Author: Ameen Marashi, MD

History

Documentation of age, floaters location, duration, and shape, which can be in the form of spiderwebs or hairs, visual field defect in the form of a curtain, and photopsia ^[1] .

Myopia ^[2] or ocular history of ocular trauma ^[3] or surgery, such as retinal detachment surgery, cataract extraction ^[4], refractive, lens extraction surgery ^[5], YAG laser capsulotomy, or intravitreal injection ^[6], should be documented.

Family history of previous retinal detachment or genetic disorders such as Stickler syndrome should be recorded ^[7].

Ocular Examination

A list of ocular examination should set

1) Confrontation visual field examination

2) Best-corrected visual acuity (BCVA) for near and far is an essential step that can be performed by a trained optometrist or certified ophthalmologist to document the visual impairment.

3) A slit-lamp examination done with a thorough exam of clarity and regularity of the cornea and conjunctival abnormality such injection of conjunctival vessels should be documented, and any other inflammations of the conjunctiva or eyelids documented, along with iris exam and crystalline lens exam to rule out cataract or intraocular lens (IOL) to document the position and clarity of the posterior capsule, it integrity wither it ruptured during cataract extraction or YAG laser capsulotomy was done.

“Mild relative afferent pupillary defect can be presented in cases of rhegmatogenous retinal detachment.”

4) Anterior hyaloid examination with retro illumination using slit-lamp microscopy to rule out tobacco dust (pigmented cells) and differentiate it from blood and inflammatory cells.

5) Intra Ocular Pressure (IOP) documentation is essential as high IOP may be associated with pathological myopia and patients with glaucoma history; however, in eyes with retinal detachment has a lower IOP from the contralateral eye; Note when high IOP spotted a corrected IOP documented after central corneal thickness measurement

6) Bilateral dilated fundus exam is an essential and detailed examination of the optic disc, macula, posterior pole, a mid-peripheral and peripheral retinal exam with specialized indirect wide-field lenses using slit-lamp biomicroscopy using wide-field lenses and indirect ophthalmoscopy with scleral indentation ^[8] to document the following:

A. Documentation of retinal detachment extent is it confined to one quadrant or more, is it subtotal or total detachment, is it superior or inferior detachment. However, acute rhegmatogenous retinal detachment appears convex with a corrugated surface extending from periphery to the optic disc, which ripples with eye movements.

B. The status of the macula is it attached? Or detached as acute retinal detachment associated with attached macula have a better visual outcome from cases with the detached macula and warrant emergent surgical intervention ^[9].

C. Full peripheral retinal examination to document the location of retinal breaks Lincoff’s rules cab help to predict the location of the offending retinal break:

1. Shallow inferior detachment with slightly higher subretinal fluid in the temporal side, the offending retinal break would be located inferiorly at the temporal side.

2. Shallow inferior detachment with equal levels of subretinal fluids, the offending retinal break would be located inferiorly at 6 o’clock.

3. Bullous inferior retinal detachment, the offending retinal break would be located above the horizontal line.

4. In the case of offending retinal break located in the upper nasal quadrant, the subretinal fluids will progress around the optic nerve and rise again in the temporal side, reaching the level of the break.

5. In the case of subtotal retinal detachment, the superior wedge will point to the location of the offending retinal break.

6. In superior retinal detachment crossing the vertical line, the offending retinal break will be located near to 12 o’clock toward the side of the lower edge of subretinal fluid.

D. Documentation with a drawing of a subretinal fluid extent and location of offending retinal breaks is a must before surgery or referral to a retinal specialist; this will help to locate the retinal breaks during surgery.

E. The presence of retinal thinning, demarcation line (which may present with pigmentation but do not limit subretinal fluid progression), or retinal cysts indicate chronicity of retinal detachment.

F. Presence of Proliferative vitreoretinopathy (PVR) ruled out during examination, which has three main grades:

1. Grade A: which presented as hazy vitreous or/and pigmented clumps on the inferior surface of the retina.

2. Grade B: which presented as wrinkling of inner retinal surface and tortuosity of retinal vessels along with stiffness of the retina with decreased mobility of the vitreous gel.

3. Grade C: Which features a full-thickness retinal fold, which could be in a star-shaped, PVR in grade C can be presented anteriorly or posteriorly along with vitreous condensation or even strands.

