Dimitrios G. Mikropoulos

Corneal stroma demarcation line after standard and high-intensity collagen crosslinking determined with anterior segment optical coherence tomography

Purpose To use anterior segment optical coherence tomography (AS‐OCT) to compare corneal stroma demarcation line depth after corneal collagen crosslinking (CXL) with 2 treatment protocols. Setting Vardinoyiannion Eye Institute of Crete, Faculty of Medicine, University of Crete, Heraklion, Crete, Greece. Design Prospective comparative interventional case series. Methods Corneal collagen crosslinking was performed in all eyes using the same ultraviolet‐A (UVA) irradiation device (CCL‐365). Eyes were treated for 30 minutes with 3 mW/cm2 according to the standard Dresden protocol (Group 1) or for 10 minutes with 9 mW/cm2 of UVA irradiation intensity (Group 2). One month postoperatively, 2 independent observers measured the corneal stroma demarcation line using AS‐OCT. Results Sixteen patients (21 eyes) were enrolled. Group 1 comprised 7 patients (9 eyes) and Group 2, 9 patients (12 eyes). The mean corneal stroma demarcation line depth was 350.78 &mgr;m ± 49.34 (SD) (range 256.5 to 410 &mgr;m) in Group 1 and 288.46 ± 42.37 &mgr;m (range 238.5 to 353.5 &mgr;m) in Group 2; the corneal stroma demarcation line was statistically significantly deeper in Group 1 than in Group 2 (P=.0058, t test for unpaired data). Conclusion The corneal stroma demarcation line was significantly deeper after a 30‐minute CXL treatment than after a 10‐minute CXL procedure with high‐intensity UVA irradiation. Financial Disclosure No author has a financial or proprietary interest in any material or method mentioned.

Peak Intraocular Pressure and Glaucomatous Progression in Primary Open-Angle Glaucoma

PURPOSE To evaluate the effect of 24-h peak intraocular pressure (IOP) on the progression of primary open-angle glaucoma (POAG) and the 24 h time points that best predict peak pressure. METHODS A retrospective analysis of clinical data evaluating long-term glaucomatous progression in patients with POAG who were previously in a 24-h study of the authors (IOP readings at 2/6/10 A.M. and 2/6/10 PM); had ≥3 treated 10 A.M. (±1 h) IOP measurements over 5-years after an untreated 24-h baseline; and had a treated 24-h curve with a 10 A.M. IOP±2 mmHg within the 10 A.M. mean IOP over 5-years. RESULTS We included 98 nonprogressed and 53 progressed patients with POAG (n=151). The mean 24-h peak IOP (mmHg) was 19.9±2.7 for progressed and 18.3±2.0 for nonprogressed patients (P<0.001). Progressed patients also showed a higher mean 24-h IOP. Generally, patients with a mean or peak daytime (readings at 10 A.M., 2 and 6 P.M.) or 24-h peak IOP of ≤18 remained nonprogressed in 75%-78% of cases. Further, measuring IOP at night found a higher peak in only 20% of cases, which was ≤2 of the daytime peak in 98% of cases. A multivariate regression analysis showed only 24-h peak IOP as an independent risk factor for progression (P=0.002). CONCLUSIONS This study suggests that daytime peak IOP may be clinically important in predicting long-term glaucomatous progression. Further, daytime peak IOP may assist, as much as daytime mean IOP and, in most cases, 24-h peak IOP, in helping to guide long-term treatment in POAG.

Twenty-four-hour intraocular pressure control with bimatoprost and the bimatoprost/timolol fixed combination administered in the morning, or evening in exfoliative glaucoma

Aim To compare 24 h intraocular pressure (IOP) control of morning and evening administered bimatoprost/timolol fixed combination (BTFC) and evening administered bimatoprost in exfoliative glaucoma (XFG). Methods One eye of 60 XFG patients was included in this prospective, observer-masked, crossover comparison. Following wash-out, all patients received bimatoprost monotherapy for 6 weeks. They were then randomised to morning, or evening, administered BTFC for 3 months and then switched to the opposite therapy. Results At baseline, mean 24 h pressure was 29.0 mm Hg. Bimatoprost reduced the mean IOP by 8.1 mm Hg (27.8%, p<0.001). The evening administration of BTFC reduced 24 h IOP to a statistically lower level than morning administration (10.2 mm Hg (35.3%) vs 9.8 mm Hg (33.8%); p=0.005). Both dosing regimens reduced IOP significantly more than bimatoprost (p≤0.006, for all time points). A 24 h IOP reduction ≥30% was seen in 43 patients (72%) with evening BTFC compared with 39 patients (65%) with morning BTFC (p=0.344) and only 24 patients (40%) with bimatoprost monotherapy (p<0.001 vs both BTFC regimens). Conclusion Both BTFC dosing regimens significantly reduce 24 h IOP in XFG compared with bimatoprost monotherapy. The evening dosing gives rise to statistically better 24 h IOP control and could be considered in these patients.

