Slit-lamp Optical Coherence Tomography Research Articles

Intrastromal implantation of chicken corneal grafts into the cornea of rabbits for corneal thickening: an experimental study.

To evaluate the feasibility and effects of the intrastromal implantation of chemically modified corneal stroma obtained from chicken into the corneas of rabbits for corneal thickening. Chicken corneas were cut, debrided, treated with cross-linking and implanted in an intrastromal pouch created in the cornea of 10 white New Zealand rabbits with femtosecond laser. Slit-lamp biomicroscopy and optical coherence tomography were performed immediately, 7, 30 and 90days postoperatively. Corneas were removed at 90daysand cut in two halves. One half was sent to histological analysis for the presence of necrosis, polymorphonuclear inflammatory cells, blood vessels and fibrosis, while the other half was evaluated with transmission electron microscopy to verify tissue organization and the presence of keratocytes and inflammatory cells. Corneal thicknesses were comparatively analyzed over time with Wilcoxon test (p ≤ 0.05). The chicken grafts were incorporated into the cornea of all animals over time. Mean rabbit cornea thickness increased from 338µm preoperatively to 538µm (p < 0.0077) at 90days, while mean chicken graft thickness decreased from 350 to 215µm (p < 0.0077). No clear signs of rejection attributable to the xenograft were observed in any of the implanted eyes. However, some macroscopic and histological events were observed in some of the eyes, probably due to procedural issues during implantation. The intrastromal implantation of chicken grafts was shown to be feasible and predictable to thicken the recipient rabbit cornea without apparent rejection. However, before being considered in humans, further meticulous clinical trials are required to establish the clinical utility, safety and efficacy of xenografts for the treatment of patients with advanced keratoconus.

Intraoperative floppy iris syndrome – epidemiology and clinical assessment.

Purpose: To assess the incidence, and to identify medications and clinical features associated with intraoperative floppy iris syndrome in patients undergoing cataract surgery. Material and methods: The non-randomized, observational, prospective study was performed in 616 eyes (610 patients) after cataract surgery to determine the incidence of intraoperative floppy iris syndrome and the medications associated with itshigher prevalence. We used a slit lamp adapted optical coherence tomography to evaluate anterior segment of 155 eyes (154patients), measuring pupil diameter before and after the use of mydriatics and assessing the pre-dilated iris thickness at thedilator and sphincter muscle region. Results: The overall incidence of intraoperative floppy iris syndrome was 4% (25/616 eyes). The highest prevalence of intraoperative floppy iris syndrome was shown in patients exposed to tamsulosin (39%). Pupil diameter in mm before and after mydriasis was significantly smaller in patients with intraoperative floppy iris syndrome as compared to the syndrome-free ones (pre-dilated – 1.85 ± 0.43 vs. 2.16 ± 0.37; p < 0.01; dilated – 5.04 ± 1.01 vs. 5.70 ± 0.87; p < 0.01). The thickness of the iris insphincter muscle region in µm was similar in patients with and without intraoperative floppy iris syndrome (520.3 ± 76.1 vs.520.6 ± 72.4; p > 0.05). Significantly thinner iris in dilator muscle region was found in patients with intraoperative floppy iris syndrome as compared to the syndrome-free ones (409.9 ± 55.7 vs. 448.6 ± 55.8; p < 0.05). The presence of intraoperative floppy iris syndrome was correlated with a higher risk of intraoperative complications. Conclusions: Patients with intraoperative floppy iris syndrome have decreased pupil diameter and a thinner iris in dilator muscle region. Slit lamp optical coherence tomography is a useful device to preoperatively detect clinical features associated with intraoperative floppy iris syndrome. These findings may warn the surgeon of potential intra-operative difficulties. Słowa kluczowe: zespół śródoperacyjnie wiotkiej tęczówki (IFIS), epidemiologia, operacja zaćmy, optyczna koherentna tomografia skojarzona z lampą szczelinową (sl-OCT).

