Impact of intravitreal injection therapy on contrast sensitivity in patients with nAMD and DME.

PURPOSE: The study aims to evaluate changes in contrast sensitivity (CS) during therapy with intravitreal vascular endothelial growth factor (VEGF) inhibitors in patients with neovascular age-related macular degeneration (nAMD) and diabetic macular edema (DME). METHODS: Prospective, uncontrolled, multicenter study on patients with neovascular AMD or DME who underwent intravitreal injection therapy with Ranibizumab, Aflibercept, or Bevacizumab was conducted. Best corrected visual acuity (BCVA) and CS measured by Mars Letter Contrast Sensitivity Test (MLCS) and Freiburg Visual Acuity and Contrast Test (FrACT) in logCS were evaluated before 3 consecutive VEGF inhibitor injections, which followed the pro renata regimen in treatment-naïve and pretreated eyes with a maximum of 9 injections. Correlation of MLCS and FrACT was calculated by the Spearman's rank correlation coefficient. RESULTS: Eighty eyes of 74 patients (mean age 72.7; SD ± 9.96) were included. BCVA improved significantly from 0.44 (SD ± 0.21) logMAR to 0.38 (SD ± 0.23) logMAR by 0.06 (SD ± 0.14) logMAR values (p < 0.001). CS measured by MLCS increased significantly from 1.27 (SD ± 0.25) logCS to 1.39 (SD ± 0.22) logCS (p < 0.001). CS measured by FrACT also improved significantly from 1.22 (SD ± 0.32) logCS to 1.30 (SD ± 0.29) logCS (p = 0.035). A positive correlation between MLCS and FrACT was found (r = 0.389; p < 0.001). Despite statistical significance, results for BCVA, MLCS, and FrACT failed clinical significance. Overall best test results were achieved with MLCS. CONCLUSIONS: Intravitreal injection therapy with VEGF inhibitors led to an improvement of BCVA and CS measured by MLCS and FrACT. MLCS was superior and more sensitive compared to FrACT and even BCVA to evaluate CS in elderly patients with macular pathology.

[Effectivity and Safety of a Modified Tip Design in Torsional Phacoemulsification]. / Effektivität und Sicherheit eines modifizierten Tipdesigns bei der torsionalen Phakoemulsifikation.

BACKGROUND: Torsional mode phacoemulsification results in more effective fragmentation of the nucleus due to a different movement of the phacotip. In this clinical study, we investigated the influence of a modified tip design and active fluidics on the efficacy of phacoemulsification and safety for the corneal endothelium. MATERIAL AND METHODS: We conducted a prospective randomized 2 : 1 study in which 40 patients were operated on with the mini-flared Kelman Tip using the Infiniti® System (group 1), and 20 patients were operated on with the Intrepid® Balanced Tip and the Centurion® System. We analyzed the intraoperative cumulative dissipated energy and also the density of the corneal endothelium measured with an endothelial microscope (CEM 530, Nidek) pre- and postoperatively. RESULTS: Both groups did not differ preoperatively in age, sex, axial length of the globe or corneal endothelium cell density nor cataract density (LOCS3). All surgeries were uneventful. The cumulative dissipated energy in group 1 (mini-flared Kelman tip, Infiniti System) was 38% higher than in group 2 (balanced tip, Centurion System; p < 0.05). The endothelial cell loss was 8% in group 1 and 10.3% in group 2 (p > 0.05). The cell size (polymegathism) increased in both groups significantly with + 37 µm in group 1 (p < 0.05) und + 54 µm in group 2 (p < 0.05). There was no statistically significant difference between both groups (p > 0.05). The number of hexagonal cells (pleomorphism) and corneal thickness did not differ in both groups either pre- nor postoperatively. CONCLUSIONS: Compared to torsional phacoemulsification with a mini-flared Kelman Tip and gravity fluidics, torsional phacoemulsification with a modified tip design and active fluidics is 38% more effective regarding the cumulative dissipated energy. Endothelial cell loss occurs to a similar extend using both systems. The postoperative changes in cell size (polymegathism), number of hexagonal cells (pleomorphism) and corneal thickness (pachymetry) were similar among both systems. We conclude, that the intraoperative stress on the endothelium is equivalent with both systems used.

