The preoperative evalution of cataract.pptx

Preoperative evaluation of cataract

1. Preoperative evaluAtion Of cataract By RA.Ritesh Roll no.169

2. Preoperative assessment ◇OCULAR HISTORY ◇SYSTEMIC HISTORY ◇OCULAR EXAMINATION ◇LABORATORY INVESTIGATION

3. Ocular history Ocular symptoms - blurring of vision diplopia , glare colored halos H/0 previous cataract surgery H/0 Previous intraocular injuries and intraocular diseases .

4. Systemic history H/0 Previous systemic diseases Diabetes mellitus Hypertension Cardiac problems , obstructive lung diseases. Urinary tract infections , septic gums etc..

5. H/0 of current medications Anticoagulants – stop prior to surgery Drug allergy - like Sulfonamide avoid it Systemic alpha blocker ( tamsulosin ) – floppy iris syndrome Long term use of steroids – delays healing

6. OCULAR EXAMINATIONS Head posture and forehead examination . Examination of LIDS : Blepharitis Ectropion , Entropion Lagophthalmos

7. LACRIMAL APPARATUS - lacrimal sac infection Lacrimal syringing - done on patient with a history of persistent watering from eyes . Dacrocystectomy - performed before cataract surgery .

8. CONJUNCTIVA: conjunctival infections Congestion Scarring , symblepharon CONJUNCTIVAL swab Culture and Sensitivity should be carried out .

9. CORNEA : examine to note any scarring Corneal guttata ( endothelial status )

10. SPECULAR MICROSCOPY EXAMINATION For Endothelial cell count and its morphology. A normal cell count in elderly patient is 2000 to 2500 cells / mm². CORNEAL PACHYMETRY : is also used to assess endothelial cell functions accurately .

11. Pupil Reacting to both direct and indirect light reactions. To check for RAPD and ability of pupil to dilate adequately before surgery . It is dialated with mydriatics .

12. Lens Lens are evaluated for morphology and maturity of cataract and for grading of nuclear sclerosis. Size of lens nucleus and grade of nuclear sclerosis is planning for size of incision and type of surgery . INTRAOCULAR PRESSURE It is measured by tonometry .Raised IOP occurs in swelling of lens , needs management.

13. VISUAL STATUS ASSESSMENT Visual Acuity : with pin hole test Perception of light Projection of light rays Potential visual Acuity tests : Pam test Laser interferometry

14. Fundus examination Retinal and optic nerve Functions are assessed by fundus examination preopertaively . Pathology such as ARMD , Retinal detachment can affect visual outcome , hence thorough fundus examination is necessary.

15. Macular function test In patient with very dense cataract, fundus examination is not possible . Two light discrimination Maddox rod test C olour Perception Ectopic visualization

16. Maddox rod test : Asking the patient to look at a distance bright light through Maddox rod . An accurate perception of red light indicates normal function .

17. Entoptic visualization : It is evaluated by rubbing a point source of light against closed eyelids . If he perceive the retinal vascular pattern , it is indication of retinal function . Color perception : it indicates presence of macular Functions and normal optic nerve .

18. B scan ultrasonography : It is important to detect any vitreous hemorrhage, Retinal detachment , intraocular tumor and posterior staphyloma. It is used in presence of dense cataract which does not allow any fundus examination .

19. BIOMETRY : It is used to calculate IOL POWER ( Intraocular lens) Formula called SRK formula ( Sanders , Retzlaff , Kraff ) . P= A – 2.5 L – 0.9 K P , power of IOL A , is constant L , Axial length of eyeball in mm K , Average Corneal curvature , by Keratometry .

20. Laboratory investigation ECG , to rule out coronary artery disesase . RBS , ( Random blood sugar ) to screen for diabetes . X ray , urine , RFT , APTT , PT INR in patients with indiual risk factors .

21. Preoperative medication Preoperative Antibiotics 4 th generation fluroquinolones - QID for 3 days before surgery to eradicate conjunctival bacterial flora . Povidone iodine solution as eye drops . IOP Lowering drugs - azetazolamide Mydriatics - topical tropicamide 1 % + phenylephrine 2.5 % every 15 minutes before surgery .