Comparison of the Efficacy of Dexamethasone, Nepafenac, and Bromfenac for Preventing Pseudophakic Cystoid Macular Edema: an Open-label, Prospective, Randomized Controlled Trial

ABSTRACTPurpose: To evaluate the incidence of pseudophakic cystoid macular edema (PCMO) in patients treated with corticosteroids alone or in combination with bromfenac or nepafenac eyedrops after uneventful cataract surgery.Materials and Methods: Prospective, randomized, open-label, placebo-controlled clinical trial. Patients who underwent routine cataract surgery with intraocular lens (IOL) implant were randomly divided into three groups receiving either bromfenac or nepafenac in association with dexamethasone or dexamethasone alone (control group) postoperatively. Best-corrected visual acuity (BCVA) measurement, slit lamp and fundus examination and optical coherence tomography (OCT) were performed preoperatively, 1 and 5 weeks after surgery. Primary outcome was defined as patients (%) in whom macular edema developed within 5 weeks after cataract surgery; secondary end points were patients (%) with BCVA improvement from pre-op through 5 weeks after surgery and corneal toxicity.Results: A total of 144 patients completed the study, 48 for each group. In all groups, mean central subfield thickness at OCT increased significantly 5 weeks after surgery (p < 0.01). However, at this time point, four patients (8.3%) of the control group and none in nepafenac and bromfenac groups developed PCMO (p = 0.016). Compared with baseline, mean BCVA significantly improved both at 1 and 5 weeks in all groups (p < 0.01). At 1 week, the nepafenac group showed a mean BCVA significantly lower compared with both the control (p = 0.038) and bromfenac group (p = 0.002).Conclusions: Co-administration of nepafenac or bromfenac and steroids in patients who underwent routine cataract surgery is associated with a lower incidence of PCMO compared with steroid monotherapy.

Correlation of Ocular Pulse Amplitude, Choroidal Thickness, and Internal Carotid Artery Doppler Ultrasound Findings in Normal Eyes

ABSTRACTIntroduction: The choroid receives about 65–85% of ocular blood flow, which comes from the ophthalmic artery (OA), the first branch of the internal carotid artery (ICA). In the foveal avascular zone, there is no retinal vascular supply; therefore, choroidal blood supply plays a significant role in this subfoveal region. The ocular pulse amplitude (OPA) provides useful information about intraocular blood flow and is an indirect indicator of choroidal perfusion. In this study, we aimed to assess the correlation between the OPA, subfoveal choroidal thickness (CT), and ICA Doppler ultrasound findings in healthy eyes. Methods: In total, 48 eyes of 48 healthy volunteers were included in this study. All eyes underwent detailed ophthalmic evaluation, including slit-lamp biomicroscopy, fundus examination, axial length, OPA measurements, and optical coherence tomography (OCT) with enhanced depth imaging mode. Carotid Doppler ultrasound examination was performed by the radiologist. The correlation between the OPA, subfoveal CT, and ICA Doppler findings [peak systolic velocity (PSV) and end-diastolic velocity (EDV)] were evaluated, considering gender and age. Results: The mean OPA was 3.06 ± 1.34 mmHg. The mean subfoveal CT was 305.85 ± 33.98 µm. The mean PSV and EDV of ICA were 73.25 ± 23.63 cm/s and 26.93 ± 13.42 cm/s, respectively. A moderate positive correlation was found between OPA and subfoveal CT (p = 0.001; rho = 0.481). This relationship was present in both men and women. While a positive correlation was found between the OPA and subfoveal CT in subjects under the age of 50 years, there was no correlation in those over the age of 50 years. Conclusions: A fair correlation was found between the OPA and subfoveal CT in healthy subjects under the age of 50.

