33 EyeWorld Asia-Pacific | June 2025 CORNEA Zeba A. Syed, MD, said that slit lamp evaluation prior to cataract surgery will generally reveal clues as to what is causing the opacified cornea. “During preoperative evaluation, it is crucial that the clinician obtain additional history or testing to ascertain possible underlying etiologies for the corneal opacification,” she said. “Specifically, the surgeon should identify the chronology of the opacification, progression, and history of prior infection. Diagnostic tools may include topography, tomography, pachymetry, specular microscopy, and anterior segment OCT.” Dr. Syed also noted that corneal opacification may be due to a number of etiologies. “Prior infection is a common cause of corneal scarring. While bacterial keratitis is common, the surgeon must also consider the possibility of herpetic infection because viral reactivation is a concern after intraocular surgery. In these latter cases, prophylactic antiviral in the perioperative period should be considered,” she said. Keratoconus is another common cause of cornea scarring, often in those with prior hydrops, and Dr. Syed said these patients may have a chronic history of poor vision or hard contact lens use. In cases where it is hard to ascertain whether visual impairment is arising primarily from the cataract or the cornea, a hard contact lens over refraction can be performed, she said. “A careful history should be performed to understand what the patient’s vision was prior to the cataract forming but after the opacity developed, as this helps manage postoperative expectations,” Dr. Syed said. “In cases of dense corneal scarring, combined penetrating keratoplasty with cataract surgery can be considered. In younger patients, I often discuss staged penetrating keratoplasty followed by cataract surgery after topographic stabilization. When cataract surgery is performed in the presence of corneal scarring, patients can be referred for a hard contact lens fitting 4–6 weeks after cataract surgery.” In other cases, Dr. Syed said corneal opacification may be due to underlying endothelial dysfunction, and edema with possible haze or scarring may be the primary clinical features. “Specular microscopy should be performed bilaterally to determine endothelial cell density, and pachymetry should be obtained to determine corneal thickness,” she said. “Patients should be counseled on the risk of further endothelial decompensation after cataract surgery. In more advanced cases, combined endothelial keratoplasty with cataract surgery may be indicated. Alternatively, staged keratoplasty may be better for patients with unreliable keratometry or higher refractive demands. Intraoperative visibility is the primary concern when performing cataract surgery under an opacified cornea, Dr. Syed said. “With poor visibility, surgical complications, such as capsular tears, are more likely. Depending on the underlying etiology of the opacity, various approaches may be taken to improve visibility prior to surgery. In the case of superficial stromal scars, superficial keratectomy with PTK laser may be an option, she added. “I perform an anterior segment OCT to measure the depth of pathology and to plan my PTK treatment,” Dr. Syed said. “The benefit of this approach is that it can, in a fairly predictable way, laser away the scarring while leaving the cornea smooth enough for reliable keratometry and predictable refractive outcomes. If this approach is taken, I typically wait about 3 months before repeating biometry for cataract surgery.” When considering the challenge of intraoperative visibility, Dr. Syed said there are various tools to help overcome this. The light microscope’s settings can be tweaked to improve the red reflex, which can be extremely helpful during capsulorhexis construction, she said. “I often use capsular staining with trypan blue to help enhance visibility of the Patient with stromal rejection following DALK treated with alternating mitomycin-C and bevacizumab injections for 18 months, resulting in improvement in lipid and scarring; underwent cataract surgery and received a scleral lens— now 20/20. Source: David R. Hardten, MD Example of corneal opacities from granular corneal dystrophy. Source: Kevin M. Miller, MD Example of Haab’s striae from forceps delivery birth trauma. Source: Kevin M. Miller, MD
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