Femtosecond Laser vs Mechanical Microkeratome for Hyperopic Laser In Situ Keratomileusis

PURPOSE To compare the outcomes of laser in situ keratomileusis (LASIK) performed with a femtosecond laser vs a mechanical microkeratome for the correction of low to moderate hyperopia. DESIGN Retrospective, nonrandomized, interventional, comparative case series. METHODS settings: Vissum Santa Hortensia, Madrid, Spain.study population and procedures: Patients who had undergone LASIK to correct their hyperopia using the 60-kHz IntraLase femtosecond laser were compared to age- and refraction-matched patients in whom the Moria M2 microkeratome was used. Visual and refractive results 3 months postoperatively were compared between both groups. RESULTS A total of 144 eyes were analyzed (72 in each group). Mean preoperative sphere was +3.45 ± 1.0 diopters (D) in the IntraLase group vs +3.18 ± 1.3 D in the M2 group (P = .1). Results 3 months postoperatively were: mean residual sphere, +0.44 ± 0.6D vs +0.72 ± 0.8 D (P = .02), respectively; uncorrected visual acuity (UCVA), 0.89 ± 0.2 vs 0.80 ± 0.2 (P = .04); best spectacle-corrected visual acuity (BSCVA), 0.96 ± 0.2 vs 0.92 ± 0.2 (P = .2); safety index, 0.97 ± 0.1 vs 0.98 ± 0.1 (P = .5); efficacy index, 0.89 ± 0.2 vs 0.84 ± 0.2 (P = .3). CONCLUSIONS Hyperopic LASIK performed with the IntraLase femtosecond laser seems to achieve better refractive results 3 months after the surgery compared to the M2 microkeratome, without significant differences in safety between both procedures.

Twenty-four-hour intraocular pressure control with the travoprost/timolol maleate fixed combination compared with travoprost when both are dosed in the evening in primary open-angle glaucoma

Objective: To evaluate the 24 h efficacy and safety of the travoprost/timolol maleate fixed combination (TTFC) versus travoprost when both are dosed in the evening in primary open-angle glaucoma patients. Methods: Prospective, double-masked, crossover, active-controlled, randomised 24 h comparison. After a 6 week medicine-free period, patients were randomised to either TTFC or travoprost for 8 weeks and were then switched to the opposite treatment for another 8 weeks. At the end of the washout and treatment periods, a 24 h pressure curve was performed. Results: Thirty-two patients completed the study. The TTFC group demonstrated a lower absolute intraocular pressure level (2.4 mm Hg) for the 24 h curve and at all time points, compared with travoprost (p⩽0.047). The pressure reduction from untreated baseline was significantly different between treatments for all time points (p = 0.018). The mean 24 h pressure fluctuation was lower with TTFC (3.0 mm Hg) compared with travoprost (4.0 mm Hg, p = 0.001). No statistical difference existed between the two treatment groups for any adverse event (p>0.05). Conclusions: This study suggests that when both drugs are dosed in the evening the TTFC provides improved intraocular pressure reduction, compared with travoprost, over the 24 h curve and for each individual time point in primary open-angle glaucoma patients.

Prooxidant–antioxidant balance, peroxide and catalase activity in the aqueous humour and serum of patients with exfoliation syndrome or exfoliative glaucoma

BackgroundOxidative stress plays an important role in the pathobiology of exfoliation syndrome (XFS) and exfoliative glaucoma (XFG).MethodsWe investigated the prooxidant-antioxidant balance (PAB) in aqueous humour and serum samples of 20 consecutive cases of XFS, 20 of XFG, and 20 age-matched controls, employing a recently described novel assay. The activity of catalase and the levels of (hydrogen) peroxide were also measured in these samples.ResultsThere was no significant difference between the PAB in the aqueous humour of the XFS group (82.5 ± 10 AU) and age-matched control patients (78.9 ± 13.4 AU; p > 0.05). A significant shift of the PAB balance in favour of oxidants was detected in the XFG group (90.2 ± 7.6 AU) compared with controls (p  <  0.001). In the serum of patients with XFS (138.8 ± 13.2 AU) and XFG (124.08 ± 13.50 AU), PAB was significantly altered in favour of oxidants as compared to age-matched controls (114.9 ± 9.91 AU); p < 0.001). Catalase activity in the aqueous from XFS (10.1 ± 4.5 U/ml) and XFG (12.2 ± 6 U/ml) patients was significantly lower than that measured in the normal aqueous (14.6 ± 1.9 U/ml). Similarly, a significantly lower catalase activity was found in XFS (103 ± 21.4 U/ml) and XFG (116 ± 38 U/ml) serum samples compared with controls (189.6 ± 84.3 U/ml). Finally, (hydrogen) peroxide concentration in aqueous and serum samples from patients with XFS (aqueous: 26.9 ± 6.6 μM; serum: 41 ± 10 μM) and XFG (aqueous: 21.7 ± 7 μM; serum: 32 ± 4 μM) were significantly higher than that of the controls (aqueous: 9.6 ± 5.8 μM; serum: 24 ± 9 μM; p < 0.001).ConclusionsThese findings suggest that in XFS oxidative stress is counterbalanced in the aqueous, whereas the development of XFG is accompanied by a disruption of this balance in favour of oxidants.