Features of full field electroretinogram responses in children with early type 1 diabetes

Objective To observe the features of the full field electroretinogram (FF-ERG) in type 1 diabetes (T1D) children without diabetic retinopathy (DR). Methods Retrospective case study. Forty-one T1D children and 25 age-matched normal controls underwent a complete ophthalmic examination, including best-corrected visual acuity, refraction, intraocular pressure, slit lamp, fundus photography, indirect ophthalmoscopy, and spectral domain optical coherence tomography to exclude DR. All FF-ERG tests were performed by an experienced technician. The ERG series includes six protocols: dark-adapted 0.01 ERG (r-b 0.01); dark-adapted 3 ERG (mix-a 3.0, mix-b 3.0); dark-adapted 10 ERG (mix-a 10.0, mix-b 10.0); dark-adapted oscillatory potentials (OPS); light-adapted 3 ERG (c-a 3.0, c-b 3.0); light-adapted 30 Hz flicker (30 Hz FP) ERG. To compare the amplitudes and implicit times of the FF-ERG between the T1D and control group children. Results Compared with the control subjects , the FF-ERG amplitudes decreased and the implicit times increased in T1D. Except for r-b 0.01 (t=-0.228, P>0.05), the amplitudes of other FF-ERGs were all significantly attenuated (t=-1.664, -3.645, -4.324, -6.123, -5.846, -12.9, -14.4, -5.23; P 0.05). Conclusion The FF-ERG amplitudes decreased and implicit times increased in T1D children compared with the control normal subjects. Key words: Diabetes mellitus, type 1; Child; Electroretinography

Long-term analysis of IOL stability of the Lewis technique for scleral fixation.

To demonstrate that in case of absence of capsular support intraocular lens (IOL) scleral fixation is both effective and stable over years. A total of 13 eyes from 13 patients who underwent an IOL scleral fixation according to Lewis suturing technique between January 2001 and December 2008 were studied. Patients underwent a complete ophthalmologic evaluation. The IOL stability was assessed using slit-lamp and anterior segment optical coherence tomography (AS-OCT) examination. The IOL stability was evaluated in terms of centration and tilting. All the knots were photographed and their integrity assessed. Follow-up was 60-129 months. Eleven knots appeared evident and undamaged, 6 knots were eroded, and 9 knots were not detectable. All IOLs were stable in the sulcus. Two patients presented a slight decentration of the IOL at the slit-lamp examination, while the AS-OCT demonstrated slight tilting of the lenses in 4 patients. The Lewis technique for IOL scleral fixation is an optimal surgical technique in case of absence of capsular support. No IOL luxation in the vitreous chamber has been reported; only 2 of the 10 patients with at least one eroded knot presented a minimal decentration of the lens with no influence on visual acuity. Although knot erosion is not an uncommon occurrence, IOL remains stable in the long term, probably due to a fibrotic process around the suture, and the IOL haptics, which prevent IOL dislocation.

Comparison of central corneal thickness: ultrasound pachymetry versus slit-lamp optical coherence tomography, specular microscopy, and Orbscan.

BackgroundCentral corneal thickness (CCT) can be measured by using contact and non-contact methods. Ultrasound pachymetry (US pachymetry) is a contact method for measuring CCT and is perhaps the most commonly used method. However, non-contact methods like scanning slit topography (Orbscan II), slit-lamp optical coherence tomography (SL-OCT), and specular microscopy are also used. Not many studies have correlated the measurement of CCT with all four modalities. The purpose of this study was to compare and correlate the CCT measurements obtained by US pachymetry with SL-OCT, specular microscopy, and Orbscan.MethodThis is a prospective, comparative study done in an institutional setting. Thirty-two eyes of 32 subjects with no known ocular disease and best-corrected visual acuity of 20/20 were enrolled. CCT measurements were obtained using SL-OCT, specular microscopy, scanning slit topography (Orbscan), and US pachymetry. Three measurements were made with each instrument by the same operator. Mean, standard deviation, and coefficient of variation were calculated for CCT measurements acquired by the four measurement devices. Bland–Altman plot was constructed to determine the agreements between the CCT measurements obtained by different equipment.ResultsThe mean CCT was 548.16±48.68 μm by US pachymetry. In comparison, CCT averaged 546.36±44.17 μm by SL-OCT, 557.61±49.92 μm by specular microscopy, and 551.03±48.96 μm by Orbscan for all subjects. Measurements by the various modalities were strongly correlated. Correlations (r2) of CCT, as measured by US pachymetry compared with other modalities, were: SL-OCT (r2=0.98, P<0.0001), specular microscopy (r2=0.98, P<0.0001), and Orbscan (r2=0.96, P<0.0001). All modalities had a linear correlation with US pachymetry measurements.ConclusionIn subjects with healthy corneas, SL-OCT, specular microscopy, and Orbscan (with correction factor) can be used interchangeably with US pachymetry in certain clinical settings. The four modalities showed significant linear correlations with one another.

