Cataract surgery in patients with multiple corneal «segmentations» after radial keratotomy
At a Glance
Section titled “At a Glance”| Metadata | Details |
|---|---|
| Publication Date | 2025-07-16 |
| Journal | POINT OF VIEW EAST – WEST |
| Authors | A.A. Petukhova, S.Y. Kopaev, A.A. Troshina, Y.V. Grigoryeva |
| Analysis | Full AI Review Included |
Technical Documentation & Analysis: Precision Diamond in Ophthalmic Surgery
Section titled “Technical Documentation & Analysis: Precision Diamond in Ophthalmic Surgery”Executive Summary
Section titled “Executive Summary”This documentation analyzes a clinical case study concerning complex cataract surgery in patients previously treated with extensive Radial Keratotomy (RK). The findings underscore the critical requirement for ultra-high precision materials in advanced ophthalmic procedures.
- Application Focus: Management of complicated cataract surgery (Phacoemulsification) in corneas compromised by numerous, deep RK incisions (up to 32 cuts).
- Material Requirement Validation: The paper explicitly validates the historical shift in RK technique toward diamond blades over metal blades, citing diamond’s ability to create cleaner, deeper incisions with reduced epithelial damage and faster healing.
- Precision Tooling: Successful outcomes relied on advanced diagnostics (OCT, Pentacam-HR) and standardized surgical steps facilitated by femtosecond laser systems (CATALYS), requiring materials capable of micron-level accuracy.
- 6CCVD Core Value: 6CCVD specializes in high-purity Single Crystal Diamond (SCD) and Polycrystalline Diamond (PCD), the foundational material for the next generation of ultra-sharp, low-friction surgical blades and high-power optical components.
- Key Achievement: The surgical team achieved excellent functional results (VIS 0.5 in both eyes 3 months post-op) through meticulous planning and the use of high-precision instrumentation.
- Sales Driver: The necessity for superior cutting edge quality in corneal surgery directly aligns with 6CCVD’s capability to supply SCD wafers polished to Ra < 1nm for surgical tool fabrication.
Technical Specifications
Section titled “Technical Specifications”The following hard data points were extracted from the clinical case study, highlighting the extreme conditions managed by the surgical team:
| Parameter | Value | Unit | Context |
|---|---|---|---|
| RK Incisions (OD / OS) | 32 / 16 | Cuts | Pre-operative corneal status |
| Axial Length (OD / OS) | 28.95 / 26.40 | mm | High myopia status |
| Endothelial Cell Density (OD) | 2289 | cells/mm2 | Cell count for surgical prognosis |
| Endothelial Cell Density (OS) | 2460 | cells/mm2 | Cell count for surgical prognosis |
| Pre-op Visual Acuity (OD) | 0.15 | n/k | Uncorrected visual acuity |
| Pre-op Visual Acuity (OS) | 0.20 | sph 5.0 | Corrected visual acuity |
| Corneal Thickness (OS, Thinnest) | 534 | µm | Measured by Pentacam-HR |
| Post-op VIS (OD / OS, 3 months) | 0.5 / 0.5 | Corrected | Final functional outcome |
| Post-op IOP (OD / OS, 3 months) | 16 / 20 | mm Hg | Intraocular Pressure (within normal limits) |
| Pre-op Astigmatism (OD) | -2.50 | Diopters | Measured by Autorefractometry |
Key Methodologies
Section titled “Key Methodologies”The successful management of this high-risk case relied on a multi-modal diagnostic and surgical approach, emphasizing material precision at the cutting edge:
- Advanced Pre-operative Diagnostics: Comprehensive assessment using Optical Coherence Tomography (OCT), IOL-Master optical biometry, and Scheimpflug topography (Pentacam-HR).
- Corneal Status Evaluation: OCT was used specifically to confirm the integrity and depth of the keratotomy scars, crucial for surgical planning.
- IOL Calculation Optimization: Multiple IOL calculation formulas and data sources were utilized to overcome the refractive unpredictability caused by the RK-altered cornea.
- Femtosecond Laser Assistance: The CATALYS Johnson & Johnson system was employed for standardized, precise anterior capsulotomy (capsulorhexis) and phacofragmentation, reducing stress on the zonular fibers.
