Medical Hypothesis, Discovery, and Innovation in Ophthalmology最新文献

Background: In patients with type 2 diabetes mellitus, the development of diabetic retinopathy (DR) correlates positively with elevated serum chemerin levels. This study was aimed at investigating the probable association between the serum chemerin level and the development of DR in patients with type 1 diabetes mellitus (T1DM).

Methods: In this cross-sectional study, we included Egyptians and classified them into four groups: group 1, including healthy individuals; group 2, including patients with T1DM without DR; group 3, including patients with T1DM with non-proliferative DR (NPDR); and group 4, including patients with T1DM with proliferative DR (PDR). The assessment included best-corrected distance visual acuity assessment, slit-lamp biomicroscopy, funduscopy, fundus fluorescein angiography, and macular ocular coherence tomography. Fasting blood samples were obtained from all participants to measure serum chemerin, glycated hemoglobin (HbA1c), total cholesterol, triglyceride, and creatinine levels. Serum chemerin levels were compared among the groups, and their correlations with age, duration of diabetes, HbA1c, total cholesterol, triglyceride, and creatinine levels were analyzed.

Results: We recruited 209 participants, including 46 healthy individuals in group 1, 52 patients (T1DM and no DR) in group 2, 61 patients (T1DM and NPDR) in group 3, and 50 patients (T1DM and PDR) in group 4, with comparable mean ages and sex ratios among groups. The diabetes duration, body mass index, HbA1c, total cholesterol, triglyceride, and serum chemerin levels differed significantly among the groups (all P < 0.001), whereas the creatinine level did not (P > 0.05). The serum chemerin level was significantly higher in group 4 than in groups 3 and 2, in group 3 than in group 2, and in groups 3 and 4 than in group 1 (all P < 0.001). However, it was comparable between groups 1 and 2 (P > 0.05). It correlated with the duration of T1DM and HbA1c, total cholesterol, triglyceride, and creatinine levels but not with age.

Conclusions: Patients with T1DM with DR showed higher serum chemerin levels than those with T1DM without DR or healthy individuals. Serum chemerin levels were higher in those with PDR than in those with NPDR. Thus, serum chemerin levels are a potential biomarker of the development and severity of DR in patients with T1DM. Nevertheless, future diagnostic accuracy studies are required to confirm these potential applications.

Background: Pediatric corneal transplantation can be indicated in congenital and acquired conditions. Challenges include preoperative evaluation, multiple intraoperative obstacles, and postoperative problems in follow-up and management. This study was aimed at identifying the indications and clinical outcomes of pediatric penetrating keratoplasty (PKP) in Jordan.

Methods: This retrospective cohort study was conducted in Amman, Jordan. Using the hospital's electronic database, all medical records of patients aged < 18 years who underwent PKP between January 2004 and October 2019 were reviewed. Preoperative evaluations included best-corrected distance visual acuity (BCDVA) and anterior and posterior segment examinations. Postoperative complications, BCDVA, and graft survival were examined 1 year postoperatively.

Results: A total of 149 cases of pediatric PKP were performed on 141 eyes of 118 patients with an age mean ± standard deviation (SD) of 11.44 ± 4.97 years at the time of surgery. Acquired non-traumatic corneal pathologies accounted for 65.8% of indications for PKP. The most frequent indication was advanced keratoconus (55.7%). Preoperative and 1-year postoperative BCDVAs significantly differed (P < 0.001), with 111 (74.5%) patients showing improved BCDVA, 12 (8.05%) patients showing worsened BCDVA, and 26 (17.45%) patients showing no change in BCDVA. The overall 1-year graft survival rate was 80.54%.

Conclusions: This was the largest study in Jordan involving pediatric patients who underwent PKP for various indications, showing a significant improvement in BCDVA, with a high survival rate at 1 year. Future studies with longer follow-up periods could provide stronger evidence for surgical outcomes and graft survival. Further, the option of lamellar keratoplasty in the pediatric age group should be assessed.

Background: Vascular endothelial growth factor (VEGF) is a significant modulator of ocular angiogenesis, including that of neovascular age-related macular degeneration (nAMD). Intravitreal injection of anti-VEGF is the benchmark treatment for most retinal vascular diseases, including nAMD, diabetic maculopathy, and macular edema secondary to retinal venous occlusion. Anti-VEGF treatment is a high-frequency, time-consuming, non-cost-effective therapy, especially in countries and regions with limited resources. This treatment is easily restricted, and in practice, maintaining long-term periodic care is challenging for patients.