Evaluation of scleral-fixated intraocular lens position anomalies by anterior segment optical coherence tomography.

To measure the positions of scleral-fixated intraocular lenses (IOLs) using anterior segment optical coherence tomography (OCT) and to evaluate the influence of the position of scleral-fixated IOL on the quality of vision. Twenty-six eyes of 26 patients were included in the study. The average age was 57.5 (11 to 78) years. Anterior segment images were taken using slit lamp optical coherence tomography (SL-OCT) and were used to evaluate the position of the IOL. The average amounts of tilt and decentration were 2.25° ± 1.93° and 359.28 ± 194.70 µm, respectively. There was a positive and moderate relationship between tilt and astigmatism caused by the position of the IOL (P = 0.030). No relationship was detected between decentration and the astigmatism caused by the position of the IOL (P = 0.285). Scleral-fixated IOL position can be evaluated with SL-OCT, which is a noncontact, noninvasive, reproducible, and reliable method of evaluation. Anterior segment OCT has been shown to provide sensitive measurements but not in all cases. The present study showed that a tilted scleral-fixated IOL behaved like a toric IOL, and the astigmatism caused by the position of the scleral-fixated IOL therefore could increase or decrease total astigmatism.

Descemet’s stripping automated endothelial keratoplasty in abnormal anterior segment: scleral indentation technique to enhance donor adherence

To describe a scleral indentation technique to enhance donor adherence in Descemet's stripping and automated endothelial keratoplasty (DSAEK) in patients with abnormal anterior segment. In patients with visual potential, we performed transscleral fixation of a foldable intraocular lens (IOL) and DSAEK. In patients only for pain relief, we performed DSAEK without IOL implantation. During air tamponade, we injected only a medium air bubble instead of big bubble into anterior chamber and used scleral indentation technique as an aid. The position of the grafts was checked by the slit lamp and anterior segment optical coherence tomography (AS-OCT). Five eyes of five patients of aphakic bullous keratopathy (ABK) or pseudophakic bullous keratopathy (PBK) with anterior chamber IOL (AC IOL) were included in this non-comparative interventional case series. The grafts attached well in all patients without any graft dislocation intraoperatively and during the follow-up period. There was no pupillary block or peripheral anterior synechiae postoperatively. Scleral indentation technique with or without transscleral fixation of a foldable IOL in DSAEK can facilitate the air tamponade and enhance the donor adherence in certain anterior segment abnormities.

