Anterior segment research review

April 3, 2026 Dr Kieran OKane

Advanced imaging of corneal neovascularisation with a novel swept-source AS-OCTA system

Lucchino L, Vaccaro S, Airaldi M, et al

Br J Ophthalmol 2026;110:25–30

Review: OCT angiography has been used to great effect in retinal diseases to assess flow in new vessels and attempt to quantify treatment. This study looked at whether anterior segment OCT angiography can be used to the same effect in corneal neovascularisation.

The study recruited 10 eyes with established corneal neovascularisation, plus 10 control eyes. Each eye underwent OCT-A before the instillation of 10% phenylephrine. From this, the scanner’s software determined the flow area in mm² for corneal, limbal and episcleral layers, from which the corneal layers were subdivided into total (epithelium to endothelium), superficial (epithelium to 150µm) and deep (150µm to endothelium) layers.

There was a statistical difference in flow area between the study and control groups in both total corneal flow area (13,944 +/- 6,487mm² vs 4,609 +/- 3,004mm²) and deep corneal flow areas (13,090 +/- 5,600mm² vs 4,496 +/- 3,071mm²), but not for superficial areas. A statistical difference was also noted for limbal vascularity for study (29,439 +/- 7,938mm²) and control eyes (18,278 +/-4,556mm²).

Despite the small set of patients, the study’s authors concluded that anterior segment OCT angiography can reliably be used to assess and monitor the treatment of corneal neovascularisation.

Comment: With the increasing availability of modern treatments for corneal neovascularisation – such as subconjunctival anti-vascular endothelial growth factor injections and mitomycin intrastromal chemoembolisation – the ability to monitor flow area in these vessels may help us monitor treatment effectiveness, especially given the potentially harmful side effects of these treatments. The authors also point out the potential to analyse neovascularisation in scarred corneas where deep vessels may not be visible on slit-lamp examination, owing to the OCT’s enhanced sensitivity.

Long-term clinical outcomes and anterior segment OCT findings after artificial endothelial replacement membrane implantation

Fontana L, Di Geronimo N, Versura P, Moramarco A

Cornea 2026;45:141–147

Review: Many research institutions and commercial enterprises are attempting to develop artificial corneas and corneal implants to ease the global shortage of tissue availability. The EyeYon Endoart is the first commercially available artificial corneal implant to be made available. It is sutured to the posterior cornea and deturgesces the stroma, in a similar way to endothelial transplants but without the associated risks of failure and rejection. Despite receiving lots of media attention, concerns regarding the device’s long-term efficacy remain.

This study looked at seven eyes undergoing Endoart insertion for late endothelial graft failure (five eyes) or bullous keratopathy (two eyes). Visual acuity (VA) and central corneal thickness measurements were taken immediately prior to surgery and at 1-, 3-, 6-, 12-, 18- and 24-month intervals. Device detachment was assessed using high resolution corneal OCT.

There was a statistically significant improvement in VA from 1.32 +/- 0.23 logmar to 0.95 +/-0.28 logmar two years after surgery (p=0.03). Central corneal thickness reduced from 805 +/- 131µm preoperatively to 577 +/-90µm. Detachment of the device was noted in four patients, requiring at least one rebubbling. These patients all underwent single-suture fixation, whereas the remaining three patients underwent three-point ‘Y-shaped’ fixation, none of whom developed detachment. All implants were retained at two years.

Comment: Given the increasing rates of endothelial transplantation and ongoing difficulties with tissue supply, it is reassuring to see long-term success from the Endoart device. As the authors state, more research is required to refine the fixation technique and minimise detachments. As newer synthetic corneas and corneal implants are developed it will be interesting to see how they are used alongside, or as replacements for, traditional corneal transplantation.

Topical antibiotics for treating bacterial keratitis: a network meta-analysis (review)

Song A, Yang Y, Henein C, Bunce C, Qureshi R, Ting DSJ

Cochrane Database Syst Rev 2025 Jul 29;7(7)

Review: This Cochrane review looked at 23 parallel-grouped randomised controlled trials to compare the benefits and harms of topical antibiotics for bacterial keratitis to produce a systematic review and network meta-analysis. In total, 2,692 patients were included from Australia, Canada, India, Iran, Israel, Japan, the Philippines, Serbia, Thailand, the UK and the US.

They classified six groups of intervention: monotherapy with fluoroquinolone, cephalosporin or penicillin, dual- and triple-therapy, and ‘other monotherapy’, which included povidone-iodine, honey and placebo.

They found the most effective treatments were moxifloxacin monotherapy, dual therapy with vancomycin with ceftazidime, and cefazolin with tobramycin. The least effective therapy was ciprofloxacin monotherapy.

The authors described the evidence as “mostly moderate- to very low-certainty evidence” and noted that 12 of the 23 studies were thought to be at ‘high risk of bias’, while 10 raised some concerns for bias but encouraged future research to further strengthen the results.

Comment: Ciprofloxacin is the most common first-line antibiotic in secondary care, so its poor effectiveness here is surprising. Moxifloxacin is also prohibitively expensive here in New Zealand, although it is used frequently in other countries so hopefully its use may increase. As fluoroquinolones, both are proteolytic, so patients need regular monitoring during treatment due to the risk of corneal melt. Hopefully this review will guide future research to better define local and international antibiotic efficacy.

 

Dr Kieran O’Kane is a senior corneal fellow at the University of Auckland.