Statement of Principles concerning pterygium (Reasonable Hypothesis) (No. 33 of 2025)

The SOP organises its medical test and operational rules around a small number of explicit concepts: the clinical meaning of pterygium, the inclusion of death where pterygium contributed to a terminal event, the list of qualifying exposure factors, the relationship-to-service requirement, and an explicit method to deal with cross‑referenced SOPs. Each is defined or explained in the main body or in Schedule 1 - Dictionary; the instrument also references an ICD-10-AM code while relying on its own clinical definition (s7(2)-(3)).

Pterygium is defined precisely: a triangular or wedge‑shaped fibrovascular tissue growth extending from conjunctiva to cornea, immovably united to the cornea at its apex, firmly attached to the sclera in its mid-portion, and merged with the conjunctiva at its base. The instrument excludes pseudo-pterygium, pinguecula and several anatomical uses of the word pterygium outside the ocular context (s7(2)). The SOP notes that although pterygium attracts ICD‑10‑AM code H11.0, the operative meaning for this instrument is the textual definition in subsection 7(2) (s7(3)).

Death from pterygium is captured where pterygium contributed to a terminal event or condition, and the Schedule defines terminal events widely to include pneumonia, respiratory failure, cardiac arrest, circulatory failure and cessation of brain function (s7(4); Schedule terminal event). This links clinical causation beyond the ocular lesion itself to proximate deaths where pterygium played a contributory role.

The core causation mechanism is the list of four factors in section 9. The Authority says that at least one of these must exist before a reasonable hypothesis can be said to be raised (s9). The factors are:

• cumulative sunlight exposure to an unprotected eye of at least 2,250 latitude equivalent hours before clinical onset (s9(1)); the Schedule defines latitude equivalent hours and sets latitude weighting multipliers for tropical, subtropical, warm temperate and cool temperate zones;
• exposure to electric arc welding light while welding without appropriate eye protection, for an average of at least 20 hours per week over at least the two years before clinical onset (s9(2));
• heavy exposure of the unprotected eye to sawdust, in an environment where the person is covered in sawdust, for an average of at least 20 hours per week for at least one year before clinical onset (s9(3)); and
• inability to obtain appropriate clinical management for pterygium before clinical worsening (s9(4)).

The Schedule clarifies how to calculate latitude equivalent hours by multiplying hours of exposure in each latitude by a weighting factor (1.0 for tropical, 0.75 for subtropical, 0.5 for warm temperate, 0.25 for cool temperate) and summing the results for all latitudes in which exposure occurred (Schedule latitude equivalent hours). The instrument also defines the statutory terms MRCA, VEA and relevant service (Schedule). Section 10 requires that any factor relied upon must be related to the person’s relevant service and provides a temporal limitation for factor 9(4) so that it only applies to material contribution or aggravation where the pterygium was suffered or contracted before or during, but did not arise out of, relevant service (s10(1)-(2)).

Finally, section 11 sets the rule for overlap with other SOPs: where a section 9 factor refers to an injury or disease that is the subject of another SOP, the factors in that other SOP apply as in force (s11). The instrument therefore creates a network of SOP dependencies where exposure types or mechanisms that are covered elsewhere will be adjudicated according to the rules in those other SOPs.

This SOP affects three principal groups defined by its scope and operational use. First, it affects claimants , veterans, members of Peacekeeping Forces, and members of the Forces whose claims fall under section 120A of the VEA or section 338 of the MRCA (s5; Schedule relevant service). The SOP is not a general medical guideline; it is specifically applied in the statutory claims context referenced in section 5. Second, it affects decision-makers and administrators: the Repatriation Medical Authority (as issuer), the Department and tribunal or agency officers who apply the VEA or MRCA provisions when assessing whether a reasonable hypothesis has been raised, and medical advisers who prepare opinions that address the SOP factors (s3, s5, s8). Third, it affects clinicians whose diagnoses and records are relied upon to establish clinical onset, the nature of the lesion described in subsection 7(2), and any evidence about exposures and management.

