Cataract surgery

FDA approved intraocular injections include mio-tics, viscoelastics, and viscoadherents and an antiviral agent for intravitreal injection. The approved intraocular miotics, carbachol (Miostat ) and acetylcholine (Miochol ), are injected into the anterior chamber at the end of cataract surgery to constrict the pupil and allow the iris to cover the implanted intraocular lens. Carbachol is formulated in a BSS vehicle in sterile water for injection at a physiological pH... 

Acetylcholine does not have therapeutic value as a drug for intravenous administration because of its multi-faceted action and rapid inactivation by cholinesterase. Likewise, it is possible for a collaptoid state to develop, and arterial pressure can rapidly fall and the heart can stop. However, it is used in the form of eye drops to cause miosis during cataract surgery, which makes it advantageous because it facilitates quick post-operational recovery. A synonym of this drug is miochol. 

Advanced chronic simple glaucoma and glaucoma secondary to cataract surgery Instill 0.03% solution twice daily, as above. 

Cataract surgery The use of steroids after cataract surgery may delay healing and increase the incidence of bleb formation. 

Another group which is used to mask polar groups in molecules in order to improve GC peak shape is the trimethylsilyl group. Atropine Eye Drops BP are used to dilate the pupil prior to cataract surgery. The 1993 BP method for the analysis of Atropine Eye Drops BP uses derivatisation with a trimethylsilyl group to mask an alchohol group as shown in Figure 11.17. 

Because ACh is rapidly inactivated by cholinesterases, its use is best suited for clinical applications requiring only a brief duration of action, such as when it is employed to cause miosis during cataract surgery. ACh... 

Unlabeled Uses Postcycloplegic intraocular pressure spikes, intraocular pressure from post cataract surgery. 

Cataract surgery Ophthalmic Apply 1 drop to eye 4 times a day commencing 24 hr after cataract surgery. Continue for 2 wk afterward. 

Unlabeled Uses Treatment of vascular headaches (oral) to reduce the occurrence and severity of cystoid macular edema after cataract surgery (ophthalmic form)... 

Mechanism of Action Aphenylalkanoicacid that produces analgesic and anti-inflammatory effect by inhibiting prostaglandin synthesis. Also relaxes the iris sphincter Therapeutic Effect Reduces the inflammatory response and intensity of pain. Prevents or decreases miosis during cataract surgery. 

Soliman MM, Macky TA, Samir MK. Comparative clinical trial of topical anesthetic agents in cataract surgery lidocaine 2% gel, bupivacaine 0.5% drops, and benoxinate 0.4% drops. J Cataract Refract Surg. 2004 30 1716-1720. 

Bullous keratopathy is a major complication of cataract surgery. In the past, penetrating keratoplasty was considered the most effective therapy for the symptomatic stage of the disease. Other surgical options have included conjunctival flaps, enucleation (reserved for blind, painful eyes) and, more recently, deep phototherapeutic keratectomy and amniotic membrane transplantation. Medical therapy of bullous keratopathy using hypertonic saline (Nad 5%) has been of marginal benefit due to its relatively weak osmotic effect. 

Watsky MA, McDermott ML, Edelhauser HF (1989) In vitro corneal endothelial permeability in rabbit and human the effects of age, cataract surgery and diabetes. Exp Eye Res 49(5) 751—767... 

Chang DF, Garcia IH, Hinkeler JD, Minas T. Phase II results of an intraocular steroid delivery system for cataract surgery. Ophthalmology 1999 106 1172-1177. 

Tan DT, Chee S, Lim L, LimA. Randomized clinical trial of a new dexamethasone delivery system (Surodex) for treatment of post-cataract surgery inflammation. Ophthalmology 1999 106 223-231. 

Use of intracameral lidocaine has been introduced as a method of supplementing topical anesthesia during cataract surgery. Unpreserved 1% lidocaine is injected into the anterior chamber immediately after the paracentesis incision before injection of viscoelastic agent. 

Crandall AS, Zabriskie NA, Patel BCK, et al. A comparison of patient comfort during cataract surgery with topical anesthesia versus topical anesthesia and intracameral Udocaine. Ophthalmology 1999 106 60-66. 

Maclean H, Burton T, Murray A. Patient comfort during cataract surgery with modified topical and peribulbar anesthesia. J Cataract Refract Surg 1997 23 277-283. 

Tetracaine, an ester of para-aminobenzoic acid (PABA), has been widely used for topical anesthesia of the eye. It is currently available in a 0.5% solution. Its onset, intensity, and duration of anesthesia are comparable with those of proparacaine and benoxinate (Figure 6-2). Onset of anesthesia sufficient to permit tonometry or other minor procedures involving the superficial cornea and conjimc-tiva is 10 to 20 seconds, and duration of anesthesia is 10 to 20 minutes. It has been reported, however, that the 1% solution produces anesthesia lasting nearly an hour. Tetracaine 1% has also been used successfully to provide anesthesia during phacoemulsification cataract surgery and intraocular lens implantation. 

Levobunolol is used for the chronic treatment of elevated lOP in ocular hypertension and open-angle glaucoma. Also like timolol, levobunolol is effective for prophylactic treatment of elevations in lOP after cataract surgery and anterior segment laser procedures. 

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