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Scleral buckling and vitrectomy procedures are most frequently performed under local anesthesia, but general anesthesia is sometimes preferred. Variables regarding this decision include surgeon and patient preference, expected duration of the procedure, and the patient’s health and mental status. In selected cases, topical anesthesia may be considered.
Preparation for office procedures
Pneumatic retinopexy is generally performed as an office procedure under local or topical anesthesia. The medical history is relevant, but a full physical exam and preoperative laboratory testing is usually not necessary. An empty stomach is not required. The risk of hemorrhage with pneumatic retinopexy is low, even for a patient on warfarin.
Retinal photocoagulation usually requires no anesthesia for indirect laser, although topical anesthesia is applied if a contact lens is used with slit lamp laser delivery. Sometimes patient sensitivity requires a retrobulbar anesthetic. Cryopexy usually requires topical, subconjunctival, peribulbar, or retrobulbar anesthesia; an empty stomach is not required.
POSTOPERATIVE MANAGEMENT
At the time of discharge after surgery, it is useful to supply the patient with written postoperative instructions. The majority of patients probably would have a satisfactory surgical result without most of these restrictions. However, imposing them routinely seems justified because they can be important for the occasional patient.
ACTIVITY RESTRICTIONS AND POSITIONING
Surgeon preferences regarding postoperative restrictions will differ, but the following guidelines may be helpful. Since most reattachment procedures are performed on an outpatient basis, restrictions in general have become less stringent over the years.
As a general rule, postoperative restrictions are most important for the first week, or until subretinal fluid has reabsorbed. The majority of patients are able to return to work within 1 to 2 weeks, but if a patient’s occupation requires clear binocular vision or significant physical activity, convalescence may be longer.
Early ambulation minimizes postoperative problems such as decubitus ulcers, thrombophlebitis, and generalized weakness. Unless gas has been injected into the vitreous, it is usually not necessary for the patient to maintain a set head position, but chemosis and lid edema are minimized if the patient rests on the unoperated side. It is generally acknowledged that ocular rest encourages the absorption of subretinal fluid. However, watching television or reading involves relatively small eye movements, and is not restricted by most surgeons.
Most patients do well with patching of the affected eye only for 1 to 3 days. Change the eye pad at least daily, or whenever wet.
Stooping, bending, and heavy lifting are often restricted initially following surgery, especially if there has been intraocular hemorrhage, but the value of these practices is uncertain.
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If gas has been injected into the vitreous, the patient must be warned not to fly until the bubble is relatively small. Specific positioning of the head to place the causative retinal breaks uppermost is prescribed. Longer restrictions on activity may be called for, particularly if a long-acting gas bubble is used.
POSTOPERATIVE MEDICATIONS
Patients who have had general anesthesia may have nausea and vomiting for a time after surgery. An antiemetic, such as promethazine, droperidol, or prochlorperazine, may be helpful.
Pain is rarely a problem for retinal patients. Meperidine, 50 to 100 mg, is seldom required beyond the first postoperative day. Propoxyphene napsylate with acetaminophen is an adequate analgesic thereafter. Unexpectedly severe or increasing pain calls for prompt evaluation to rule out endophthalmitis, scleral abscess, or markedly increased intraocular pressure.
Antibiotics and corticosteroids, either topical or systemic, are not mandatory for routine cases, but many surgeons prefer a combination of drugs such as neomycin, polymyxin B, and dexamethasone (Maxitrol) three times a day. Topical scopolamine 0.25% or homatropine 5% help prevent posterior synechiae formation and add comfort in the presence of inflammation. These may be particularly helpful in pseudophakic eyes, especially in diabetic patients. Daily use of a cycloplegic and an antibiotic–corticosteroid combination for 2 weeks is sufficient. In the occasional case in which significant inflammation is noted, appropriate corticosteroid medication should be prescribed.
FOLLOW-UP EXAMINATIONS
As a rough guideline, the routine patient should be examined on the first or second postoperative day, at 1 and 3 weeks, and at 2 and 6 months, after which annual examinations are recommended. However, more frequent examinations are frequently necessary following pneumatic retinopexy, for giant retinal tears, or other high risk cases, and particularly if complications develop. Therefore, no f irm guidelines can be recommended and follow-up examinations are scheduled on a case-by-case basis. Examination should include an interval history, best corrected visual acuity, tonometry, biomicroscopy, and thorough binocular indirect ophthalmoscopy. Annual examinations help assure the discovery of such asymptomatic problems as new retinal breaks, peripheral detachment, erosion of the implant, or glaucoma.