- Surgical Incision Placement: The main surgical access (limbal approach) was strategically placed, often intersecting existing keratotomy scars, necessitating a clean, controlled incision to prevent wound dehiscence.
- Historical Context (Material Selection): The paper notes that the shift from metal blades to diamond blades for RK was driven by the superior material properties of diamond, which allowed for deeper, more controlled cuts without excessive mechanical force or pressure on the delicate corneal tissue.
6CCVD Solutions & Capabilities
Section titled “6CCVD Solutions & Capabilities”The research highlights the enduring need for ultra-precise cutting tools in corneal surgery. 6CCVD is uniquely positioned to supply the foundational diamond materials required for manufacturing these high-performance instruments, whether for surgical blades or advanced optical components used in diagnostic equipment.
Applicable Materials
Section titled “Applicable Materials”To replicate or extend the precision required for corneal incisions, 6CCVD recommends the following materials:
| Material Grade | Application Relevance | 6CCVD Capability |
|---|---|---|
| Optical Grade Single Crystal Diamond (SCD) | Ideal for surgical blades (diamond knives) requiring the sharpest possible edge (Ra < 1nm) for clean, low-trauma incisions, minimizing epithelial plug formation and promoting rapid healing, as discussed in the paper. | SCD plates up to 500 µm thick, polished to Ra < 1nm. |
| High-Purity Polycrystalline Diamond (PCD) | Suitable for high-durability components, heat spreaders in laser systems (like the CATALYS femtosecond laser), or large-area optical windows. | PCD wafers up to 125mm in diameter, polished to Ra < 5nm. |
| Boron-Doped Diamond (BDD) | Relevant for future electrochemical sensors or high-sensitivity diagnostic probes used in complex ocular environments (e.g., measuring intraocular fluid dynamics). | Custom BDD films and substrates available. |
Customization Potential
Section titled “Customization Potential”The complexity of modern ophthalmic tools demands highly customized material solutions. 6CCVD offers tailored manufacturing services to meet the exact specifications of surgical instrument developers and research teams:
- Custom Dimensions: We provide SCD and PCD plates/wafers in custom geometries, essential for manufacturing specialized surgical tips or optical windows used in diagnostic equipment like OCT or keratotopography devices.
- Ultra-Precision Polishing: 6CCVD guarantees surface roughness (Ra) < 1nm for SCD, ensuring the material can be ground into the ultra-sharp, low-friction cutting edges preferred historically for RK and currently for micro-incisions.
- Advanced Metalization: For integrating diamond components into surgical handles or sensors, 6CCVD offers in-house metalization services, including Au, Pt, Pd, Ti, W, and Cu layers, ensuring robust electrical and mechanical interfaces.
Engineering Support
Section titled “Engineering Support”The successful outcome of this complex cataract surgery project depended on meticulous material selection and surgical technique. 6CCVD’s in-house team of PhD material scientists is available to assist engineers and researchers in optimizing diamond material properties for similar high-precision projects:
- Material Selection: Consultation on selecting the optimal diamond grade (SCD vs. PCD) based on required hardness, optical transparency, and thermal management needs for ophthalmic tools and laser components.
- Design for Manufacturing: Support in designing custom diamond components (e.g., specific thickness, edge geometry, or metalization patterns) to maximize performance in complex surgical applications like Phacoemulsification or Corneal Refractive Surgery.
For custom specifications or material consultation, visit 6ccvd.com or contact our engineering team directly.
View Original Abstract
Abstract Incisional keratotomy was originally used to correct astigmatism, including keratoconus. Anterior radial keratotomy (RK) has gained popularity since its modification by S.N. Fedorov. Surgical technique varied among surgeons; most of them agreed that a diamond blade was the preferred instrument, but they didn’t come to this opinion immediately and for a long time RK was performed using a metal blade. In addition, opinions differed regarding the number of incisions, their direction, and the choice of diameter of the optimal safe optical zone. These parameters determined the refractive outcome after RK. Today, the type of scars and their localization play a very important role in cataract surgery in such patients, since the necessity of optimization of intraocular lens (IOL) calculations and techniques of phacoemulsification is r equired. Keywords: radial keratotomy, surgical technique, optical zone, phacoemulsification