Chloroplast phosphatases LPPγ and LPPε1 facilitate conversion of extraplastidic phospholipids to galactolipids.

Galactolipids comprise the majority of chloroplast membranes in plants, and their biosynthesis requires dephosphorylation of phosphatidic acid at the chloroplast envelope membranes. In Arabidopsis (Arabidopsis thaliana), the lipid phosphate phosphatases LPPγ, LPPε1, and LPPε2 have been previously implicated in chloroplast lipid assembly, with LPPγ being essential, as null mutants were reported to exhibit embryo lethality. Here, we show that lppγ mutants are in fact viable and that LPPγ, LPPε1, and LPPε2 do not appear to have central roles in the plastid pathway of membrane lipid biosynthesis. Redundant LPPγ and LPPε1 activity at the outer envelope membrane is important for plant development, and the respective lppγ lppε1 double mutant exhibits reduced flux through the ER pathway of galactolipid synthesis. While LPPε2 is imported and associated with interior chloroplast membranes, its role remains elusive and does not include basal nor phosphate limitation-induced biosynthesis of glycolipids. The specific physiological roles of LPPγ, LPPε1, and LPPε2 are yet to be uncovered, as does the identity of the phosphatidic acid phosphatase required for plastid galactolipid biosynthesis.

An important detail that is still not clear in amniotic membrane applications: How do we store the amniotic membrane best?

The use of fresh amniotic membrane (AM) is not a viable option, as it has many disadvantages. Preserving the AM reduces the risk of cross-infection and maintains its effectiveness for a long time. In order to maximize the therapeutic effects of the AM, the basic need is to preserve its vitality and the bioactive molecules it contains. However, the effect of preservation procedures on cell viability and growth factors is a still matter of debate. Optimum preservation method is expected to be cost-effective, easily-accessible, and most importantly, to preserve the effectiveness of the tissue for the longest time. However, each preservation technique has its advantages and disadvantages over the other, and each one compromises the vitality and bioactive molecules of the tissue to some extent. Therefore, the best method of preservation is still controversial, and the question of 'how to preserve the AM best?' has not yet been definitively answered.

Ocular manifestations of granulomatosis with polyangiitis: report from a tertiary eye care center.

PURPOSE: To report demographic characteristics and ophthalmological manifestations of patients with granulomatosis with polyangiitis (GPA) in a tertiary eye care center in Turkey. METHODS: Medical records of patients with GPA-related ocular manifestations evaluated between 2013 and 2023 were included. Demographic and clinical characteristics of the patients including nature of systemic involvement, ophthalmologic symptoms and signs, laboratory investigations and treatment modality were reviewed. RESULTS: Twelve eyes of 10 patients (5 female/5 male) were included. The mean age was 57.2 ± 12.2 (35-71) years. Five (50%) patients were already diagnosed with GPA. Ocular involvement was the first manifestation of GPA in 3 patients. The remaining 2 patients had simultaneous systemic and ocular symptoms at presentation. Conjunctival hyperemia (9 eyes) and pain (7 eyes) were the most frequent presenting symptoms followed by blurred vision (3 eyes). The frequencies of ocular manifestations were as follows:episcleritis (3 eyes), isolated peripheral ulcerative keratitis (PUK) (3 eyes), scleritis (3 eyes), simultaneous PUK and scleritis (2 eyes) and periorbital mass (1 eye). CONCLUSION: Ophthalmological manifestations can be the initial findings in GPA. Since GPA can affect different structures of the eye, it sometimes might be challenging for ophthalmologists. Therefore, it is crucial for ophthalmologists to be well-informed about GPA-related ocular findings and to have a high index of suspicion for GPA. Although PUK associated with scleritis is highly suggestive for GPA, isolated cases of PUK or scleritis can be seen in GPA. Therefore, it is important to adopt a multidisciplinary approach, consider GPA in differential diagnosis, and benefit from accurate diagnostic tests.

Evaluation of scleral thickness in patients with Fuchs endothelial dystrophy.

