EDTA chelation for calcific band keratopathy: results and long-term follow-up

Modified Transepithelial Phototherapeutic Keratectomy for Band Keratopathy

Objectives: To report the outcomes of novel modified transepithelial phototherapeutic keratectomy (PTK) in treating band keratopathy (BK). Methods: A retrospective analysis was performed on patients who underwent PTK for BK at the Sussex Eye Laser Clinic, Nuffield Health, Brighton. Patients with BK obscuring the visual axis, affecting visual acuity, or causing discomfort were considered for PTK. All the patients underwent preoperative evaluation, including preoperative corneal topography and optical coherence tomography. Modified transepithelial PTK was performed without using EDTA for chelation or alcohol for epithelium debridement. Patients were followed up for one week and then every two weeks after that until two months. Preoperative and postoperative best corrected visual acuities (BCVA) were compared using a paired t-test. Results: We studied 15 eyes of nine patients undergoing novel PTK for BK. The mean age was 80 ± 5.73 years. The mean pre-treatment visual acuity was 0.68 ± 0.17 logMAR (range: 0.6 logMAR to 1 logMAR) and improved to 0.22 ± 0.09 logMAR (p < 0.05), ranging from 0.18 to 0.48 logMAR at two months following PTK. None of the patients complained of ocular discomfort following the procedure. A repeat procedure was not required for any of these patients. Conclusions: Modified transepithelial PTK is an effective procedure for improving visual outcomes in patients with band keratopathy and should be considered for the treatment of band keratopathy.

A genetic investigation in five Chinese families with keratoconus

Background

This study investigated the genetic characteristics of five Chinese families with keratoconus (KC).

Methods

In the five families affected by KC, medical records, clinical observations, and blood samples were collected from all individuals. All KC family members (n = 20) underwent both whole exome sequencing of genomic DNA and Sanger sequencing to confirm the variants. Online software was utilized to analyze all variants, and the online server I-TASSER was employed for in silico predictions of the three-dimensional protein structures of the variants. The newly discovered variants and single nucleotide polymorphisms were further examined in 322 sporadic KC patients.

Results

The Pentacam tomographic composite index in those affected first-degree family members of the probands showed a pathological change. Five new variants were detected in the five probands and other affected members in their families: a heterozygous missense variant g.19043832C>T (p.Ser145Asn) in the homer scaffolding protein 3 (HOMER3) gene; a heterozygous missense variant g.99452113G>A (p.Gly483Arg) in the insulin-like growth factor 1 receptor (IGF1R) gene; a heterozygous missense variant g.55118280G>T (p.Trp843Leu) in the echinoderm microtubule-associated protein like 6 (EML6) gene; a heterozygous frameshift variant c. 1226_1227del (p.Gln410Glufs*17) in the DOP1 leucine zipper-like protein B (DOP1B) gene; and a heterozygous splice-site variant c.7776+2T>A in the neurobeachin-like protein 2 (NBEAL2) gene. These variations were predicted to be potentially pathogenic and associated with KC.

Conclusion

Five novel variants in HOMER3, IGF1R, EML6, DOP1B, and NBEAL2 genes were identified in this study and may be associated with the pathogenesis of KC. This study provides new information about the gene variants and their protein changes in KC patients. The findings should be explored further and could potentially be applied to the early diagnosis of KC before clinical onset.

Partial incision blunt scissors lamellar keratectomy under topical anesthesia for the treatment of presumed calcific corneal degeneration in dogs

OBJECTIVE

The aim of the study was to investigate clinical features of lamellar keratectomy for presumed calcific corneal degeneration in a population of geriatric dogs using blunt scissors dissection under topical anesthesia.

ANIMALS STUDIED AND PROCEDURES

Retrospective analysis of dogs with clinically diagnosed calcific degeneration treated by keratectomy under topical anesthesia between 2015 and 2021 at two veterinary ophthalmology practices was performed. Descriptive data regarding signalment, concurrent systemic and ocular disease, complications, healing time, and recurrence were collected. Kaplan-Meier survival analysis was performed to calculate 1-year recurrence probability.

RESULTS

Sixty-five eyes in 57 dogs met inclusion criteria. All 54 eyes with follow-up healed within a median of 14 days (7-74), including 17 with complicating factors of infection or deep stromal ulceration. Globe rupture occurred intraoperatively in three eyes (4.6%), for which subsequent conjunctival graft was performed. Calculated 1-year recurrence probability from 47 eyes followed long term was 25%. Multivariate Cox proportional hazard modeling showed a significant association between documented systemic disease and time to recurrence (p = .035), irrespective of topical EDTA use (p = .432). Median follow-up time available for all cases was 249 days.

CONCLUSIONS

Blunt lamellar dissection with corneal scissors can be performed in dogs under topical anesthesia, yielding healing times and recurrence comparable to previously reported treatments for calcific corneal degeneration. Globe rupture is an inherent risk of both the disease and procedure and occurred in 4.6% of treated eyes. This approach expands non-anesthetic treatment options for affected patients but should only be performed with advanced microsurgical training and client counseling on individual risk and benefit.

Diamond burr debridement of calcific band keratopathy in 24 eyes of 22 horses

PURPOSE

To evaluate the safety and effectiveness of diamond burr debridement (DBD) for the treatment of calcific band keratopathy (CBK) in horses.

METHODS

Medical records from horses with CBK were reviewed over a period of 4 years. Diagnosis of CBK was based on slit-lamp examination findings, and DBD was performed on standing sedated horses. Follow-up was obtained by clinical reevaluation of the treated eyes or a telephone survey with the referring veterinarian.

