Reading Eye Certifications: What Those Codes Mean
The first eye certification form I received looked like a medical textbook exploded onto a single page. Abbreviations everywhere: PPM, PHTVL, PRA, CEA, RD. Checkboxes with terms I had never seen. A section labeled "Breeder Option" that nobody had explained to me. I stared at that form for an hour trying to figure out what it actually meant about my dog.
Now I can glance at an eye form and understand it in seconds. But that understanding took years to develop, and I wish someone had given me a plain-English translation earlier. Here is that translation, covering the most common codes you will see and what they mean for your breeding decisions.
Understanding the Form Structure
The OFA Eye Certification Examination form is divided into sections corresponding to different parts of the eye. Each section lists potential abnormalities, and the ophthalmologist checks boxes or writes notes for anything found.
At the bottom, there is an overall certification decision: Normal (passes), Breeder Option (findings present but potentially acceptable), or Not Recommended for Breeding (fails). But that bottom-line result only makes sense when you understand what was found above it.
Key Sections of the Form
- Lids: Eyelid abnormalities like entropion, ectropion, distichiasis
- Third Eyelid: Problems with the nictitating membrane
- Cornea: Clarity and health of the outer eye surface
- Anterior Chamber: Space between cornea and iris, including angle for gonioscopy
- Lens: Cataracts and lens positioning
- Vitreous: Gel filling the eye
- Fundus/Retina: Back of the eye including retina, optic nerve, choroid
Common Codes and Their Meanings
Persistent Pupillary Membranes (PPM)
PPM refers to remnants of the blood vessel network that supplied nutrition to the lens during fetal development. These vessels normally disappear before birth, but sometimes strands persist.
PPM is graded by where the strands attach:
- Iris-to-iris: Strands stretch across the pupil from one part of the iris to another. Usually minor.
- Iris-to-lens: Strands attach to the lens capsule. Can cause small opacities.
- Iris-to-cornea: Strands attach to the cornea. May cause minor scarring.
Most PPM is classified as "Breeder Option" because minor iris-to-iris strands are extremely common and rarely affect vision. Iris-to-lens and iris-to-cornea are more significant because they can leave permanent marks, but even these are often minor.
In my Collies, I see mild iris-to-iris PPM occasionally. I do not consider it disqualifying unless it is extensive. My current stud has a single iris-to-iris strand in his left eye that has been there since his first exam at eight weeks. It has never changed and has produced no problems in his offspring.
Cataracts
Cataract codes indicate cloudiness in the lens. The form specifies type, location, and stage:
- Location: Nuclear (center), cortical (outer layer), capsular (lens covering), equatorial (edge)
- Stage: Incipient (early/small), immature, mature, hypermature
- Progression: Static (unchanging), progressive (worsening)
Some cataracts are clearly hereditary and disqualifying. Others are age-related, traumatic, or of uncertain significance. The ophthalmologist's notes help distinguish these, but interpreting cataract findings often requires discussion.
In breed-specific terms, what matters varies. For my Collies, posterior polar cataracts are a known hereditary form and any finding of this type is serious. Punctate cortical cataracts in an older dog might be age-related and less concerning. Context matters enormously with cataracts.
Not all cataracts are hereditary. Age-related cataracts, diabetic cataracts, and trauma-induced cataracts look different and have different implications. If cataracts are found, ask your ophthalmologist specifically whether they appear hereditary or have another cause.
Progressive Retinal Atrophy (PRA)
PRA is a group of inherited diseases causing progressive vision loss ending in blindness. It affects dozens of breeds, though different genes and forms exist in different breeds. Your veterinary ophthalmologist can explain the specific implications for your breed.
Early PRA may appear as increased retinal reflectivity or subtle changes in the tapetum (reflective layer). Advanced PRA shows blood vessel attenuation and optic disc changes. Any finding suggestive of PRA is serious.
For breeds where PRA is common, DNA testing now exists for many forms. The eye exam detects clinical signs, but DNA testing identifies carriers before any eye changes appear. Both tests are valuable. Eye exams catch forms without DNA tests available; DNA tests catch problems before clinical manifestation.
Collie Eye Anomaly (CEA)
CEA is a complex of abnormalities specific to Collies and related breeds (Shetland Sheepdogs, Australian Shepherds, Border Collies). The classic sign is choroidal hypoplasia, a patchy appearance to the choroid visible with ophthalmoscopy. Understanding when to retest is particularly important for breeds at risk of CEA.
CEA grades range from mild choroidal hypoplasia (minimally affected) to severe with colobomas, retinal detachment, and hemorrhage (seriously affected). The mild form has minimal impact on vision; the severe form can cause blindness.
What complicates CEA is that mild cases can be harder to detect in adult dogs due to pigment changes. Puppy exams at 6-8 weeks are actually more reliable for detecting mild CEA than adult exams. This is why Collie breeders screen litters as puppies, not just breeding stock as adults.
DNA testing for CEA is now standard in Collie breeding. The eye exam remains valuable for detecting severe forms and monitoring, but DNA testing has largely replaced eye exams as the primary CEA screening tool.
Retinal Dysplasia (RD)
Retinal dysplasia refers to abnormal development of the retina. It ranges from minor folds (slight wrinkles) to geographic changes (larger malformations) to complete detachment (serious).