Isolated infratentorial demyelinating lesion

A 46-year-old man presented with subacute right-sided hemifacial sensory loss since 1 week. Brain MRI showed an isolated hyperintense lesion and a hypointense rim on T2-weighted imaging in the right-sided middle cerebellar peduncle associated with restricted diffusion in a concentric closed ring pattern, without gadolinium enhancement (Fig. 1). Spinal MRI was normal. C-reactive protein, antinuclear antibody, angiotensin-converting enzyme, paraneoplastic autoantibody evaluation, Lyme/HIV/syphilis serology were all normal. CSF analysis was normal apart from the presence of oligoclonal bands. Thoraco-abdominal-pelvic CT, whole-body FDG-PET, salivary gland biopsy, eye fundus, slit lamp examination, visual-evoked potentials, and optical coherence tomography scanner were all normal. While symptoms persisted, MRI 2 weeks later showed an increase in lesion size with a pattern of alternating bands of signal intensity (Balo-like) on T2-weighted imaging, partial gadolinium enhancement, and signal reversal (now hyperintense) on ADC map in the gadolinium-enhancing part of the lesion (Fig. 1). A stereotactic biopsy showed a demyelinating lesion (loss of myelin, foamy macrophages, perivascular inflammation, reactive astrocytes) in the absence of a tumoral process. Biopsy led to transient worsening of the hemifacial sensory loss. A diagnosis of an isolated infratentorial biopsy-proven demyelinating lesion was made. Intravenous methylprednisolone 500 mg od for 5 days led to improvement of the sensory symptoms. Nine months later, MRI still showed the (now only slightly) hyperintense T2-weighted lesion, in the absence of gadolinium enhancement or diffusion restriction (Fig. 1). No other lesions were seen. After 1 year of clinical and radiological follow-up, only very slight right-sided hemifacial paresthesias persisted (probably a sequella of the inflammatory lesion and/or the stereotactic biopsy performed). Restricted diffusion, T2-weighted hypointense rim, and Balo-like lesions seen in our patient correspond to what can be seen in patients with atypical idiopathic inflammatory or biopsy-proven demyelinating brain lesions [1, 2]. In a series of 69 patients with atypical idiopathic inflammatory demyelinating brain lesions (including megacystic, Balolike, infiltrative, ring-like, and unclassified type), only one had an infratentorial lesion (of the unclassified category) [2]. Recently, a series of 7 patients with a solitary demyelinating lesion in the brainstem (n = 2), the cervicomedullary junction (n = 3) or the upper cervical spinal cord (n = 2), called solitary sclerosis, has been described [3]. Evolution (follow-up of 6-year period) in these patients, in contrast to our patient (follow-up of only 1 year), was progressive leading to disability essentially due to motor impairment. In the reported 7 patients, none except one (with a post-mortem examination demonstrating an isolated pontine demyelinating lesion) had histological confirmation of demyelination. The presence of CSF oligoclonal bands, present in our case and in 4 of the 7 reported patients with solitary sclerosis, is concordant with a demyelinating process. Thus, overall, biopsy-proven isolated demyelinating lesions in the posterior fossa are very rare. Recognition of the radiological features of these often atypical lesions is D. Renard (&) G. Castelnovo P. Labauge Department of Neurology, CHU Nimes, Hopital Caremeau, Place du Pr Debre, 30029 Nimes Cedex 4, France e-mail: dimitrirenard@hotmail.com

The Posterior Location of the Dilator Muscle Induces Anterior Iris Bowing during Dilation, Even in the Absence of Pupillary Block

To examine the effect of the posterior location of the dilator on iris anterior curvature during dilation. An in vivo human study, an ex vivo porcine experiment, and an in silico computational model were performed in parallel. Iris anterior curvature was measured in vivo before and after dilation by time-domain slit lamp optical coherence tomography (SL-OCT). All patients (n = 7) had undergone laser peripheral iridotomy to eliminate any pupillary block due to primary angle-closure glaucoma. In the ex vivo experiments, isolated porcine irides (n = 30) were secured at the periphery and immersed in an oxygenated Krebs-Ringer buffer. Dilation was induced pharmaceutically by the addition of 2.5% phenylephrine and 1% tropicamide. An in-house optical coherence tomography (OCT) system was used to obtain iris images before and after dilation. A finite element model was also developed based on typical geometry of the iris from the initial OCT image. The iris was modeled as a neo-Hookean solid, and the active muscle component was applied only to the region specified as the dilator. An increase in curvature and a decrease in chord length after dilation were observed in both experiments. In both the in vivo and ex vivo experiments, the curvature-to-chord length ratio increased significantly during dilation. Computer simulations agreed well with the experimental results only when the proper anatomic position of dilator was used. The posterior location of the dilator contributes to the anterior iris bowing via a nonpupillary block dependent mechanism.