RESULTS

Twenty-two horses of different ages (median: 11 years; range: 5-23) representing 24 CBK-affected eyes (14 left eyes and 10 right eyes) were included in the study. The patients had a medical history of chronic and recurrent uveitis, which required repeated long-term treatments with various combinations of ophthalmic corticosteroids. DBD alone cleared the cornea in 22 affected eyes (92%), but it was combined with blade scraping in two cases with thick calcium plaques. The postoperative medication included a topical antibiotic, atropine drops, and oral flunixin meglumine. Corneal healing was achieved in 21 eyes (87%), 5-21 days (median time 13 days) postoperatively. The three remaining horses were lost to follow-up. Recurrence occurred in 5 of the 21 (24%) reexamined eyes, 3-12.5 weeks (median 8 weeks) postoperatively, and required a second DBD. Four of the 21 eyes ended up being enucleated due to sequelae of uveitis. The main limitations of the study include those inherent to all retrospective clinical data collections.

CONCLUSION

Mechanical DBD can readily and safely clear the cornea in horses with CBK, but recurrence of calcium deposition is possible.

Dissolution of presumed calcareous corneal degeneration with 13.8% ethylenediaminetetraacetic acid solution in 17 dogs

PURPOSE

To describe a novel treatment for dissolving calcareous corneal degeneration (CCD)-associated mineral in 17 dogs with 13.8% ethylenediaminetetraacetic acid (EDTA) solution.

METHODS

Cases seen between 2021 and 2023 were reviewed. Seventeen dogs with CCD associated with corneal ulcerations were treated with a mineral dissolution procedure using 13.8% EDTA solution. A diamond burr keratotomy (DBK) was subsequently performed in some cases when residual mineralization remained present.

RESULTS

Of the 19 eyes (17 dogs) included in the study, 10 eyes (8 dogs) required a DBK procedure. One eye (one dog) required a repeat procedure 26 weeks following the initial procedure and two eyes (one dog) required a repeat procedure 24 and 37 weeks following initial treatment in the left and right eye, respectively. Mean follow-up time to last recheck for eyes not requiring a second chelation procedure was 20.4 weeks (range, 10-47 weeks). At the last follow-up examination for all 17 dogs, the CCD resolved in 26.3%, improved in 57.9%, and recurred in 15.8% of eyes. Complications occurred in two eyes (two dogs) and included an infected stromal ulcer at 2-week recheck and the creation of a 40% depth stromal defect immediately following debridement. Both complications were successfully addressed with medical management.

CONCLUSIONS

The utilization of 13.8% EDTA solution appears to be an effective and safe means of treating lesions associated with CCD.

Familial primary calcific band-shaped keratopathy with late onset systemic disease: a case series and review of the literature

BACKGROUND

Familial calcific band-shaped keratopathy (BSK) is a very rare disease, with no underlying cause. There is no underlying disease in this form of the disease. This article introduces a family with seven children, three of whom were diagnosed with familial primary calcific BSK. One of them developed a systemic disease 38 years after ocular manifestation.

CASE PRESENTATION

In this case report, three Iranian siblings from a family with familial calcific band-shaped keratopathy (BSK) are introduced. Systemic and ocular examinations performed on these patients indicated the occurrence of chronic kidney disease in the older child, a 41-year-old woman, 38 years after ocular manifestation. The examinations conducted on the other two siblings revealed no pathological findings. The 41-year-old sister and 37-year-old brother underwent unilateral deep anterior lamellar keratoplasty (DALK), while the 33-year-old sister underwent bilateral superficial keratectomy (SK).

CONCLUSION

Considering the late onset of systemic disease in one of the siblings diagnosed with familial calcific band-shaped keratopathy (BSK), it is crucial to emphasize the necessity of long-term follow-up for these patients and their families.

Comparative Analysis of Alternative Calcium Chelators for the Treatment of Calcific Band Keratopathy

PURPOSE

In this study, we compared clinically relevant biochemical properties of each chelator for pH, osmolarity, and calcium chelation potential.

METHODS

In total, 0.2 M K 2 EDTA and K 3 EDTA (BD vacutainer tubes by Becton, Dickinson and Company) and Na 2 EDTA (Sigma Aldrich) solutions were made. The pH of each solution was measured (Mettler Toledo pH meter), and the theoretical osmolarity was calculated. Next, we determined the calcium chelation potential of each EDTA salt by titrating it with 10 μmol of calcium hydroxyapatite or CaCl 2 containing Patton-Reeder colorimetric indicator. Statistical significance was analyzed using analysis of variance.

RESULTS

The 0.2 M solutions of Na 2 EDTA, K 2 EDTA, and K 3 EDTA have pH values of 4.43, 5.71, and 9.191 and theoretical osmolarities of 600, 600, and 800 mOsm/L, respectively. Calcium chelation ability was similar among all 3 solutions: 0.94 to 0.98 mol of EDTA was needed to fully chelate 1 mol calcium ions of CaCl 2 ( P = 0.296), 0.100 to 0.108 mol of EDTA for 1 mol calcium ions of the hydroxyapatite aqueous suspension ( P = 0.296), and 0.992 to 0.996 mol for 1 mol calcium ions of hydroxyapatite in acidic solution ( P = 0.178). Compared with the clinical standard of 3% (30 mg/mL) Na 2 EDTA, approximately 3.3% (33 mg/mL) K 2 EDTA and 3.6% (36 mg/mL) K 3 EDTA are needed to chelate an equivalent amount of calcium.

CONCLUSIONS

In this article, we provide clinically relevant biochemical properties of 2 alternatives to Na 2 EDTA and demonstrate comparable calcium chelation ability among all 3 solutions. In situations where sterile sources of Na 2 EDTA are unavailable, potassium EDTA may provide a convenient and equally effective method of treatment for band keratopathy.

Use of Ethylenediaminetetraacetic Acid in Chronic Calcium-Based Chemical Injury

PURPOSE

This study presents the successful management of a patient with chronic chemical-based injury using ethylenediaminetetraacetic acid (EDTA) chelation.

METHODS

This is a case report of a 59-year-old man who presented to us 2 months after a bilateral, accidental, ocular injury with lime particles at his workplace.