PURPOSE: To evaluate scleral thickness using anterior segment-optical coherence tomography (AS-OCT) in Fuchs endothelial dystrophy (FED) and compare the results with healthy individuals. METHODS: Thirty-two eyes of 32 patients with FED and 30 eyes of 30 age, gender, spherical equivalent and axial length matched healthy participants were included. All subjects underwent a detailed ophthalmological examination including endothelial cell density and central corneal thickness (CCT) measurements. Scleral thickness was measured by AS-OCT (Swept Source-OCT, Triton,Topcon,Japan) in 4 quadrants (superior, inferior, nasal, temporal) from 6 mm posterior to the scleral spur. RESULTS: The mean ages were 62.5 ± 13.2 (33-81) for FED group; 64 ± 8.1 (48-81) for control group. CCT was significantly greater in FED group than in the control group (586.8 ± 33.1 (514-635) vs 545.0 ± 20.7 (503-587), respectively)(p = 0.000). In FED group, mean scleral thickness in the superior, inferior, nasal and temporal quadrants were 434.0 ± 30.6 (371-498), 442.8 ± 27.6 (395-502), 447.7 ± 31.4 (382-502), 443.4 ± 30.3 (386-504) µm, respectively. In control group, the mean scleral thickness in the superior, inferior, nasal and temporal quadrants were 381.3 ± 20.0 (341-436), 383.2 ± 16.0 (352-436), 389.2 ± 21.0 (353-440), 383.2 ± 19.2 (349-440) µm, respectively. The mean scleral thickness was significantly higher in all quadrants in FED group than in control group (p = 0.000). CONCLUSION: In patients with FED, scleral thickness was significantly higher. FED is a progressive corneal disease that results in the accumulation of extracellular material in the cornea. These findings suggest that the accumulation of extracellular deposits may not be limited to the cornea. Due to their functional similarity and anatomical proximity, sclera may also be affected in FED.

Ten Years of Pediatric Ocular Chemical Burn Experience in a Tertiary Eye Care Center in Turkey.

OBJECTIVES: To report 10 years of pediatric ocular chemical burn experience in a tertiary eye care center in Turkey. METHODS: Thirty-three patients aged 18 years and younger who presented with ocular chemical burn between 2011 and 2021 were enrolled. Demographic data and clinical characteristics of patients were reviewed. Limbal stem cell deficiency (LSCD) stage was assessed according to LSCD working group's staging system. The initial and final best-corrected visual acuities were recorded. RESULTS: The mean age was 10.4±5.5 (0.25-18) years with an F/M ratio of 12/21. Eleven (33.3%) of the patients were injured with acid and 5 (15.1%) with alkaline. The most common causative agent was nail polish remover (n=7, 21.2%), followed by cologne (n=5, 15.1%) and hand sanitizer (n=4, 12.1%). The severity of burn was ≥grade 4 in 20 patients (60.6%). Chemical injury resulted in LSCD in 18 patients (54.5%). Surgery was performed (LSCD ≥Stage 2 B) in 13 patients (39.3%); limbal stem cell transplantation (LSCT) (n=11), staged amniotic membrane transplantation, and symblepharon release (n=2). Penetrating keratoplasty after LSCT was performed in three of 11 patients. The mean follow-up time was 31.9±28.6 months (6-102.33) after the surgery. CONCLUSIONS: In pediatric population, accurate diagnosis and management of ocular chemical burns are challenging. Although the severity of burn and consequently LSCD rate seems to be high in children, comparative studies in a larger population are still needed.

Shifting trends in demographic features of chemical eye injuries during COVID-19 pandemic.

OBJECTIVES: To evaluate the etiological cause distribution in chemical eye injuries during COVID-19 pandemic. METHODS: In this retrospective case series, the medical records of patients, who presented with chemical eye injuries between March 30, 2020, and March 1, 2021, were evaluated and compared with the data covering 10 years before the pandemic. RESULTS: Twenty-seven eyes of twenty-three patients (19 adults, 4 children) who presented in pandemic period were included. Alcohol-based hand sanitizer was one of the two most common agents (n = 6 eyes) in the pandemic era. In the last 10 years before the pandemic, 137 eyes of 102 patients were treated for chemical eye injuries. Injuries due to alcohol-based hand sanitizer increased from 3.1 to 21.1% among all patients, and from 0 to 75% among pediatric patients during the pandemic era compared to the pre-pandemic period. The increase was statistically significant both in all patients (p = .003) and in the pediatric patient group (p = .048). CONCLUSION: Due to COVID-19 pandemic, alcohol-based hand sanitizer use became more common. Consequently, the frequency of hand sanitizer related chemical injuries showed a 13-fold increase and the age group affected by such accidents is altered during the pandemic. Three out of four pediatric patients (75%) were injured with alcohol-based hand sanitizers, which draws attention to the fact that improperly placed hand sanitizer stations, being just at the eye level of children, can cause chemical eye injuries in the pediatric population even more.