Who pays: the SOP itself does not create a payment obligation; rather it is a medico‑factual instrument used to determine whether a causal threshold is met for statutory entitlements. The instrument applies only to claims to which s120A VEA or s338 MRCA apply (s5). Any financial consequences flow from application of those Acts and associated decision rules, not from the SOP itself.

Who decides: the SOP transfers the Authority’s view about medical‑scientific relationships to decision makers under the VEA and MRCA. The Authority’s view is expressed as the factors that it considers sufficient to raise a reasonable hypothesis (s8, s9). The SOP does not itself set the legal standard of proof or the administrative decision process; those remain in the parent statutes and adjudicative practice.

Indirectly affected parties include employers and third parties who may be asked to provide records and testimony about exposure patterns, protective equipment, workplace controls, and whether clinical management was available. Military unit logs, leave and duty records, equipment issue records and occupational health files will be probative in establishing the section 9 factors. The Schedule’s definition of latitude equivalent hours means that the geographic history of service matters: service locations across different latitude bands will be weighted and summed when calculating whether the 2,250 threshold in s9(1) is met (Schedule latitude equivalent hours).

Finally, the SOP creates potential procedural interaction effects for claimants whose exposures or injuries are also the subject of other SOPs. Section 11 requires application of other SOPs when section 9 factors refer to an injury or disease covered by a different SOP, which will require claimants and advisers to consult multiple instruments to compile a full evidentiary picture.

The SOP does not itself create statutory duties or private rights; rather it establishes medical‑factual prerequisites that must exist for a reasonable hypothesis of service connection to be raised in claims governed by the cited provisions of the VEA and MRCA (s5, s9). The key operational duties are therefore implicit and attach to decision makers and to claimants gathering evidence.

Duties on decision-makers and medical advisers: decision-makers applying the VEA or MRCA must treat this SOP as the Repatriation Medical Authority’s view of the relevant medical-scientific evidence when assessing causation. The Authority states that there is sound medical‑scientific evidence supporting the relationships set out (s8). Where at least one section 9 factor exists and is related to relevant service, that will be the minimum factual basis to establish a reasonable hypothesis (s9, s10). Section 11 imposes a duty on decision-makers to apply other SOPs’ factors on a cross-referenced basis where relevant.

Duties on claimants: claimants seeking to rely on the SOP must adduce evidence that one or more of the section 9 factors existed in a way that is connected to their relevant service. For example, a claimant relying on sunlight exposure must produce evidence of cumulative unprotected exposure amounting to at least 2,250 latitude equivalent hours before clinical onset and linked to relevant service locations (s9(1); Schedule latitude equivalent hours). A claimant relying on welding exposure must show average exposure of at least 20 hours per week over at least two years prior to clinical onset while welding without appropriate eye protection (s9(2)). For sawdust exposure the claimant must show a similar 20 hours per week average for at least one year where the affected eye was unprotected and the person was covered in sawdust (s9(3)). If relying on section 9(4), the claimant must show inability to obtain appropriate clinical management before clinical worsening and that the pterygium pre‑existed or was contracted before or during relevant service; the SOP limits application of s9(4) to material contribution or aggravation where the pterygium was suffered or contracted before or during, but did not arise out of, the relevant service (s10(2)).

Rights: the instrument formalises what evidence will be considered sufficient to raise a reasonable hypothesis; claimants have the right to have their claims assessed against these specified criteria within the statutory framework cited in section 5. Decision-makers must give effect to the SOP in claim assessment; cross-references to other SOPs must be followed where applicable (s11). The SOP also provides claimants a clear list of exposure thresholds and definitional criteria (for example the clinical definition of pterygium in s7(2) and the Schedule weighting formula) which can be used to frame evidence and medico-legal reports.

Limitations and gaps that affect duties and rights: several terms relied upon in the factors are not defined in the Schedule, even though the instrument refers to them. The text of section 9 refers to "unprotected eye", "clinical onset", "appropriate clinical management", and "clinical worsening" and a note to section 9 refers to "unprotected eye" being defined in the Schedule, but that term is not present in Schedule 1 as provided. This creates an evidentiary and interpretive gap that decision-makers and claimants will need to address in practice. The SOP itself does not prescribe evidentiary standards, burdens of proof, or administrative steps; those remain within the VEA and MRCA frameworks and implementing practice.