G.Core and posterior cortical of the vitreous searching for pigmented, blood, and inflammatory cells along with the presence of Weiss ring.

H.Documenting the extent of posterior vitreous detachment and syneresis if possible.

I. Posterior pole examination to rule out the presence of a macular hole, vitreomacular traction, or epiretinal membrane.

J. Peripheral and mid-peripheral retinal exam to rule out lattice degeneration, tufts, degenerative schisis, retinal breaks, retinal dialysis, and vascular avulsion.

K. Vitreous hemorrhage has a direct relation with the risk of retinal detachment. Therefore, in the case of vitreous hemorrhage precluding a complete fundus examination, a headrest in 45 degrees and exam repeated weekly to locate the source of bleeding. As it could be vascular avulsion or/and retinal break which at least one break, in two-thirds of cases, is found, especially in the upper temporal quadrant in 88% of cases and may include more than one break ^[10].

L. Documentation of subclinical retinal detachment, which has a size of more than one disc and doesn’t extend to the equator are documented as subclinical retinal detachments.

M. In a nutshell, the physician should determine the extent of the detachment and its surface configuration (convex or concave). Locate the offending retinal break according to the Lincoff rule and rule out any signs of PVR along with the presence or absence of PVD then assess whether the macula is on or off. All the up mentioned features should be documented by drawing before any surgical intervention.

Diagnostic tests

Fundus images

Usually not enough to diagnose rhegmatogenous retinal detachment. However, wide-field fundus imaging techniques such as OPTOS can provide wide-field viewing images up to 200 degrees and can be suitable for patients that can’t be dilated or have miosis and in cases of telemedicine, but it should never replace clinical examination.

Wide viewing images may document the presence of rhegmatogenous retinal detachment along with other peripheral retinal pathologies such as retinal breaks, lattice, and subclinical retinal detachment.

They can help to monitor the progression of retinal breaks or subclinical retinal detachment to clinical retinal detachment or changes in the retina associated with lattice degeneration as the formation of retinal breaks on the posterior edge of the lattice or elsewhere.

Wide viewing images may assess the post-surgical success for retinal reattachment and to rule out any new or missed retinal breaks or post-operative residual or new subretinal fluids.

Optical Coherence Tomography (OCT)

OCT may help to assess the attachment of the macula accurately, and to assess the presence of intraretinal fluid and increased reflectivity or/and disruption of the photoreceptor layer which are biomarkers for the poor visual outcome while the absence of intraretinal fluid may indicate better visual prognosis ^[11] .

Another factor that may affect the visual prognosis is the continuity of external limiting membrane and ellipsoid zone, which are best evaluated using SS-OCT in macula OFF RRD ^[30].

OCT may help to document the presence of vitreomacular traction, macular hole or epiretinal membrane and help to study the areas of PVD and its stages ^[12] using volumetric OCT.

Currently, some OCT machines may provide wide-field OCT cross-sections, which are very helpful in diagnosing rhegmatogenous retinal detachment, and retinal breaks. OCT helps in evaluating areas of vitreous adhesions.

B-scan

It is excellent to study the PVD extension and vitreous syneresis along that B-scan can diagnose the presence of retinal detachment and retinal breaks, especially in cases with no clear media such as cataract or vitreous hemorrhage.

B-scan can differentiate the retinal detachment from PVD as the former may exhibit whiplash movement with one free edge, and the other attached to the optic disc with increased high reflectivity membrane like in the vitreous cavity and induce high A-scan spikes and do not disappear in low gains where the latter may have a washing machine movement and with no attachments in cases of complete PVD and disappears in low gain and usually don’t cause A-scan spikes.

Managing patients with rhegmatogenous retinal detachment

Treatment options

Scleral buckle

Scleral buckle used to be the method of choice in the treatment of retinal detachment and still used in special cases such as in young phakic cases and cases with retinal dialysis and retinal breaks without vitreous traction. ^[13] Especially in the absence of PVD.

The principle of the scleral buckle is to approximate the retinal pigment epithelium to the retina by displacing the sclera after closing all retinal breaks and reducing the tractional forces.

Surgical techniques:

Scleral buckle usually is done under general anesthesia, and after draping eyelashes and conjunctiva, a sterile drape is installed.