Negative Corneal Fluorescein Staining as an Exceptionally Early Sign of Acanthamoeba Keratitis: A Case Report.

OBJECTIVES: To report the negative fluorescein staining as an early sign of Acanthamoeba keratitis (AK). METHODS: Case report and brief review of related literature. REPORT OF CASE: A 30-year-old, contact lens wearer, woman presented with mild irritation and pain in the right eye. The best-corrected visual acuity (BCVA) was 20/20 in both eyes. Slit-lamp examination revealed a peripheral corneal infiltration. Empirical antimicrobial therapy was initiated. Within the third day, peripheral corneal opacity regressed but a Y-shaped linear epitheliopathy with a negative fluorescein staining, because of a ridge-like epithelial irregularity, was observed in the central cornea. Clinical findings progressed rapidly. Confocal microscopy revealed hyper-reflective cysts with the typical double-ring sign consistent with AK. Therefore, topical chlorhexidine and propamidine were initiated. Clinical findings regressed subsequently. The final BCVA was 20/20 in both eyes. CONCLUSION: Acanthamoeba keratitis usually manifest as superficial epitheliopathy and progresses to the stroma. Findings may be obscure or atypical; comprehensive and careful examination may reveal mild findings in the early stages.

Ocular Manifestations of Fabry Disease: Report from a Tertiary Eye Care Center in Türkiye.

Objectives: To report ocular manifestations in patients with Fabry disease (FD) from a tertiary eye care center in Türkiye. Materials and Methods: This prospective, cross-sectional study included 30 eyes of 15 patients with FD. The diagnosis of FD was made based on a combination of clinical findings, genetic analysis, and biochemical evaluation. All participants underwent a detailed ophthalmic examination with special focus on the typical ocular features of FD (cornea verticillata, conjunctival aneurysms, cataract, retinal vessel tortuosity). Results: The mean age was 45±17 years (range: 22-75 years), with a female/male ratio of 2:3. All patients had tortuous conjunctival vessels and 12 patients (80%) had conjunctival aneurysms. Cornea verticillata was present in 10 patients (66.6%), lens opacification in 4 patients (26.6%), and retinal vascular tortuosity in 8 patients (53.3%). All patients had at least two different ocular findings; most (3 heterozygotes/7 hemizygotes) had a combination of corneal verticillata and conjunctival vessel abnormality. The conjunctiva, cornea, and retina were affected together in 5 hemizygous patients (33.3%). One hemizygous patient had all FDrelated ocular manifestations in both eyes. Conclusion: To our knowledge, this study is the first to describe the ocular manifestations of FD in the Turkish population. Although cornea verticillata is considered a hallmark of FD, it was absent in approximately one-third of patients. Moreover, cataract, another well-known feature of FD, was present in only 26.6% of the patients. Conjunctival vascular abnormality alone seems to be quite rare in FD, although it often accompanies other ocular manifestations. Therefore, recognition of other mild findings and special consideration of their associations may increase the diagnostic value of ocular findings in FD.

Effect of Cycloplegia on Anterior Segment Structures and Scleral Thickness in Emmetropic Eyes.