Lenticular meridional astigmatism secondary to iris mesectodermal leiomyoma

A 61-year-old African American man presented with decreased vision of 2 months duration. Examination revealed a significant lenticular astigmatism and sectoral cataract as a result of an amelanotic iris lesion. Slitlamp optical coherence tomography (OCT) revealed angle crowding. An excisional biopsy was performed along with phacoemulsification in the right eye, with intraocular lens implantation for meridional lenticular astigmatism. Histopathology and histoimmunochemistry confirmed a diagnosis of uveal mesectodermal leiomyoma. Lenticular astigmatism may be a subtle sign of an anterior segment tumor. Anterior segment slitlamp OCT is an effective tool in diagnosing as well as monitoring small interval changes in these types of tumors.

Evaluation of Sustained Release of PLC-Loaded Prednisolone Acetate Microfilm on Postoperative Inflammation in an Experimental Model of Glaucoma Filtration Surgery

Purpose: To evaluate the effect of a biodegradable microfilm with sustained release of prednisolone acetate (PA) on postoperative wound healing after experimental glaucoma filtration surgery (GFS).Methods: Biodegradable microfilms composed of poly (d-, l-lactide-co-caprolactone) (PLC) were fabricated and then pre-loaded PA-20% total weight. Fourteen New Zealand White rabbits were randomly divided into 3 treatment groups: GFS alone (n = 4), GFS with PLC microfilms (n = 4) and GFS with PA-loaded microfilm (n = 6). Microfilms were inserted subconjunctivally, adjacent to the filtering surgical site. We monitored all eyes with slit-lamp examination, bleb photography and anterior segment optical coherence tomography (AS-OCT). Histology with immunohistochemistry was performed to determine the presence of any inflammation.Results: Prednisolone acetate 20%-loaded microfilms exhibited steady, sustained release in vitro. Eyes implanted with PA-loaded microfilms showed a significantly better bleb survival (100% vs. 37.5%, p < 0.001) and reduced bleb vascularity (58%; 95% CI 54–62% vs. 30%; 95% CI 23–37%, p = 0.001) compared to the control at 30 days postoperatively. Histology and immunohistochemistry demonstrated less T-cell infiltration in the eye implanted with PA-loaded microfilms.Conclusion: Subconjunctival insertion of a PA-loaded biodegradeable microfilm exhibit sustained release of PA to reduce postoperative inflammation and prolong bleb survival in rabbit GFS.

Comparison of Non-Contact Methods for the Measurement of Central Corneal Thickness

This study examined the repeatability of and agreements between central corneal thickness measurements obtained by four different non-contact pachymetry devices. Seventy-eight eyes of 39 subjects were included. Central corneal thickness of each eye was measured by Visante optical coherence tomography (OCT) (Carl Zeiss Meditec Inc., Dublin, CA), Pentacam (Oculus Optikgeräte GmbH, Wetzlar, Germany), Orbscan IIz topography (Bausch & Lomb Surgical Inc., San Dimas, CA), and slit-lamp OCT (SL-OCT) (Heidelberg Engineering GmbH, Heidelberg, Germany). Inter-device agreements and correlations and repeatability of each device were examined. All measurement methods correlated well with each other with a correlation coefficient greater than 0.90 and P value of less than .001 for all comparisons. However, Pentacam overestimated central corneal thickness: 546.7 ± 38.2, 535.5 ± 42.7, 531.7 ± 37.6, and 531.2 ± 36.0 μm for Pentacam, Orbscan IIz, Visante OCT, and SL-OCT, respectively (P < .001 for all comparisons versus Pentacam). Despite good correlation, magnitude of differences was high and this bias was proportional (ie, not constant across a range of corneal thickness values) for the following pairs: Orbscan versus Visante OCT, Orbscan versus SL-OCT, and Orbscan versus Pentacam (P < .001 for all comparisons). Although measurements obtained by various non-contact methods correlate well, numerical agreement of the results may not be sufficient for their interchangeable use in clinical practice.

