Ocular surgery, complications

Lidocaine gel 2% has been compared with 0.5% tetracaine drops for topical anesthesia in cataract surgery in 25 patients (331). There were no corneal epithehal or ocular surface complications, demonstrating the safety of the gel, which may provide a more practical and efficient method of anesthesia, because it needs to be applied only once as opposed to three applications of the drops. 

Lee WB, Hamilton SM, Harris JP and Schwab IR. 2005b. Ocular complications of hypovitaminosis A after bariatric surgery. Ophthalmology 112 1031—1034. 

CME is a well-documented complication of cataract surgery. The pathogenesis includes accumulation of fluid in the macular intracellular and extracellular spaces as a result of increased permeability of perifoveal capillaries. The mechanism is likely mediated by release of prostaglandins and leukotrienes from the injured tissue or as a direct result of traction on the macula by vitreal tissue movement, especially secondary to vitreous entrapment in the wound. Prostaglandin analogue ocular hypotensive agents may play a role in pseudophakic CME. 

Retinal detachment associated with vitreoretinopathy is a complication of ocular trauma and vitreoretinal surgery. The mechanism leading to the detachment is not completely understood (Weller etal., 1991 McGillem and Dacheux, 1998 Valeria Canto Soler etal., 2002). Several studies suggest a role of MP, however their origin was not... 

The authors added that retinal toxicity of the local anesthetic agent did not affect the visual outcome in this patient. Scleral perforation is a well-known complication of eye blocks for ophthalmic surgery. The incidence with retrobulbar techniques is 0.075% and with peribulbar blocks 0.0002%. When recognized, ocular perforation usually requires a vitreoretinal procedure and is associated with a poor visual outcome. Risk factors include an anxious or oversedated patient, long sharp needles, superior injection, incorrect angle of needle insertion, and myopic eyes. If the intraocular pressure is increased, paracentesis may acutely reduce it, preventing retinal and optic nerve ischemia and possible permanent visual loss. 

No serious systemic or ocular complications were observed, and retinal reattachment was achieved in 60% of patients postoperatively. The number of patients studied was small. However, the authors believed this therapy resulted in an improved success rate compared with other studies of the reattachment rate following surgery for advanced PVR without use of silicone oil and that the reattachment rate was comparable with the reattachment rate achieved in studies using silicone oil tamponade (47). 

Sodium hyaluronate is applied in the treatment of postoperative ocular hypo-tony in glaucoma surgery. Ocular hypotony caused by overfiltration (Fig. 104) is not only relevant in the development of visual acuity (Schwenn et al., 1996) but also subject to numerous complications. Sodium hyaluronate is particularly well suited for treatment of shallowed anterior chambers (Fig. 105) with threatening lentocorneal contact. 

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