EyeWorld India December 2017 Issue

EWAP FEATURE 19 Ensure optimal corneal health before cataract surgery by Vanessa Caceres EyeWorld Contributing Writer AT A GLANCE • Careful assessments can help determine how much treatment patients need for corneal disease before they have cataract surgery. • A variety of treatments are available for dry eye and lid margin disease; these problems are common in the cataract-age population. • In less severe cases of endothelial dysfunction, surgeons prefer to perform cataract surgery and endothelial surgery separately. • Generally speaking, FLACS does not provide much of an advantage when performed in combination with endothelial surgery. Views from Asia-Paci c YAO Ke, MD Professor, Eye Insittue of Zhejiang University Eye Cen- ter, Second Af liated Hospital of Zhejiang University, College of Medicine 99 Jiefang Road, Hangzhou, 310009, China Tel. no. +86-571-87783897 Fax no. +86-571-87783897 xlren@zju.edu.cn Ensure optimal corneal health before cataract surgery T he opinion about corneal health before cataract surgery raised by the global experts is worth deep consideration. Evaluation of corneal health is important before cataract surgery, consistent with Drs. Yeu andMian’s points. First, dry eyemay cause inaccuracy in IOLmeasurement and calculation, especially with toric IOLs. There is a great variance in assessment between blink and no blink during measurement. Corneal health may also affect the visual outcomes of patients implanted with multifocal IOLs. Ocular surface disease usually leads to blurred vision after surgery. In addition, both femtosecond laser-assisted cataract surgery (FLACS) and conventional phacoemulsification have adverse effects on dry eye. Furthermore, FLACS has a higher risk for staining and dry-eye symptoms, and worsens ocular staining of preexisting dry eye patients. 1 Therefore, preop assessment and treatment are indispensable steps. Although Drs. Yeu and Mian do not always perform specular microscopy, I still recommend measuring endothelial cell density before cataract surgery. The corneal endothelium is responsible for maintaining corneal transparency. When endothelial cell density significantly decreases, corneal edema may develop. In addition to academic use, endothelial cell count is intuitionistic when used to explain to patients with lower endothelial cell density why they need more time to get rehabilitation and recover after surgery. In addition, the preoperative data is a kind of evidence while meeting medical disputes. Preoperative corneal health assessment also helps recommend operation options. FLACS, as a safer and more effective choice in reducing endothelial cell loss 2 , is beneficial for patients with lower endothelial cell counts. What’s more, in patients with hard nuclear cataracts, FLACS uses lower phacoemulsification powers and reduces the potential for corneal edema and endothelial cell injury. 3 Like Dr. Chan, I would not use the femto laser to create incisions either. In our latest research, we found femtosecond laser incisions resulted in more surgically induced astigmatism and incision edema, possibly due to inaccurate or uncertain incision positioning of the LenSx machine, so manual corneal incision is recommended in FLACS before the LenSx incision locating system is updated. 4 Reference 1. Yu Y, Yao K, et al. Evaluation of dry eye after femtosecond laser-assisted cataract surgery. J Cataract Refract Surg. 2015;41(12):2614–2623. 2. Chen X, Yao K, et al. Comparing the Curative Effects between Femtosecond Laser-Assisted Cataract Surgery and Conventional Phacoemulsification Surgery: A Meta-Analysis. PLOS ONE. 2016;11(3):e0152088. 3. Chen X, Yao K, et al. Clinical outcomes of femtosecond laser-assisted cataract surgery versus conventional phacoemulsification surgery for hard nuclear cataracts. J Cataract Refract Surg. 2017;43(4):486–491. 4. Zhu S, Yao K, et al. Morphological Features and Surgically Induced Astigmatism of Femtosecond Laser versus Manual Clear Corneal Incisions. J Cataract Refract Surg. 2 017. (Accepted) Editors’ note: Dr. Yao declared no relevant financial interests. continued on page 20 December 2017 When needed, plan timing of endothelial surgery, cataract surgery depending on endothelial health E nsuring optimal health of the cornea before cataract surgery will help surgeons create the best possible surgical outcome for patients. Seasoned cataract surgeries use a number of preop assessments and treatments to evaluate and improve corneal health—and sometimes, those treatments must extend postoperatively. The goal with the preop and postop treatments is to offer great quality of vision. One important starting point when assessing corneal health is the patient history, said Elizabeth Yeu, MD, Virginia Eye Consult- ants, Norfolk, Virginia. She will inquire about things like corneal pain upon awakening, recur- rent erosions, and fluctuations in vision. She also likes to ask about glare symptoms at night. “Corneal guttata can lead to glare disproportionate to cataract,” Dr. Yeu said. If she evaluates a patient with early nuclear changes but significant guttata, she knows she will need to manage both the cornea and cataract. Assessment for ocular surface disease before cataract surgery is important, said Shahzad Mian, MD , Terry J. Bergstrom Collegiate Professor for Resident Education in Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor. Tests that he will use include tear breakup time, fluo- rescein staining, and lissamine green staining. “Many patients in the age group for cataract surgery often have dry eye disease, and it’s associated with increased tear evaporation caused by lid dis- ease,” he said. Sometimes Dr. Mian will ob- tain a Schirmer’s score, which can potentially indicate low aqueous tear dysfunction. “I also look for other causes of surface irregularity. Some are subtle, and some are easy to see,” he said. This includes searching for signs of anterior basement membrane dystrophy, which can be identified carefully with a narrow slit beam, Salzmann’s nodules, corneal scarring from previous trauma, and limbal conditions such as pterygium or