Ultrathin DSAEK versus DMEK - Review of systematic reviews.

The efficacy and safety of Descemet's membrane endothelial keratoplasty (DMEK) and ultrathin Descemet stripping automated endothelial keratoplasty (UT-DSAEK) have been recently compared in several systematic reviews (SRs). The aim of this study was to assess the evidence quality of such SRs, in order to obtain a scientifically rigorous comparison between the two techniques. We performed a systematic review of SRs and meta-analyses comparing the efficacy and safety between UT-DSAEK and DMEK up to 24th March 2023, using 3 electronic databases (PubMed, Cochrane Library, Google Scholar) plus manual reference search. Specific outcomes analyzed included best-corrected visual acuity (BCVA), endothelial cell density (ECD), rebubbling rate, and other postoperative complications. Of 90 titles/abstracts screened, four SRs met the inclusion criteria. All SRs adequately analyzed potential bias of the included studies. One SR raised concern for potential literature search bias and two SRs have heterogeneity in some outcomes analyzed. All SRs found higher BCVA after DMEK, but one SR reported significant heterogeneity. All SRs found significant heterogeneity in ECD analysis, with one SR providing inconsistent analysis of this outcome. Three SRs analyzed rebubbling rates, favoring UT-DSAEK over DMEK. Three SRs concluded a higher overall complication rate after DMEK, although rebubbling may be a confounding factor. This systematic review clarifies the strengths and weaknesses of published SRs and reinforces the conclusion that DMEK leads to superior visual outcomes compared to UT-DSAEK, with the trade-off of higher rebubbling rates and possibly other postoperative complications. Studies with longer follow-up are needed to ascertain these differences between procedures.

Descemet's Membrane Endothelial Keratoplasty for Corneal Endothelial Failure Secondary to Three Types of Phakic Intraocular Lens - Retrospective Study.

Purpose: To analyze the outcomes of Descemet's membrane endothelial keratoplasty (DMEK) for corneal endothelial failure secondary to phakic intraocular lens implantation (PIOL) at a reference center for corneal transplantation in Spain. Design: Retrospective, single-surgeon case series. Methods: Single-center analysis of patients who underwent DMEK for PIOL-related corneal decompensation between July 2011 and July 2020 with at least 6 months of follow-up postoperatively. Primary outcome was final best-corrected visual acuity (BCVA, logMAR) compared to pre-DMEK BCVA. Secondary outcomes analyzed included post-DMEK refractive spherical equivalent, endothelial cell loss (%ECL), and graft failure. Results: Sixteen eyes (14 patients) underwent DMEK for PIOL-related corneal decompensation. Mean (SD) time to PIOL explantation was 9.3 (5.0) years, and median (P25-P75) time between PIOL explantation and DMEK surgery was 3 (2-4) months. Median pre-DMEK BCVA was 0.80 (1.08-0.60) logMAR. A statistically significant improvement in BCVA was observed 1 month after DMEK (p = 0.001), and median final BCVA was 0.15 (0.0-0.35) logMAR (p = 0.002). Mean %ECL was 55.6 (18.7) % at 2-year follow-up and 61.7 (11.7) % in eyes with over 4 years of follow-up. Two eyes required re-bubbling (12.5%), one of which ended in primary graft failure (6.2%) and one eye had late endothelial graft failure (LEGF) at 4-year follow-up (1/15 grafts, 6.7%). Conclusion: In patients with PIOL-related corneal decompensation, DMEK leads to good and clinically significant refractive and visual outcomes in the medium-long term, with a good safety profile. Prospective studies are encouraged to ascertain whether these cases are at increased risk of accelerated endothelial cell loss and LEGF.

Outcomes of cystoid macular edema following Descemet's membrane endothelial keratoplasty in a referral center for keratoplasty in Spain: retrospective study.