Anterior Segment Imaging for Iris Melanocytic Tumors

To determine the role of anterior segment optical coherence tomography (AS-OCT) and other anterior segment imaging techniques (Pentacam, slit-lamp optical coherence tomography [SL-OCT]) for analysis of iris melanocytic tumors and to compare results with clinical features and ultrasound biomicroscopy (UBM). Between 2006 and 2009, 61 patients with melanocytic iris tumors were examined using different anterior segment imaging techniques: Pentacam, SL-OCT, AS-OCT, and UBM (50 MHz). Pentacam was performed in 17 patients, SL-OCT in 12, AS-OCT in 46, and UBM in 49. The Pentacam images identified the tumor in 3 of 17 patients (18%), SL-OCT in 8 of 12 (67%), and AS-OCT in 44 of 46 (96%). Anterior segment optical coherence tomography results were compared with UBM in 42 patients: in 86% the results were comparable, although AS-OCT visualized a ciliary body extension of iris tumors only in 1 out of 3 cases analyzed. Iris melanocytic tumors were located by AS-OCT in 96% of cases and results were comparable to UBM imaging, while both SL-OCT and Pentacam are less reliable for detecting and measuring anterior segment lesions. Anterior segment optical coherence tomography gives precise anterior eye segment diameters, which are useful for the brachytherapy dosage calculation module developed at the Leiden University Medical Center. Therefore, AS-OCT is a reliable, convenient, and noncontact method for detecting and measuring pure iris tumors, but UBM is superior in detecting a ciliary body extension of these tumors.

Pressure-Induced Interlamellar Stromal Keratitis After Laser In Situ Keratomileusis

To describe a patient with interlamellar stromal keratitis induced by increased intraocular pressure (IOP) [Pressure-induced interlamellar stromal keratitis (PISK)] after laser in situ keratomileusis (LASIK) surgery. Case report and review of the literature. We report a case of interlamellar stromal keratitis induced by increased IOP after LASIK surgery. A 42-year-old man presented with persistent interface haze after uneventful LASIK. The patient described onset of decreased visual acuity after the first 2 postoperative weeks, failed to improve with high-dose topical steroid drops, and had significantly elevated IOP values up to 48 mm Hg. IOP was resistant to maximal topical antiglaucomatous therapy. The patient showed both improvement in visual acuity and decrease in interface haze after discontinuation of topical steroids and lowering of IOP by both topical and systemic treatment. Slit-lamp optical coherence tomography ruled out a fluid accumulation in the interface. PISK appears clinically almost identical to diffuse lamellar keratitis after LASIK. It is important to measure the IOP and be suspicious when a diffuse interface haze occurs after the first postoperative week, is resistant to or even exacerbates in response to an increase in topical steroid treatment, and is not associated with other causative events. Slit-lamp optical coherence tomography is a valuable tool that allows differentiation between space-occupying interface fluid collection and non-space-occupying interface fluid collection to avoid falsely low or normal IOP measurements in PISK.

Comparison and Repeatability of Anterior Segment Parameters Obtained by Galilei and Slit-lamp Optical Coherence Tomography

Comparison and Repeatability of Anterior Segment Parameters Obtained by Galilei and Slit-lamp Optical Coherence Tomography

Correlation analysis of the post-surgery visual outcomes of idiopathic macular hole and the macular hole index