Conjunctival peritomy 2mm from the limbus is done depending on the location of retinal breaks, and the size of the buckle decided to use; therefore, it is not always necessary to do 360-degree peritomy, as for circumferential tire placement a 360-degree peritomy is needed.

After peritomy is done, the rectus muscle is hooked. Then 2.0 or 3.0 silk suture is slung behind each of the exposed rectus muscles. Each exposed scleral quadrant inspected for scleral deformities, as cryotherapy or suturing in dark ectatic areas of the sclera, may lead to complications.

A full peripheral retinal exam is done either by indirect ophthalmoscopy or by microscope wide viewing system using chandelier as a light source. The preoperative drawing of the location of retinal tears may be very helpful in locating retinal breaks intraoperatively. Scleral indentation used to indent the sclera behind the retinal break, which induced a transit scleral thinning, which then marked with surgical pen or cautery, the clarity of the cornea maintained with viscoelastic or saline.

Correctly locating the retinal breaks is an essential step as failure to do so may lead to surgery failure, and one of the difficulties of the surgery is to accurately locate the retinal break on bullous or high elevated detachment. Therefore, the DACE (drain, air injection, cryopexy, and explant) approach to overcome this problem by draining the subretinal fluid then reforming the globe with air and then closing the break with cryopexy before suturing the explants done, though seeing the break via air can be difficult.

There are several ways to do retinopexy in scleral buckle surgery there is laser photocoagulation around the retinal break either intraoperatively using laser indirect ophthalmoscopy which requires full retinal attachment or days postoperatively

Cryotherapy is used in most of the cases, which sometimes only one cryopexy application needed for small breaks. In contrast, large breaks may need several contiguous with minimal overlap cryopexy applications, in which the center of the retinal break is not treated to avoid RPE dispersion.

The probe may approximate RPE to the retina, and cryopexy may freeze simultaneously where in cases of high elevated detachments, subretinal drainage needed to do cryopexy correctly.

Before removing the probe after each application, the probe should thaw completely to avoid choroidal hemorrhage or scleral avulsion.

At this stage, the explant should be sutured to the sclera before that the choice of explant depends on the location, size, and quantity of the retinal breaks as areas of detachment don’t contain retinal breaks don’t need any explant placement.

There are several types of explants; the most popular are silicone tire, which produces lower indent, and sometimes it needs subretinal fluid drainage or gas and placed circumferentially. In contrast, silicone sponge may induce higher indent but may increase intraocular pressure and may place circumferentially or radially.

As mentioned above, the location, size, and quantity of breaks influence the type of silicone explant; for example, if there is a single retinal break causing retinal detachment, then a radial silicone sponge is needed without the need of subretinal fluid drainage. However, if there are multiple holes anterior to the equator with various distances from the Ora Serrata, then a circumferential silicone tire is placed. In contrast, when three retinal breaks can be treated with separated radial sponges or one circumferential tire, especially when they are close to each other, subretinal fluid drainage used +/- air injection may be needed. In contrast, in retinal dialysis, a 3 mm silicone sponge placed circumferentially.

After marking the location of the retinal break on the sclera the explant is sutured to the sclera using a box (not cross) mattress suture using a mersilene double-arm needle passing the needle ⅓ to ½ of the sclera without perforating the sclera by passing the needle anterior-posterior, the placement of the suture should be accurately measured using calipers and should be placed parallel to explant and significantly wider than explant so if 5 mm explant used then suture bites should be 8 mm apart when circumferential tire used then two mattress suture used in each quadrant. In contrast, suture bites are 2 mm greater than tire width; the circumferential tire usually goes under recti muscles and fixed usually 12 mm from the limbus.

There are several ways to tie the sutures either by slip, locking or surgeon knot to tight the mattress suture to induce the local indent.

If the drainage decision made then the drainage site would be at the higher elevated retinal detachment under indirect ophthalmoscopy or microscope viewing system to make sure that subretinal fluid is deep enough, the best area is at equator under the explant avoiding areas of vortex veins, long ciliary nerves (6 and 9 o'clock) and under the recti muscles.

There are two techniques to do subretinal drainage; the first is cut down technique, which is a 3 mm cut on the sclera, then a puncture of the choroid using needle, diathermy, or laser. The other technique is a single-stage technique in which a hypodermic needle is used with an open syringe.