- Retinal folds: Often noted in young dogs, may or may not persist. Significance depends on breed and number of folds.
- Geographic RD: Larger areas of abnormal retina. More concerning.
- Detachment: Serious condition affecting vision.
Minor retinal folds in puppies sometimes resolve or become less visible as the eye matures. This is why retesting is recommended if folds are found in a young dog. Geographic or detached forms do not improve.
Distichiasis
Extra eyelashes growing from abnormal locations. Ranges from a few scattered extra lashes to extensive rows. The issue is whether these lashes contact and irritate the cornea.
Mild distichiasis with no corneal contact is typically "Breeder Option." The extra lashes exist but are not causing problems. Distichiasis with corneal contact or damage is more serious and may fail certification.
Many breeds commonly carry mild distichiasis with no clinical significance. I have seen forms with "distichiasis - multiple" that sound alarming but the ophthalmologist notes "no corneal contact, clinically insignificant." Understanding the actual finding matters more than the label.
Entropion and Ectropion
Entropion is inward rolling of the eyelid, causing lashes or skin to contact the cornea. Ectropion is outward rolling, exposing the inner eyelid. Both are structural lid abnormalities.
These are breed-related to some degree. Breeds with loose facial skin are prone to ectropion. Breeds with tight skin around the eyes may have entropion. Severity matters: mild entropion might be noted but not disqualifying, while severe entropion causing corneal ulcers would fail.
| Code | Full Name | Typical Outcome |
|---|---|---|
| PPM I-I | Persistent Pupillary Membrane, iris-to-iris | Usually Breeder Option |
| PPM I-L | Persistent Pupillary Membrane, iris-to-lens | Breeder Option to Fail |
| CAT | Cataract (various types) | Depends on type/location |
| PRA | Progressive Retinal Atrophy | Fail |
| CEA | Collie Eye Anomaly | Fail (affected) |
| RD | Retinal Dysplasia | Depends on severity |
| DIST | Distichiasis | Usually Breeder Option |
| ENT | Entropion | Depends on severity |
| ECT | Ectropion | Depends on severity |
| PHTVL | Persistent Hyperplastic Tunica Vasculosa Lentis | Breeder Option to Fail |
Understanding the Bottom Line Results
Normal
This means the eye exam found nothing disqualifying. The dog passes and can be certified. Minor findings that do not affect the certification may still be noted in the comments, but the overall result is clear for breeding.
Breeder Option
This is the confusing category. It means the ophthalmologist found something, but that something falls into a gray area where breeding decisions are left to the individual breeder.
Common "Breeder Option" findings include:
- Minor iris-to-iris PPM
- Mild distichiasis without corneal contact
- Small retinal folds in young dogs
- Punctate cataracts of uncertain significance
The breeder decides whether to breed based on the specific finding, its significance in the breed, and the overall quality of the dog. For example, I have bred dogs with minor PPM because it is extremely common and benign in Collies. I would not breed a dog with even mild cataracts because cataracts are a serious concern in my breed.
"Breeder Option" does not mean "probably fine." It means the decision is yours, and you need to understand what was found. Ask questions. Research the finding in your breed. Consult your breed club health committee. Make an informed choice.
Not Recommended for Breeding
This means something was found that disqualifies the dog from certification. Clear-cut hereditary conditions like PRA, significant cataracts, or severe structural abnormalities fall here.
A dog that fails can still be a wonderful pet. Failing certification does not mean the dog will go blind or suffer. Many disqualifying conditions cause minimal to no clinical problems for the individual dog. The concern is heredity. Breeding affected dogs passes the problem to future generations.
Practical Interpretation Tips
Read the Full Form
Do not just look at the bottom line. Read every section and every note. The overall result tells you pass/fail, but the details tell you what was actually found and why.
Ask Your Ophthalmologist
If you do not understand something, ask. At the time of the exam, ask for explanation. Call the practice later if you have follow-up questions. A good ophthalmologist expects these questions and would rather you understand than guess.
Consider Breed Context
What matters depends on breed. A finding common and accepted in one breed might be rare and concerning in another. Know your breed's specific issues and consult breed health resources.
Track Changes Over Time
Some findings are more significant if they change. A small cataract that stays stable for three years is different from one that grows every exam. Keep records and compare them.
DNA Testing Complements Eye Exams
For conditions with available DNA tests (PRA variants, CEA, others), DNA testing adds information that eye exams cannot provide. A dog might pass eye exams but carry a PRA gene. The combination of clinical exams and genetic testing gives the most complete picture. For comprehensive information on DNA testing options, refer to the resources available through OFA's DNA testing programs.
My Approach to Interpreting Results
When I get an eye form back, here is my process:
- Look at the bottom line first. Pass, Breeder Option, or Fail?
- Read every section to see what was found.
- For any finding, ask: Is this hereditary? Is it common in my breed? Does it affect vision? Has it changed from previous exams?
- If Breeder Option, research the specific finding and make a deliberate decision about breeding.
- File the form with all previous eye records so I can track any dog's eye history easily.
Over time, this becomes second nature. You learn what codes mean, what matters in your breed, and how to make sound breeding decisions based on exam results.