The instrument contains no express penalties, fines, or enforcement mechanisms. It is a Statement of Principles setting out the Repatriation Medical Authority’s view of medical‑scientific relationships relevant to causation in claims under particular provisions of the VEA and MRCA (s3, s8). The SOP therefore functions as evidentiary guidance rather than a sanctions instrument. Any enforcement outcomes, for example acceptance or rejection of a claim, follow from the application of the SOP in the decision-making processes established under the VEA or MRCA; those Acts and their administrative and judicial review processes determine legal consequences. The SOP itself does not create criminal or civil penalties.

Enforcement in practice means that administrative decision-makers will use the SOP’s factors to determine whether a reasonable hypothesis is raised. If the decision-maker accepts that the section 9 threshold is met and that the factor(s) are related to relevant service (s9, s10), that finding will typically move a claim forward under the statutory framework. Conversely, failure to establish any of the listed factors will leave a claimant without the SOP-based factual foundation for a reasonable hypothesis of service connection. The instrument gives no time limits for decisions, no auditing arrangements, and no specified mechanisms for dispute resolution; those procedural matters are governed by the VEA, MRCA and any departmental or tribunal rules.

The SOP references external material that may affect evidentiary practice. It states that pterygium attracts ICD‑10‑AM code H11.0 but that the instrument’s operative meaning is its own clinical description (s7(3)). The ICD reference points decision-makers and clinicians to an international classification system for coding, but the instrument makes clear that the textual definition in s7(2) governs the SOP’s operation. The Schedule also references the ICD-10-AM Tenth Edition effective 1 July 2017 and notes its copyright (s7(3)). This means that coding may play a supporting role in claims but will not displace the SOP’s definitional text.

Because the SOP is silent on enforcement mechanisms, the practical effect is that any administrative or judicial challenge to a decision will be conducted within the appeal and review mechanisms of the VEA or MRCA. The SOP may be a primary piece of expert material used in litigation or merits review, but the instrument itself does not set penalties for non-compliance or prescribe remedies beyond informing decision-making.

The instrument is expressly made under subsection 196B(2) of the Veterans’ Entitlements Act 1986 (s3), and it applies only to claims to which section 120A of the VEA or section 338 of the Military Rehabilitation and Compensation Act 2004 apply (s5). The SOP therefore operates within the legal architecture of those Acts: it is not freestanding but a delegable technical instrument that the Repatriation Medical Authority has been empowered to make for use in the statutory claims process. The SOP itself does not amend the VEA or MRCA, nor does it purport to modify statutory standards of proof or administrative procedure; it supplies the medical-scientific criteria that decision-makers will apply in those statutory contexts.

Section 11 creates an operational rule for overlap with other SOPs: where a section 9 factor refers to an injury or disease that is the subject of another SOP, the decision-maker must apply the factors in that other SOP in accordance with the terms of that SOP as in force from time to time (s11). This clause creates a cross‑referencing network among SOPs and requires interpreters to consult the current versions of other Statements of Principles when exposures or mechanisms refer to those conditions. Practically this may mean that, for example, if sawdust exposure or welding exposure is already addressed in a different SOP for an ocular or respiratory disease, the factors and thresholds in that other SOP will be applied for the overlapping issue.

The instrument also references ICD‑10‑AM coding (s7(3)) and explicitly states that while pterygium attracts ICD‑10‑AM code H11.0, the instrument’s meaning is its textual description. This means that clinical coding systems are referenced but subordinated to the SOP definition. Decision-makers and medical advisers will therefore use ICD codes for record-keeping and cross-referencing with clinical material, but the SOP governs the legal-medical description used in claims determinations.

