Intravitreal air in retinal detachment surgery.

Abstract

The use of intravitreal air in the treatment of retinal detachment was described by Rosengren (1938, I951), and Norton, Aaberg, Fung, and Curtin (I969) applied this technique to the treatment of giant tears. The method described in this paper differs from that of Rosengren in several features.A series of forty patients is divided into two broad groups:(A) Those appearing de novo at the Outpatient Department and undergoing a first operation for retinal detachment.(B) Relapsed detachments following some other previous operative technique. Eight aphakic patients previously described in detail (Chawla, I973) are included.The method described is used in all cases in which tears lie superiorly between the 8 and 4 o'clock meridians. If additional inferior tears exist, some other manoeuvre must be included. Method EXAMINATIONThe patient is admitted to the ward, and examination is undertaken with the binocular indirect ophthalmoscope. The periphery of both eyes is examined using transpalpebral indentation of the sclera; no local anaesthetic drops are instilled into the conjunctival sac. The patients are not compelled to rest in bed unless a functioning macula is in imminent danger of detachment. Double padding is never used.Slit-lamp examination is essential to determine the state of the vitreous. If narrow anterior chamber angles are suspected, gonioscopy is performed.In the preoperative state, a large amount of subretinal fluid is an advantage for two reasons:(i) Subretinal fluid can be released with greater safety. (2) Removal of fluid at operation makes way for the requisite I to 3 ml. air to be injected. Thus rest in bed may be unhelpful. OPERATIONThe patient is operated upon as soon as possible under general anaesthesia. A 360°limbal conjunctival incision is made and the rectus muscles are secured with 5/o silk stay sutures. The sclera is examined; any thinning and the position of the vortex veins are noted.Cryopexy to the areas of tear(s) is performed; the monitoring of each application prevents overfreezing. The onset of iceball formation is clearly seen. The cryoprobe must not be removed from the sclera until it has defrosted, thus avoiding scleral cracking (Shea, I969) and rupture of vortex veins during posterior applications.

The fishmouth phenomenon in retinal detachment: old concepts revisited.

“…It has been this author's practice to treat all primary detachments with superior tears, as defined, by means of an intravitreal air injection, cryopexy, and a no. 40 silicone tape, as previously described (Chawla and Birchall, 1973). Only patients with tears below the 4 o'clock and 8 o'clock meridia have had silicone-guttered explants placed securely beneath the no.…”

“…The significance of these meridia in relation 507 Fig. I after circumferential scleral buckle has caused reduction in width of tear with elevation of operculum and increase in radial retinal fold to the use of intravitreal air to float the retina up against the cryocoagulated choroid and scleral bed in detachment surgery has been indicated in a previous paper (Chawla and Birchall, 1973). After routine evaluation patients undergo surgery, and all encircling tapes and explants are removed at the outset.…”

Retinal detachment treated with intravitreal air: an evaluation of 241 cases.

“…The use of intravitreal air has already been described in detail (Chawla and Birchall, 1973;Chawla, 1974). The basic operation may be briefly summarised here.…”

V.B.7. Pneumatic Retinopexy

“…The use of pure air rather than long-acting expansile gases has many benefi ts including a larger initial tamponade, shortened postoperative positioning, reduced retinal toxicity, the ability to treat RDs in-offi ce, lower cost, and higher accessibility [ 18 , 20 ]. Some advocate that in cases of bullous detachments, 1-3 ml of pure air should be injected through the pars plana [ 67 ]. Obviously, this causes signifi cant elevation of intraocular pressure, and either aqueous, liquid vitreous, or both must be released to lower the pressure.…”