situ keratomileusis (LASIK) with a 1000-Hz scanning spot excimer laser.

Purpose:  To evaluate the safety, efficacy, predictability and stability of laser in situ keratomileusis (LASIK) with a 1000‐Hz scanning spot excimer laser (Concept System 1000; WaveLight GmbH, Erlangen, Germany).

Cataract is a self-defence reaction to protect the retina from oxidative damage

Age-related macular degeneration (AMD) is the leading cause of blindness in developed countries. Cataract extraction is the most common surgical procedure in developed countries. Lutein (L) and zeaxanthin (Z), retinal carotenoids, are the most powerful retinal anti-oxidants and absorb the harmful blue light. The depletion of L+Z induces the development of the lens opacification-cataract. Cataract reduces the retinal oxidative stress (OS), which causes a reduction of the probability to develop AMD. Oxidative Stress at the retinal level is the common pathway in the development of AMD and cataract. AMD and cataract are not two independent processes. Cataract is a self-defense reaction of the retina to reduce OS and retinal damage. Restoring the anti-oxidative capabilities of the retina by increasing intake of L+Z reduces the likelihood of AMD and cataract. Extracting the opaque lens elevates the retinal OS and increases the rate of AMD.

Neurosensory retinal detachment due to sunitinib treatment.

Sir, Sunitinib is an oral inhibitor of various tyrosine kinases as well as vascular endothelial growth factor receptors 1 to 3.1, 2 Sunitinib is used to treat metastatic renal cell carcinoma (RCC). Here we describe, for the first time, a neurosensory retinal detachment due to sunitinib treatment.

Eintrübung einer hydrophilen Intraokularlinse 4 Jahre nach Kataraktoperation

ZusammenfassungDie Kalzifikation von hydrophilen Intraokularlinsen (IOL) ist eine seltene Komplikation. Wir berichten über den komplikationslosen Austausch einer eingetrübten hydrophilen IOL. Vier Jahre nach unproblematischer Kataraktoperation war es zu einer Kalzifikation der IOL mit resultierender Visusminderung gekommen. Makroskopisch zeigte sich eine Eintrübung der Optik und Haptiken. Licht- und rasterelektronenmikroskopisch konnten wir neben granulären Auflagerungen auf der IOL zahlreiche feine, granuläre Ablagerungen in der Optik nachweisen, die in einer zur Oberfläche parallelen Linie angeordnet waren.AbstractCalcification of hydrophilic intraocular lenses (IOL) is a rare complication. We report about the uneventful replacement of an opacified hydrophilic IOL. The patient presented 4 years after uneventful cataract surgery with a reduction of visual acuity due to calcification of the IOL. Macroscopically, the optic and the haptics were opacified. Light and scanning electron microscopy revealed granular deposits on the external surface of the IOL and numerous fine granular deposits within the optic of the IOL which were distributed in a line parallel to the surface of the IOL.Calcification of hydrophilic intraocular lenses (IOL) is a rare complication. We report about the uneventful replacement of an opacified hydrophilic IOL. The patient presented 4 years after uneventful cataract surgery with a reduction of visual acuity due to calcification of the IOL. Macroscopically, the optic and the haptics were opacified. Light and scanning electron microscopy revealed granular deposits on the external surface of the IOL and numerous fine granular deposits within the optic of the IOL which were distributed in a line parallel to the surface of the IOL.