Beyond these cross-references, the SOP leaves other legal interactions to the parent statutes. It does not specify interaction with workers’ compensation schemes, private law tort claims, or employment law; any overlaps between those regimes and the VEA/MRCA will be governed by the relevant statutory and common law rules, not by this SOP. The SOP’s repeal of the earlier No. 116 of 2015 instrument (s4) creates a change in the body of SOPs in force for pterygium; therefore, historical claims and decisions made under the earlier SOP may need re-evaluation in light of the new SOP depending on transitional policy and the application of the VEA and MRCA. The instrument does not itself provide transitional rules.

Finally, the SOP imposes definitional and calculative obligations on adjudicators with respect to geographic exposure: the Schedule prescribes latitude weighting factors to calculate latitude equivalent hours, which will require assessment of the geographic locations and durations of exposure during service and any civilian or non-service exposure if relevant to the claim (Schedule latitude equivalent hours). The SOP therefore interacts operationally with records of service locations, unit diaries and other documentary evidence which are produced under other administrative or legal regimes.

The instrument itself records its key dates and its relationship to the prior Statement of Principles concerning pterygium. It is dated 18 February 2025, was determined by the Repatriation Medical Authority (signed by the Chairperson) and commences on 25 March 2025 (header and ss1-2). Section 4 expressly repeals the Statement of Principles concerning pterygium No. 116 of 2015 (Federal Register of Legislation No. F2015L01671) that was made under the same subsection 196B(2) of the VEA (s4). No other amendments, revocations, or transitional arrangements are recorded in the text provided.

Because the instrument repeals the 2015 SOP, it replaces the earlier medical‑scientific positions set out in that instrument. The instrument does not include an express transitional provision about how claims that were determined under the repealed SOP should be treated after commencement; any transitional handling will therefore follow the parent statutes and administrative policy. The text provides no staged amendments or subsequent variations; it is a single instrument that takes effect on the stated commencement date and supersedes the prior SOP.

The Schedule itself contains the definitional content that supports operation of the SOP. The instrument references the ICD‑10‑AM Tenth Edition effective 1 July 2017 and notes the ISBN and copyright of that external publication (s7(3)). Any future amendment to ICD coding, or a subsequent edition, is not adopted automatically by this instrument; the SOP explicitly references the 2017 edition as the ICD source cited. The instrument does not provide a mechanism for automatic incorporation of future ICD revisions.

In short, the amendment history recorded in the instrument is limited to the repeal of the 2015 SOP and the making and commencement dates in 2025. The instrument contains no schedule of prior amendments or a history of iterative changes beyond that repeal. Users and advisers should therefore treat this instrument as the operative SOP for pterygium from 25 March 2025 unless and until the Repatriation Medical Authority issues a further SOP or amendment.

The instrument itself contains no record of litigation. It is a Statement of Principles which states the Repatriation Medical Authority’s scientific view for use in claims under the VEA and MRCA (s3, s8). The text does not mention any judicial or tribunal proceedings in which this or the earlier SOP has been litigated, nor does it list any cases. Therefore, on the sole basis of the document provided, there is no litigation history recorded within the instrument.

That absence has practical implications. The SOP is likely to be used in administrative decision-making and may be challenged or relied upon in merits review or judicial review proceedings under the VEA and MRCA, but any such litigation would appear elsewhere, in tribunal and court records, not in the instrument itself. Because the SOP repeals the 2015 instrument, prior decisions that turned on the earlier SOP may have created precedents or interpretive approaches in administrative practice; however, the SOP text does not catalogue those decisions.

Where advisers or decision-makers require an understanding of how tribunals or courts have treated the Repatriation Medical Authority’s SOPs or the reasonable hypothesis test, they will need to consult external case law and tribunal decisions. The instrument does not provide guidance on that jurisprudence and does not purport to bind courts on the legal effect of the SOP beyond being the Authority’s medical view. Any litigation history relevant to pterygium claims would therefore need to be researched in judicial and tribunal databases and is not captured by this instrument.

There are several technical, definitional and practical pitfalls within the instrument that advisers and claimants should note because they create interpretive friction in claims assessment.

