Optimizing Genipin Concentration for Corneal Collagen Cross-Linking: An ex vivo Study.

PURPOSE: Studying genipin variable concentrations, treatment durations, and delivery methods as a substance to increase corneal stiffness by inducing corneal collagen cross-linking (CXL). MATERIALS AND METHODS: 100 bovine corneas treated with different genipin concentrations (0.1, 0.5, and 1%) and treatment durations (15 min, 40 min, 2 h, and 3 days) through different delivery methods compared to 10 controls treated with riboflavin/UV. Histology examination, enzymatic digestion with collagenase and thermal differential scanning calorimetry were performed on the different samples. RESULTS: Bovine corneas soaked in 0.5% genipin morphologically showed 4.7% CXL in comparison to 5.6% in controls (p < 0.05). Corneas treated with topical 0.5% genipin, by a 140-µL drop applied hourly for 2 h, showed 7% corneal CXL. Corneas treated with topical genipin 0.5% for 30 min, 1 and 2 h showed 54 ± 6, 40 ± 7, and 39 ± 9% enzymatic degradation, respectively, in comparison to controls (74%). Corneas treated with 0.5% genipin for 1, 2, and 8 h showed higher thermal denaturation resistance (Td values of 64.9 ± 0.3, 64.7 ± 0.0 and 67.3 ± 0.9), respectively, in comparison to the control group (64.6 ± 0.5) (p < 0.05). CONCLUSIONS: Genipin 0.5%, in a 140-µL drop applied hourly for 2 h, showed better potential to enhance corneal stiffness and stability through inducing CXL.

Prevalence of thrombophilic genetic factors among patients with retinitis pigmentosa.

PURPOSE: To determine the prevalence of thrombophilic factors in patients with retinitis pigmentosa (RP). METHODS: Fifty consecutive patients with RP and 50 controls matched by age and gender were tested for the presence of the following mutations: factor II (GA20210), factor V Leiden (GA1691), methylenetetrahydrofolate reductase (CT677), factor XIIIa (Val→Leu), ß-fibrinogen (GA455), tumor necrosis factor receptor (TNFRII) (M196R), plasminogen activator inhibitor-1 (PAI-1) (4 G/5 G), and plasminogen activator inhibitor-1 (PAI-1) (GA844). RESULTS: The following heterozygous mutations were found in patients/controls: factor V Leiden (12/14), factor XIIIa (20/30), methylenetetrahydrofolate reductase 677 TT (48/52), ß-fibrinogen GA455 (36/36), TNFRII (M196R) (40/42), PAI-1 4 G/5 G (40/48), and PAI-1 GA844 (50/52). The difference between patients with RP and the control group was not statistically significant for the prevalence of any of the studied factors (P > 0.05). CONCLUSION: In this study, thrombophilic mutations were not increased in patients with RP. Thrombophilic mutations do not seem to be risk factors for RP. Routine investigation of hereditary thrombophilia in these patients is not justified.

Intravitreal bevacizumab in the treatment of diabetic ocular neovascularization.

PURPOSE: To evaluate the efficacy of intravitreal bevacizumab for treating diabetic retinal and/or iris neovascularization. METHODS: Consecutive, prospective, interventional case series study of 60 eyes with diabetic retinal and/or iris neovascularization. Patients had a complete ocular examination before receiving 1.25 mg (0.05 mL) of intravitreal bevacizumab. Abnormal new vessels elsewhere in the retina, optic disk, or iris were graded by size and associated hemorrhage or glaucoma. Patients had complete postinjection ophthalmic evaluations with regrading of the abnormal new vessels at 3 months and 6 months. The main outcome measures included clinical partial or total regression of abnormal new vessels, changes in visual acuity, and complications related to the intravitreal injections. RESULTS: Twenty-six patients (47.3%) were men (mean age, 59 years). Abnormal new vessel regression at 6 months occurred in 65% of new vessels of the iris (P = 0.001), 45% of new vessels of the optic disk (P = 0.009), and 43% of new vessels elsewhere (P = 0.008). The visual acuity improved in 20% of eyes, which was not significant (P = 0.235); the visual acuity deteriorated in 23% of eyes (P = 0.163). No systemic or ocular side effects developed except for postinjection hypotony in one eye. CONCLUSION: Intravitreal bevacizumab is a well-tolerated medication that causes regression of abnormal diabetic neovascularization. New vessels of the iris responded more than new vessels of the optic disk and new vessels elsewhere.