The aim of this study was to analyze the outcomes of eyes with visually significant cystoid macular œdema (vs-CMO) after Descemet membrane endothelial keratoplasty (DMEK) in a referral center for keratoplasty in Spain. We conducted a retrospective, single-surgeon case series of eyes that developed post-DMEK vs-CMO performed between January 2011 and December 2020. Data collected included: indication for DMEK; biometric data; ocular comorbidities; past medical history; time to detection of vs-CMO after DMEK (T, weeks); best-corrected visual acuity (BCVA, logMAR) and central retinal thickness (CRT, µm) at diagnosis of vs-CMO, after resolution of CMO, and at last follow-up; and management strategy. Main outcomes analyzed were incidence of vs-CMO, improvement in BCVA and CRT after treatment of vs-CMO. Of 291 consecutive DMEK surgeries, 14 eyes of 13 patients (4.8%) developed vs-CMO. Five patients (38.5%) had history of CMO, and 28.6% of eyes had ophthalmic comorbidities. Median (P25-P75) T was 4 (3-10) weeks. Treatment success was observed in 12/13 eyes (92.3%), two of which required second-line treatment. In successful cases (median time-to-resolution 3.0 (2.0-3.5) months), median BCVA improved from 0.60 (0.40-0.80) logMAR to 0.30 (0.15-0.40) logMAR (p = 0.002) after treatment, and median CRT improved from 582.5 (400.0-655.0) µm to 278.0 (258.0-294.0) µm (p = 0.005). In our study, we found a 4.8% rate of post-DMEK vs-CMO, with most cases occurring in the first 3 months after surgery. Good functional and anatomical outcomes are expected in most eyes, without treatment-related complications or implications in graft outcomes. Additional studies are encouraged to determine a standardized protocol for post-DMEK vs-CMO.

Ten-year outcomes of pseudophakic mini-monovision correction of hyperopic presbyopia.

PURPOSE: To evaluate long-term efficacy, safety, and spectacle independence after the treatment of hyperopic presbyopia with pseudophakic mini-monovision using standard monofocal intraocular lenses (IOLs) after bilateral cataract surgery. SETTING: Private practice in Barcelona, Spain. DESIGN: Retrospective, noncomparative case series. METHODS: Patients with hyperopic presbyopia underwent bilateral cataract surgery with pseudophakic mini-monovision using standard monofocal IOLs between 2008 and 2018. Main outcomes analyzed were uncorrected distance visual acuity (UDVA), uncorrected near distance visual acuity (UNVA), and rates of spectacle independence at postoperative day 1 (POD1), months 1, 6 and 12, and at 5 and 10 years (Y10) postoperatively. RESULTS: The study enrolled 463 patients. Both UDVA and UNVA significantly improved postoperatively ( P < .05). The mean binocular UDVA improved from 0.47 ± 0.3 logMAR preoperatively to 0.096 ± 0.14 at POD1 to 0.16 ± 0.2 at Y10 ( P = .0033). The binocular UNVA was 0.05 logMAR at Y10, whereas in preoperative visits, all patients needed spectacles. The mean UDVA for the dominant eye ≤0.20 logMAR was achieved in 84.29% at the Y10. Self-reported and measured complete spectacle independence for near vision was achieved in 79.61% of patients at POD1 and 71.92% at Y10 postoperatively. For distance, respectively, in 86.29% of patients at POD1 and 78.43% at Y10. The achieved results were stable. No serious events were reported, as well as no photic phenomena. CONCLUSIONS: Pseudophakic mini-monovision in hyperopic presbyopes is a safe, effective, and low-cost approach for the long-term correction of presbyopia. It significantly reduces spectacle dependence and fulfils patients' expectations after bilateral cataract surgery.

Photorefractive keratectomy after DMEK for corneal decompensation by phakic IOL.

