Cataract Phacoemulsification and Intraocular Lens Implantation in a Small Pupil Case

A Thornton fixation ring is placed around the cornea to stabilize the eye as a 1.2-mm side port blade is used to make a corneal incision. A mixture of epinephrine 2% and preservative-free 1% lidocaine is injected into the anterior chamber for extra dilation and anesthesia. Viscoelastic is then injected to replace the aqueous humor and maintain the anterior chamber. The main clear-corneal incision is made at the temporal limbus with a 2.4-mm keratome blade. A continuous circular capsulorrhexis is carried out using a cystotome. The anterior capsular flap is then removed with Utrata forceps. Hydrodissection is performed by injecting balanced saline solution between the anterior capsule and the lens, creating a fluid wave that separates the lens from the capsular bag. The nucleus is removed using a divide and conquer technique. A Drysdale second instrument is placed through the side port while the phacoemulsification handpiece is used through the main corneal incision. The nucleus is rotated 90 degrees at a time as the phacoemulsification handpiece grooves the nucleus into four quadrants. The nucleus is then cracked into four quadrants using a cross-handed technique. Each nuclear quadrant is then removed one at a time using the phacoemulsification handpiece on higher vacuum settings. The irrigation and aspiration handpiece is used to remove contiguous sectors of cortex from the capsular bag. Viscoelastic is injected to inflate the capsular bag in preparation for IOL insertion. A folded posterior chamber intraocular lens is then inserted using a lens injector. The lens spontaneously unfolds in the proper “backwards S” orientation. A Kuglen hook is used to facilitate the position of the intraocular lens in the capsular bag. The viscoelastic is then removed from the capsular bag and anterior chamber with the irrigation and aspiration handpiece. The wounds are sealed by hydration with balanced saline solution using an irrigating cannula. This maintains the appropriate intraocular pressure. A Weck Cel cellulose spear is used to check for wound leaks, and the intraocular pressure is assessed by palpating with the other end of the Weck Cel. The procedure concludes with the application of topical prednisolone acetate and ofloxacin drops.

Phacoemulsification is the gold standard procedure for removing cataracts in developed countries. Cataract surgery is indicated when patients have symptoms due to their cataracts that can affect their lifestyle and removal of the cataracts is expected to improve their visual acuity. These symptoms include blurred vision, glare, poor night vision, change in refractive status, reduced contrast sensitivity, and difficulty discerning colors.[1]

Extracapsular cataract extraction may be preferred over phacoemulsification in patients with very dense cataracts, compromised corneal endothelium, or loose zonules.

The patient was positioned supine in the operating room. A proparacaine hydrochloride 0.5% eyedrop, betadine (povidone-iodine 5%) antiseptic drops, and then lidocaine ophthalmic gel for topical anesthesia were applied to the operative eye. Sterile drapes were placed over the face and head in the usual fashion for intraocular surgery. An eyelid speculum was placed in the eye to keep the eyelids open during the procedure. The patient received mild intravenous sedation during the surgery.

Preoperative workup entails obtaining a history of present illness, complete ocular history, medical history, dilated physical examination of the eyes, and neuropsychiatric evaluation to assess the patient’s ability to follow commands. The goals of the preoperative evaluation are to confirm that the patient’s symptoms are attributable to cataracts, identify and prevent potential sources of intraoperative complications, provide informed consent, and define patient and surgeon expectations for outcomes of the surgery.[2][3] The history of present illness should include details about the patient’s symptoms and the effects of cataracts on their quality of life. Measurements of the eye’s axial length and curvature of the cornea are taken and then used in formulas to calculate an ideal intraocular lens power.

The lens is suspended behind the iris by zonular fibers that are attached to the ciliary body and lens capsule on opposite ends. The three layers of the lens from outermost to innermost are the capsule, cortex, and the nucleus. Cataracts can form in the different lens layers. Posterior subcapsular cataracts form at the back of the lens on the inner surface of the posterior capsule. Cortical cataracts appear in the lens cortex. Nuclear sclerotic cataracts affect the lens nucleus.

Cataract surgery is a short procedure that safely and effectively removes cataracts from the eye. Intraocular lens placement can correct significant amounts of a patient’s refractive error. The advantages of phacoemulsification over extracapsular cataract extraction include small self-sealing incisions, reduced requirement for sutures, and less induced astigmatism.

The rates of complications associated with cataract surgery are low.[4] Posterior capsular rupture is the most common intra-operative complication and can lead to a dropped nucleus, vitreous loss, retinal detachment, and cystoid macular edema. A vitrectomy is required to manage the complication of vitreous prolapse and its associated risks.[5] Endophthalmitis is an uncommon but devastating complication of cataract surgery. Measures routinely taken to prevent endophthalmitis include using povidone-iodine antiseptic, appropriately draping the surgical field to ensure that the eyelashes are excluded, and administering antibiotic drops at the end of surgery and for 1 week postoperatively. The most common post-operative complication is posterior capsular opacification, which is treated with YAG laser capsulotomy when visually significant. Smaller pupils can present added challenges to the cataract surgeon and are associated with potential complications, including capsular tear, postoperative ocular hypertension, iris damage, inappropriate intraocular lens placement, retained lens fragments, and cystoid macular edema from inflammation caused by iris manipulation.[6-9] Risk factors for intraoperative miosis include certain medical conditions, such as pseudoexfoliation syndrome, uveitis, diabetes, and past ocular trauma.[10] Previous intraocular surgeries, femtosecond laser treatment, and prolonged duration of surgery are also associated with pupillary miosis.[10] Many pharmacologic agents cause miosis, most notably alpha adrenergic antagonists. Intracameral mydriatics, such as lidocaine-epinephrine, known as epi-Shugarcaine, are often used for intraoperative management of small pupils. In addition, instruments such as iris hooks and expansion rings can be used to mechanically enlarge a pupil if it is very small.

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