RESULTS

The patient was initially managed with extensive debridement and amniotic membrane grafting for both eyes. At 4-month follow-up, the left eye appeared to have extensive calcium-based plaques. 0.02N EDTA chelation was performed for his left eye. Postchelation, the visual acuity improved to 20/800. At 1-week follow-up, a repeat EDTA chelation was performed. The corneal clarity improved further, and the patient recovered a visual acuity of 20/200.

CONCLUSIONS

EDTA chelation in the setting of calcium deposition in the chronic phase of chemical injuries can be reasonably effective.

The effect of EDTA solution on corneal endothelial cells in rabbits

Corneal disease threatens vision globally. Among corneal diseases, calcific band keratopathy has severe effects on vision owing to its unique location. Currently, ethylene diamine tetraacetic acid (EDTA) chelation remains the most important treatment. However, only the safety of low-dose topical EDTA eye drops is well established in humans. Therefore, the purpose of this study was to determine the safe dose range of EDTA for calcific band keratopathy surgery and its toxic effects on rabbit eyes. Rabbits were administered different doses of EDTA solutions (0.50, 0.20, 0.10, 0.05, and 0.01 M) for twenty minutes. In day seven, the rabbits were euthanized and pathological examination was performed for cornea. We found severe corneal edema in 0.50 M group, while milder edema in lower-concentration treated groups. Followed by corneal thickness measurement, the measured values increase to the peak in post-operative three day (0.20 M group) or one day (lower-concentration groups), then decreased. Groups comparison shown significant difference between BSS control group and higher concentration groups (0.20 M and 0.10 M) (P < 0.001) in observation period, but no significance was observed between low concentration and control group in the day seven after surgery (P > 0.05). Confocal microscopy examination suggested, the number of corneal endothelial cells significantly decreased from 3428.6 ± 180.3 cells/mm² to 2808 ± 80.6 cells/mm² in the 0.50 M group, while the lower-concentration groups showed lesser toxic effects on corneal endothelial cells. Finally, our histological examination demonstrated inflammation in each experimental group and dose-dependent, compared with control group. Our study found 0.05 M and 0.01 M EDTA solutions had no obvious toxic effect on the corneal endothelium compared with higher concentration. However, further study of EDTA side effect by clinical trials, and therapeutic effect observation with different concentration are necessary.

Topical Ethylenediaminetetraacetic acid (EDTA) administration following corneal diamond burr keratotomy for calcareous corneal degeneration in canines

OBJECTIVE

To evaluate the outcomes of canine patients diagnosed with corneal ulceration associated with presumed calcareous corneal degeneration (CCD) that were treated with diamond burr keratotomy (DBK) and ongoing postoperative topical 3% or 4% Ethylenediaminetetraacetic acid (EDTA).

PROCEDURES

Retrospective assessment of CCD cases treated with ongoing topical EDTA following DBK between 2011 and 2020 at Veterinary Ophthalmic Referrals. Descriptive statistics of the study population were assessed, and a survival analysis was performed using R statistical software.

RESULTS

A total of 51 eyes from 41 dogs were assessed, with small terrier breeds overrepresented (27/41, 65.9%). Median age of dogs at the time of diagnosis was 14.3 years (range 8-17.2 years). Following DBK, the median time to commencement of topical EDTA was 11 days (range 0-28 days). Cases were followed for a median duration of 216 days (range 42-1379 days). Corneal ulceration recurred in 7/51 (13.7%) eyes at a median duration of 80 days (range 63-156 days). The probability of recurrence of corneal ulceration associated with CCD at 12 months was 15.6% (95% CI: 4.1-25.7%). A second DBK procedure followed by ongoing topical EDTA was performed in 4/7 (57.1%) of the recurred eyes. These retreated eyes had no further recurrence recorded and a median follow-up time of 401 days (range 120-858 days).

CONCLUSION

Ongoing topical EDTA following DBK is an effective adjunct treatment method for CCD with reduced rates of recurrence of CCD-associated corneal ulceration when compared to published rates of recurrence when treated with DBK alone.

CHELATION OF BAND KERATOPATHY IN LONG-TERM MONITORING

AIM

To report the clinical results of chelation of band keratopathy in long-term follow-up.

MATERIAL AND METHODS

The long-term results of 5 patients (5 eyes) with symptomatic band keratopathy with a follow-up period of at least 6 months, in whom 2% EDTA was chelated on the affected eye in the study period from April 2018 to March 2021, were retrospectively evaluated. The follow-up period was 9-37 months.

RESULTS

In all patients, there was a significant improvement in the local findings and an increase in the transparency of the cornea. The effect of therapy was verified on a color photograph of the anterior segment and on AS-OCT by the disappearance of subepithelial hyperreflective foci and accompanying optical shadows. Postoperatively, this enabled a more detailed visualization of the deeper layers of the cornea and other structures of the anterior segment. In a patient with the potential to improve vision, it was also possible to significantly improve visual functions. In the other three patients with pain in the affected eye, the pain subsided, and they also benefited cosmetically from the operation.

CONCLUSION

Based on our experience and previously published reports, EDTA corneal chelation is able to causally resolve the pathology and improve vision in eyes with visual potential. At the same time, it reduces discomfort and has an analgesic effect in long-term irritated eyes. The operation is also suitable for amaurotic, cosmetically unsightly bulbs, as a successful intervention preserving the eye and improving the appearance of such eyes leads to satisfaction and a subjective increase in the quality of life of the patients.

Effects of piperazine and EDTA in garden snail towards electrolytic variation and antimicrobial activities

The present study has been carried out to evaluate the effects of piperazine and EDTA (ethylenediaminetetraacetic acid) in the garden snail, Cornu aspersum. EDTA and piperazine-like chemicals are widely used in various pharmaceutical, household, and industrial applications. The snails after collection were kept in different earthen pots and treated with these chemicals at different concentrations. A higher concentration of these chemicals led to a change in foot color from light to dark brown and loss in average weight with time. It has been found that a 10-fold increase in piperazine and EDTA concentration reduces weight by approximately 12.7- and 11.6-fold, respectively. Further, the study provides an insight into the altered antimicrobial activity of crude extract when treated with ligands. Additionally, the variations in the electrolytes in the mucus sample have been observed with the mean standard deviation (± SD) of 6.4 and 2.4 for Na⁺ and K⁺ ions, respectively.

