Alfonso Casado

OCT: New perspectives in neuro-ophthalmology

Optical coherence tomography (OCT) has become essential to evaluate axonal/neuronal integrity, to assess disease progression in the afferent visual pathway and to predict visual recovery after surgery in compressive optic neuropathies. Besides that OCT testing is considered a powerful biomarker of neurodegeneration and a promising outcome measure for neuroprotective trials in multiple sclerosis (MS). Currently, spectral-domain OCT (SD-OCT) technology allows quantification of retinal individual layers. The Ganglion Cell layer (GCL) investigation has become one of the most useful tools from a neuro-ophthalmic perspective. It has a high correlation with perimetry, is predictive of future progression and is a highly sensitive, specific of several neuro-ophthalmic pathologies. Moreover the superior correlation with clinical measures compared to peripapillary retinal nerve fiber layer (pRNFL) suggests that GCL analysis might be a better approach to examine MS neurodegeneration. In disorders with optic disk edema, such as ischemic optic neuropathy, papillitis and papilledema, reduction in RNFL thickness caused by axonal atrophy is difficult to distinguish from a swelling resolution. In this setting, and in buried optic nerve head drusen (ONHD), GCL analysis may provide more accurate information than RNFL analysis and it might be an early structural indicator of irreversible neuronal loss. Enhanced depth imaging OCT (EDI-OCT) provides in vivo detail of ONHD, allowing to evaluate and quantify the drusen dimensions. OCT is improving our knowledge in hereditary optic neuropathies. Furthermore, there is growing evidence about the role of OCT as an adjunctive biomarker of disorders such as Alzheimer and Parkinsons disease.

Adipose-derived mesenchymal stem cell administration does not improve corneal graft survival outcome.

The effect of local and systemic injections of mesenchymal stem cells derived from adipose tissue (AD-MSC) into rabbit models of corneal allograft rejection with either normal-risk or high-risk vascularized corneal beds was investigated. The models we present in this study are more similar to human corneal transplants than previously reported murine models. Our aim was to prevent transplant rejection and increase the length of graft survival. In the normal-risk transplant model, in contrast to our expectations, the injection of AD-MSC into the graft junction during surgery resulted in the induction of increased signs of inflammation such as corneal edema with increased thickness, and a higher level of infiltration of leukocytes. This process led to a lower survival of the graft compared with the sham-treated corneal transplants. In the high-risk transplant model, in which immune ocular privilege was undermined by the induction of neovascularization prior to graft surgery, we found the use of systemic rabbit AD-MSCs prior to surgery, during surgery, and at various time points after surgery resulted in a shorter survival of the graft compared with the non-treated corneal grafts. Based on our results, local or systemic treatment with AD-MSCs to prevent corneal rejection in rabbit corneal models at normal or high risk of rejection does not increase survival but rather can increase inflammation and neovascularization and break the innate ocular immune privilege. This result can be partially explained by the immunomarkers, lack of immunosuppressive ability and immunophenotypical secretion molecules characterization of AD-MSC used in this study. Parameters including the risk of rejection, the inflammatory/vascularization environment, the cell source, the time of injection, the immunosuppression, the number of cells, and the mode of delivery must be established before translating the possible benefits of the use of MSCs in corneal transplants to clinical practice.

Suspected granulomatous anterior uveitis associated with brimonidine tartrate 0.2% and timolol maleate 0.5% ophthalmic solution.