After subretinal fluids drainage, the eye becomes hypotonic, and this may lead to suprachoroidal hemorrhage for that an immediate suturing and reforming of the globe with saline or air is mandatory. During subretinal fluid drainage, if the retina exhibits star-shaped folds with or without stopping of drainage before than anticipated, then retinal incarceration is suspected and is managed with explant and retinopexy if there is a retinal break. However, if there is no retinal incineration, only the subretinal fluid drainage stopped, then a massage on the globe or drainage site, or new drainage site is indicated. In the case of subretinal hemorrhage is noted, then the drainage is stopped, and the site is sutured with intraocular injection of air and position of the head toward the drainage site.

Air injection is done with hypodermic needle 4 mm from the limbus or by 23 gauge needle airline attached to bump pressure that produces pressure to physiological levels, instead of air an expansile gas used but nitrous oxide should be turned off in general anesthesia 15 mins before gas injection to prevent gas expansion.

If a circumferential band is used, then it is fastened using Watzke sleeve, then sides of the band are pulled to produce an encircling indent as a 6 mm shortening of the band will cause 1 mm indent.

The retinal exam carried out to assess the scleral buckle effect, location and support to retinal breaks to rule out fish mouthing and the need for moving or adding more explants

The status of the optic disc is very important as pink color indicates a below diastolic optic disc pressure. In contrast, arterial pulsation on optic disc indicates between systolic and diastolic. Still, the pale optic disc is higher than systolic, and in this situation, a lowering on intraocular pressure is needed by paracentesis.

If pressure on the globe will cause arterial pulsation, this is an acceptable intraocular pressure.

The tenon is closed as a separate layer covering the explant then the conjunctiva closed using 7.0 vicryl sutures by approximating conjunctival edges.

Postoperative complication:

Recurrent detachment:

The presence of subretinal fluid post-surgery, especially if subretinal fluids drainage not done does not mean a redetachment but persisting or increasing of subretinal fluid is a sign of surgical failure and can be due to the following:

· Missed retinal breaks, which indicate a repeat surgery, especially if dialysis is found or pars plana vitrectomy.

· Inadequate buckle may be fixed by adding more suture to support the buckle

· Misplaced buckle which managed by augmenting the circulating band or radial sponge.

· Fish mouthing managed by intravitreal injection of 0.3 ml pure SF6 gas.

Glaucoma:

This can be either an open-angle, which is usually steroid-induced or closed-angle, which requires steroids and cycloplegia where miosis and iridotomy won't be helpful and, if conservatively, didn’t solve this problem a loosen of Watzke sleeve is needed.

Infection:

This is more common in radial than encircling explant. When a biofilm of infection is created, it is impossible to treat it medically. It needs to remove the explant with no worries to redetach an additional retinopexy can be carried out in case of doubt.

Band migration:

May induce vitreous hemorrhage or detachment, which managed with pars plana vitrectomy.

Diplopia and strabismus:

Diplopia usually don’t persist and managed with prisms and removal of explant indicated when diplopia persists even with prisms

While strabismus surgery is challenging in the presence of buckle, therefore a repeated botulinum injection may be needed if buckle cannot be removed.

Anterior segment ischemia:

Presented with the deep anterior chamber with flair corneal edema and pain and managed conservatively with topical steroids and cycloplegia if this fails, then a loosening of the encircling band.

Pars Plana Vitrectomy (PPV)

The scleral buckle was the gold-standard surgery to repair retinal detachment and pars plana vitrectomy reserved for complicated cases with PVR however the PPV advancement in wide-field viewing system and transition to sutureless PPV has shortened the operation time and improved postoperative recovery and results.

PPV offered better surgical outcomes in cases of pseudophakic patients, giant tears, tears with vitreous traction, PVR (grade C) or/and media opacity patients. ^[14]

PPV may offer complete subretinal fluid removal, attached retina, and traction release with less refractive errors and fewer complications when compare it to scleral buckle surgery such as retinal incarceration highly unlikely.

The principle of PPV is to remove any tractions on the retinal surface, either it is vitreous or membranous, then to reattach the retina by heavy liquid or air, then sealing the retinal breaks with laser or cryotherapy and then installing tamponade.

Surgical techniques:

The type of anesthesia depends on surgeon preference as young patients and complicated cases requires general anesthesia while other simpler cases may be done with local anesthesia and sedation.