Cisd2 plays an essential role in corneal epithelial regeneration

Background

Age-related changes affecting the ocular surface cause vision loss in the elderly. Cisd2 deficiency drives premature aging in mice as well as resulting in various ocular surface abnormalities. Here we investigate the role of CISD2 in corneal health and disease.

Methods

We studied the molecular mechanism underlying the ocular phenotypes brought about by Cisd2 deficiency using both Cisd2 knockout (KO) mice and a human corneal epithelial cell (HCEC) cell line carrying a CRISPR-mediated CISD2KO background. We also develop a potential therapeutic strategy that targets the Ca²⁺ signaling pathway, which has been found to be dysregulated in the corneal epithelium of subjects with ocular surface disease in order to extend the mechanistic findings into a translational application.

Findings

Firstly, in patients with corneal epithelial disease, CISD2 is down-regulated in their corneal epithelial cells. Secondly, using mouse cornea, Cisd2 deficiency causes a cycle of chronic injury and persistent repair resulting in exhaustion of the limbal progenitor cells. Thirdly, in human corneal epithelial cells, CISD2 deficiency disrupts intracellular Ca²⁺ homeostasis, impairing mitochondrial function, thereby retarding corneal repair. Fourthly, cyclosporine A and EDTA facilitate corneal epithelial wound healing in Cisd2 knockout mice. Finally, cyclosporine A treatment restores corneal epithelial erosion in patients with dry eye disease, which affects the ocular surface.

Interpretation

These findings reveal that Cisd2 plays an essential role in the cornea and that Ca²⁺ signaling pathways are potential targets for developing therapeutics of corneal epithelial diseases.

Funding

This study was supported by the Ministry of Science and Technology (MOST) and Chang Gung Medical Research Foundation, Taiwan.

Case Report: Phototherapeutic Keratectomy for Band Keratopathy Secondary to Chemo-Laser-Cryotherapy for Retinoblastoma

Purpose: To report the clinical outcomes of phototherapeutic keratectomy (PTK) for pediatric band keratopathy after treatment for retinoblastoma.

Methods: A 5-year-old boy presented with a 2-year history of poor visual acuity and a horizontal gray-white band across the central cornea in the right eye. He was diagnosed with band keratopathy after chemo-laser-cryotherapy for retinoblastoma. The band keratopathy was treated via PTK using the Mel-90 excimer laser with an optical treatment zone of 7.0 mm and ablation depth of 120 μm. The patient was followed at 1 week and 3 months postoperatively.

Results: Surgery and postoperative follow-up were uneventful. At the 3-month follow-up, the uncorrected distant visual acuity of the right eye improved to 20/125, and the corrected distance visual acuity improved to 20/70 with a refraction of +10.00 D/−2.50 DC × 15. The clarity of the ablated area was evidently improved. The central corneal thickness decreases from 612 to 584 μm. The optical coherence tomography showed the thin band of hyperreflectivity in the ablated area disappeared, corneal transparency improved and the corneal surface smoothened.

Conclusions: PTK is a safe and effective procedure to treat band keratopathy following treatment of retinoblastoma in children. Early intervention can reduce the risk of developing deprivation amblyopia.

Acute onset of deep calcareous degeneration treated with keratoplasty procedures: Two cases report

There are two types of corneal calcium deposition, one is calcific band keratopathy and another is calcareous degeneration. We report two cases of acute onset of calcareous degeneration after using topical eye drops for their corneal wounds. The calcification in both the cases developed within 1 month. Due to the deeper stromal opacity, calcareous degeneration was impressed. In our cases, the deposits were too deep that they required keratoplasty procedures as better treatment options. One of the cases was treated with penetrating keratoplasty and another case was treated with deep anterior lamellar keratoplasty. Both of our cases had stable corneal grafts, and there were no ocular inflammation and no recurrence of calcification at least for 6 months.

Ethylenediaminetetraacetic Acid Chelation in Herpes Zoster Ophthalmicus Is Associated With a High Rate of Corneal Melt and Perforation

PURPOSE

To examine the rate and risk factors for band keratopathy after herpes zoster ophthalmicus (HZO) and the outcomes of ethylenediaminetetraacetic acid (EDTA) treatment.

METHODS

This is a retrospective review of all subjects with HZO seen at Auckland District Health Board between January 2006 and December 2016.

RESULTS

A total of 869 subjects with HZO were included in the study. Median follow-up was 6.3 years (total 5504.4 patient-years). Band keratopathy developed in 13 subjects (1.5%). On multivariate analysis, older age at onset [hazard ratio (HR), 1.092; P = 0.034], intraocular pressure ≥30 mm Hg at presentation (HR, 5.548; P = 0.013), and number of recurrences (HR, 1.849; P < 0.001) were associated with increased risk for band keratopathy. Corneal melt occurred in 22 subjects (2.5%) during the follow-up period. On multivariate analysis, uveitis (HR, 8.618; P = 0.004) and disodium EDTA chelation (HR, 8.666; P < 0.001) were associated with increased risk for corneal melt. EDTA chelation was performed in 8 subjects. Corneal melt occurred after EDTA chelation in 4 subjects, and corneal perforation occurred in 2 subjects. One subject was eviscerated due to severe endophthalmitis after repeated corneal perforation and another required enucleation for recurrent corneal melt and microbial keratitis.

CONCLUSIONS

Band keratopathy is an uncommon complication of HZO. Treatment with EDTA chelation might be associated with a significant risk for severe complications in these eyes and should be approached with caution.

