US Patent 6,395,294 (Scope, Claims, and US Landscape for “Corticosteroid Vitreous Delineation”)
United States Patent 6,395,294 claims methods and compositions for visualizing/ delineating vitreous during ophthalmic surgery (vitrectomy) by injecting a corticosteroid that “associates with vitreous fibers” to render the vitreous visible, then surgically removing the vitreous.
What is the core invention?
Across independent claim themes, the invention is narrowly anchored to three functional elements:
-
A surgical workflow for vitreous-caused structural disorder
The procedure is a vitreous-driven structural disorder treated with intraocular injection followed by surgical correction by removing vitreous.
-
A vitreous delineating agent that is a corticosteroid
The claims require a composition “consisting essentially of a corticosteroid” (or “corticosteroid formulation”) that makes vitreous visible for surgery.
-
A corticosteroid selection set
The corticosteroid is selected from an enumerated list (including steroid classes and salts/derivatives), with dependent claims narrowing to formulation/vehicle and a specific exemplified agent.
What do the claims actually cover? (Claim-by-claim scope)
Independent claims in the set you provided: claims 1 and 6 and 8
Even though you supplied claims 1 through 15, the independent coverage is carried primarily by:
- Claim 1: surgical method using “composition consisting essentially of a corticosteroid” as vitreous delineating agent, then removing vitreous.
- Claim 6: similar to claim 1 but uses slightly different enumerated steroid list and “corticosteroid formulation” phrasing.
- Claim 8: composition for visualizing vitreous in a mammalian eye for surgical use, requiring association with vitreous fibers.
Claim-by-claim map (provided claims 1-15)
| Claim |
Claim type |
Required limitations (high signal) |
What it captures broadly |
| 1 |
Method |
(i) structural disorder of eye caused by vitreous; (ii) inject composition consisting essentially of a corticosteroid as vitreous delineating agent; (iii) amount renders vitreous visible for surgical correction; (iv) surgically correct by removing vitreous; (v) corticosteroid from enumerated set |
Injection of a corticosteroid (within list) into eye to make vitreous visible for vitrectomy-like removal |
| 2 |
Method dependent on 1 |
corticosteroid agent includes an additional therapeutic or inert agent, i.e., “selected from therapeutic agent/inert agent/combination” |
Mixed formulations where the corticosteroid is the delineating component but other agents can be present |
| 3 |
Method dependent on 1 |
corticosteroid agent formulated as vesicle: liposome or microsphere |
Delivery vehicles for corticosteroid vitreous delineation |
| 4 |
Method dependent on 1 |
corticosteroid formulation is solution, emulsion, or suspension |
Broad liquid/dispersion formats |
| 5 |
Method dependent on 2 |
therapeutic agent is one of: anti-infective, immunosuppressant, antiproliferative, anti-angiogenesis |
Adds defined drug classes beyond corticosteroid |
| 6 |
Method independent (as written) |
Same concept as claim 1 but recites “corticosteroid formulation” and uses a steroid list that omits some items found in claim 1 while including others; still requires injection + vitreous visible + removal |
Coverage of method variants using corticosteroid formulation and a different enumerated set |
| 7 |
Method dependent on 6 |
corticosteroid incorporated in microsphere or liposome |
Vehicle narrowing tied to claim 6’s formulation set |
| 8 |
Composition independent |
injectable composition that “associates with vitreous fibers” to render vitreous visible to surgeon; corticosteroid enumerated set |
A product claim to “injectable formulation” for vitreous delineation |
| 9 |
Composition dependent on 8 |
formulation is translucent |
Optical property limitation |
| 10 |
Composition dependent on 8 |
formulation is opaque |
Optical property limitation |
| 11 |
Composition dependent on 8 |
formulation is semi-opaque |
Optical property limitation |
| 12 |
Composition dependent on 8 |
vesicle is liposome or microsphere |
Vehicle narrowing |
| 13 |
Composition dependent on 12 |
further comprising a therapeutic agent |
Combination product with corticosteroid vesicle |
| 14 |
Composition dependent on 8 |
injected during vitrectomy |
Ties composition use context to vitrectomy |
| 15 |
Method dependent on 1 |
corticosteroid is triamcinolone acetonide |
Narrow “golden” steroid within the broader enumerated set |
What “consisting essentially of” narrows (and what it does not)
Claims 1 and 6 require a composition that consists essentially of a corticosteroid (or “corticosteroid formulation”). That typically permits:
- the corticosteroid as the required delineating component,
- formulation excipients/vehicles that do not materially alter the essential delineating characteristics.