When using the trocar system, the available sizes are 23, 25, and 27 gauge the conjunctiva displaced using cotton applicator or conjunctival forceps. The trocar knife is inserted 30 degrees into the sclera then perpendicular to create a self-sealed scleral incision 4.00 mm from the limbus in phakic eyes and 3.5 mm in pseudophakic or aphakic eyes.

The trocar is inserted in the inferior temporal just below the horizontal meridian, and this site is used for infusion cannula. The infusion is turned on before inserting it to release air bubbles, then inserted.

Insertion of infusion in the intravitreal cavity should be inspected under the microscope with an external light source. Care is taken, not to insert the infusion cannula in the suprachoroidal space.

While the other trocars one trocar is inserted in the superior nasal. The trocar is inserted from the lowest point of the nose bridge, and the additional trocar is interested in the superior temporal.

Areas of conjunctival scar or abnormalities should be not used as trocar insertion sites.

If a 20 gauge system is used then, conjunctival peritomy is needed and sclerotomies made with MVR blade and the inferior temporal sclerotomy made after placing fixation suture which will fixate the infusion cannula.

The core vitrectomy is initiated, and the core vitreous removed then posterior vitreous detachment (PVD) is provoked if it is not already presented using triamcinolone which stains the vitreous and helps to complete removal of posterior vitreous in case of attached membranous posterior vitreous presented then a diamond-dusted scraper used to remove it so it won’t cause macular pucker in the future.

After core vitrectomy and removal of the posterior vitreous and with the help of wide viewing systems the peripheral vitrectomy initiated to release the traction over the retinal tear, and this can be done by completing vitreous bridge separation between the retinal break and Ora Serrata in post equatorial posterior retinal break or removing the retinal break flap in anterior pre equatorial breaks with the help of scleral indentation.

Bullous retinal detachment may be flattened using perfluorocarbon liquid (PFCL) to stabilize the retina while doing vitreous shaving without causing iatrogenic retinal tears. PFCL can be used in cases of peripheral retinal breaks anterior to the equator as it helps to stabilize the retina while releasing peripheral vitreous tractions or/and cutting peripheral vitreous.

After releasing the vitreous traction and completed removal of the vitreous gel the retinal tear edges can be marked with gentle cautery at this stage and the retina flattened by injecting PFCL up to the posterior edge of the break displacing the subretinal fluid to the vitreous cavity throughout the retinal break; alternatively, the subretinal fluid can be aspirated from the retinal break using a vitreous cutter with aspiration only while switching the cutting function off or using a backflushed needle with a soft-tipped cannula connected to active aspiration which may reduce the risk of injuring the choroid while aspirating then air irrigation initiated with tilting the patient head toward the retinal break while aspirating the residual subretinal fluid and drying the edges of the retinal break, if the PFCL is presented while doing fluid-air exchange the air reaches the top of the PFCL bubble to complete removal of subretinal fluid anteriorly.

Retinal detachments presented with giant tears are managed with PPV by doing PFCL silicone oil exchange to avoid slippage.

After the retina is attached and there are no sub-retinal fluids the fluid air exchange continues to remove any fluids or heavy liquid left and then laser photocoagulation around the retinal breaks with three confluent rows of laser burns where cryopexy can be used in anterior breaks.

After treating retinal breaks, a final inspection of the retinal periphery making sure there is no residual subretinal fluids and untreated retinal breaks after that air-gas exchange either by 20% SF6 or 14% C3F8, in complicated cases or single seeing eye a silicone oil used as a tamponade.

All sclerotomies are closed with 8.0 vicryl suture especially when silicone oil used as tamponade and subconjunctival steroids and antibiotic injection administered.

Postoperative complications:

The most common postoperative complication is redetachment with or without PVR may be due to missed retinal breaks or reopening of the previous retinal breaks and managed with pneumatic retinopexy in non-silicone-oil filled eyes or with fluid air exchange after subretinal fluid drainage, and then a gas or silicone oil tamponade is used depends on the case and the surgeon preference. However, in cases of silicone-oil filled eyes, revision of PPV is needed.

Increased IOP post PPV can be related to increased gas concentration and managed with removal of gas via 30 gauge needle on slit-lamp. In contrast, when the eye is filled with excess silicone oil suffering from increased IOP, a release of a small amount of silicone oil via a 23 gauge trocar can be done to normalize the IOP.

