In the “Cataract Surgery in Patients with Corneal Disease” session at the 2025 meeting of the American Society of Cataract and Refractive Surgery, Zeba A. Syed, MD, Director of Cornea Fellowship and Associate Professor of Ophthalmology at Wills Eye Hospital, Thomas Jefferson University, said there are 3 reasons why we should care about the cornea.
“First, corneal diseases can affect accurate intraocular lens (IOL) selection; second, cataract surgery has the potential to contribute to the progression of preexisting corneal diseases; and third, corneal diseases can limit optimal visual outcomes after cataract surgery,” she said.
Dr. Syed then provided an overview of several corneal diseases and what physicians need to know when it comes to treating cataract patients.
Dry Eye Syndrome
In her presentation, Dr. Syed explained that significant dry eye affects topography, and as a result, prevents precise keratometry readings for accurate IOL calculations. This is particularly important, she said, if you are planning to place a premium lens. She also pointed out that surgery and postoperative drops—especially, nonsteroidal anti-inflammatory drugs (NSAIDs)—exacerbate dry eye.
"Significant dry eye can inhibit our ability to obtain reliable keratometry readings, and thus it is critical to treat the ocular surface prior to performing biometry for IOL selection," explained Dr. Syed.
Anterior Basement Membrane Dystrophy
Next, Dr. Syed discussed anterior basement membrane dystrophy (ABMD) and said that it should be treated if the patient is symptomatic, desires a premium IOL, or if there is irregular astigmatism involving the central cornea. She also emphasized that the physician should get topography on all cases, especially those with ABMD, prior to cataract surgery.
Dr. Syed said that the treatments available for ABMD are epithelial debridement with or without diamond burr and phototherapeutic keratectomy (PTK).
"After surgically treating ABMD, I generally wait at least 3 months until topography has stabilized prior to performing biometry," she explained.
Herpes Simplex Keratitis
Dr. Syed also discussed herpes simplex keratitis, noting that HSV-1 is the most common cause of infection-related vision loss in developed countries. Anterior segment manifestations, she said, include conjunctivitis, keratitis, uveitis, and trabeculitis. She also noted that cataract surgery may trigger recurrence of HSV keratitis.
"The disease should be inactive for at least 3 months prior to cataract surgery, and antiviral prophylaxis at the time of surgery can also reduce the risk of recurrence," said Dr. Syed.
Keratoconus
Dr. Syed also explained that visually significant cataracts are found at an earlier age in keratoconus (KCN) patients, and lack of progression of keratoconus must be documented—if there is progression, corneal cross-linking can be performed if the patient is a candidate.
Dr. Syed said that incisions can be placed at the limbus or sclera for less induced astigmatism. She also pointed out that toric IOLs will not correct the irregular component of astigmatism.
"It is important to keep in mind that toric IOLs only correct the regular component of astigmatism. In an individual with a significantly irregular cornea, avoid a toric IOL as it would make future contact lens fitting challenging.”
In addition, Dr. Syed said, if a rigid gas permeable lens or future keratoplasty is needed, the astigmatism of the toric IOL will become manifest. The ideal patient for a toric IOL, she said, has stable KCN, has no interest in wearing contact lenses after surgery, and has had significant vision improvement with refraction.
Fuchs Endothelial Corneal Dystrophy
Finally, Dr. Syed explained that Fuchs endothelial corneal dystrophy often exists concurrently with cataracts, and in mild cases, the physician may perform cataract surgery alone.
Dr. Syed also stressed several concerns for performing a combined triple procedure—the viscoelastic used in cataract surgery may impede graft adherence; the IOL optic may damage the graft or increase endothelial cell loss; and postoperative inflammatory responses could contribute to increased graft rejection or failure.
“In cases of mild Fuchs, cataract surgery should be performed with extra viscoelastic use and with surgical techniques that reduce phacoemulsification energy requirements," she concluded. OM