Claims 2 and 5 explicitly allow inclusion of therapeutic or inert agents while keeping corticosteroid as the delineating core.
How broad is the steroid scope? (Enumerated corticosteroids)
Claim 1 steroid list (as provided)
Includes (non-exhaustive transcription from the claim text you provided):
dexamethasone, triamcinolone, hydrocortisone, cortisol, cortisone, corticosterone, 11-desoxycorticosterone, 11-desoxycortisol, aldosterone, prednisolone, 6α-methylprednisolone, paramethasone, betamethasone, fludrocortisone, tetrahydrocortisol, prednisone, methylprednisolone, salts and derivatives, and combinations.
Claim 6 steroid list (as provided)
Includes:
dexamethasone, triamcinolone, corticosterone, 11-desoxycorticosterone, 11-desoxycortisol, aldosterone, 6α-methylprednisolone, betamethasone, fludrocortisone, tetrahydrocortisol, prednisone, methylprednisolone, prednisolone, salts and derivatives, and combinations.
Claim 15 explicit fallback
- triamcinolone acetonide is singled out as a dependent narrowing position under claim 1.
Bottom line: the inventive concept does not hinge on a single steroid; it hinges on steroid class members functioning as the vitreous delineating agent, with a composition/vehicle toolbox that is wide (solution/emulsion/suspension and vesicles).
What formulation/vehicle scope is captured?
The claim set contains three layers of formulation coverage:
1) Vehicle type
- Solution
- Emulsion
- Suspension (claim 4)
- Liposome
- Microsphere (claims 3, 7, 12)
2) Optional added therapeutic payload
- claim 2 allows an agent selected from therapeutic/inert/combination
- claim 5 defines therapeutic categories as:
- anti-infective
- immunosuppressant
- antiproliferative
- anti-angiogenesis
3) Optical property constraints (composition only)
- translucent (claim 9)
- opaque (claim 10)
- semi-opaque (claim 11)
4) Procedural context anchor (composition)
- claim 14 specifies injection during vitrectomy
Bottom line: product and method claim coverage is aligned to how surgeons encounter vitreous during surgery, not to pharmacokinetic endpoints.
What is the “functional” requirement the claims enforce?
Independent claim 8 has the clearest statement of performance:
- the injectable corticosteroid formulation associates with vitreous fibers
- and renders vitreous visible to a surgeon
Independent method claims 1 and 6 impose a parallel functional requirement:
- injection in an amount effective to render the vitreous visible for surgical correction
- followed by removing vitreous as part of correcting the disorder caused by vitreous.
This means the delineation claim hinges on visualization capability (fiber association plus visibility), not on a specified imaging modality.
What does this mean for infringement risk? (Practical coverage boundaries)
Strongest claim targets
A party that does any of the following is inside the literal core:
- Injects an enumerated corticosteroid intraocularly during surgery to make vitreous visible
- Uses a liposome/microsphere or solution/emulsion/suspension that contains one of the enumerated steroids
- Performs surgery where vitreous removal is the corrective act
- Markets or supplies an injectable corticosteroid composition intended to associate with vitreous fibers for surgeon visibility
Design-around pressure points (within the provided claim language)
Without relying on external legal doctrine, the only obvious mechanical levers created by the text you provided are:
- Use a corticosteroid not enumerated in the claims
- Avoid “consists essentially of” by changing the essential composition concept (this is not a clean technical workaround because the claims also allow certain other agents)
- Avoid the function of making vitreous visible by association with vitreous fibers (but that would defeat the stated purpose)
The claim set you provided does not show an alternate non-steroid delineating agent route; it is corticosteroid-locked.
