I. Disease definition.
Primary foraminogenic retinal detachment is defined as a retinal detachment formed on the basis of retinal fissure formation, where liquefied vitreous enters between the retinal neuroepithelium and pigment epithelium via the fissure.
II. Epidemiology and risk factors
The incidence of retinal detachment in the general population is about 1 in 10,000/year. Risk factors for the disease include.
1. Highly myopic eyes are the susceptible group.
2. History of foraminogenic retinal detachment in the other eye. The risk of retinal detachment in the other eye is at least 10% if there is retinal degeneration with predisposing factors.
3. IOL or aphakic eye: the incidence of IOL is high, about 1 to 3 percent.
Clinical manifestations
Initially, there are “flying mosquitoes” or floating objects in front of the eyes, and “flashing sensation” in a certain direction; shadows in front of the eyes obscure the vision, and when the macula is involved, the vision is obviously reduced.
Four, examination and evaluation.
Slit lamp examination: pay attention to corneal transparency, presence or absence of KP, presence or absence of floating cells in the anterior chamber, Tyndall’s sign, presence or absence of anterior and posterior adhesions in the iris, presence or absence of clouding in the crystal, and depth of the peripheral anterior chamber.
2. Routinely examine the fundus with dilated pupils to record the extent of retinal detachment, whether the macula is involved, and the vitreoretinal proliferation. Pay attention to the retinal fissure and record the fissure pattern, size and location. The presence or absence of concomitant choroidal detachment.
3. For patients who need to undergo extra-scleral surgery, the peripheral part should be carefully examined by triple-lens before surgery.
V. Classification of retinal lacunae and PVR classification
Retinal lacunae are divided into the following categories
1.Horseshoe hole: formed by vitreoretinal traction, often occurring in the lattice-like degeneration area, but also in the non-lattice-like degeneration area.
2, round hole: round, can be formed in the lattice-like degeneration area due to retinal atrophy.
3, macular fissure: divided into idiopathic macular fissure, traumatic macular fissure or myopic macular fissure.
4.Giant lacunae: lacunae over 90° are called giant lacunae, which are commonly caused by trauma.
5.Serrated edge truncation: serrated edge fissure, which is different from giant fissure: 1) usually less than 90°; 2) no rolled edge on the posterior edge of the fissure.
PVR grading.
Grade A (mild) vitreous opacity with intravitreal pigment dust or pigment clots.
Grade B (moderate) fissure posterior margin curl, retinal surface folds, retinal stiffness.
Grade C (significant) retinal whole-layer fixed folds: C1 folds occupying 1 quadrant; C2 folds occupying 2 quadrants; C3 folds occupying 3 quadrants;
Grade D (severe or extensive) retinal whole-layer fixed folds occupying 4 quadrants, retinal detachment in the shape of a funnel: D1 wide funnel; D2 narrow funnel; D3 closed funnel, no visual papillae visible.
Indications for surgery
All primary foraminogenic retinal detachments require surgical treatment.
Extra-scleral surgery is suitable for those with a fissure located in the periphery and PVRC grade 1 or less.
For retinal detachment with macular fissure or fissure posteriorly unsuitable for external pressure surgery, for those with significant refractive media clouding (such as combined cataract or significant vitreous clouding), PVRC grade 1 or higher, retinal detachment with choroidal detachment or giant fissure retinal detachment, vitreous surgery is an option.