PURPOSE: To provide the first description of photorefractive keratectomy (PRK) for the correction of mild residual refractive error after Descemet membrane endothelial keratoplasty (DMEK). METHODS: Case report. RESULTS: A 45 year-old woman presenting with phakic intraocular lens (PIOL)-related corneal decompensation underwent staged DMEK surgery following PIOL explantation and cataract surgery. Eighteen months after DMEK, uncorrected distance visual acuity (UDVA) was 20/60 and best-corrected visual acuity (BCVA) was 20/22, with a stable refraction. The patient requested refractive surgery to decrease spectacle dependance, and wavefront-optimized PRK was performed. At last follow-up observation thirty-three months after PRK (54 months after DMEK surgery), UDVA was 20/20, the cornea remained clear without signs of rejection or endothelial failure, and the endothelial cell loss rate was not accelerated after PRK. CONCLUSION: Since long-term visual and refractive stability can be expected after DMEK, PRK may be a particular safe and effective approach for the correction of mild residual refractive errors after DMEK. However, we consider that surgeons must exercise caution when considering keratorefractive surgery in these eyes due to postoperative changes in corneal curvature and thickness, and further studies are encouraged.

Acute corneal allograft rejection following SARS-CoV-2 vaccination-A systematic review.

All documented cases of acute corneal allograft rejection following SARS-CoV-2 vaccination were examined, to characterize possible risk factors and graft outcomes. Comprehensive search (4 electronic databases: PubMed, CENTRAL, ClinicalTrials.gov, Google Scholar, plus manual search in articles' reference lists) until March 1st 2022 to identify studies reporting acute corneal allograft rejection following SARS-CoV-2 vaccination; study protocol was developed in line with PRISMA statement. We analysed demographics, allograft type, rejection prophylaxis regime at the time of vaccination, transplantation-to-vaccination time (G-Vt), vaccination-to-immune reaction onset time (V-Rt), management, best-corrected visual acuity before and after rejection, and graft survival. Of 169 titles/abstracts screened, 16 studies (n  = 36 eyes) met the inclusion criteria. Fourteen eyes (38.9%) had received >1 graft, and 11.1% of cases had history of immune reactions; 52.9% of cases occurred after the first dose. Median (P25-P75) G-Vt was 48 (10-78) months; median V-Rt was 9 (7-14) days. In eyes with resolved rejection, median time-to-resolution was 3 (1-4) weeks. Four eyes (11.1%) had partial resolution of corneal decompensation, and 5 grafts (13.9%) failed. Acute corneal allograft rejection after SARS-CoV-2 vaccination is a rare event, but may occur any time post-keratoplasty. Early recognition and prompt, aggressive treatment is warranted to optimize vision and graft survival. Well-known risk factors for rejection may be confounding factors, including the high proportion of cases with a history of previous grafts and the rejection prophylaxis regimes at the time of vaccination. Increasing immunosuppressants in the peri-vaccination period may decrease the risk of immune reactions, especially in high-risk cases.

DMEK for the treatment of interface fluid syndrome secondary to failed DSAEK graft: A case report and review of the literature.

Purpose: To report a case of Descemet membrane endothelial keratoplasty (DMEK) for the management of post-laser in situ keratomileusis (LASIK) interface fluid syndrome (IFS) secondary to failed Descemet stripping automated endothelial keratoplasty (DSAEK) graft, and to provide a literature review on endothelial keratoplasty (EK) for this indication. Observations: A 52-year-old patient presented with LASIK interface fluid accumulation and a non-functioning primary DSAEK graft. Past ophthalmic history was relevant for: (1) phakic intraocular lens (PIOL) implantation with later refinement by LASIK; (2) combined PIOL explantation and refractive lens exchange due to accelerated endothelial cell loss (ECL); (3) primary DSAEK due to corneal decompensation.A secondary EK graft (DMEK) was performed, and the patient was prospectively followed for 6 months (M6). DMEK surgery was uneventful, without postoperative graft detachment. Corneal clearing and resolution of interface fluid accumulation occurred during the first postoperative month. Best-corrected visual acuity (BCVA) improved from 20/800 Snellen to 20/25 Snellen at 3-month follow-up, remaining stable at M6. Due to a persistent rise in intraocular pressure (IOP), the patient underwent uneventful non-penetrating deep sclerectomy 2 months after DMEK, with controlled IOP and without accelerated ECL. Conclusions and Importance: DMEK is feasible, effective, and safe in the management of IFS in cases where corneal endothelial failure plays a major role, even in complex eyes with previous EK grafts. Aggressive postoperative IOP control is warranted to decrease the risk of interface fluid recurrence and damage to the optic nerve. Studies with larger patient numbers are encouraged to ascertain the role of EK for this indication.