[Improvement of Phaco Tip Geometry During Torsional Phacoemulsification]. / Verbesserung der Phakotip-Geometrie bei der torsionalen Ultraschallphakoemulsifikation.

BACKGROUND: Advanced cataract with hard lens nuclei frequently challenge the ophthalmologic surgeon when doing phacoemulsification. In the present study, we examined the effect of a new phaco tip design during cataract surgery. PATIENTS AND METHODS: 100 patients were assigned to two groups. In group 1 (50 patients), the Kelman® tip design (Alcon) was used during phacoemulsification, while in group 2 (50 patients), the Intrepid® Balanced Tip was applied. Trypan blue was used in both groups, if necessary, to stain the anterior lens capsule prior to capsulorhexis. RESULTS: Preoperative visual acuity was 0.11 ± 0,16 (decimal equivalent; means ± standard deviation) in the Kelman tip group and 0.10 ± 0.14 in the Intrepid Balanced Tip group (p > 0,05). Applied cumulative displaced energy was 43.38 ± 21.84 s% in the Kelman tip group and 21.55 ± 13.25 s% in the Intrepid Balanced Tip group (p < 0,001). No intraoperative or postoperative complications occurred. CONCLUSIONS: The improved Intrepid Balanced phaco tip design has led to a significant reduction in ultrasound energy required to successfully perform phacoemulsification in medium to hard lenses.

[Role of Intraoperative Indirect Channelography in Glaucoma Stent Implantation]. / Bedeutung der intraoperativen indirekten Kanalografie bei der Glaukomstentimplantation.

Several glaucoma stents are available to surgically reduce the intraocular pressure in primary open-angle glaucoma (POAG). In comparison to conjunctival opening procedures, the advantages of microinvasive glaucoma surgery (MIGS) are relatively atraumatic ab-interno procedures through a paracentesis, conjunctival sparing for later filtrating surgery, and possible combined cataract surgery. In this overview, the principle of intraoperative indirect channelography as a decision criterion for the individual selection of glaucoma stent implantation is presented. Through a paracentesis a slight hypotony was induced and retrograde blood filling of Schlemm's canal was observed gonioscopically. Good blood filling was an indicator for an intact drainage system through the collector channels and the episcleral veins. In these patients a trabecular bypass stent system can be placed in Schlemm's canal of the anterior chamber angle to improve drainage of aqueous humour and reduce the intraocular pressure (IOP). In patients with a negative intraoperative indirect channelography, which can be recognized through an absent or insufficient retrograde blood filling of Schlemm's canal, an alternative drainage path should be considered by using supraciliary or subconjunctival glaucoma stents. A significant mean IOP reduction of 17 to 36% can be achieved with a reduction of local glaucoma therapy. Relevant complications with choroidal detachment and decreased visual acuity due to postoperative hypotony are rare.

Comparison of slit lamp-adapted optical coherence tomography features of fellow eyes of acute primary angle closure and eyes with open angle glaucoma.

PURPOSE: The aim of this study was to assess the possibility of discriminating a narrow and occludable chamber angle by means of digital gonioscopy. METHODS: In a prospective controlled clinical study 40 eyes of 40 patients were enrolled. 20 patients that had suffered acute angle closure glaucoma (ACG) on the fellow eye were compared to 20 patients with open angle glaucoma (OAG). Anterior segment imaging with SL-OCT (Heidelberg Engineering, Heidelberg, Germany) enabled the delineation, by means of automatic signal analysis, of several important parameters of the anterior chamber angle region, which were compared to those revealed from direct contact glass gonioscopy and ultrasound biometry. RESULTS: The anterior segment structures were automatically recognized by the SL-OCT software in 70 % of the ACG patients and in all of the OAG cases (100 %) (p = 0.025). Anterior chamber angle (ACA) was 15.55° ± 6.92° in the ACG group and 34.6° ± 8.9° in the OAG group, whereas angle opening distance (AOD) was 199.55 ± 62.29 µm in ACG and 452.67 ± 123.91 µm in OAG. A good correlation was found in the direct gonioscopic findings (r = 0.85, p < 0.001), but there were significant differences between both groups (p < 0.001). Mean real central anterior chamber depth (rACD) was evaluated to be 1.75 and 2.79 mm in ACG and OAG, respectively, showing a significant difference (p < 0.0001) and the highest (although not statistically significant) sensitivity and specificity above all other parameters tested in discriminating between OAG and ACG eyes. Discrimination criteria revealed a relevant narrowing of the anterior chamber angle region for values below 22° (ACA), 276 µm (AOD) and 2.08 mm (rACD). CONCLUSIONS: Digital gonioscopy by means of SL-OCT allowed a non-invasive and objective imaging of the anterior chamber configuration that could be used as a screening method for narrow and occludable angles. The method could contribute to a timely identification of angle closure and alert clinicians to further determine whether a peripheral iridotomy should be performed.