Hypothesis: Light peripheral panretinal photocoagulation (PPRP) is applied in a mild form (barely visible mild light gray mark) anterior to the equator so as not to jeopardize the visual field. PPRP lessens the ischemia that causes neovascularization and decreases the metabolic demand in the peripheral retina. PPRP reduces serum angiopoietin-2 and VEGF levels in patients with type 2 diabetes mellitus with proliferative diabetic retinopathy. We propose using light PPRP to suppress VEGF secretion, aiming to attenuate the VEGF drive and halt choroidal neovascular growth in eyes with nAMD. Our regimen is based on two concepts: first, nAMD is a diffuse or generalized disease that affects the posterior segment; and second, PPRP is very effective in regressing diabetic retinopathy. PPRP has reportedly been successful in cases of macular edema (diabetic or following venous occlusion) resistant to VEGF antagonists. Light PPRP may be used as prophylaxis, adjunctive treatment, or monotherapy in nAMD when intravitreal injections of VEGF antagonists are not feasible.

Conclusions: The established light PPRP therapy could be promising as a one-time, cost-effective therapy or prophylaxis in patients with nAMD or at high risk. This proposed modality could be suitable for patients who have injection phobia or prefer a one-time affordable therapy to the long-term monthly visits to retinologists. Future trials are necessary to verify the safety and efficacy of this proposed treatment modality in selected patients with nAMD.

Background: Neovascular age-related macular degeneration (nAMD) is one of the main causes of blindness in developed countries. Complement factor H (CFH) is one of the genes involved in the pathogenesis of nAMD. This study investigated the rs10737680 polymorphism in CFH and its conferred susceptibility to nAMD in Yogyakarta, Indonesia.

Methods: This case-control hospital-based study recruited participants consisting of 96 patients with nAMD and 101 controls without nAMD from the Eye Polyclinic of Sardjito Hospital, YAP Eye Hospital, and Hardjolukito Hospital Yogyakarta. nAMD was diagnosed when fundus examination, fundus photographs, and optical coherence tomography revealed hard or soft drusen in the macular area measuring > 63 µm that appeared below the retinal pigment epithelium, with or without macular hypo- or hyperpigmentation, and was accompanied by choroidal neovascularization. Genomic DNA was extracted using a commercial DNA isolation kit. The restriction fragment length polymorphism technique was used to identify the rs10737680 polymorphism in CFH.

Results: The mean (standard deviation [SD]) age of the nAMD group was not homogeneous with that of the control group (P < 0.05); 65.41 (9.74) years versus 68.24 (7.82) years. The number of patients with hypertension in the nAMD group was significantly higher than in the control group (P < 0.05). In the nAMD group, the genotype distribution indicated homozygous risk allele in 34.38%, heterozygous risk allele in 57.29%, and homozygous non-risk allele in 8.33%. In the control group, the genotype distribution indicated homozygous risk allele in 21.78%, heterozygous risk allele in 36.63%, and homozygous non-risk allele in 41.58%. Statistical analysis between the two study groups according to homozygous risk allele genotype (odds ratio [OR], 7.87; 95% confidence interval [CI], 2.88-22.79) and heterozygous genotype (OR, 7.80; 95% CI, 3.11-21.19) showed a significant difference (both P < 0.01).

Conclusions: Homozygous risk allele was less frequent than heterogeneous risk allele in patients with nAMD; however, both increased the risk for nAMD. Although the homozygous or heterozygous risk-alleles were detected in most patients, yet other important genetic or environmental factors could be involved in the pathogenesis of nAMD. Overall, we found a significant association between rs10737680 polymorphism in CFH and the susceptibility to nAMD in Yogyakarta, Indonesia; however, future studies are needed to fully delineate the mechanism.

Background: Proliferative diabetic retinopathy (PDR) is a serious sight-threatening disease, and half of the patients with high-risk PDR can develop legal blindness within 5 years, if left untreated. This study was aimed at comparing panretinal photocoagulation (PRP) and intravitreal ranibizumab injections in terms of radial peripapillary capillary (RPC) density on optical coherence tomography angiography (OCTA) in patients with treatment-naive PDR.

Methods: This open-label, prospective, randomized clinical trial included 50 patients with treatment-naive PDR with optic disc neovascularization and randomized them into two groups: group 1, with patients undergoing two sessions of PRP 2 weeks apart, and group 2, with patients received three intravitreal ranibizumab injections (0.5 mg) 1 month apart for 3 consecutive months. Patients underwent a full ophthalmological examination, including best-corrected distance visual acuity (BCDVA) measurement in the logarithm of minimal angle of resolution (logMAR) notation and OCTA before intervention and monthly after the last laser session or the first intravitreal ranibizumab injection for 3 months of follow-up. Visual field (VF) was tested at the beginning and end of 3 months.