Long-term efficacy and safety profiles of iris-fixated foldable anterior chamber phakic intraocular lens implantation in eyes with more than 10 years of follow-up.

PURPOSE: To evaluate the long-term efficacy, safety, predictability, and stability of a foldable anterior chamber phakic intraocular lens (pIOL) (Artiflex) implantation in eyes with more than 10 years of follow-up. SETTING: Instituto de Microcirugía Ocular, Barcelona, Spain. DESIGN: Retrospective study. METHODS: Patients who underwent Artiflex pIOL implantation during 2008 to 2011 and with more than 10 years of follow-up were included. Variables analyzed were as follows: uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), manifest refraction, spherical equivalent (SE), endothelial cell count (ECC), and intraocular pressure (IOP) preoperatively and at 1 month, 1 year, 5 years, and the final follow-up. Descriptive statistics were performed and results reported following the Standard for Reporting Refractive Surgery Outcomes. RESULTS: 76 eyes (40 patients) were analyzed, and the mean follow-up was 10.67 ± 0.64 years. The mean preoperative SE was -8.26 ± 2.47 diopters (D), and the mean preoperative cylinder was -0.95 ± 0.86 D. At the final follow-up, efficacy and safety indices were 0.82 and 1.11, respectively. In total, 58 eyes (76%) achieved a UDVA of ≥20/40. 30 eyes (39%) gained ≥1 line of CDVA, and no eye lost ≥2 lines of CDVA. At the final follow-up, 46 (61%) and 58 (76%) eyes were within ±0.50 D and ±1.00 D of attempted SE correction, respectively. 72 eyes (95%) had ≤1.00 D of postoperative astigmatism, and 46 eyes (61%) were within ±15 degrees from the intended correction axis. At the last visit, a statistically significant myopic progression of -0.56 ± 0.83 D was observed ( P = .01). The mean ECC loss at the final follow-up was 12.2 ± 12.5%. IOP remained stable. Two eyes (2.63%) developed cataract after 10.3 years. CONCLUSIONS: Long-term results demonstrated that Artiflex pIOL implantation was effective, predictable, stable, and safe.

Long-term efficacy and safety profiles following small incision lenticule extraction in eyes with ≥ 5-year follow-up.

PURPOSE: To evaluate long-term efficacy, safety, predictability and stability (refractive and keratometric) of myopic and myopic astigmatism correction with Small Incision Lenticule Extraction (SMILE). METHODS: Single center retrospective review of eyes undergoing SMILE from 2012-2015. Forty-two eyes (23 patients) with ≥ 5-year follow-up. Variables analyzed were preoperative, 3-month, 1-year and last follow-up uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), manifest refraction, spherical equivalent (SE) and mean keratometry. Descriptive statistics were performed and results reported following the Standard for Reporting Astigmatism Outcomes. RESULTS: Mean follow-up of 5.98 ± 0.90 years. Mean preoperative SE was -5.26 ± 1.22D (range -2.50 to -8.12D). Mean preoperative cylinder was -0.66 ± 0.61D (range 0.00 to -2.25D). Efficacy and safety indices were 0.86 and 0.98, respectively. In total, 81% of operated eyes achieved an UDVA of ≥ 0.09 logMar (20/25 Snellen). At the last follow-up, ≥1 line of CDVA was gained in 14% of eyes. Five percent lost 1 line of CDVA, and no eye loss ≥2 lines of CDVA. Sixty-nine percent of eyes were within ± 0.50D and 86% within ± 1.00D of the attempted SE correction. Ninety-one percent of eyes had ≤0.50D of postoperative astigmatism and 71% were within ± 15° from the intended correction axis. At the final follow-up, a statistically significant myopic regression of 0.19 ± 0.50D was observed (p = 0.01). CONCLUSIONS: Long-term results demonstrate that SMILE is effective, predictable and safe. SMILE has good stability, low regression compared to LASIK, and no signs of corneal ectasia staging within our standard criteria.