Diode laser cyclophotocoagulation versus cyclocryotherapy in the treatment of refractory glaucoma.

PURPOSE: The aim of the present study was to evaluate the efficacy of diode laser cyclophotocoagulation (DCPC) and cyclocryotherapy (CCT) in the treatment of refractory glaucoma and compare the postoperative complications and discomfort rates. METHODS: In a prospective, randomized, controlled clinical study, 40 eyes of 40 patients with refractory glaucoma were randomly assigned in 2 groups of 20 eyes each to receive either DCPC or CCT. Patients underwent follow-up examinations on the first 3 days and then 1 week and 1, 3, 6, and 12 months after initial treatment. Complications and discomfort after treatment using a visual pain analogue scale were recorded. RESULTS: In the DCPC group, the mean intraocular pressure (IOP) decreased (p<0.05) from 44.3 ± 16.4 mmHg preoperatively to 24.1 ± 7.6 mmHg, 22.8 ± 5.6 mmHg, and 22.5 ± 5.1 mmHg 3, 6, and 12 months posttreatment, respectively. Regarding the CCT group, the mean IOP was reduced (p<0.05) from 46.5 ± 10.4 mmHg to 26.6 ± 12.2 mmHg, 21.2 ± 7.7 mmHg, and 20.6 ± 5 mmHg at the same time intervals. In the DCPC group, the mean IOP reduction was strongly correlated with the number of laser effects (r = 0.65; p<0.01), but 35% needed retreatments. The mean postoperative pain was 5.6 ± 2.9 (DCPC) vs 5.7 ± 2.3 (CCT) (p = 0.91). No severe complications were observed. CONCLUSIONS: Both DCPC and CCT proved to be safe and effective IOP-lowering methods in patients with refractory glaucoma. Diode laser cyclophotocoagulation should be considered as the primary treatment option in refractory glaucoma using an individual treatment dosage.

Biometric evaluation of keratoconic eyes with slit lamp-adapted optical coherence tomography.

PURPOSE: To evaluate slit lamp-adapted optical coherence tomography for morphological imaging and morphometrical measurements in keratoconic eyes. METHODS: Using slit lamp-adapted optical coherence tomography, we examined 32 eyes of 20 consecutive patients with keratoconus and described morphological attributes of the cornea. Furthermore, in a subgroup of 19 eyes, we measured morphometrical values of the cornea and compared these values with those of an age-matched control group of 19 normal eyes. RESULTS: Of the 32 keratoconic eyes, 23 eyes had marked corneal thinning of less than 450 µm, 18 eyes had central stromal scarring, and 3 eyes had intrastromal cysts from acute hydrops formation. Central corneal thickness was measured as 374 ± 106 µm in the group of 19 keratoconic eyes, compared with 503 ± 127 µm in the control group (P < 0.05); anterior chamber depth was 3.6 ± 0.4 mm versus 3.1 ± 0.4 mm (P < 0.05); anterior curvature mean radius was 7.2 ± 1.2 mm versus 8.6 ± 1.0 mm (P < 0.05); posterior radius was 5.5 ± 0.7 mm versus 6.8 ± 0.7 mm (P < 0.05). CONCLUSIONS: This study provides further validation that anterior segment optical coherence tomography is a reliable method to assess important parameters for diagnosis and therapeutic outcome control of patients with keratoconus. This method may be particularly useful as a safe and well-defined preoperative diagnostic tool before keratoplasty or corneal cross-linking.

Significance of the riboflavin film in corneal collagen crosslinking.

