Clinical manifestations of bullous keratopathy

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Clinical features of bullous keratopathy:

Clinical features of bullous keratopathy Dr Navrit kaur

Bullous keratopathy.:

Bullous keratopathy. Bullous keratopathy is a pathological condition in which there is formation of microcysts and bullae in the corneal epithelium. It follows persistant corneal oedema due to endothelial dysfunction. It is of special clinical relevance as it can occur after many clinical conditions involving endothelial layer. The endothelial dysfunction can be due to trauma, inflammations or dystrophies.

BULLOUS KERATOPATHY occurs secondary to the following conditions:- 1] Endothelial dystrophies-- as fuchs dystrophy, CHED[congenital hereditory endothelial dystrothy]. 2]Surgical trauma-- as pseudophakic or aphakic bullous keratopathy in cataract extractions, -- with IOL implantations, -- with anterior chamber lens,. -- following glaucoma surgeries. 3]Raised IOP conditions-- as in chronic glaucoma. 4]Inflammations – as in herpetic ocular diseases. 5]Immunogenic response-- in cases of graft rejection 6]Donor tissue has defective corneal endothelium in PKP. :

BULLOUS KERATOPATHY occurs secondary to the following conditions:- 1] Endothelial dystrophies- - as fuchs dystrophy, CHED[congenital hereditory endothelial dystrothy]. 2]Surgical trauma- - as pseudophakic or aphakic bullous keratopathy in cataract extractions, -- with IOL implantations, -- with anterior chamber lens,. -- following glaucoma surgeries. 3]Raised IOP conditions- - as in chronic glaucoma. 4]Inflammations – as in herpetic ocular diseases. 5]Immunogenic response- - in cases of graft rejection 6]Donor tissue has defective corneal endothelium in PKP.

Pathophysiology .:

Pathophysiology . The normal properties of cornea are modified by disease and the reaction of the cornea can be complex. In advanced cases,the development of corneal oedema if not interruped by treatment can lead to formation of painful bullous changes in the following manner:- 1.Endothelial changes- the increased permeability or decreased transport function or both in this cellular layer can lead to the subsequent corneal changes.

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- a)In cases of TRAUMATIC conditions such as - ---- pseudophakic bullous keratopathy ( or aphakic bullous keratopathy )— --- Rapid cell degeneration and death occurs which is then repaired by sliding and rearrangment of neighboring cells. ---The resulting endothelium is characterised by decreased cell number and enlarged and irregularly shaped cells showing polymegathism and pleomorphism . --- When the cell density falls below 200-400 cells/mm2 ,their pump function begins to fail and stroma begins to swell. . ---In slit lamp examination folds in the descemet`s membrane are seen.

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- 2) In DYSTROPHIC condition as in:- FUCHS DYSTROPHY – -Its slowly progressing disease seen in old age,more in females. -Abnormal production of collagenous material by the affected endothelial cell causes marked thickening of descements membrane. -It becomes studded with characteristic warts like structures called ` GUTTAE`which progress to give`beaten metal`appearenc - Epithelial edema develop when stromal thickness increases by about 30%. - persistant epithelial edema causes formation of microcysts and bullae . Following slide shows pic a]pas stained section with abnormal descement , pic ] b,c,d show the specular reflection in FED:-

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.Bullae as seen on slit lamp biomicroscopy.:

. Bullae as seen on slit lamp biomicroscopy .

a] corneal endothelium with specular reflection seen with slit lamp biomicroscopy. b]Specular microscopy in fuchs dystrophy.`Guttae` are seen.:

a] corneal endothelium with specular reflection seen with slit lamp biomicroscopy . b] Specular microscopy in fuchs dystrophy.`Guttae ` are seen.

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- -In CHED(congenital hereditory endothelial dystrophy ) -It’s a rare condition associated with scanty or absent endothelium and thickened descement`s membrane.Its of 2 types- 1) DOMINANT FORM- apoptosis or a genetic defect in cell metabolism and production of an abnormal posterior collagenous layer more typically seen here.Presents in first yr and progress upto tenth yr. 2)RECESSIVE FORM- Persistant loss of growth regulation might lead to thickened but structurally normal posterior non-branded layer. Presents at birth and doesnot progress. ( absense of ` guttae`help in differentiating it from fuchs dystrophy).

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. 3)Due to INFLAMMATIONS:-as in - herpes simplex ocular disease - focal bullous keratopathy may develop. --Pathogenesis may be due to active infection or immune response or both. -- Disciform edema of cornea develop which later becomes diffuse. -- Descemet`s folds are present in severe cases . -- Iritis and keratic precipitates are invariably present with epithelial bullae . -------The following slide shows-a]central epithelial and stromal edema b]underlying keratic precipitates.

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- 2) Stromal edema - When the ability of endothelium to maintain stromal hydration begins to falter the stromal edema develops gradually. Stroma swells in the posterior direction[corneal anterior curvature and diameter remain normal],its thickness increases mostly in center as peripheral oedema is restricted by limbus . Flattening of the posterior surface can throw descement`s membrane in multiple folds visible as straie on slit lamp examination.

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- 3)Epithelial edema - occurs resulting from endothelial dysfunction or elevated IOP or combination of both. Its predominantly extracellular. Thus fluid begins to accumulate in the space between the basal epithelial layer, stretching the bridging desmosomes .Later in the process these fluid filled spaces enlarge to form fine blisters,visible as microcystic edema . Finally layer bullae develop characteristic of bullous keratopathy . The scar tissue appears and replaces the epithelial bullae if the pathological process is not interrupted by treatment. The condition may be complicated by occurance of secondary infection .

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. CLINICAL FEATURES-- 1)Decreased vision- Initially patient have painless decreased vision especially upon waking. Vision may improve as day progress as evaporation promotes corneal deturgescence . 2) Glare and halos are noted. -As disease progresses irregular fluid accumulation occurs in the stroma which reduce transparency furthur . 4) Pain -when epithelial and sub epithelial bullae develop and rupture resulting in severe pain as under lying nerve endings are exposed. Patient is rendered susceptible to infection. 5)Erosive symptoms present as- - discomfort,foreign body sensation,photophobia and watering.

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. 6)In the end when scarring occures ,cornea is opaque and compact. -pain is decreased. -vision reduced to hand motion. -corneal sensation is decreased or absent. -peripheral corneal vasculisation may occur.

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. EVALUATION TECHNIQUES :- 1]Slit- lamp biomicroscopy -a thorough slit-lamp examination shows diffuse stromal and epithelial edema with microcysts or bullea .(Disease specific changes has already been discussed.) 2]C0rneal pachymetry (ultrasonic or optic):-measures corneal thickess .[normal:500-550 microns] -Readings exceding 650 microns suggest a higher risk for edema after intra-ocular surgery. -readings exceding 700 microns suggest corneal decompensation requiring PKP.

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. 3] Specular microscopy -demonstrates reduced endothelial cell density and abnormal morphology. Its helpful in detecting --`warts or guttae`in fuchs dystrophy, also polymegathism and pleomorphism . 4]Clinical confocal microscopy -It provides more spacial resolution and magnification at cellular and sub cellular levels. Its used to study cell layers of cornea even in edema and scarring.Thus its of great help in diagnosis of bullous keratopathy .

THANK YOU :

THANK YOU .

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