Transepithelial phototherapeutic keratectomy for the treatment of severe band keratopathy

PURPOSE

The goal of this study was to investigate the clinical outcomes of transepithelial phototherapeutic keratectomy (transepithelial PTK) for the treatment of severe band keratopathy.

METHODS

A consecutive series of severe band keratopathy cases treated with transepithelial PTK were retrospectively analysed between January 2018 and December 2019. Severe band keratopathy was defined as corneal plaques apparent in the obscuration of iris details. Patients' medical histories, preoperative and postoperative symptomatic relief, cosmesis, best-corrected visual acuity (BCVA), complications, and recurrences were analysed.

RESULTS

Seventeen eyes of 16 patients were included in the study, with a mean follow-up of 9.8 ± 5.2 months (3 to 19 months). The mean age of the patients was 15.8 ± 10.2 years (8 to 46 years). Symptoms were significantly or completely relieved in all patients (100%). The results of cosmesis were good in 14 eyes (82.4%). Among those eyes that had BCVA of hand motion or better preoperatively, seven eyes (100%) showed an improvement in BCVA postoperatively. There were no complications or recurrences associated with transepithelial PTK treatment during the follow-up period.

CONCLUSIONS

Transepithelial PTK is an effective treatment to eliminate corneal opacity and alleviate symptoms in patients with severe band keratopathy. This technique could be an alternative approach to managing severe band keratopathy.

Band keratopathy in children previously treated with diode laser for type 1 retinopathy of prematurity

Band keratopathy is a corneal degeneration caused by chronic inflammation, systemic abnormalities, or, rarely, a primary biallelic SLC4A4 mutation leading to calcium hydroxyapatite deposition in Bowman's layer. We report a series of 16 eyes of 10 children with a remote history of diode laser treated retinopathy of prematurity who developed late-onset band keratopathy without evidence of other prior risk factors. The majority of patients developed band keratopathy bilaterally. Five eyes had visually significant central band keratopathy that required treatment with disodium ethylenediaminetetracetic acid (EDTA) chelation or phototherapeutic keratectomy. Band keratopathy may be an underreported late ophthalmic complication of diode-laser treated retinopathy of prematurity.

Phototherapeutic keratectomy

Phototherapeutic keratectomy is an excimer laser-based surgical procedure widely performed by corneal surgeons for treating anterior corneal stromal pathologies. Phototherapeutic keratectomy helps by ablating the corneal stroma, thereby improving corneal clarity and smoothening the surface. Transient discomfort and induced hyperopia from corneal flattening are the immediate postoperative concerns. The long-term course is often marked by the recurrence of original corneal pathology and corneal haze formation. Phototherapeutic keratectomy, however, allows for repeat stromal ablation for managing recurrences, as the corneal thickness permits, without affecting the outcome of future keratoplasty. Adjunctive methods such as topical mitomycin-C may be additionally used to reduce recurrence rates. Also, various masking agents such as carboxymethyl cellulose, sodium hyaluronate, and dextran are used in eyes with irregular corneal surface to allow for uniform stromal ablation. Overall, phototherapeutic keratectomy has provided corneal surgeons an additional surgical tool, particularly those residing in developing nations where the availability of donor corneal tissue is an important limiting factor.

Superficial keratectomy: indications and outcomes

INTRODUCTION

To evaluate the indications and outcomes of manual blade superficial keratectomy STUDY DESIGN: Retrospective, nonrandomized, consecutive case series METHODS: Database search of patients from 2012-2017 who underwent superficial keratectomy was conducted at a tertiary care hospital cornea clinic. Charts of 121 patients (156 eyes) were reviewed who had at least 4 weeks of follow-up and both preoperative and postoperative measurements of best-corrected visual acuity or corneal cylinder. Outcome measures included: patient demographics, surgical indication, prior ocular history, best-corrected visual acuity (BCVA) changes, corneal and refractive astigmatism changes, recurrence of pathology, additional treatments required, and intraoperative and postoperative complications.

RESULTS

Mean patient age at time of operation was 63.3 (±14.8), 39% were male. Indications included epithelial basement membrane dystrophy, recurrent corneal erosion syndrome, Salzmann nodular degeneration, band keratopathy, and suspected ocular surface neoplasia. In eyes with epithelial basement membrane dystrophy, mean BCVA (20/47 to 20/40, P = 0.033), refractive astigmatism (1.76 ± 1.83 D to 1.15 ± 1.08 D, P = 0.010), and corneal astigmatism (1.44 ± 0.88 D to 1.06 ± 0.88 D, P = 0.022) significantly improved. Twenty-four percent (5/21) of eyes with recurrent erosions had symptoms return at a mean 6.5 months follow-up. No intraoperative complications were noted. The epithelium healed completely in all 156 eyes at final follow-up.

CONCLUSION

Superficial keratectomy is a simple, safe procedure that can be performed for a variety of conditions to improve visual acuity, reduce corneal astigmatism, and alleviate symptoms secondary to ocular surface pathology.

"Off-the-Shelf" K2-EDTA for Calcific Band Keratopathy

PURPOSE

To explore the effectiveness of "off-the-shelf" dipotassium-ethylenediaminetetraacetic acid (K2-EDTA) as an alternative to sodium EDTA as chelation therapy in removal of calcific band keratopathy (CBK).

METHODS

This study was a retrospective case series involving 4 patients with CBK who underwent superficial keratectomy and subsequent chelation therapy with K2-EDTA in a single center (Coastal Eye Clinic) by the same surgeon. Visual acuity and symptomatic relief were the main outcomes measured in our study.

RESULTS

All 4 participants in this study were female with an average age of 80.3 years. Three of the patients with reasonable baseline visual acuity experienced improved visual acuity at 1 month. The other patient with multiple ocular comorbidities and severely reduced visual potential reported symptomatic pain relief at 1-month follow-up after the intervention.

