Pathophysiology and pharmacology of intraocular surgery.
Meticulous studies of the pathophysiology of postoperative eyes are mandatory to find the means of reducing the risks of intraocular surgery. Various methods of examination developed for this purpose are described and their clinical significance discussed. The corneal endothelium shows no proliferative capacity even after injury and great care must be taken to protect this vulnerable cell layer. Drugs may be toxic to the corneal endothelium and their use during surgery must be exercised with caution. The intraocular irrigating solutions must contain calcium and have an appropriate salt composition. Pupillary constriction that occurs during extracapsular cataract extraction is due mainly to prostaglandins synthesized as a result of surgical trauma; this can be prevented by the preoperative use of topical indomethacin. Breakdown of the blood-aqueous barrier after intraocular surgery may also be due to a similar mechanism, and preoperative topical non-steroidal anti-inflammatory agents (indomethacin, flurbiprofen and diclofenac) can prevent this phenomenon, as studied by fluorophotometry. Topical indomethacin also prevents cystoid macular oedema after cataract surgery. Based on the biochemical findings on inflammation after tissue injury, a protocol for the preoperative and postoperative use of corticosteroid and non-steroidal anti-inflammatory agents is proposed for anterior segment surgery.
D000869:Anterior Eye Segment / Q000378:metabolism; D001082:Aqueous Humor / Q000098:blood supply; D002387:Cataract Extraction / Q000009:adverse effects; D002452:Cell Count; D003315:Cornea / Q000187:drug effects / Q000473:pathology / Q000601:surgery; D004727:Endothelium / Q000187:drug effects / Q000473:pathology / Q000601:surgery; D005128:Eye Diseases / Q000188:drug therapy / Q000378:metabolism / Q000503:physiopathology / Q000601:surgery*; D005470:Fluorometry; D006801:Humans; D007249:Inflammation / Q000209:etiology / Q000378:metabolism; D007432:Intraoperative Period; D008269:Macular Edema / Q000209:etiology; D010539:Permeability; D010808:Physical Examination / Q000379:methods; D011183:Postoperative Complications; D011292:Premedication; D011680:Pupil; D013523:Surgical Equipment; D007507:Therapeutic Irrigation; D014822:Vitreous Body / Q000378:metabolism