Long-term efficacy and safety profiles after posterior chamber phakic intraocular lens implantation in eyes with more than 10 years of follow-up.

PURPOSE: To evaluate long-term efficacy, safety, predictability, and stability of a posterior chamber phakic intraocular lens (Visian implantable collamer lens [ICL]) in eyes with ≥10 years of follow-up. SETTING: Instituto de Microcirugía Ocular, Barcelona, Spain. DESIGN: Retrospective study. METHODS: Eyes undergoing ICL implantation from 2008 to 2011 with ≥10 years of follow-up were included. Variables analyzed were preoperative, 1-month, 1-year, 5-year, and last follow-up uncorrected distance (UDVA) and corrected distance visual acuity (CDVA), manifest refraction, spherical equivalent (SE), endothelial cell count (ECC), and intraocular pressure (IOP). Descriptive statistics were performed and results reported following the Standard for Reporting Refractive Surgery Outcomes. RESULTS: 45 eyes (26 patients) were analyzed; the mean follow-up 11.35 ± 1.30 years. The mean preoperative SE was -10.06 ± 3.40 diopters (D) and the mean preoperative cylinder -1.55 ± 1.45 D. At the last follow-up, efficacy and safety indices were 0.79 and 1.12, respectively. In total, 32 eyes (71%) achieved an UDVA of ≥20/40. 22 eyes (49%) gained ≥1 line of CDVA, and 2 eyes (4%) lost ≥2 lines of CDVA. At the final follow-up, 19 eyes (42%) and 29 eyes (64%) were within ±0.50 D and ±1.00 D of attempted SE correction, respectively. 31 eyes (69%) had ≤1.00 D of postoperative astigmatism, and 29 eyes (74%) were within ±15 degrees from the intended correction axis. At the last visit, a statistically significant myopic progression of -0.75 ± 1.20 D was observed ( P = .01). ECC loss at the last follow-up was 9.85 ± 11.35%. IOP remained stable. There were no intraoperative complications. 3 eyes (7%) developed cataract after 10 years. CONCLUSIONS: The long-term results demonstrated that ICL was effective, predictable, stable, and safe.

Secondary Endothelial Keratoplasty-A Narrative Review of the Outcomes of Secondary Corneal Endothelial Allografts.

BACKGROUND: We review the literature on the efficacy and safety outcomes of secondary Descemet stripping endothelial keratoplasty (DSEK) and Descemet membrane endothelial keratoplasty (DMEK). METHODS: Literature search of English-written publications up to September 27, 2020 in PubMed database, using the terms "endothelial keratoplasty" in combination with keywords "secondary" or "repeat." In addition, we manually searched the references of the primary articles. RESULTS: Twenty-seven studies (n = 651 eyes) were retained and reviewed, including 10 studies on repeat DSEK, 8 studies on repeat DMEK, 6 studies of DMEK following DSEK, and 3 studies of DSEK after failed DMEK. All studies reported significant improvement in visual acuity after secondary endothelial keratoplasty (EK). Twelve studies compared visual outcomes between primary and secondary EK, reporting conflicting findings. Sixteen studies reported endothelial cell loss rates after secondary EK, and only 1 study reported significantly increased endothelial cell loss rates compared with primary EK. Allograft rejection episodes occurred in 1.8% of eyes (range, 0%-50%). Six studies compared complication rates between primary and secondary EK eyes, and only 1 study found a higher median number of complications. However, 2 studies reported higher regraft failure rates compared with primary EK eyes. CONCLUSIONS: Secondary EK is surgically feasible and renders significant visual improvement after failed primary EK, although it is not clear whether visual outcomes and allograft survival are comparable with primary EK, raising the question of whether secondary EK eyes are "low risk" as primary EK eyes. Further larger, prospective studies are encouraged to obtain additional quality data on secondary corneal endothelial allotransplantation.