Other complications such as cataract, especially in patients older than 50 where hypotony, which becomes more common in transconjunctival surgeries, especially when sclerotomies are not sutured; however, it resolves spontaneously, endophthalmitis is a rare complication with devastating outcomes.

Pneumatic retinopexy

This procedure aimed to minimize costs of surgical intervention to repair certain cases of retinal detachment such as macular on superior retinal detachment with superiorly located one retinal break with a size less than one clock hour or multiple superior retinal breaks located in one to three clock hours without any significant PVR. ^[15]

Pneumatic retinopexy may offer functional advantages such as better photoreceptor integrity, minimal retinal folds, and alignment (minimal to no retinal displacement).

The principle of pneumatic retinopexy is in office injecting of pure gas to reattach the retina after applying transconjunctival cryotherapy or laser around the offending retinal break then post-operative head posture.

Presurgical consideration includes those cases that may fail with pneumatic retinopexy such as:

· Retinal breaks are larger than one clock hour or multiple breaks that extended more than two quadrants or inferior breaks causing retinal detachment located four clock hours of the retina.

· Cases presented with PVR grade B or C, however, a distant mild PVR from offending retinal break may not be a contraindication for pneumatic retinopexy.

· Patients cannot maintain head position due to neck or back problems, or patients are not mentally competent, as horizontal and retinal breaks between 11 and 1 o’clock have easiest head positioning in contrast to retinal breaks located obliquely.

· Cases with cloudy media that preclude an adequate view of peripheral retinal breaks are relatively contraindicated; this applies for pseudophakic and aphakic patients.

· Any preexisting retinal breaks not involved in the retinal detachment requires prophylactic laser retinopexy.

· Retinal detachment with cases with severe lattice degeneration is best managed with pars plana vitrectomy.

· Cases of severe or uncontrolled glaucoma are contraindicated for pneumatic retinopexy, but cases of opened angle glaucoma are not contraindication and can offer advantageous over scleral buckle procedure, especially for cases of a functioning bleb or planned for future glaucoma surgery.

· Complete posterior vitreous detachment has a more success rate than partial posterior vitreous detachment.

· Pneumatic retinopexy has advantages such as cost and limited access to the operating room and those who have a risk of macular detachment, which will push the subretinal fluid away from the macula until the operating theater is ready for vitrectomy, in phakic patients that are prone to develop cataract after PPV.

· Pneumatic retinopexy has advantages over scleral buckle in cases of posterior or macular breaks, cases with bullous retinal detachment, isolated retinal tears that are located behind a rectus muscle which adding an explant will cause diplopia and re-detachments after the scleral buckle.

· All mentioned above should be explained to the patient with details, and the patient should understand that this procedure requires post-operative head posture and that this procedure is prone to failure and may need further surgical intervention or two sessions pneumatic retinopexy especially in cases of bullous retinal detachment, persistent subretinal fluids, media opacities, over scleral buckle, large or extensive retinal breaks.

Surgical technique:

Usually, pneumatic retinopexy is done with subconjunctival anesthesia and rarely general anesthesia where nitrous oxide should be turned off in general anesthesia 15 mins before gas injection to prevent gas expansion.

Cryopexy applied transconjunctivally surrounding the retinal breaks avoiding the application of cryopexy in the center of large retinal breaks, and the cryopexy appears as dull orange glow at the level of RPE, the cryoprobe shouldn’t move until it completely thaws.

Cryopexy may be used in cases of media opacities, laser indirect ophthalmoscopy not available, far peripheral retinal breaks that are hard to reach with the laser.

Laser delivery using slit-lamp microscopy or laser indirect ophthalmoscopy is very helpful in pneumatic retinopexy because it allows treatment for retinal periphery with the use of scleral indentation and allows gas bubble maneuvering.

The laser applied as three rows of contiguous gray-white burns surrounding the retinal break with generous laser application to the anterior edge of the break.

The laser can be applied after pneumatic retinpexy and may be preferred over cryopexy in scleral buckle cases; however, the laser has reduced the risk of developing PVR.

Usually 0.3 ml of pure C3F8 or 0.5 ml of pure SF6 used in pneumatic retinopexy, the syringes are filled using a 20 mm filter after evacuating all air from syringes.