Purpose: To evaluate the effects of topical cyclopentolate hydrochloride-induced cycloplegia on anterior segment biomechanics in emmetropic eyes using anterior segment-optical coherence tomography (AS-OCT). Methods: Twenty-five emmetropic eyes of 25 volunteers were included. All underwent central corneal thickness (CCT) and anterior chamber depth (ACD) measurements. Anterior scleral thickness (AST) was measured at the level of the scleral spur (SS)(AST-0), 1,000 µm posterior of the SS (AST-1), and 2,000 µm posterior of the SS (AST-2) in the nasal and temporal quadrants using AS-OCT. All measurements were repeated after cycloplegia. Results: The mean age was 30.6 ± 12.4 (8-45) years. The mean CCT did not significantly change after cycloplegia (P = 0.7). The mean ACD was significantly increased [3.3 ± 0.2 (2.7-3.9) to 3.7 ± 0.3 (3-4.2) µm; P = 0.001]. In the nasal quadrant, the mean AST-1 and AST-2 were 512.3 ± 34.4 (433-570) and 529.6 ± 34.2 (449-599); decreased to 478 ± 26.8 (423-530) and 486.2 ± 28.3 (422-544) µm, respectively, after cycloplegia (P = 0.00; P = 0.00). In the temporal quadrant, the mean AST-1 and AST-2 were 522.5 ± 24.7 (473-578) and 527.2 ± 39.9 (450-604); decreased to 481.1 ± 33.7 (421-550) and 484.6 ± 26.6 (433-528) µm, respectively (P = 0.00; P = 0.00). There was no significant difference in AST-0 after cycloplegia in both quadrants [from 697.5 ± 46 (605-785) to 709.5 ± 64.7 (565-785) for nasal and from 718.4 ± 40.1 (632-796) to 722.9 ± 60.6 (596-838) for temporal; P = 0.2; P = 0.3, respectively]. Conclusion: After cycloplegia, there was a significant thinning of ASTs posterior to SS and a slight increase in AST in the SS level. ACD deepened after cycloplegia, and there was no significant change in CCT. Cycloplegic agents temporarily inhibit ciliary muscle contraction and may affect anterior segment parameters and sclera. Inhibition of forward-inward movement of the ciliary body by cycloplegia affects ASTs and ACD by causing a change in the mechanical force of the ciliary muscle on the sclera.

Evaluation of Limbal Stem Cell Transplant Success in Ocular Chemical Injury.

OBJECTIVES: We evaluated limbal stem cell transplant success in limbal stem cell deficiency due to chemical injury at a tertiary eye care center in Turkey with a novel system for describing limbal stem cell deficiency, as developed by the Limbal Stem Cell Working Group. MATERIALS AND METHODS: Medical records of 80 eyes of 80 patients after limbal stem cell transplant for limbal stem cell deficiency secondary to chemical injury were included, with patients grouped according to surgical procedure, ie, limbal autograft, limbal allograft, and cultivated limbal epithelial cell transplant. Surgical success was defined as improvement in postoperative year 1 of limbal stem cell deficiency stage. RESULTS: Patients' mean age was 37.9 ± 15.7 years (range, 4-71 years). Male/female ratio was 2.4. Forty-five patients (56.3%) were injured with alkaline substance, and 16 (20%) with acid substance. Mean follow-up time was 60.3 ± 30.6 months (range, 6-118.6 months). Limbal autograft, allograft, and cultivated limbal epithelial cell transplants were performed in 58 (72.5%), 12 (15%), and 10 (12.5%) eyes, respectively. Intervals between injury and surgery in limbal autograft, limbal allograft, and cultivated limbal epithelial cell transplants were 43.3 ± 94.1 months (range, 0.5-592 months), 14.5 ± 10.6 months (range, 2.4-32.5 months), and 122.8 ± 158.9 months (range, 21.1-504 months),respectively (P = .02); and surgical success rates in each group were 65.5%, 41.7%, and 90%, respectively (P = .03). Overall surgical success rate was 65%. CONCLUSIONS: Accurate determination of the limbal stem cell deficiency stage is crucial for proper evaluation of surgical success. Surgery type and interval between injury and surgery were the most important factors associated with higher surgical success rates. Despite the limited number of patients in the subgroups, the results were remarkable to emphasize the significance of a novel limbal stem cell deficiency scoring system.

Evaluation of the factors that influence surgical outcome in conjunctival-limbal allograft transplantation.

