To use ultra-high-resolution optical coherence tomography (OCT) subclinical anatomic alterations to explain suboptimum vision despite pseudophakic cystoid macula edema (CME) resolution.
University of ...California-Davis, Sacramento, California, USA.
Case study.
This study comprised patients who had cataract phacoemulsification surgery. Cases of resolved postoperative CME (diagnosed postoperatively by 1 month and resolved by 1 year) were included. Exclusion criteria included any other cause for decreased vision or compounding factors. Patients with a history of resolved pseudophakic CME were imaged using a purpose-built ultra-high-resolution OCT system with 4.5 μm axial resolution and an acquisition speed of 9 frames/sec (1000 A-scans/frame). The corrected distance visual acuity (CDVA) was determined by Early Treatment Diabetic Retinopathy Study standards. Statistical analysis was by the unpaired t test. A P value less than 0.05 was considered significant.
The review identified 56 patients with a pseudophakic CME diagnosis at least 1 month postoperatively. Fifteen eyes (26.8%) had less than 20/20 CDVA despite resolution of CME; 7 participated. Four patients with 20/20 CDVA after resolution of pseudophakic CME participated. Eyes with reduced CDVA after macula edema showed ultra-high-resolution OCT evidence of blurring of outer segments of photoreceptors, while controls showed normal outer retina morphology (P<.05).
Persistent anatomic alteration of photoreceptors visualized by ultra-high-resolution OCT correlated with reduced CDVA in patients with pseudophakic CME compared with patients who had 20/20 CDVA after macula edema. This anatomic alteration in outer photoreceptor morphology is a plausible explanation for the reduced CDVA in this disease.
No author has a financial or proprietary interest in any material or method mentioned.
(1) To evaluate the accuracy of nomogram-based adjustment of intraocular lens (IOL) power to achieve a desired refractive target after cataract surgery in postmyopic LASIK and photorefractive ...keratectomy (PRK) eyes and (2) to compare the accuracy of the nomogram-based method with the clinical history method.
Multicenter, retrospective, interventional, noncomparative case series.
Fourteen patients (19 eyes) after myopic LASIK or PRK with visually significant cataracts.
All eyes underwent cataract extraction and posterior chamber intraocular lens implantation. In each case, IOL power was determined with standard keratometry and biometry. Power adjustment was made by use of a theoretical nomogram followed by implantation.
(1) Final refraction and spherical equivalent after cataract surgery and (2) deviation of the final spherical equivalent from the refractive target.
After cataract extraction, by use of nomogram adjustment, 63.2% of eyes were within 0.5 D of the intended spherical equivalent, 84.2% were within 1.0 diopter of the intended spherical equivalent, and 100% were within 1.5 D of the intended spherical equivalent. The clinical history method was accurate in predicting the correct IOL power in 37.5% of cases, regardless of whether spectacle or corneal plane refraction was used.
(1) Given the change in spherical equivalent induced by myopic LASIK/PRK, IOL power can be adjusted accurately to avoid undercorrection without the need for the prerefractive surgery corneal power. (2) The nomogram-based method was more accurate than the clinical history method.
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