The injection should be carried out in sterile conditions where the injection site is prepared by disinfecting the skin using povidone-iodine 10%.

After installing topical anesthesia, and the conjunctiva disinfected using povidone-iodine 4%. Then placing sterile drape and lid speculum isolating eyelashes, then paracentesis performed first.

The injection site is measured with calipers 4 mm from the limbus in phakic patients and 3.5 mm in pseudophakic patients. A 30 gauge half-inch needle is used to inject gas; perpendicularly in the uppermost site needle should penetrate only one-third of the needle and inject moderately and briskly, then the head is rotated before withdrawing the needle.

In case that fish eggs occurred, then head positioned in a way that bubbles will be far from the retinal break, then flicking the eye with a sterile cotton applicator or gloves to coalesce the air bubbles. This maneuver indicated in large retinal breaks to avoid subretinal gas migration as in small retinal breaks don’t warrant this maneuver as the gas bubbles will coalesce spontaneously within 24 hours.

Steamroller procedure used in cases of bullous retinal detachment as the patient asked to have a face-down position so the gas bubble will traverse the attached retina, then the patient moves head slowly over 1 to 10 minutes to position where the retinal break is uppermost. This technique prevents iatrogenic macular detachment in bullous retinal detachments, where cryopexy applied after the Steamroller procedure.

The IOP is assessed along with patency of central retinal artery, which should be checked using ophthalmoscopy; if this failed to achieve, then secondary paracentesis is required.

Postoperative complications:

New or missed retinal breaks may be treated with laser photocoagulation if not associated with retinal detachment, especially in cases of incomplete PVD, and gas itself may be the cause of new retinal tears. However, cases with new retinal breaks associated with retinal detachment may require reoperation or managed with pars plana vitrectomy.

Subretinal gas migration is managed by teasing it back into the intravitreal cavity before it expands if this fails, then aspiration of the gas bubble transscleral.

Treatment plan

A treatment plan tailored depends on the retinal detachment severity, surgeon abilities, and skills the following guidelines aimed to help ophthalmologists to choose between the available procedures.

In cases of subclinical retinal detachment

- A laser treatment used in peripheral asymptomatic small areas of retinal detachment, encircling laser applied from Ora to Ora, and just posterior to the edge of retinal detachment. Cryopexy can be applied, and it takes more time to achieve adhesion with more complications; laser needs up to 14 days to achieve adhesion; therefore, laser treatment is not suitable for the rapid progression of retinal detachment.

- Scleral buckle indicated when a subclinical retinal detachment is progressing to clinical retinal detachment.

In cases of limited retinal detachment due to horseshoe tear

Laser treatment is prone to failure in this type of retinal detachments (especially in superior breaks) even if it is limited detachments due to the rapid progression of subretinal fluid accumulation. There wouldn’t be enough time for adequate adhesion; therefore, when the laser is planned, space is left between the edges of detachment and laser burns to allow some progression of subretinal fluid before the development of adequate adhesion.

In the case of retinal detachment due to retinal breaks extending less than two quadrants in the superior retina

Pneumatic retinopexy is considered especially in a phakic patient with an adequate view of the periphery and able to maintain head position without extensive lattice degeneration or significant PVR. ^[18]

In case of retinal detachment due to one or multiple retinal breaks that may involve any quadrants and not a candidate for pneumatic retinopexy

- PPV considered for patients presented with PVD, especially pseudophakic patients with or without bullous retinal detachment with mild to medium complexity (such as PVR) ^[20], retinal detachments associated with posterior retinal breaks, and patients with a thin sclera.

- Segmental scleral buckling is considered for patients presented without PVD especially, in young phakic patients with an adequate view of the periphery and limited retinal detachments with single breaks, especially in cases with anterior and inferior retinal breaks. With or without using an encircling band, which it may not be necessary if retinopexy applied to all retinal breaks. ^[19]

In the case of retinal detachment due to giant tears

Retinal detachment presented with giant tears is managed with PPV by doing PFCL silicone oil exchange to avoid slippage.

In cases of retinal detachment due to retinal dialysis

- Laser treatment considered in cases of inferior temporal retinal dialysis with limited retinal detachment; the patient should be warned that this treatment may cause a superior nasal visual field defect. ^[16]

-Treating with laser the posterior and lateral edges along with the horns of the dialysis and then followed every week, then every four weeks, then every three months and then six months and then annually.