Patent landscape: where this sits in the US system
Coverage shape
The patent family coverage is defined by:
- Method claims (claims 1 and 6 style): procedural steps tied to vitreous visibility and vitreous removal
- Composition claims (claim 8 style): injectable corticosteroid composition that associates with vitreous fibers and enables surgeon visualization
Likely competitive classes around it (based on claim structure)
In the US ophthalmic space, competing offerings typically fall into one of two buckets that matter for this particular patent’s scope:
-
Corticosteroid-based intraocular “delineation” products
Close technical competitors because they hit both the steroid enumeration and the visualization function.
-
Non-steroid dye or imaging adjuncts
These are less likely to intersect these specific claims because the claims are corticosteroid-defined. They can still compete clinically, but the literal overlap is lower unless they also use an enumerated corticosteroid and meet the functional visibility requirement.
Expiration/term reality check (high-level)
You asked for “patent landscape,” which depends on legal status (expiration, terminal disclaimers, continuation filings, citations, and reexams). That legal status is not included in your inputs. Without the patent’s maintenance/expiration history or prosecution data, no definitive landscape statements (e.g., which claims remain enforceable vs. expired, which continuations extend coverage, or which cited references define priority) can be produced from the provided record.
How to read claim coverage for diligence (what to check in competitor products)
Use a checklist aligned to the claim elements:
Product composition checklist
- Is the active corticosteroid one of the enumerated items?
- Is the formulation injectable and does it include solution/emulsion/suspension or liposome/microsphere?
- Does the product claim or evidence support “associates with vitreous fibers” and makes vitreous visible to a surgeon?
- Does the formulation present as translucent/opaque/semi-opaque (if they target those properties)?
Procedure checklist
- Is the injection administered to treat an eye disorder caused by vitreous?
- Is the surgical corrective action removal of vitreous?
- Is the injection done in a context that maps to vitrectomy (explicitly in claim 14 for compositions)?
Payload checklist (if any)
- Are they adding other therapeutic agents in the enumerated classes (anti-infective, immunosuppressant, antiproliferative, anti-angiogenesis)?
- Are they using inert additives that still keep the corticosteroid as the “essential” delineating component?
Key Takeaways
- US 6,395,294 claims corticosteroid-based vitreous delineation for ophthalmic surgery: inject an enumerated corticosteroid to make vitreous visible, then surgically remove vitreous.
- The independent composition claim (claim 8) is centered on an injectable corticosteroid formulation that associates with vitreous fibers to render vitreous visible to the surgeon.
- The claim set is formulation-flexible (solution/emulsion/suspension; liposomes/microspheres) and optionally supports added therapeutic classes, but it is steroid-enumerated and functionally anchored to visualization.
- The narrowest “spot” within the set you provided is triamcinolone acetonide (claim 15), while the broadest positions cover multiple corticosteroid members and multiple vehicle types.
FAQs
1) Does the patent cover non-corticosteroid vitreous dyes?
No. The claims you provided define the vitreous delineating agent as a corticosteroid selected from enumerated items, and the composition is “essentially” a corticosteroid formulation.
2) Are liposomes and microspheres explicitly covered?
Yes. Liposomes and microspheres are explicitly recited in method and composition dependent claims.
3) Does the patent require that vitrectomy be performed?
The method claims require surgical correction by removing vitreous. The composition claim further specifies injection “during a vitrectomy” (claim 14).
4) Can additional therapeutic agents be included?
Yes. Claims 2 and 5 allow addition of therapeutic or inert agents, with claim 5 restricting therapeutic-agent categories.
5) What is the practical “design-around” lever suggested by the claim text?
The clearest technical lever inside the claim language is using a corticosteroid outside the enumerated steroid set and/or avoiding the claimed functional behavior (association with vitreous fibers to render vitreous visible).
References
[1] US Patent No. 6,395,294 (claims as provided in the prompt).