Results: Forty-two (84%) eyes completed the 3-month follow-up, including 22 eyes in the PRP group (88%) and 20 (80%) eyes in the ranibizumab group. The two groups were comparable in terms of demographic characteristics, diabetes duration, baseline BCDVA, glycated hemoglobin level, OCTA parameters, VF indices, and intraocular pressure (all P > 0.05). The RPC density change from baseline to the 3-month follow-up was significantly lower in the PRP group than in the ranibizumab group (mean difference in RPC density change: - 3.61%; 95% confidence interval: - 5.57% to - 1.60%; P = 0.001). The median (interquartile range) logMAR change from baseline to the 3-month follow-up (0.0 [0.2]) was significantly higher in the PRP group than in the ranibizumab group (- 0.15 [0.3]; P < 0.05). The median changes in central foveal thickness from baseline to the 3-month follow-up differed significantly between the two groups (P = 0.001).

Conclusions: In eyes with PDR and neovascularization of the disc RPC density on OCTA increased in the ranibizumab group and decreased in the PRP group. Visual acuity gain was higher in the ranibizumab group than in the PRP group. Future multicenter trials addressing our limitations are required to verify the findings of this study.

Background: The effectiveness of internal limiting membrane (ILM) peeling in the surgical treatment of tractional diabetic macular edema (DME), although widely examined, remains controversial. This study aimed to assess the efficacy of pars plana vitrectomy (PPV) in the management of tractional DME and to highlight any benefits of additional ILM peeling.

Methods: This was an open-label, prospective, comparative, and interventional study that enrolled 50 eyes with tractional DME that underwent PPV and allocated each to one of two groups: group A consisted of 25 eyes that had no ILM peeling and group B consisted of 25 eyes that underwent ILM peeling. Postoperative assessments of best-corrected distance visual acuity (BCDVA) in the logarithm of minimal angle of resolution (logMAR) notation and central macular thickness (CMT) were performed at 1, 3, and 6 months postoperatively.

Results: At baseline, the two groups were comparable in terms of sex ratios, phakic status, insulin use, coexistence of hypertension, and mean (standard deviation [SD]) age, BCDVA, CMT, duration of diabetes mellitus, and glycosylated hemoglobin (HbA1c) levels. In group A, the mean (SD) BCDVA improved significantly from 0.89 (0.12) logMAR preoperatively to 0.64 (0.24) logMAR (P < 0.001), and the mean (SD) CMT declined significantly from 471.28 (80.83) µm to 228.20 (26.45) µm (P < 0.001), at the 6-month postoperative assessment. Likewise, in group B, the mean (SD) BCDVA improved significantly from 0.83 (0.10) logMAR preoperatively to 0.58 (0.24) logMAR (P < 0.001), and the mean (SD) CMT decreased significantly from 496.84 (89.82) µm to 226.20 (18.04) µm (P < 0.001), after 6 months. There were no significant differences between groups A and B in the changes in BCDVA (Delta BCDVA) or CMT (Delta CMT) at 1, 3, and 6 months postoperatively with respect to the baseline values (all P > 0.05). Postoperative complications were comparable between the two groups. A significant negative correlation was detected between the preoperative HbA1c level and BCDVA improvement in all participants (r = - 0.82; P < 0.001).

Conclusions: PPV is an effective treatment for tractional DME. Additional ILM peeling was not significantly associated with functional and anatomical benefits over a short period. Long-term glycemic control plays a role in vision gain after vitrectomy in patients with diabetes. Further long-term studies are required to verify our findings.

Background: Magnetic resonance imaging (MRI) has been used to investigate eye shapes; however, reports involving children are scarce. This study aimed to determine ocular dimensions, and their correlations with refractive error, using three-dimensional MRI in emmetropic versus myopic children.

Methods: Healthy school children aged < 10 years were invited to take part in this cross-sectional study. Refraction and best-corrected distance visual acuity (BCDVA) were determined using cycloplegic refraction and a logarithm of the minimum angle of resolution (logMAR) chart, respectively. All children underwent MRI using a 3-Tesla whole-body scanner. Quantitative eyeball measurements included the longitudinal axial length (LAL), horizontal width (HW), and vertical height (VH) along the cardinal axes. Correlation analysis was used to determine the association between the level of refractive error and the eyeball dimensions.

Results: A total of 70 eyes from 70 children (35 male, 35 female) with a mean (standard deviation [SD]) age of 8.38 (0.49) years were included and analyzed. Mean (SD) refraction (spherical equivalent, SEQ) and BCDVA were -2.55 (1.45) D and -0.01 (0.06) logMAR, respectively. Ocular dimensions were greater in myopes than in emmetropes (all P < 0.05), with no significant differences according to sex. Mean (SD) ocular dimensions were LAL 24.07 (0.91) mm, HW 23.41 (0.82) mm, and VH 23.70 (0.88) mm for myopes, and LAL 22.69 (0.55) mm, HW 22.65 (0.63) mm, and VH 22.94 (0.69) mm for emmetropes. Significant correlations were noted between SEQ and ocular dimensions, with a greater change in LAL (0.46 mm/D, P < 0.001) than in VH (0.27 mm/D, P < 0.001) and HW (0.22 mm/D, P = 0.001).