CONCLUSIONS

K2-EDTA seems to be an effective alternative to disodium EDTA in its ability to clear calcific plaques and restore visual function. Because of the logistical difficulties associated with acquiring disodium EDTA, and the relative abundance of K2-EDTA in health-care facilities, we believe that our findings warrant further investigation into its use as a more accessible and cost-effective chelating agent in CBK.

Band Keratopathy: A Modified Treatment

PURPOSE

The surgical treatment of band keratopathy usually consists of abrasion of the corneal epithelium followed by removal of the subepithelial calcium deposits by means of an ethylenediamine-tetraacetic acid (EDTA) solution. In order to reduce the discomfort and pain that occur after corneal abrasion, the authors developed a modified technique that avoids the abrasion of the epithelium.

METHODS

In three patients (four eyes) with long-standing band keratopathy, the epithelium was detached with a 19% ethanol solution and placed gently toward the limbus, a method also used in laser-assisted subepithelial keratectomy (LASEK). After clearing the anterior stroma with EDTA solution, the epithelial flap is unrolled and a bandage contact lens applied.

RESULTS

Postoperative pain was greatly reduced and after removal of the contact lens no pain was reported.

CONCLUSIONS

This modified epithelium-sparing treatment of band keratopathy shows good results while reducing postoperative pain.

[Corneal degenerations]

Degeneration is the process of change occurring in cells, their parts or intracellular matter that happens due to external factors affecting the life of an organism and results in gradual disruption of normal condition of the tissue or the organ, and possibly complete loss of its functionality. Corneal degenerations may be caused by age-related physiological changes, associated with a certain systemic disease or local inflammations, or be the consequence of chronic toxic action of unhealthy environmental factors on the eye. Unlike dystrophies, corneal degenerations cannot be inherited and do not onset early. When corneal degenerations significantly affect visual acuity, the treatment should aim at alleviating the primary disease before inducing changes in the cornea. The existence of such pathology is important to remember and timely differentiate from acute inflammatory processes of various etiology that require immediate treatment. The right diagnosis is the key factor in choosing effective treatment strategy and thus achieving positive clinical results.

EDTA chelation for symptomatic band keratopathy: results and recurrence

PurposeTo identify causes of symptomatic band keratopathy, and assess the results and long-term recurrence rates following chelation with topical ethylene-diamine-tetra-acetic acid (EDTA).Patients and methodsA retrospective review of surgical logbooks identified patients managed by EDTA chelation for symptomatic band keratopathy from 2009 to 2015.ResultsWe identified 108 cases; 89 case notes were available for analysis. Most cases of band keratopathy were idiopathic (36%). The most commonly identified underlying diagnosis was long-term topical glaucoma therapy (27%). Median presenting visual acuity was 6/18 (range 6/6-NPL) with the visual axis affected in 97.8% of cases. Treatment involved corneal epithelium removal, recurrent application of topical EDTA, and subsequent debridement. The mean duration of the operation was 20 min (range 10-45). Mean initial follow-up time was 40 days, and the visual axis was clear in 97.8%. Visual acuity was maintained or improved in 79.8%, with 13.5% improving by two lines or more. The mean length of follow-up was 581 days (median 374, maximum 2438). Twenty-five eyes (28.1%) showed localised recurrence of calcium with a mean time of 546 days (median 374), but only four cases required repeat EDTA chelation. The median time between operations was 430 days. Thirty-two per cent of the recurrence cases were associated with hypotony or chronic presence of silicone oil.ConclusionsChelation of calcium with topical EDTA is a safe and effective treatment for band keratopathy. Visual acuity improves in most eyes and while the rate of recurrence is moderate, the need for retreatment is low (4.5% overall).

Risk of Band Keratopathy in Patients with End-Stage Renal Disease

This study is a retrospective, nationwide, matched cohort study to investigate the risk of band keratopathy following end-stage renal disease (ESRD). The study cohort included 94,039 ESRD on-dialysis patients identified by the International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM), code 585 and registered between January 2000 to December 2009 at the Taiwan National Health Insurance Research Database. An age- and sex-matched control group comprised 94,039 patients selected from the Taiwan Longitudinal Health Insurance Database 2000. Information for each patient was collected from the index date until December 2011. In total, 230 ESRD patients and 26 controls had band keratopathy (P < 0.0001) during the follow-up period, indicating a significantly elevated risk of band keratopathy in the ESRD patients compared with controls (incidence rate ratio = 12.21, 95% confidence interval [CI] = 8.14-18.32). After adjustment for potential confounders including sarcoidosis, hyperparathyroidism, iridocyclitis, and phthisis bulbi, ESRD patients were 11.56 times more likely to develop band keratopathy in the full cohort (adjusted HR = 11.56, 95% CI = 7.70-17.35). In conclusion, ESRD increases the risk of band keratopathy. Close interdisciplinary collaboration between nephrologists and ophthalmologists is important to deal with band keratopathy following ESRD and prevent visual acuity impairments.

Treatment of Juvenile Idiopathic Arthritis-Associated Uveitis

Pediatric uveitis may be a serious health problem because of the lifetime burden of vision loss due to severe complications if the problem is not adequately treated. Juvenile idiopathic arthritis (JIA)-associated uveitis is characterized by insidious onset and potentially blinding chronic anterior uveitis. Periodic ophthalmologic screening is of utmost importance for early diagnosis of uveitis. Early diagnosis and proper immunomodulatory treatment are essential for good visual prognosis. The goal of treatment is to achieve enduring drug-free remission. The choice of therapeutic regimen needs to be tailored to each individual case. One must keep in mind that patients under immunomodulatory treatment should be monitored closely due to possible side effects. Local and systemic corticosteroids have long been the mainstay of therapy; however, long-term corticosteroid therapy should be avoided due to serious side effects. Steroid-sparing agents in the treatment of JIA-associated uveitis include antimetabolites and biologic agents in refractory cases. Among the various immunomodulatory agents, methotrexate is generally the first choice, as it has a well-established safety and efficacy profile in pediatric cases and does not appear to increase the risk of cancer. Other classic immunomodulators that may also be used in combination with methotrexate include azathioprine, mycophenolate mofetil, and cyclosporin A. Biologic agents, primarily tumor necrosis factor alpha inhibitors including infliximab or adalimumab, should be considered in cases of treatment failure with classic immunomodulatory agents.