OBJECTIVE: To evaluate the surgical results and the variables affecting the outcomes in conjunctival-limbal allograft transplantation (CLAL). METHODS: Patients who underwent CLAL for limbal stem cell deficiency (LSCD) between 2007 and 2019 were included in the study. LSCD staging was performed according to the staging system developed by the 'Limbal Stem Cell Working Group'. Stage 1C and higher stage LSCD patients were included in the study. 'Successful surgical outcome' was defined as improvement in LSCD stage at 1 year postoperatively. RESULTS: A total of 19 eyes of 19 LSCD patients were included. The mean age of the patients was 40.21 ± 14.65 (6-65) years, and the male/female ratio was 12/7. CLAL was performed in 9 (47.3%) patients with Stage 2B, 9 (47.3%) patients with Stage 3 and 1 (5.4%) with Stage 1C. LSCD aetiology; chemical injury (12), vernal keratoconjunctivitis (2), aniridia (1), corneal degeneration (1), and unknown (3). Surgery was successful in 52.6% of cases. Surgical success was associated with lower LSCD stage (p = 0.04). Lower grades of chemical injury at presentation and a longer time interval between injury and CLAL were associated with higher surgical success (p = 0.001; p = 0.001). The mean postoperative follow-up time was 50.77 ± 29.46 (6-98) months. CONCLUSIONS: Despite graft rejection and long-term use of immunosuppressants, CLAL is still one of the most preferred techniques in the treatment of bilateral LSCD. Preoperative LSCD stage and degree of chemical burn are important factors affecting the surgical outcome. Also, CLAL surgery should not be rushed and should be performed when inflammation has subsided.

Clinical Approach to Ocular Cicatricial Pemphigoid.

Objectives: To evaluate the demographic data, ocular and systemic findings, clinical management, and outcomes of patients with ocular cicatricial pemphigoid (OCP). Materials and Methods: The medical records of 11 patients diagnosed as having OCP in the ophthalmology department of Ege University between 2008 and 2021 were evaluated retrospectively. Results: The patients' mean follow-up time was 14±5.76 months. All eyes (100%) had conjunctival involvement and 18 (81.81%) had corneal involvement. According to the Tauber staging system, 7 (31.81%), 8 (36.36%), and 7 (31.81%) of the eyes were stage 2, 3, and 4, respectively. The diagnosis was confirmed in 6 (66.66%) of 9 patients who underwent biopsy. Amniotic membrane transplantation was performed in 7 eyes, entropion surgery in 2 eyes, and electrocauterization for trichiasis in 5 eyes. Systemic involvement was observed in 45.45% (5/11) of patients, most commonly oral mucosal involvement (18.18%). Review of medical records showed that alkylating agents, steroids, and dapsone were used in patients treated before 2020. Mycophenolate mofetil was preferred to be used in combination with corticosteroids. Although treatment responses before mycophenolate mofetil usage could not be evaluated well because of loss to follow-up, 4 (66.66%) of 6 patients who received steroid treatment combined with mycophenolate mofetil showed partial or complete clinical remission. No serious side effects and drug withdrawal were observed. Conclusion: OCP is a sight-threatening autoimmune disease that affects older adults. Although positive biopsy results are valuable for diagnosis, negative results do not exclude the diagnosis. The main treatment is systemic immunosuppressives. Disease activity can be suppressed, especially with early initiation of drug therapy. These patients require a multidisciplinary approach. Especially in the presence of isolated ocular findings, ophthalmologists should be able to make the decision to start immunosuppressive treatment, and systemic treatment should not be delayed.

X-ray imaging of 30 year old wine grape wood reveals cumulative impacts of rootstocks on scion secondary growth and Ravaz index.

Annual rings from 30 year old vines in a California rootstock trial were measured to determine the effects of 15 different rootstocks on Chardonnay and Cabernet Sauvignon scions. Viticultural traits measuring vegetative growth, yield, berry quality, and nutrient uptake were collected at the beginning (1995 to 1999) and end (2017 to 2020) of the lifetime of a vineyard initially planted in 1991 and removed in 2021. X-ray Computed Tomography (CT) was used to measure ring widths in 103 vines. Ring width was modeled as a function of ring number using a negative exponential model. Early and late wood ring widths, cambium width, and scion trunk radius were correlated with 27 traits. Modeling of annual ring width shows that scions alter the width of the first rings but that rootstocks alter the decay of later rings, consistently shortening ring width throughout the lifetime of the vine. Ravaz index, juice pH, photosynthetic assimilation and transpiration rates, and instantaneous water use efficiency are correlated with scion trunk radius. Ultimately, our research indicates that rootstocks modulate secondary growth over years, altering physiology and agronomic traits. Rootstocks act in similar but distinct ways from climate to modulate ring width, which borrowing techniques from dendrochronology, can be used to monitor both genetic and environmental effects in woody perennial crop species.