Conclusions: Myopic eyeballs are larger than those with emmetropia. The eyeball elongates as myopia increases, with the greatest change in LAL, the least in HW, and an intermediate change in VH. These changes manifest in both sexes at a young age and low level of myopia. These data may serve as a reference for monitoring the development of refractive error in young Malaysian children of Chinese origin.

Background: Proliferative vitreoretinopathy (PVR) is the leading cause of recurrent retinal detachment after surgical repair of rhegmatogenous retinal detachment (RRD). Our study aimed to assess the efficacy and safety of intravitreal methotrexate infusion (IMI) for the prevention of PVR after pars plana vitrectomy (PPV) in eyes with RRD.

Methods: This prospective comparative interventional study was conducted from September 2020 to November 2021 at Ain Shams University Hospitals, Egypt. We recruited a consecutive, non-randomized sample of 47 eyes of 47 patients with RRD undergoing PPV. Participants were allocated to a control group or an intervention group that received IMI during surgery. Each group was subdivided into subgroups of eyes at high-risk of developing PVR and eyes with established preoperative PVR grade C. Outcome measures at the 3-month postoperative follow-up were the rate of retinal attachment, incidence of PVR, reoperation rate to flatten the retina, and changes in the retina and/or optic nerve function as assessed by full-field electroretinogram and flash visual evoked potential.

Results: Data from 47 eyes (23 and 24 eyes in the intervention and control groups, respectively) were evaluated. Subgroups IA, IB, and IIB each included 12 eyes, subgroup IIA included 11 eyes, and all subgroups had comparable sex ratios and age distributions. Postoperative PVR at 1 month and between 1 and 3 months was present in 13% and 4% of eyes in the intervention group, respectively. Reoperation to flatten the retina was required in 2 (9%) eyes in the intervention group, while 22 eyes (96%) had complete flattening of the retina at 3 months. No significant differences were found between the study groups and the corresponding subgroups regarding the outcome measures (all P > 0.05). No adverse events attributable to IMI were detected up to 3 months postoperatively.

Conclusions: Although IMI was safe for intraocular use in eyes with RRD and PVR grade C or a high risk of developing PVR, it did not affect the anatomical success rate or development of PVR up to 3 months after PPV. Further multicenter randomized clinical trials with longer follow-up periods and larger sample sizes are needed to verify these preliminary outcomes.

Background: Vernal keratoconjunctivitis (VKC) is a bilateral, recurrent, chronic conjunctival inflammatory disease with seasonal exacerbations. This study aimed to assess the efficacy and safety of tacrolimus 0.03% eye ointment in the management of chronic VKC.

Methods: This was an open-label, prospective, non-randomized, comparative interventional study that enrolled 50 patients with chronic VKC, who were allocated to one of two groups. The first group was treated with tacrolimus 0.03% eye ointment twice daily for 2 months then once daily for 2 months, followed by once every other day for another 2 months. The control group was treated with standard anti-allergic drugs, topical fluorometholone 0.1% eye drops three times daily for 2 weeks and gradually tapered for another 2 weeks, with topical olopatadine 0.1% administered twice daily during the follow-up period. Disease severity was assessed using a four-point scale for symptoms and signs. Treatment efficacy was assessed by analyzing changes in symptoms and signs, and by clinical photography.

Results: Fifty patients with bilateral chronic VKC completed the follow-up. The mean (standard deviation) ages of the tacrolimus and control groups were comparable (16.20 [5.10] years versus 16.48 [4.19] years, P > 0.05). The most commonly reported symptom was itching, and the most common signs were papillary hypertrophy and conjunctival hyperemia. All symptoms and signs were significantly reduced after treatment in both groups. The tacrolimus group showed a more significant improvement at 3 and 6 months in the mean composite symptom score (both P < 0.05) and in the mean composite sign score (both P < 0.05). Regarding complications, one case of increased intraocular pressure occurred in the control group (4%) after 2 weeks of steroid treatment, while there were no complications in the tacrolimus group, except for some reports of stinging sensation, which was well tolerated.

Conclusions: Treatment of chronic bilateral VKC with tacrolimus 0.03% eye ointment is effective and safe. It could be considered an alternative treatment to reduce steroid-associated complications in patients with chronic VKC. Future double-blinded clinical trials with a longer follow-up period are necessary to confirm our findings and to determine the long-term safety of topical tacrolimus 0.03% ointment in VKC.