PURPOSE: To evaluate the role of the preocular riboflavin film in ultraviolet-A (UVA) absorption in corneal collagen crosslinking (CXL). SETTING: Eye Laser Institute, Department of Ophthalmology, Martin-Luther-University, Halle, Germany. METHODS: The absorption of UVA light was measured in human donor and porcine postmortem corneas with and without riboflavin film using 3 solutions: standard dextran-riboflavin, methylcellulose-riboflavin, and hypoosmolar riboflavin-sodium chloride without dextran. The breakup time of the solutions and their absorbance were also determined. RESULTS: After 30-minute instillation of riboflavin solution, the corneal absorption coefficient of the combined stroma-riboflavin film system was 56.36 cm(-1) in human corneas and 51.46 cm(-1) in porcine corneas using dextran-riboflavin; 69.87 cm(-1) and 53.86 cm(-1), respectively, using methylcellulose-riboflavin; and 48.19 cm(-1) and 42.68 cm(-1), respectively, using hypoosmolar riboflavin. For the stroma alone without riboflavin film, the absorption coefficient was reduced to 36.95 cm(-1) in human corneas and 28.91 cm(-1) in porcine corneas using dextran-riboflavin; 38.26 cm(-1) and 32.49 cm(-1), respectively, using methylcellulose-riboflavin; and 38.88 cm(-1) and 28.42 cm(-1), respectively, using hypoosmolar riboflavin solution. The breakup time was 22 minutes for the dextran-riboflavin film, 32 minutes for methylcellulose, and 90 seconds for the hypoosmolar solution. CONCLUSION: Results indicate that the cornea including the riboflavin film can be considered a composite 2-compartment system and that the riboflavin film is an integral part of the CXL procedure and important in achieving the correct stromal and endothelial UVA irradiance. FINANCIAL DISCLOSURE: No author has a financial or proprietary interest in any material or method mentioned.

Influence of corneal curvature on central and paracentral pachymetry with optical coherence tomography.

PURPOSE: Optical coherence tomography (OCT) has been found to be valuable to measure the corneal thickness (CT). The purpose of this clinical study was to determine the influence of corneal curvature on central and paracentral pachymetry with slit lamp-adapted OCT using a linear scanning geometry. METHODS: In a prospective, comparative observational study, a total of 77 consecutive patients (77 eyes) participated. Central and paracentral (4 mm) CT with slit lamp-adapted OCT (Heidelberg Engineering, Heidelberg, Germany) and with ultrasound (US) pachymetry were performed. The corneal curvature was determined with manual keratometry, and the influence of the corneal curvature on CT with OCT was compared with curvature-independent US values. RESULTS: The overall mean central CT values were 533 +/- 53 microm (OCT) and 546 +/- 56 microm (US) and paracentrally 562 +/- 55 microm (OCT) and 569 +/- 55 microm (US). The mean central and paracentral differences (P < 0.001) between both methods were 12.7 and 6.4 microm, respectively. The mean corneal curvature was 7.79 +/- 0.30 mm corresponding to a mean corneal power of 43.39 +/- 1.69 diopters. In the central area, there was no influence on the OCT measurements (r = -0.01, P = 0.935), whereas there was a minimal influence (r = 0.131, P = 0.021) on paracentral pachymetry with OCT using a linear scanning module. In paracentral areas, the systematic difference between OCT and US decreased from 8.4 microm in flat corneas (P < 0.001) to 5.0 microm in steeper corneas (P = 0.06). CONCLUSIONS: Slit lamp-adapted OCT allowed noncontact central and paracentral CT measurements. Although there were significant differences between OCT and US measurements, the corneal curvature had only a minimal influence on paracentral pachymetry with OCT using a linear scanning geometry. For more peripheral measurements or in marked alterations of the corneal curvature, correction factors may be needed.

Potential use of riboflavin/UVA cross-linking in bullous keratopathy.