Evaluation of the corneal collagen cross-linking demarcation line profile using anterior segment optical coherence tomography.

Purpose: To evaluate the depth of the stromal demarcation line after corneal collagen cross-linking (CXL) using anterior segment optical coherence tomography. Methods: In this prospective, interventional case series, 23 patients (27 eyes) with progressive keratoconus were enrolled. All patients underwent uneventful CXL treatment. Corneal stromal demarcation line depth was measured centrally, 3 mm temporally, and 3 mm nasally by 2 independent observers using anterior segment optical coherence tomography at 1 month postoperatively in all patients. Results: Mean depth of the corneal stromal demarcation line measured by the first observer was 310.67 ± 31.04 &mgr;m (range, 258–364 &mgr;m) centrally, 212.07 ± 24.5 &mgr;m (range, 178–279 &mgr;m) nasally, and 218.04 ± 21.91 &mgr;m (range, 191–261 &mgr;m) temporally. Mean depth of the corneal stromal demarcation line measured by the second observer was 308.78 ± 29 &mgr;m (range, 262–381 &mgr;m) centrally, 211.04 ± 23.93 &mgr;m (range, 180–277 &mgr;m) nasally, and 217.22 ± 25.51 &mgr;m (range, 179–271 &mgr;m) temporally. There was a statistically significant difference (P < 0.001) between central and both nasal and temporal depths of the corneal stromal demarcation line (paired samples t test) for both observers. There was no statistically significant difference between nasal and temporal corneal stromal demarcation line depths (paired samples t test, P > 0.05) for each observer. Conclusions: Mean depth of the corneal stromal demarcation line after CXL treatment is greater centrally in comparison with nasal and temporal depths.

Critical Appraisal on Orbital Decompression for Thyroid Eye Disease: A Systematic Review and Literature Search.

IntroductionOrbital decompression is the indicated procedure for addressing exophthalmos and compressive optic neuropathy in thyroid eye disease. There are an abundance of techniques for removal of orbital bone, fat, or a combination published in the scientific literature. The relative efficacy and complications of these interventions in relation to the specific indications remain as yet undocumented. We performed a systematic review of the current published evidence for the effectiveness of orbital decompression, possible complications, and impact on quality of life.MethodsWe searched the current databases for medical literature and controlled trials, oculoplastic textbooks, and conference proceedings to identify relevant data up to February 2015. We included randomized controlled trials (RCTs) comparing two or more interventions for orbital decompression.ResultsWe identified only two eligible RCTs for inclusion in the review. As a result of the significant variability between studies on decompression, i.e., methodology and outcome measures, we did not perform a meta-analysis. One study suggests that the transantral approach and endonasal technique had similar effects in reducing exophthalmos but the latter is safer. The second study provides evidence that intravenous steroids may be superior to primary surgical decompression in the management of compressive optic neuropathy requiring less secondary surgical procedures.ConclusionMost of the published literature on orbital decompression consists of retrospective, uncontrolled trials. There is evidence from those studies that removal of the medial and lateral wall (balanced) and the deep lateral wall decompression, with or without fat removal, may be the most effective surgical methods with only few complications. There is a clear unmet need for controlled trials evaluating the different techniques for orbital decompression. Ideally, future studies should address the effectiveness, possible complications, quality of life, and cost of each intervention.

Repeatability, reliability and reproducibility of posterior curvature and wavefront aberrations in keratoconic and cross-linked corneas.

The aim was to assess the intra‐session, inter‐session and inter‐observer repeatability of curvature and aberrometric measurements of Pentacam‐derived posterior corneal surface in normal control (CG), keratoconic (KCG) and after corneal collagen cross‐linked (CXLG) groups.

Cryopreserved amniotic membrane transplantation for the management of symptomatic bullous keratopathy.

Background:  To report the results of cryopreserved human amniotic membrane transplantation for the management of symptomatic bullous keratopathy.