Following an encircling scleral buckle, a refractive shift is often noted, which generally stabilizes within 2 to 3 months and, if indicated, a permanent spectacle lens may be ordered at that time.
IF THE RETINA FAILS TO SETTLE
Postoperative photocoagulation or cryopexy
Persistent leakage of fluid through a retinal break without evidence of settling is an indication for intervention. If the break is only minimally elevated from the
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retinal pigment epithelium, supplemental photocoagulation or cryopexy may be considered. The goal is to induce swelling of the retina and choroid, thereby closing the edges of the break and allowing the subretinal fluid to be absorbed and adhesions to permanently seal the break (Figure 4–9).
If a gas bubble is present in the eye, all that may be necessary is to prescribe a new head position in order to get the retina to settle. Supplemental laser or cryo would then be applied. In other situations, injection of a small expansile gas bubble will provide closure of the open retinal break and allow laser therapy to be performed.
Where any subretinal fluid persists, it is difficult to get retinal burns with photocoagulation, and the tendency is to turn up the power of the laser. Care must be taken to avoid treating with too much intensity, or retinal breaks or hemorrhage may ensue. When photocoagulation is to be performed, it is recommended that the physician patch the patient bilaterally and restrict activity before the procedure to encourage as much settling as possible. Scleral depression at the time of laser application may assist in bringing the retina in apposition to the
A B
C
Figure 4–9. Postoperative photocoagulation. (A) Inferior leakage of subretinal fluid, anteriorly from horseshoe break and across buckle in inferior temporal quadrant. (B) Photocoagulation around horseshoe tear and at 3:30-o’clock position. (C) Reattachment of retina after photocoagulation.
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retinal pigment epithelium. Retrobulbar anesthesia may be necessary because of tenderness. Two or three rows of contiguous lesions should be placed around the leaking break.
Supplemental cryopexy is impeded by the presence of an overlying scleral buckle, but it is not as hindered by residual subretinal fluid. Still, the fluid should be shallow enough that supplemental treatment will allow the retina to settle.
Maximal restriction of activity and proper positioning following supplemental laser application may preclude the need for surgical reoperation in some cases. If the response to treatment is not adequate, the surgeon should not hesitate to proceed with a gas injection or full reoperation.
Reoperation
If there is more than minimal postoperative nonsettling subretinal fluid around the leaking break, photocoagulation or cryopexy will likely not be successful. If the leaking break is in the superior eight clock hours of the retina, one may consider pneumatic retinopexy (see Chapter 8). Pneumatic retinopexy can provide a simple salvage for selected failing scleral buckling procedures, avoiding the need to revise the buckle or perform vitrectomy. If pneumatic retinopexy is not appropriate, reoperation with scleral buckling (Chapter 7) or vitrectomy (Chapter 9) can be considered. If the break has remained open for more than a few days after surgery, supplemental cryopexy or photocoagulation should be applied around the break.
Chronic persistent subretinal fluid
Sometimes limited subretinal fluid will persist but show no evidence of progression. If there is no open retinal break, the macula is not detached, and the amount of subretinal fluid is not increasing, in most cases intervention is not required. Shallow subretinal fluid may persist in the inferior retina for many years. Multiple small, shallow blisters of residual fluid may also persist chronically after retinal detachment repair.
SUMMARY
Knowledge of the patient’s health status along with a thorough evaluation of the eye and retina provide an important basis for the diagnosis and treatment of retinal detachment. Principles of preoperative and postoperative patient management focus on detecting, avoiding, and treating potential complications.
Patients at risk for retinal detachment should be told to be seen promptly if new-onset flashes, floaters, or visual field defects develop. If examination shows detachment likely to extend soon into the macula, prompt surgery is indicated, possibly with preoperative bilateral patching and positioning.
SELECTED REFERENCES
Burton TC, Arafat NL, Phelps CD: Intraocular pressure in retinal detachment. Int Ophthalmol 1979;1:147–152.
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McMeel JW, Wapner JM: Infections and retinal surgery. Arch Ophthalmol 1965;74:42–47.
Michels RG: Scleral buckling methods for rhegmatogenous retinal detachment. Retina 1986;6:1–49.
Schepens CL: Diagnostic and prognostic factors as found in preoperative examination.
Trans Am Acad Ophthalmol Otolaryngol 1952;56:398–412.
Schepens CL, Hartnett ME, Hirose T: Schepens’ Retinal Detachment and Allied Diseases. Second Edition. Boston: Butterworth-Heinemann; 2000; pp. 221–234.
Wilkinson CP, Rice TA: Michels Retinal Detachment. St Louis: CV Mosby Co; 1997; pp 335–390, 517–538, 907–934.
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