BACKGROUND: Collagen cross-linking of the cornea has been shown by us to have an antiedematous effect in the cornea. The aim of the present study was to examine if this effect can be used for the treatment of bullous keratopathy. METHODS: This clinical interventional case series included 3 patients (3 eyes) with bullous keratopathy due to pseudophakia, corneal transplant rejection, and Fuchs' endothelial dystrophy. After dehydration for 1 day using 40% glucose, the central 8 mm of the cornea were abraded and cross-linked with the photosensitizer riboflavin and UVA (370 nm, 3 mW/cm(2)) for 30 min. Optical coherence tomography pachymetry measurements of the central cornea were performed at various time intervals. RESULTS: Corneal thickness was reduced by 90.33 +/- 17.04 microm on average 3 days after cross-linking and by 93.67 +/- 14.22 microm after 8 months. The bullous changes of the epithelium were markedly improved, resulting in loss of pain and discomfort. Visual acuity was significantly improved in the case without prior stromal scarring. CONCLUSIONS: Cross-linking might become another useful tool in the treatment of bullous keratopathy. It is primarily suited for patients with pain symptoms, restricted visual prognosis or to extend the time interval for an upcoming corneal transplantation.

Hydration behavior of porcine cornea crosslinked with riboflavin and ultraviolet A.

PURPOSE: To examine the influence of a new crosslinking treatment on corneal swelling properties that correlate with the degree of crosslinking. SETTING: Department of Ophthalmology, Vivantes-Klinikum Neukölln, Berlin, Germany. METHODS: Twenty freshly enucleated porcine eyes were crosslinked by applying the photosensitizer riboflavin and ultraviolet-A (UVA) light (370 nm, 3 mW/cm2) for 30 minutes. After the eyes were treated and incubated for 24 hours in a moist chamber, 15 eyes were examined by biomicroscopy and optical coherence tomography (OCT); 5 eyes were examined by light microscopy. Five control eyes were included. RESULTS: Using light microscopy, a characteristic swelling pattern with 3 zones was identified in the crosslinked porcine cornea: an anterior intensely crosslinked zone of 242 microm, an intermediate partially crosslinked zone of 238 microm (hydration factor 2.2), and a noncrosslinked posterior zone of 1355 microm (hydration factor 2.7). A condensed OCT signal was demonstrated in the treated portion of the anterior stroma to a depth of 520 microm with a pronounced line at 540 microm, correlating with the combined anterior and intermediate layers after hydration in the histological analysis. In the nonhydrated state of the crosslinked cornea, the anterior zone was deduced to be 242 microm; the intermediate zone, 109 microm; and the posterior zone, 501 microm. Therefore, the maximum depth of the crosslinking effect was 351 microm. CONCLUSIONS: Collagen crosslinking using riboflavin and UVA led to a significant change in the swelling behavior of the anterior stroma, confirming prior findings that the crosslinking effect is strongest in the anterior half of the stroma. Crosslinked cornea did not induce a specific signal on OCT, and OCT is therefore not suited for clinical controls of the crosslinking effect.

Online optical coherence pachymetry to evaluate intraoperative ablation parameters in LASIK.

PURPOSE: The ablation of corneal tissue with the excimer laser can be variable and can lead to miscorrections. The purpose of this study was to evaluate intraoperative ablation parameters during laser-assisted in-situ keratomileusis (LASIK) with online optical coherence pachymetry (OCP). METHODS: In a prospective, nonrandomized, comparative clinical study, the ablation parameters were continuously assessed intraoperatively with online OCP (Heidelberg Engineering, Lübeck, Germany) in 45 myopic and 10 hyperopic LASIK treatments. The central intraoperative ablation values were compared with the calculated values of the excimer laser (ESIRIS, Schwind, Germany) and the postoperative refraction. The ablation process and the ablation rate in mum per layer, time, and dioptric correction were evaluated in myopic corrections. RESULTS: In myopic LASIK treatments, a linear ablation process was measured with a mean correlation coefficient of -0.968 +/- 0.04. The intraoperative ablation rate was, on average, 0.59 +/- 0.17 microm per layer, 1.45 +/- 0.48 microm per second, and 24.63 +/- 7.81 microm per corrected diopter. These values were 28.7% to 29.6% higher (P < 0.001) than the calculated values. There was a significant correlation (P < 0.001) for the ablation rate per layer (r = 0.823), per second (r = 0.869), and corrected diopter (r = 0.892), but no correlation (r = 0.21, P = 0.239) between the measured linear ablation process and the postoperative refraction. During hyperopic LASIK treatments, without ablation of the corneal center, there was a significant decrease (P = 0.005) of the stromal thickness by 18.34 +/- 14.13 microm, which corresponded to a mean corneal dehydration rate of 0.27 microm per second. CONCLUSIONS: Online OCP allowed a clinical evaluation of intraoperative ablation parameters in LASIK. Further studies are needed to assess a possible active control of the excimer laser ablation from these continuous values, which could possibly improve current ablation nomograms.