Macular edema secondary to retinal vein occlusion in a real-life setting: a multicenter, nationwide, 3-year follow-up study.

PURPOSE: To evaluate the presence of macular edema secondary to retinal vein occlusion (RVO)-both central retinal vein occlusion (CRVO) and branch retinal vein occlusion (BRVO)-3 years after diagnosis in patients who underwent intravitreal therapy and to identify potential prognostic factors and biomarkers of persistent macular edema. METHODS: National multicenter, observational, exploratory, retrospective cohort study of 104 consecutive patients with macular edema secondary to RVO diagnosed from January 2014 to December 2015 with minimum 3-year follow-up time. Data analyzed included best-corrected visual acuity (BCVA), clinical and demographic data, and spectral domain optical coherence tomography parameters. RESULTS: At final observation, median baseline central retinal thickness significantly improved from baseline 538 to 290 µm (p < 0.001) and complete macular edema resolution was achieved in 51.0% of patients (56.3% and 42.5% in BRVO and CRVO patients, respectively). BCVA also improved (p < 0.01). Logistic regression analysis revealed a relationship between recurrence of macular edema and disorganization of retinal inner layers (DRIL) at baseline (odds ratio = 2.88; p = 0.013). CONCLUSION: Good long-term anatomical and functional outcomes are achieved with intravitreal treatments in RVO patients. Anatomical success and visual gains seen in the first year were maintained throughout the entire follow-up, though DRIL is a major risk factor for recurrence.

Paracentral acute middle maculopathy-review of the literature.

Paracentral acute middle maculopathy (PAMM) is a recently identified spectral-domain optical coherence tomography (SD-OCT) finding characterized by a hyper-reflective band spanning the inner nuclear layer (INL), which typically evolves to INL atrophy in later stages. Typical clinical features include the sudden onset of one or multiple paracentral scotomas, normal or mild reduction in visual acuity, and a normal fundus appearance or a fundus with a deep grayish lesion. Although its pathophysiology is not yet fully understood, ischemia at the level of the intermediate and deep capillary plexa has been demonstrated to play a major role. Since its first description, an increasing number of publications on PAMM have been published in ophthalmology scientific journals. The purpose of this study is to provide a review of the current literature on PAMM.

Optic neuropathy due to chronic lymphocytic leukemia: The first manifestation of the disease.

PURPOSE: Chronic lymphocytic leukemia (CLL) is the most common lymphoproliferative disorder in the western world. The involvement of the central nervous system (CNS) or the optic nerve in CLL, however, is rare. We report a case of a previously untreated patient with CLL whose first manifestation of the disease was a progressive visual loss caused by optic neuropathy. OBSERVATIONS: Clinical manifestations, optical coherence tomography (OCT), and automated visual fields pointed to the diagnosis of neuropathy. Leukemic involvement of the CNS was confirmed after cells suggestive of CLL were found by cerebrospinal fluid analysis. Optic nerve infiltration is thought to be the cause of this optic neuropathy, and the clinical course and treatment are described herein. CONCLUSIONS: When readily diagnosed, optic nerve infiltration is a rare, yet manageable complication of CLL.

Repeat Descemet Membrane Endothelial Keratoplasty for Failed Primary Descemet Membrane Endothelial Keratoplasty at a Referral Center for Keratoplasty in Spain: DIMOEK Study.