Dear Editor, The fixed combination brimonidine 0.2 % and timolol 0.5 % (Combigan®; Allergan Inc., Irvine, California) is used for the treatment of open angle glaucoma and ocular hypertension when a single agent is not sufficient to control the intraocular pressure (IOP). The most common side-effects, as included in the medication leaflet, are allergic conjunctivitis, follicular reaction, conjunctival hyperemia, pruritus and ocular stinging, that occur in 5–15 % of patients. Granulomatous anterior uveitis (GAU) with the use of brimonidine has been published in several case reports [1–3]. Although there are no reports of timolol-induced uveitis, another beta-blocker, metipranolol, has been associated with GAU [4]. Only two cases of GAU related to the use of Combigan have been published [5]. We report herein two additional cases of GAUwith the use of the fixed combination of brimonidine 0.2 % and timolol 0.5 %. The first patient (79-year-old female) attended our department complaining of a red and painful left eye (LE) for several weeks on treatment with topical prednisolone acetate every two hours and oral acyclovir 400 mg five times daily as a herpetic etiology was suspected. She was on treatment with the fixed combination brimonidine 0.2 % and timolol 0.5 % twice daily to her LE for the last 12 months. Her past ocular history was relevant for primary open-angle glaucoma since 2001 and phthisis bulbi in the right eye (RE) secondary to an expulsive choroidal hemorrhage during a combined phaco-trabeculectomy. On examination she had a visual acuity of no light perception in the RE and counting fingers in the LE. Slit lamp examination of the LE showed conjunctival hyperemia, follicular reaction, extensive mutton-fat keratic precipitates (KPs) and +1 cells in the anterior chamber. Vitreous was quiet and fundus examination did not show any signs of inflammation; IOP was 25 mmHg. Systemic evaluation, including FBC, urea and electrolytes, liver function tests, ESR, CRP, angiotensin converting enzyme, syphilis serology, tuberculin skin test and chest x-ray, was normal. Due to the lack of response to antiherpetic treatment and the associated presence of follicular conjunctivitis, a brimonidine related uveitis was suspected. The fixed combination of brimonidine and timolol was withdrawn. The clinical picture improved steadily and the IOP was finally controlled with the fixed combination of timolol 0.5 % and brinzolamide 1 %. The second patient (85-year-old female) had pseudoexfoliative glaucoma treated by trabeculectomy 18 years previously, followed by an Ahmed valve in the RE and nonpenetrating deep sclerectomy in LE. In view of the deficient IOP control (24 and 18 mmHg) and the worsening of the visual fields the combination of brimonidine 0.2 % and timolol 0.5 % twice daily was added, lowering the IOP to 20 and 14 mmHg

Impact of introducing 2 simple technique modifications on the Descemet membrane endothelial keratoplasty learning curve

Purpose To analyze the impact of performing premarking of the Descemet roll and using SF6 20% on a surgeons Descemet membrane endothelial keratoplasty (DMEK) learning process. Methods A total of 30 consecutive eyes with endothelial dysfunction undergoing DMEK during the learning curve of a surgeon were retrospectively analyzed. Prior to the study, the surgeon had already performed 10 DMEKs. The first 15 consecutive patients were included in group 1 (no premarking and air tamponade) and the other 15 consecutive patients were included in group 2 (premarking and SF6 tamponade). Main outcome parameters were best-corrected visual acuity (BCVA), endothelial cell density (ECD) loss at 6 months, and intraoperative and postoperative complications. Results Among the 2 groups, BCVA and ECD loss at 6 months were similar. However, there was a statistically significant reduction in primary graft failure (40% vs 0%) and need of rebubbling due to complete or partial graft detachment (40% vs 6%) when comparing group 1 versus group 2. In group 1, half of the patients needing rebubbling had primary graft failure. Conclusions Based on our personal experience, premarking the graft to assess orientation and using a SF6 gas tamponade dramatically reduces the risk of primary graft failure and the need for rebubbling even during the first stages of the learning curve. These findings should encourage surgeons to safely change from Descemet stripping automated endothelial keratoplasty to DMEK.

The new Bruch’s membrane opening – minimum rim width classification improves optical coherence tomography specificity in tilted discs

Background and objective To investigate and compare the false-positive (FP) diagnostic classification of the Bruch’s membrane opening – minimum rim width (BMO-MRW) and retinal nerve fiber layer (RNFL) thickness in healthy eyes with tilted optic disc. Materials and methods Fifty healthy eyes of 30 participants with tilted optic disc underwent BMO-MRW and RNFL scanning using Spectralis and macular Cirrus optical coherence tomography (OCT) scans. Results The overall FP rate was significantly lower using BMO-MRW map compared with both RNFL map by Spectralis (8% vs 62%, respectively, P<0.001) and ganglion cell analysis (GCA) map by Cirrus (8% vs 50%, respectively, P<0.001). Specificity was significantly higher using BMO-MRW than RNFL in eyes with low (89.7% vs 41.4%, P<0.001) and moderate myopia (95.2% vs 33.3%, P<0.001). Conclusion OCT-derived BMO-MRW analysis provides significantly greater specificity than RNFL in tilted disc irrespectively of the refractive error, and it is more specific than GCA analysis in tilted disc with moderate myopia.

Optic Nerve Head Biomechanic and IOP Changes Before and After the Injection of Aflibercept for Neovascular Age-Related Macular Degeneration