-Segmental scleral buckling indicated in cases of traumatic retinal detachment secondary to retinal dialysis. ^[17]

Strategies to minimize PVR

-A patient with chronic vitreous hemorrhage, extensive breaks, extensive retinal detachment, and any pre-existing PVR, as well as inability to seal the break, endolaser excess, external SRF drainage issues, air or gas use, and multiple surgeries, is at high risk for PVR.

-We need to control inflammation well, perform a thorough preoperative exam to locate all breaks and to assess the retinal status. We also need to administer steroids if there is choroidal detachment or hypotony to minimize the risk of PVR. In addition, intraoperatively, in the case of pneumatic retinopexy, we must avoid excessive cryopexy, use of high energy laser, use of long acting gas. In the case of PPV, we must avoid iatrogenic retinotomies and hemorrhage, inadequate vitreous clearance, incomplete tamponade.

Flow chart summarizes the approach and management of non-complex rhegmatogenous retinal detachment

Follow up and prognosis

- Usually, the surgical success rate is high in repairing retinal detachment 86% with scleral buckle ^[24] and from 64% to 96% in PPV which 40 % won’t achieve good reading ability and 10 to 40 % will need additional surgical intervention where 5% may not end up with good anatomical or functional success. ^[25] Surgical success depends on the presurgical anatomical status of retinal detachment in light of the presence of PVR and retinal membrane.

-Patients presented with acute retinal detachment but with attached macula have better visual prognosis than patients presented with retinal detachment with the detached macula, those patients tend to have a worse prognosis and thus depends on the duration of the detached macula, as patients with detached macula for the duration for three days better than one week and may benefit from surgery and those with detached macula up to six weeks to three months may have poor visual outcomes.^[26]

- When sealing retinal breaks using laser photocoagulation, patients have fewer complications than those with cryopexy, as the latter may cause macular pucker, cystoid macular edema, and may take more time to achieve adequate adhesion when comparing it to laser photocoagulation. However, the cryopexy is very useful in cases of anterior retinal breaks in patients with media opacities. ^[27]

-In scleral buckle patients, it is essential to do a conjunctival examination to rule out explant migration. Peripheral fundus examination to assess the scleral buckle effect, location, and support to retinal breaks to rule out fish mouthing (which managed with pneumopexy) and to lookup for untreated retinal breaks, which managed with laser photocoagulation.

-In cases of a scleral buckle, if subretinal drainage is not performed, then the first few days of surgery, there would be some subretinal fluids, and it will resolve with time, but if it persists or progresses then, this means surgical failure.

- PPV patients followed up the next day of surgery then every week then monthly during follow up IOP measured to rule out hypotony or increases IOP (which is managed topically). Anterior segment examination to rule out cells, flare, and fibrin (which managed with topical steroids and cycloplegia). A peripheral retinal exam to assess the chorioretinal adhesion and retinal attachment and to rule out any opening of retinal breaks (which managed with laser photocoagulation) or sub-retinal fluids.

- Patients treated with pneumatic retinopexy, or had gas tamponade in PPV are instructed to maintain a head position for at least one week consider face-down position (which may improve anatomical outcomes) for inferior macula off RRD. Patients are instructed not to fly with airplanes or and avoid traveling to high altitude areas above 600 meters until the gas bubble is resolved.

-Patients treated with PPV and have silicone oil tamponade should be scheduled for silicone oil removal within three to six months in noncomplex cases. However, in single eye patients with complicated retinal detachment, the removal of silicone oil depends on surgeon’s preference.

-It is mandatory to remove silicone oil in cases of increased IOP, silicone oil emulsification, and in cases that silicone oil is causing damage to the corneal endothelium.

- The most common postoperative complication is redetachment with or without PVR may be due to missed retinal breaks or reopening of the previous retinal breaks and managed with pneumatic retinopexy in non-silicone-oil filled eyes ^[28] or with fluid air exchange after subretinal fluid drainage, and then a gas or silicone oil tamponade is used depends on the case and the surgeon preference.

-Patients suffering from re detachment with subretinal silicone oil, a revision PPV with silicone oil removal, removing any tractional membranes, and treating offending retinal breaks, adding a supplementary scleral buckle depends on the case and surgeons preference. ^[29]

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These guidelines were reviewed and updated in December 2022