Comparison of corneal degeneration and calcific band keratopathy from 2000 to 2013 in 69 horses

OBJECTIVE

To compare signalment, presentation, treatment, and outcome in horses diagnosed with corneal degeneration (CD) or calcific band keratopathy (CBK) at a referral hospital.

ANIMALS STUDIED

Sixty-nine horses (87 eyes) diagnosed with either CD or CBK.

PROCEDURES

Medical records of horses diagnosed with CD or CBK at the University of California-Davis Veterinary Medical Teaching Hospital (UCD-VMTH) between 2000 and 2013 were reviewed. Signalment, concurrent ophthalmic diagnoses, previous therapies, diagnostic tests, systemic diagnoses, treatment, follow-up, and outcomes were compared between horses diagnosed with CD or CBK. Age, breed, and gender were compared between the CD/CBK and UCD-VMTH populations.

RESULTS

Thirty-three horses (42 eyes) and 36 horses (45 eyes) were diagnosed with CD and CBK, respectively. Horses with CD or CBK were significantly older (P < 0.001) than the UCD-VMTH population with a median age of 16 or 18 years, respectively. Appaloosas were significantly overrepresented in the CD/CBK population (33%) in comparison with the UCD-VMTH population (1.8%, P < 0.001). Equine recurrent uveitis was concurrently diagnosed in 67% and 84% of horses with CD or CBK, respectively. Pituitary pars intermedia dysfunction (PPID) was diagnosed significantly less often in horses with CD vs. CBK (P = 0.03). Chemical chelation with ethylenediaminetetraacetic acid was performed significantly less frequently in horses diagnosed with CD (7.1%) vs. CBK (31.1% of eyes) (P = 0.012).

CONCLUSIONS

Despite some differences, equine CD and CBK are relatively similar conditions and may represent a continuum of disease severity. Horses with PPID should be monitored closely for corneal disease including CBK.

Diamond burr debridement of 34 canine corneas with presumed corneal calcareous degeneration

OBJECTIVES

To describe the signalment, presence of systemic and/or ocular comorbidities, times to detected healing and probabilities of recurrence after diamond burr debridement (DBD) of eyes with presumed corneal calcareous degeneration and secondary ulceration and/or ocular pain.

ANIMALS STUDIED

Twenty-six dogs with 42 eyes affected, 34 eyes treated with DBD.

METHODS

A case series was conducted using medical records from a private veterinary ophthalmology referral practice. Dogs were included if they had white or gray corneal opacity consistent with corneal calcareous degeneration with either erosive or superficial ulceration and/or ocular pain in at least one eye and had at least one such eye treated with DBD. DBD was performed with a battery-operated handheld motorized burr (The Alger Company, Inc. Lago Vista, TX, USA), and a bandage contact lens was placed in the majority of eyes (30/34). Eyes were considered healed when the cornea was fluorescein negative, and there were no signs of ocular pain. Patient data (signalment, recurrence) were extracted from medical records.

RESULTS

Dogs were first re-examined 7-62 days after treatment (median: 13 days). All DBD-treated eyes healed within 62 days (% healed: 100%; one-sided 97.5% CI: 90-100%, median: 14 days), 82% of eyes (28/34) were healed at first re-examination (median: 13 days after treatment), and all were healed by their second examination (median: 24 days). Of the 34 treated eyes, 11 were lost to follow up; 11 of the remaining 23 eyes recurred. Estimated 1-year recurrence probability was 58% (95% CI: 35-83%). Seven dogs had systemic disease; 7 had a history of prior ocular disease or intraocular surgery.

CONCLUSIONS

Diamond burr debridement is a safe and effective treatment for rapid resolution of superficial corneal ulceration and ocular pain secondary to presumed corneal calcareous degeneration in dogs.

Corneal manifestations of selected systemic diseases: A review

The corneal manifestations of several selected systemic diseases are reviewed. Metabolic, immunologic and inflammatory and infectious diseases are included. A brief overview of each disease and how it manifests in the cornea is discussed. The importance of conducting a slit-lamp examination on every patient is emphasised.

Clinical management algorithm of uveitis associated with juvenile idiopathic arthritis: interdisciplinary panel consensus

Uveitis associated with juvenile idiopathic arthritis (JIA) typically involves the anterior chamber segment, follows an indolent chronic course, and presents a high rate of uveitic complications and a worse outcome as compared to other aetiologies of uveitis. Disease assessment, treatment, and outcome measures have not been standardized. Collaboration between pediatric rheumatologists and ophthalmologists is critical for effective management and prevention of morbidity, impaired vision, and irreparable visual loss. Although the Standardization of Uveitis Nomenclature Working Group recommendations have been a great advance to help clinicians to improve consistency in grading and reporting data, difficulties arise at the time of deciding the best treatment approach in the individual patient in routine daily practice. For this reason, recommendations for a systematized control and treatment strategies according to clinical characteristics and disease severity in children with JIA-related uveitis were developed by a panel of experts with special interest in uveitis associated with JIA. A clinical management algorithm organized in a stepwise regimen is here presented.

Two percent ethylenediaminetetraacetic acid chelation treatment for band-shaped keratopathy, without blunt scratching after removal of the corneal epithelium

Background

The purpose of this study was to assess the effectiveness of 2% ethylenediaminetetraacetic acid (EDTA) for the treatment of band-shaped keratopathy.

