Whether you’re a new graduate or a general practitioner, keeping up with the latest evidence in veterinary medicine can be hard work. This month, we’ve gathered some of the best studies published since 2023 in small animal ophthalmology, summarised them for you, and produced key takeaways so you can discover why and how they might change the way you practice.
Paper 1: How common is lens capsule disruption in cataract surgery?
The authors in this study published in Veterinary Ophthalmology retrospectively looked at the medical records of 520 eyes that underwent phacoemulsification at the Queen Mother Hospital for Animals, Royal Veterinary College. They included eyes with and without lens capsule disruption (LCD) and then looked at the aetiology of the LCD, the location of the LCD, whether a lens was placed, and the results of the surgery, including any vision loss up to two years later.
Why this is an important study in small animal ophthalmology
LCD is a recognised complication of cataracts and cataract surgery in humans and in small animal ophthalmology, but this study provides more information as to the prevalence and risks of LCD, which is important for surgical planning and informed consent. It also revealed the first reported cases in the literature of spontaneous LCD in non-diabetic patients with non-rapidly progressing cataracts.
Key takeaways for vets
- 27.9% of eyes had LCDs, making them more common than previously thought
- 73.1% of spontaneous LCDs were diagnosed on preoperative ocular ultrasound (eg irregularity of lens capsule, hyperechoic amorphous material within the vitreous), making this a useful method for preoperative planning, especially where opacity from the cataracts prevents good visualisation with a slit lamp
- Spontaneous LCDs are more common in diabetic patients, but were present in other types of patients, making preoperative ultrasound important in all patients, not just those at high risk
- Although placement of intraocular lens was significantly decreased in the LCD group, it was still 73.8%, showing that, with an experienced surgeon, modern lenses, and good planning, these eyes can still have optimal surgery and good potential for vision restoration.
- Despite this, eyes without LCD were significantly more likely to have vision at 1 year than those with LCD, mainly due to retinal detachment
- Postoperative complications were not significantly more likely in either group when measured across all timepoints.
Paper 2: Is corneal thermal cautery a good treatment for indolent ulcers?
In this retrospective study, the authors looked at 20 years of records from the Veterinary School of Toulouse to find patients who had had treatment for Spontaneous Chronic Corneal Epithelial Defects (SCEEDs) using Corneal Thermal Cautery (CTC) alongside debridement (eg cotton tip debridement or diamond burr debridement). They found records for 89 eyes (77 dogs from 28 breeds) that met the criteria, then examined the variables leading to healing rates and complication rates.
Why this is an important study in small animal ophthalmology
SCEEDs (also known as indolent ulcers, Boxer ulcers, and refractory/recurrent corneal erosions) are common, painful, and can last for weeks or months if not handled correctly. Corneal thermal cautery was first described in animals in 2004 with a 100% success rate, but just 9 cases were investigated. This paper aimed to describe the outcomes of CTC in a larger group of dogs.
Key takeaways for vets
- Brachycephalic breeds, especially French Bulldogs, English Bulldogs, and Boxers, continue to be over-represented in SCEEDs cases.
- The average success rate for the first procedure was about 65.1%, but didn’t differ between those treated with CTC and cotton bud debridement vs those treated with CTC and diamond burr debridement. The success rate could be underestimated though, as 23 dogs were lost to follow up.
- The complication rate was 22%, with corneal pigmentation being the most common complication.
- Corneal thermal cautery (CTC) is a safe and effective adjunct to epithelial debridement for dogs with SCEEDs, and can be undertaken with no sedation, unlike the main alternative, which is a grid keratotomy.
Paper 3: What causes ocular surface disease in cats?
The authors analysed samples from 255 cats with Ocular Surface Disease (OSD) living in animal shelters in the US. Each cat was scored using an objective scoring scheme, then the sample taken, and the pathogens present compared.
Why this is an important study in small animal ophthalmology
Ocular surface disease is extremely common, especially in young cats and those in shelters. Since many of the diseases found to be present are highly contagious and can have long-lasting effects, understanding the likelihood of particular diseases being the cause of OSD is helpful. In addition, this paper adds to the evidence that Mycoplasma and Feline Calicivirus may act as primary pathogens in OSD.
Key takeaways for vets:
- Clinical scores of OSD were similar between different numbers and types of pathogens, so clinical examination is not recommended as a way to diagnose the cause of OSD.
- While herpesvirus (FHV-1) was commonly detected (42.7%), mycoplasma was more commonly detected (76.4%). This is interesting, as FHV-1 was hypothesised by the authors as being the most common pathogen. In addition, lots of treatments for OSD target viral DNA polymerase, and these would be ineffective if FHV-1 isn’t present.
- None of the tested pathogens were found in 7.1% of the samples, suggesting that non-infectious OSD (or OSD caused by an unidentified pathogen) is also common in shelter cats. Non-infectious causes such as allergic/hypersensitivity conditions, tear film disorders and eosinophililc conjunctivitis should be considered by vets being presented with OSD.
- Mycoplasma was the most common mono-infection (12.5% of animals), increasing the likelihood of this pathogen being capable of causing OSD in cats. However, it’s also possible that these patients had a non-clinical cause or unidentified primary pathogen, and mycoplasma was incidental.
Paper 4: Should the eyes be open or closed for a Schirmer Tear Test in dogs?
In this paper in Veterinary Ophthalmology, the authors compared Schirmer Tear Test (STT) readings in healthy dogs. They tested 15 Shih Tzus (as a brachycephalic breed) and 15 Labrador Retreivers (as a non-brachycephalic breed) with their eyes open or closed, then – after a 30-minute break – with the other testing method. The objective was to discover the extent to which the eyelid status (open or closed) influenced STT readings in dogs.
Why this was an important study in small animal ophthalmology
The Schirmer Tear Test is a common test in small animal practice and is often undertaken by general practitioners as well as by veterinary ophthalmologists. STT readings are often compared over time to assess deterioration or response to treatment, so any technique-related differences in results are important to address.
Key takeaways for vets
- Closed eyelids significantly decreased the likelihood of the STT strip being dislodged and having to be replaced.
- Closed eyelids significantly increased the STT readings, so vets should be consistent with their STT technique to ensure repeatability. If other vets are likely to see the patient at follow-up appointments, the method used (closed vs open) should be outlined in the notes so that the STT results are comparable.
- A survey of the veterinary ophthalmology community showed that 34.6% of vets didn’t pay attention to whether their STT tests were open or closed, suggesting technique-based differences in results may be a common problem with this test.
Conclusion
Like all areas of veterinary medicine, the world of small animal ophthalmology is constantly evolving thanks to the hard work of researchers.
Don’t forget to log reading this article as CPD in your RCVS 1CPD account. We recommend putting the activity type as ‘Self-directed – Veterinary reading’. You’ll also need to reflect on what you learned – will any of the takeaways above change how you approach ophthalmology cases? Has this article revealed an interest in small animal ophthalmology, or made you release you need to take more ophthalmology CPD? If you’re still stuck on your reflection, try our article for help reflecting on your veterinary CPD.
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Small Animal Ophthalmology
ISVPS General Practitioner Certificate (GPCert)
HAU Postgraduate Certificate (PgC)
Sept 2026
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