Purpose We investigated the early effects of intravitreal aflibercept injection (IAI) on optic nerve head (ONH) morphology. Methods All of the participants underwent applanation tonometry and enhanced depth imaging by spectral-domain optical coherence tomography immediately before injection, and within 5 and 30 minutes after IAI. Changes in the anterior lamina cribrosa surface depth, prelaminar tissue thickness (PTT), optic cup width, optic cup depth, and Bruchs membrane opening (BMO) were assessed. Results The study included 30 eyes of 30 subjects with a mean age of 77.4 ± 6.8 years (range, 65-89 years) following IAI (2 mg in 0.05 ml). Within 5 minutes after injection, the mean cup depth, mean cup width, and BMO were significantly increased (P = 0.013, P = 0.000, and P = 0.004, respectively), whereas the mean PTT was thinned (P = 0.009). These morphologic changes returned to near baseline values 30 minutes after injection. Cup widening and BMO expansion (P = 0.000; r, 0.668), as well as cup deepening and prelaminar thinning (P = 0.000; r, -0.838), were significantly correlated. The magnitude of cup deepening and prelaminar tissue thinning correlated with the IOP change in the opposite direction than expected (P = 0.039; r, -0.379 and P = 0.377; r, 0.040). Conclusions A significant widening and deepening of the optic cup, BMO expansion, and prelaminar tissue thinning occurred following IAI for neovascular AMD. Eyes having greater optic disc cup deepening and prelaminar tissue condensation after IAI, associated with a lower IOP increase after injection, suggesting that ONH compliance might buffer the effect of additional intravitreal fluid injection on IOP values.

DEXAMETHASONE IMPLANT REMOVAL FROM ANTERIOR CHAMBER: SURGICAL TECHNIQUE.

PURPOSE To describe a surgical technique for complete and safe dexamethasone intravitreal implant (Ozurdex; Allergan, Inc., Irvine, CA) removal from anterior chamber. METHODS Description of a new surgical technique for Ozurdex removal using a lens injector cartridge. RESULTS Dexamethasone implant was removed completely from anterior chamber with no damage to corneal endothelium or posterior chamber luxation in a patient with Ozurdex anterior chamber migration. CONCLUSION Dexamethasone implants can be removed from anterior chamber in an easy, cheap, fast, and save way.

Differences in Corneal Biomechanics in Nonpenetrating Deep Sclerectomy and Deep Sclerectomy Reconverted into Trabeculectomy.

Purpose: To evaluate the differences in intraocular pressure (IOP) and in corneal biomechanics in eyes with uneventful nonpenetrating deep sclerectomy (NPDS) in 1 eye and with intended deep sclerectomy reconverted into trabeculectomy (RIT) in the fellow eye of the same patient. Participants: Forty eyes of 20 patients with both types of glaucoma surgery and more than 6 months of follow-up, and 31 eyes of 50 controls. Methods: IOP was assessed with Goldmann applanation tonometry (GAT), ocular response analizer (ORA), and dynamic contour tonometer (DCT). Student t test for independent samples and a univariate generalized estimating equations model were used to analyze the results. Main Outcome Measures: Overall, no significant differences were found between IOP of NPDS and RIT eyes when measured with 3 tonometers. Results: Although NPDS showed lower values of IOP measured with GAT and ORA, RIT presented lower IOP if DCT is the chosen tonometry. Biomechanically, NPDS eyes had higher corneal hysteresis (CH) and corneal resistance factor (CRF). When compared with control patients, eyes that underwent glaucoma surgery had lower IOP using GAT, DCT and ORA (P<0.001, 0.315, and 0.260, respectively), and lower CRF (P<0.001). Conclusions: Eyes with NPDS tended to have higher values of CH and CRF and lower IOP than RIT eyes, as measured with 3 of 4 tonometry methods; these differences did not reach statistical significance.

Nonpenetrating deep sclerectomy for glaucoma after descemet stripping automated endothelial keratoplasty: three consecutive case reports.

AbstractThe purpose of this study was to evaluate the efficacy and safety of nonpenetrating deep sclerectomy (NPDS) in 3 consecutive eyes with preexisting and uncontrolled glaucoma after Descemet stripping with automated endothelial keratoplasty (DSAEK).NPDS with intrascleral implant and topical adjunctive intraoperative mitomycin C (0.2 mg/mL 1 minute) was performed.Intraocular pressure (IOP) and number of glaucoma medication were registered before and after NPDS with at least 1-year follow-up. Intraoperative and postoperative complications were also registered.Before NPDS, IOP was 18 mm Hg in 1 patient and 32 mm Hg in the other 2 patients. Four antiglaucoma drugs were used in 2 cases and 3 in the other one. At 1 year after NPDS, all the patients had an IOP ⩽18 mm Hg. Two patients required postoperative antiglaucoma medications (1 drug in 1 case and 2 drugs in the other one). Neodymium-doped yttrium aluminum garnet laser goniopuncture was needed in 2 patients and it had to be repeated in 1 of them. No complications related to NPDS were observed. A corneal graft rejection was observed 5 months after NPDS in 1 case that resolved without sequelae with intensive corticosteroid eye-drop therapy.NPDS could be a safe and successful alternative to conventional filtration surgery after DSAEK in eyes with uncontrolled glaucoma. Larger series and a longer follow-up would be necessary to set the actual role of surgery in DSAEK patients.