Methods

We studied 24 eyes of 16 patients with band-shaped keratopathy who underwent EDTA chelation treatment from April 1, 2011 to December 31, 2012. We compared preoperative and 1 month postoperative logarithm of the minimum angle of resolution (logMAR) best corrected visual acuity, intraocular pressure, and corneal curvature radius (K1, horizontal meridian; K2, vertical meridian; Km, average of K1 and K2). The Mann-Whitney U-test was used to determine the significance of differences.

Results

There was a significant difference in preoperative and postoperative logMAR best corrected visual acuity (P=0.01). There were no significant differences in preoperative and postoperative intraocular pressure (P=0.24) or corneal curvature radius (K1, P=0.54; K2, P=0.49; Km, P=0.45).

Conclusion

After 2% EDTA chelation treatment, post-operative logMAR best corrected visual acuity improved significantly. Moreover, since there was no significant difference in corneal curvature radius, there was little influence on corneal surface form. We believe that the results of our 2% EDTA chelation treatment were comparable with results obtained with 3.75% EDTA chelation treatment in previous reports. Two percent EDTA chelation is an effective treatment for band-shaped keratopathy and a useful method for any institution.

Metal chelator combined with permeability enhancer ameliorates oxidative stress-associated neurodegeneration in rat eyes with elevated intraocular pressure

Because as many as half of glaucoma patients on intraocular pressure (IOP)-lowering therapy continue to experience optic nerve toxicity, it is imperative to find other effective therapies. Iron and calcium ions play key roles in oxidative stress, a hallmark of glaucoma. Therefore, we tested metal chelation by means of ethylenediaminetetraacetic acid (EDTA) combined with the permeability enhancer methylsulfonylmethane (MSM) applied topically on the eye to determine if this noninvasive treatment is neuroprotective in rat optic nerve and retinal ganglion cells exposed to oxidative stress induced by elevated IOP. Hyaluronic acid (HA) was injected into the anterior chamber of the rat eye to elevate the IOP. EDTA-MSM was applied topically to the eye for 3 months. Eyeballs and optic nerves were processed for histological assessment of cytoarchitecture. Protein-lipid aldehyde adducts and cyclooxygenase-2 (COX-2) were detected immunohistochemically. HA administration increased IOP and associated oxidative stress and inflammation. Elevated IOP was not affected by EDTA-MSM treatment. However, oxidative damage and inflammation were ameliorated as reflected by a decrease in formation of protein-lipid aldehyde adducts and COX-2 expression, respectively. Furthermore, EDTA-MSM treatment increased retinal ganglion cell survival and decreased demyelination of optic nerve compared with untreated eyes. Chelation treatment with EDTA-MSM ameliorates sequelae of IOP-induced toxicity without affecting IOP. Because most current therapies aim at reducing IOP and damage occurs even in the absence of elevated IOP, EDTA-MSM has the potential to work in conjunction with pressure-reducing therapies to alleviate damage to the optic nerve and retinal ganglion cells.

Techniques, indications and complications of corneal debridement

The cornea is the most exposed surface of the eye and, as such, is vulnerable to external trauma and the risk of infection. Many corneal diseases alter shape, surface, and transparency and thus result in reduced vision. The external position of the cornea, however, lends itself to diagnostic and therapeutic maneuvers that are commonly performed and readily done in the clinic. More sophisticated techniques require the use of complex equipment such as excimer and femtosecond laser. Complications that develop from poor healing and/or secondary infection are best avoided with appropriate technique, antisepsis, and modification of wound healing. We review corneal debridement in the management of corneal disease.

Calcific band keratopathy in an alpaca

A 4-year-old female Suri alpaca was presented for evaluation of acute onset weakness, lethargy, and recent development of opacities in both eyes. On ophthalmic examination, bilaterally symmetrical corneal opacities were noted along the interpalpebral fissures with a few corneal blood vessels intermingled. A presumed diagnosis of calcific band keratopathy was made based on location and appearance. The patient was euthanized a short while after diagnosis due to reasons unrelated to the eyes and histologic examination of the corneas revealed subepithelial calcium and vascularization, consistent with calcific band keratopathy. This case report is the first to document this ocular condition in an alpaca.

Imaging characteristics of delayed surface calcification in hydrophilic intraocular lens models

We report two cases of opacified explanted intraocular lenses (IOL).The first lens was explanted from a cataract patient, then treated in vitro with trypsin/ethylene-diamine-tetra-acetic acid. The second hydrophilic acrylic IOL was explanted from a patient who had undergone sulphur hexafluoride (SF6) gas endotamponade surgery to repair a retinal detachment.

Synthesis of calcium-silica composites: a route toward an in vitro model system for calcific band keratopathy precipitates

Calcific band keratopathy (CBK) is a degenerative condition resulting in the deposition of calcium salts in the superficial layers of the cornea and causing significant visual disturbance and pain of the affected eye. Unfortunately, the amount of CBK precipitates recovered from the affected eye is very small therefore; it would be beneficial to prepare a synthetic material mimicking CBK material to further the development of therapeutics. Analyses of biological samples recovered from patients show the presence of silicon in addition to calcium, as well as a distinctive fused spherical morphology. This prompted us to study the reaction of various sources of silicon (fumed silica, silicic acid, and silicone oil) with CaCO(3) under a range of reaction conditions to gain an understanding of the formation of CBK. A silicon source alone was not found to be responsible for the fused spherical morphology, and a third component, a polar surfactant-like molecule such as sodium dodecyl sulfate or tetradecylphosphonic acid, was also required. The effects of silicon:calcium ratio and reaction time have been studied. The reaction of fumed silica with CaCO(3) in presence of sodium dodecyl sulfate results in the formation of spherical shapes resembling the structures and chemical composition observed in the eye samples, while no such structures were observed in the absence of silicon. Samples closely resembling human samples were also formed from the reaction of silicone oil with CaCO(3) in the presence of tetradecylphosphonic acid. Samples were characterized by SEM, XRD, and XPS and Raman spectroscopy.