1. Missing definition mismatch. Section 9 contains a note stating that "latitude equivalent hours and unprotected eye are defined in the Schedule 1 - Dictionary" (s9 note). The Schedule defines latitude equivalent hours, but it does not define "unprotected eye". That term appears repeatedly in section 9 (s9(1), s9(3)). The instrument therefore contains an internal inconsistency between its note and the Schedule. Decision-makers will need to resolve what "unprotected eye" means in practice if it is relied on in a claim.

2. Undefined temporal and clinical terms. The SOP uses "clinical onset" as the temporal anchor for the exposure thresholds in s9(1)-(3) and "clinical worsening" in s9(4). The Schedule does not define these terms. The absence of a definition can make it difficult to determine which exposures fall within the relevant look-back period and exactly when the exposure thresholds must be met. Medical records and expert evidence will therefore be critical to establish the dates of clinical onset and worsening.

3. "Appropriate clinical management" is not defined. Section 9(4) permits inability to obtain appropriate clinical management for pterygium before clinical worsening to raise a reasonable hypothesis, but the SOP does not specify what constitutes "appropriate" management. That will be a question of fact and medical opinion in each claim and may invite disputes about standards of care in different times or locations.

4. Calculation complexity and record demands. The latitude equivalent hours calculation requires disaggregation of sunlight exposure by latitude and application of weighting factors (Schedule). For claimants with service in multiple geographic zones, this will require detailed service location records and precise exposure estimates. The 2,250 threshold can be reached or missed depending on how exposure hours are computed and attributed to service versus non-service contexts.

5. Cross‑SOP dependencies. Section 11 requires reliance on other SOPs where section 9 factors refer to an injury or disease addressed elsewhere (s11). Identifying and applying the correct versions of other SOPs may be administratively complex, and inconsistent versions over time could affect outcomes. The instrument does not provide a map of those cross-references.

6. ICD-10-AM is referenced but subordinated. The SOP notes that pterygium attracts ICD‑10‑AM code H11.0 but insists that the instrument’s own definition governs (s7(3)). Reliance on coding alone without matching the textual definition risks a mismatch. Coding may support records but will not substitute for meeting the textual criteria.

7. Temporal limit on s9(4). The inability to obtain appropriate clinical management factor applies only to material contribution or aggravation where the pterygium was suffered or contracted before or during, but did not arise out of, relevant service (s10(2)). That nuance can catch claimants who seek to rely on lack of clinical management to explain onset during service.

8. No procedural or evidentiary prescriptions. The SOP does not state how exposure averages are to be proved, what documentary standards apply, or how to treat estimates. For the welding and sawdust averages (20 hours per week), there is no guidance on whether retrospective self-report, unit records, employer logs, or other documentary evidence is preferred. That increases uncertainty and will shift the burden to claimants to assemble convincing evidence.

9. Narrow exclusions. The SOP’s clinical definition explicitly excludes pseudo-pterygium and pinguecula among other non-ocular uses of "pterygium" (s7(2)). Cases where diagnosis is ambiguous may require specialist input to determine whether the claimant’s condition falls within or outside the SOP scope.

Advisers should explicitly address these gaps in evidence or interpretation early in claim preparation to reduce delay and avoid remediable rejections based on definitional uncertainty.

Compliance in this context means preparing a claim and supporting evidence so that a decision-maker applying this SOP can determine whether a reasonable hypothesis is raised linking pterygium or death from pterygium to relevant service under the VEA or MRCA (s5, s9, s10). The following practical steps are grounded in the instrument’s text and the factual thresholds it sets.

1. Confirm diagnosis against the SOP’s clinical definition. Obtain an ophthalmology report that describes the lesion in the terms of subsection 7(2): triangular or wedge‑shaped fibrovascular tissue growing horizontally in the interpalpebral fissure, attached to the cornea at its apex, attached to sclera mid‑portion, merged at the base with conjunctiva. Ensure the report rules out pseudo-pterygium and pinguecula and other excluded conditions (s7(2)). If death is claimed, obtain clinical records and cause-of-death material that link pterygium as a contributing factor to a terminal event as defined in the Schedule (s7(4); Schedule terminal event).