Objective To evaluate the relevance of the macular hole index (MHI) and the visual outcomes of the idiopathic macular hole (IMH) after the retinal internal limiting membrane (ILM) peeling surgery. Methods Thirty IMH patients (30 eyes) undergoing vitrectomy and ILM peeling were included in this study. The IMH diagnosis was confirmed by best corrected visual acuity (BCVA), slit lamp microscope, indirect ophthalmoscope and optical coherence tomography (OCT). The central retinal thickness, the height and the base diameter of macular holes were measured by OCT. The MHI was the ratio of the height and the base diameter of macular holes. The patients were divided into two groups (MHI ≥0.5 group and MHI ＜0. 5 group) according to the MHI. The post-surgery follow-up was three to 24 months with an average of 10 months. Spearman correlation analysis was performed between BCVA (pre and post-surgery), age, disease duration and MHI. The differences in BCVA after surgery between the two MHI groups was further evaluated by independent samples t test for quantitative data. Results All the macular holes in 30 eyes closed after surgery, closure rate was 100%. Postoperative BCVA was correlated with MHI by Spearman analysis (r=0.852, P＜0.001), but not correlated with age (r=0.001, P=0.804) and disease course (r=-0. 001, P=0. 579). Postoperative BCVA was better in the MHI≥0. 5 group (t = 5. 552, P ＜ 0. 001 ). Conclusions The postoperative visual outcome of IMH patients was correlated with the MHI. MHI can be used as a prognostic factor of postoperative visual outcomes for IMH patients. Key words: Retinal perforation/surgery; Vitrectomy; Macular hole index

Scanning beyond the limits of standard OCT with a Fourier domain optical coherence tomography integrated into a slit lamp: the SL SCAN-1

With a new Fourier domain optical coherence tomography (FD OCT) device, SL SCAN-1 (Topcon Europe Medical BV, Capelle a/d IJssel, The Netherlands), integrated into a slit-lamp OCT, scans can be obtained through a handheld lens. The necessary adjustment of the reference arm is possible by fast Z-alignment. This study was performed to prove the capability of SL SCAN-1 to scan through a three-mirror contact lens, scanning the peripheral retina and anterior chamber angle. Different representative pathologies of the peripheral retina and anterior chamber were simultaneously observed and scanned with the SL SCAN-1. The scans of peripheral retinal lesions were obtained both through a handheld lens and through a three-mirror contact lens. The anterior chamber angle was scanned directly with the SL SCAN-1 in anterior mode, and through the gonio-mirror of a three-mirror contact lens with the SL SCAN-1 in posterior mode. OCT scans could be obtained with the SL SCAN-1 of the peripheral retina through both, a common handheld lens and a three-mirror contact lens. The scans obtained through a three-mirror contact lens were of better quality, visualizing details of the different layers of the retina more clearly. The scans of the anterior chamber, obtained through the gonio-mirror of a three-mirror contact lens, visualized the open anterior chamber angle, with details of fine structures. The SL SCAN-1 is a unique FD OCT system, which is able to scan not only the posterior pole and anterior segment but also the anterior chamber angle and the more peripheral retina. These four modalities combined into one device could make the SL SCAN-1 a very powerful aid in daily practice.

Parameter of anterior chamber angle in normal volunteers by examination of slit lamp OCT

目的 利用裂隙灯光学相干断层成像术(SL-OCT)对正常志愿者前房角各参数进行初步研究,讨论其变化规律.方法 选择正常志愿者52例102眼使用海德堡SL-OCT进行眼前节测量,对房角开放距离(AOD)500μm、750μm,及2个AOD情况下的小梁-虹膜空间面积(TISA)、房角隐窝面积(ARA)、房角角度(ACA)4个反映房角开放程度的参数进行研究.结果 各参数500μm系列变异较750μm系列大;反映房角开放程度的各参数值在上方象限较小,鼻上方最小,下方象限较大,以颞下象限最大;房角各测量值随着年龄的增加逐渐变小,但60岁后有增加趋势.结论 在SL-OCT测量的反映房角开放的AOD、TISA、ACA、ARA4个参数中,ARA对房角开放程度的反映较其他参数差,500μm系列参数的变异性较750μm系列大,正常人房角左右眼各参数无差异,上方象限房角较窄,下方象限较宽,并且随着年龄的增加,正常人房角变窄,50～60岁时最窄,60岁后房角有加宽趋势。