Indications and outcomes of pediatric penetrating keratoplasty: A retrospective observational study.

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.

Worldwide inequality in access to full text scientific articles: the example of ophthalmology.

BACKGROUND: The problem of access to medical information, particularly in low-income countries, has been under discussion for many years. Although a number of developments have occurred in the last decade (e.g., the open access (OA) movement and the website Sci-Hub), everyone agrees that these difficulties still persist very widely, mainly due to the fact that paywalls still limit access to approximately 75% of scholarly documents. In this study, we compare the accessibility of recent full text articles in the field of ophthalmology in 27 established institutions located worldwide. METHODS: A total of 200 references from articles were retrieved using the PubMed database. Each article was individually checked for OA. Full texts of non-OA (i.e., "paywalled articles") were examined to determine whether they were available using institutional and Hinari access in each institution studied, using "alternative ways" (i.e., PubMed Central, ResearchGate, Google Scholar, and Online Reprint Request), and using the website Sci-Hub. RESULTS: The number of full texts of "paywalled articles" available using institutional and Hinari access showed strong heterogeneity, scattered between 0% full texts to 94.8% (mean = 46.8%; SD = 31.5; median = 51.3%). We found that complementary use of "alternative ways" and Sci-Hub leads to 95.5% of full text "paywalled articles," and also divides by 14 the average extra costs needed to obtain all full texts on publishers' websites using pay-per-view. CONCLUSIONS: The scant number of available full text "paywalled articles" in most institutions studied encourages researchers in the field of ophthalmology to use Sci-Hub to search for scientific information. The scientific community and decision-makers must unite and strengthen their efforts to find solutions to improve access to scientific literature worldwide and avoid an implosion of the scientific publishing model. This study is not an endorsement for using Sci-Hub. The authors, their institutions, and publishers accept no responsibility on behalf of readers.

Corneal Stability following Hyperopic LASIK with Advanced Laser Ablation Profiles Analyzed by a Light Propagation Study.

PURPOSE: To assess anterior corneal surface stability 12 months following hyperopic LASIK correction with a light propagation algorithm. SETTING: Vissum Instituto Oftalmológico de Alicante, Universidad Miguel Hernández, Alicante, Spain. METHODS: This retrospective consecutive observational study includes 37 eyes of 37 patients treated with 6th-generation excimer laser platform (Schwind Amaris). Hyperopic LASIK was performed in all of them by the same surgeon (JLA) and completed 12-month follow-up. Corneal topography was analyzed with a light propagation algorithm, to assess the stability of the corneal outcomes along one year of follow-up. RESULTS: Between three and twelve months postoperatively, an objective corneal power (OCP) regression of 0.39 D and 0.41 D was found for 6 mm and 9 mm central corneal zone, respectively. Subjective outcomes at the end of the follow-up period were as follows: 65% of eyes had spherical equivalent within ±0.50 D. 70% of eyes had an uncorrected distance visual acuity 20/20 or better. 86% of eyes had the same or better corrected distance visual acuity. In terms of stability, 0.14 D of regression was found. No statistically significant differences were found for all the study parameters evaluated at different postoperative moments over the 12-month period. CONCLUSIONS: Light propagation analysis confirms corneal surface stability following modern hyperopic LASIK with a 6th-generation excimer laser technology over a 12-month period.

Endophthalmitis Following Pediatric Cataract Surgery: An International Pediatric Ophthalmology and Strabismus Council Global Perspective.