2. Identify which section 9 factor(s) you will rely on. At least one must be established to raise a reasonable hypothesis (s9). For sunlight exposure rely on s9(1) and prepare a calculation of latitude equivalent hours using the Schedule formula and weighting factors. For welding or sawdust exposures gather contemporaneous workplace, unit, or employer records showing average hours per week and duration requirements (s9(2)-(3)). For clinical management issues gather contemporaneous medical records that show attempts to receive care, availability of services and the timing of any worsening (s9(4)).

3. Compute latitude equivalent hours precisely. Use the Schedule weighting factors: tropical 1.0; subtropical 0.75; warm temperate 0.5; cool temperate 0.25. Multiply hours of exposure in each latitude by its weighting factor and sum across all latitudes to reach total latitude equivalent hours. The threshold set by the SOP is 2,250 cumulative latitude equivalent hours before clinical onset (s9(1); Schedule latitude equivalent hours). Document how each period of service or civilian exposure maps to the relevant latitude band.

4. Evidence for welding and sawdust exposures. For s9(2) and s9(3) you must show average exposure of at least 20 hours per week over the relevant minimum duration (two years for welding exposure, one year for sawdust). Locate trade logs, time sheets, welding job records, workshop rosters, unit tasking statements, equipment issue records and witness statements. For sawdust claims, show that the claimant was routinely covered in sawdust and that the affected eye was unprotected. The SOP does not define "unprotected eye" or prescribe what constitutes proof, so contemporaneous records and expert commentary on exposure intensity will be important.

5. Establish temporal anchors: clinical onset and worsening. Because the exposure thresholds are measured "before clinical onset" and s9(4) refers to "clinical worsening", obtain precise medical records documenting the first appearance of symptoms or lesion and dates of any documented deterioration. Where onset is uncertain, a treating clinician’s best estimate and specialist reports will be necessary.

6. Address the "appropriate clinical management" issue where relevant. If relying on s9(4) show both that appropriate care was not available or obtained and that this lack materially contributed to worsening. Provide evidence such as referral delays, clinic closures, unavailability of ophthalmic services in theatre, or denial of care, together with expert evidence linking lack of management to progression.

7. Deal with cross-references to other SOPs. If any factor refers to an injury or disease covered by another SOP, obtain and apply that SOP’s factors as current at the time of decision (s11). Identify relevant SOPs early and assemble their factors and required evidence.

8. Anticipate and address definitional gaps. Because the Schedule lacks a definition for "unprotected eye" and does not define "clinical onset" or "appropriate clinical management", supply robust contemporaneous corroboration: photographs, protective equipment issue records, witness statements, unit orders about eyewear, medical facility logs, and specialist opinions. Where necessary, obtain expert evidence that explains how the factual matrix meets the SOP’s intended meaning.

9. Use ICD-10-AM coding as supporting, not dispositive, evidence. Record the ICD‑10‑AM code H11.0 if present, but ensure the clinical narrative matches the textual definition in the SOP (s7(3)).

10. Link exposures to relevant service. Section 10 requires that the factor(s) be related to relevant service as defined in the Schedule. Establish service dates, locations and the nature of service (operational, peacekeeping, hazardous, test defence, warlike or non-warlike) with service records, muster rolls and unit histories.

11. Prepare for issues in proof. The SOP sets thresholds but not evidentiary rules. Anticipate challenges on averages and retrospective estimates. Where possible, use contemporaneous records rather than post hoc recollection. If contemporaneous records are unavailable, prepare cogent evidence and expert opinion to explain why retrospective estimates are reliable.

12. Timing and version control. This SOP commences 25 March 2025 and repeals the 2015 SOP (ss2-4). Confirm which SOP version applies to a particular claim period and be prepared to address whether decisions made under the earlier SOP are impacted by the new instrument.

Following these steps will align evidence with the SOP’s specified factual tests. Because the instrument does not define several operative terms, the quality of contemporaneous documentary evidence and clear expert medical opinion will be decisive in closing interpretive gaps and persuading decision-makers that the minimum factors required by section 9 are met and related to relevant service as required by section 10.