PURPOSE: To analyze the clinical results of repeat Descemet membrane endothelial keratoplasty (re-DMEK) for failed primary DMEK graft at a referral center for keratoplasty in Spain. DESIGN: Retrospective, interventional, comparative case series. METHODS: From a single-center, single-surgeon series of 189 consecutive DMEK surgeries, 14 (7.41%) were re-DMEK eyes. The primary outcome was best-corrected visual acuity change (ΔBCVA, logarithm of minimal angle of resolution [logMAR]) from baseline (before first DMEK) to last follow-up. Secondary outcomes were ΔBCVA from baseline at 3, 6, and 12 months postoperatively, endothelial cell loss (%ECL), rebubbling rate, and re-DMEK graft failure. Outcomes were compared with an age-matched control group of 18 successful primary DMEK eyes. RESULTS: After re-DMEK (median follow-up time 14.5 [42.5] months), mean BCVA improved from 0.55 (0.42) logMAR (Snellen 20/71 [20/53]) at baseline to 0.09 (0.26) logMAR (Snellen 20/25 [20/36]; P = .037). ΔBCVA from baseline was statistically significant at months 3 (P = .028), 6 (P = .023), and 12 (P = .012), and ΔBCVA was significant observed between months 6 and 12 (P = .028). BCVA differences between patient groups were statistically nonsignificant at 3 (P = .397), 6 (P = .468), and 12 months (P = .647). Mean %ECL in re-DMEK eyes with follow-up ≥12 months was 48.2 (15.1%), and the rebubbling rate was 28.6%; differences between groups were statistically nonsignificant for both variables (P = .580 and P = .669, respectively). Three re-DMEK eyes developed graft failure, all achieving final BCVA ≤0.30 logMAR (Snellen ≥20/40) after tertiary keratoplasty. CONCLUSIONS: Repeat DMEK produces significant, continuous visual improvement after failed primary DMEK. Although visual outcomes and %ECL were comparable to primary DMEK, there was a relatively high rate of graft failure after re-DMEK.

Choroidal binarization analysis: clinical application.

INTRODUCTION: Image processing of optical coherence tomography scans through binarization techniques represent a non-invasive way to separately asses and measure choroidal components, in vivo. In this review, we systematically search the scientific literature regarding binarization studies published so far. METHODS: A systematic research was conducted at PubMed database, including English literature articles for all of the following terms in various combinations: binarization, choroid/al, enhanced depth spectral domain/swept source optic coherence tomography, and latest publications up to November 2018 were reviewed. RESULTS: Thirty-seven articles were included and analyzed regarding studied disease, binarization method, studied variables, and outcomes. Most of the studies have focused on the more common retinal pathologies, such as age-related macular degeneration, central serous chorioretinopathy and diabetic retinopathy but binarization techniques have also been applied to the study of choroidal characteristics in ocular inflammatory diseases, corneal dystrophies and in postsurgical follow-up. Advantages and disadvantages of binarization techniques are also discussed. CONCLUSION: Binarization of choroidal images seems to represent a promising approach to study choroid subcomponents in an increasingly detailed manner.

Late-onset Leber's hereditary optic neuropathy: the role of environmental factors in hereditary diseases.

Leber's hereditary optic neuropathy (LHON) is an optic neuropathy of mitochondrial inheritance, characterised by incomplete penetrance and variable expressivity. Typically, young male patients present with sequential, severe, rapidly progressive loss of central vision, with characteristic funduscopic findings. However, LHON may present at any age, in both genders, and fundus examination may be normal. Evidence has emerged to support the role of environmental factors in triggering LHON, by disrupting the normal mechanisms of mitochondrial function. We present two clinical cases of LHON of late onset, and provide a literature review on atypical cases of LHON and the role of environmental triggers.

Rho kinase inhibitors-a review on the physiology and clinical use in Ophthalmology.

The Rho kinase (ROCK) signaling pathway is involved in several cellular events that include cell proliferation and cytoskeleton modulation leading to cell adhesion. The ROCK pathway in the human eye has been hypothesized to play important roles in corneal endothelial cell physiology and pathologic states. In addition, ROCK signaling has been identified as an important regulator of trabecular meshwork (TM) outflow, which is altered in glaucomatous eyes. These roles in corneal and glaucomatous disease states have led to the growing interest in the development of drugs selectively targeting this pathway (ROCK inhibitors). The authors provide a review of the literature on the pathobiology of the ROCK signaling in corneal endothelial disease, glaucoma, and vitreoretinal disease, as well as the clinical usefulness of ROCK inhibitors in Ophthalmology.