Management of the red eye for the primary care physician.

For the primary care physician, the occurrence of a red eye is a frequent and prominent finding of a disease process in patients. A careful history and simple examination with the observation of typical clinical signs are important for the management of this common disorder. The causes can be classified as painful red eye, trauma, and other common conditions. The most frequent causes of a red eye, such as dry eye, conjunctivitis, keratitis, iritis, acute glaucoma, subconjunctival hematoma, foreign bodies, corneal abrasion, and blunt or penetrating trauma, are described in this article. Simple diagnostic methods and an emergency management with some useful topical ophthalmic preparations are included. Although several conditions can be treated by the primary care physician the clinical signs that require an urgent ophthalmic consultation are chemical burns, intraocular infections, globe ruptures or perforations, and acute glaucoma.

Continuous measurement of corneal dehydration with online optical coherence pachymetry.

PURPOSE: Online optical coherence pachymetry (online OCP) allows continuous central corneal thickness measurements over time. In this study, the effect of dehydration on corneal tissue was investigated with online OCP. METHODS: Twelve eyes of 11 patients were examined with online OCP, and the central corneal thickness was registered over 5 minutes after insertion of an eyelid speculum. RESULTS: Online OCP measurements revealed no decrease in reproducibility after 5 minutes of dehydration. The initial mean central corneal thickness was 538 +/- 48 microm. After 5 minutes the central corneal thickness decreased to 483 +/- 43 microm (P = 0.001). This corresponded to a mean corneal thinning of 55 +/- 4 microm (10.2%) at a rate of 0.19 microm/s. CONCLUSIONS: Online OCP was suitable for continuous measurements of corneal changes caused by dehydration. These dehydration effects should be particularly considered in refractive corneal surgery.

Imaging interface fluid after laser in situ keratomileusis with corneal optical coherence tomography.

A 41-year-old myopic patient who had laser in situ keratomileusis 6 months earlier was treated for a complete retinal detachment (RD) with proliferative vitreoretinopathy. Surgical treatment consisted of an encircling band, pars plana vitrectomy, and silicone oil filling. Postoperatively, the patient developed marked corneal edema with no increase in intraocular pressure (IOP) as measured by applanation tonometry. Interface fluid was confirmed by corneal optical coherence tomography. Quantification of the corneal structures revealed that corneal edema was in the residual posterior stroma predominantly. The epithelial and flap thickness did not change significantly. The case demonstrated that after vitreoretinal surgery for RD repair, transient corneal endothelial cell dysfunction developed, causing marked edema of the posterior corneal stroma and interface fluid accumulation. However, an increase in IOP cannot be excluded.

Noncontact goniometry with optical coherence tomography.

OBJECTIVE: To assess the value of noncontact goniometry with optical coherence tomography (OCT) compared with current clinical parameters in the evaluation of the anterior chamber angle (ACA). DESIGN: Prospective observational study of 138 eyes of 109 patients. METHODS: The ACA parameters and angle-opening distance (AOD) were measured with slitlamp-adapted OCT goniometry. The iris and scleral thickness and the iris convexity were assessed with OCT. Both ACA and AOD were compared with the clinical parameters of gonioscopy grade, limbal anterior chamber depth (ACD), ultrasonographic central ACD, and lens-axial length (LAL) ratio. RESULTS: Noncontact goniometry with OCT revealed mean +/- SD values of 28 degrees +/- 16 degrees for the ACA and 381 +/- 234 mum for the AOD. The mean +/- SD iris thickness was 369 +/- 84 mum, and the scleral thickness at the scleral spur was 943 +/- 148 mum. There was a significant correlation (P<.001) with the clinical parameters of gonioscopic grading, limbal ACD, ultrasonographic central ACD, and LAL ratio. The sensitivity and specificity of OCT goniometry to detect an occludable angle were 86% and 95% for ACA and 85% and 90% for AOD, respectively. CONCLUSIONS: Noncontact goniometry with OCT was helpful in evaluating the anterior chamber structures and as a screening modality. Goniometry with OCT could improve the noninvasive clinical assessment and treatment of patients with glaucoma.