PURPOSE: To compile international data on the risk factors, diagnosis, and treatment of endophthalmitis following pediatric cataract surgery. METHODS: An e-mail containing a link to an online survey was sent to all members of the American Association for Pediatric Ophthalmology and Strabismus. The questionnaire examined the incidence, risk factors, treatment, outcomes, and prophylaxis of endophthalmitis following pediatric cataract surgery around the world. RESULTS: Two hundred thirty-seven ophthalmologists answered the questionnaire. Eight ophthalmologists (3.4%) encountered 22 cases of endophthalmitis following pediatric cataract surgery during their practice. Most patients with endophthalmitis following pediatric cataract surgery were 2 to 4 years of age (36.4%). An intraocular lens was implanted in 59.1% of cases, most of which were acrylic intraocular lenses (53.8%). The main presenting symptoms were photophobia (50%) and pain (40.9%). The most common signs were conjunctival injection (36.4%) and hypopyon (31.8%). The final visual acuity was counting fingers or worse in 86% of cases. The most common cultured organism was Staphylococcus aureus (31.8%). The most common management of endophthalmitis following pediatric cataract surgery was a combination of intravitreal, systemic, and topical antibiotics (36.4%). Most ophthalmologists (68.2%) administered prophylactic intracameral antibiotic treatment during surgery and 50% used vancomycin. CONCLUSIONS: Endophthalmitis following pediatric cataract surgery is an uncommon, multifactorial complication with poor visual prognosis. Efforts directed at minimizing its risk, such as treating potential predisposing systemic conditions, improving sterilization techniques, optimizing operative conditions to reduce complications and surgery duration, and using subconjunctival and intracameral antibiotics, decrease its incidence. Early postoperative evaluation, subsequent follow-up visits, and keeping a high index of suspicion should facilitate the recognition of endophthalmitis following pediatric cataract surgery to avoid delaying treatment. [J Pediatr Ophthalmol Strabismus. 2018;55(1):23-29.].

KeraRing intrastromal corneal ring segments for correction of keratoconus.

PURPOSE: Intrastromal corneal ring segments (ICRSs) are small arc-like implants that are being used increasingly as a minimally invasive treatment for patients with keratoconus. This study assessed the effectiveness of KeraRing implants, a type of ICRS, to treat keratoconus. METHODS: Retrospective case series descriptive study of 43 patients (55 eyes) with keratoconus who underwent KeraRing implantation from February 2008 to June 2009. Patients who had intraoperative or postoperative complications and/or did not complete at least 6 months of follow-up were excluded. All patients underwent complete ophthalmologic examinations that included measurement of the uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), manifest refraction, and keratometry before and 2 days, 2 weeks, 1 month, and 3 and 6 months after surgery. The ring segments were chosen based on a nomogram from the manufacturer. RESULTS: Six months postoperatively, the mean UCVA increased significantly (P < 0.05) from 0.10 ± 0.11 to 0.32 ± 0.25 and the mean BSCVA increased from 0.36 ± 0.23 to 0.57 ± 0.24 (P < 0.05). The mean spherical refractive error significantly (P < 0.05) improved from -4.85 ± 2.90 diopters (D) to -1.89 ± 2.68 D, and the mean cylindrical refractive error significantly (P < 0.05) improved from -3.65 ± 1.70 D to -2.60 ± 1.62 D. The mean spherical equivalent significantly (P < 0.05) decreased from -6.68 ± 2.93 D to -3.19 ± 2.75 D, and the mean keratometry value decreased from 51.83 ± 4.14 D to 47.27 ± 3.68 D. The improvement in the UCVA and BSCVA continued over the 6-month postoperative period, but significant changes occurred only during the first 3 months. These changes occurred in patients with all grades of keratoconus. CONCLUSIONS: KeraRing implantation provided significant improvement in visual acuity, spherical equivalent, and keratometry results. This ICRS is an effective treatment for managing keratoconus and might delay or even avoid the need for penetrating keratoplasty.

Ferrara ring segments implantation for treating keratoconus.

AIM: To investigate the efficacy of Ferrara rings (FR) implantation in the treatment of keratoconus. METHODS: It was a retrospective case series descriptive study. The sample was comprised of 50 patients 79 eyes diagnosed with progressive keratoconus. This included 24 (48%) males and 26 (52%) females between the age of 13 and 44 years. All participants underwent surgical implantation of FR in the period between January 2009 and September 2010 at Jordan University Hospital. Thorough ophthalmologic examinations were applied to measure vital variables for each pathological condition before and after surgery. RESULTS: Findings indicated an overall significant postoperative improvement in both uncorrected visual acuity (UCVA) and best spectacle corrected visual acuity (BSCVA) throughout follow up visits. Moreover, results illustrated a significant decrease in spherical equivalent (SE) and keratometric readings (lower, higher and the average). CONCLUSION: Surgical intervention strategies are being frequently developed to meet the needs of patients with keratoconus. The implantation of Ferrara rings has proven to be a safe and feasible alternative procedure for the treatment of mild-moderate keratoconus especially for patients with contact lenses intolerance. We have found that this procedure has improved visual outcomes in all eyes studied. Nevertheless, further research is needed to investigate long term outcomes.