CATARACT SURGERY

A i.e. 6 weeks

A i.e. Prevents cystoid macular oedema; B i.e. Decreases endothelial damage

In ECCE (extra capsular cataract extraction) central part of anterior capsule is removed along with nucleus & cortex of lens. The posterior capsule & equatorial and peripheral part of anterior capsule are being left inside. 

A i.e. Less chances of vitreous h’ge & RD; B i.e. Decreased chances of CME 

A i.e. Nd:YAG Laser

B i.e. Nd-YAG laser

Nd. YAG (Neodymium-Yttrium-Aluminium-Garnet) laser is used for posterior capsulotomy in after cataract.Q After cataract/ Secondary cataract/ Posterior Capsular Opacification (PCO)

– It is the opacity which persists or develops after ECCE

–  It may present as thickened posterior capsule or dense membranous after cataract or Soemmering’s ringQ (thick ring of after cataract formed behind the iris, enclosed between the two layers of capsule) or Elschnig’s pearlsQ (vacuolated subcapsular epithelial cells are clustered like soap bubbles along the posterior capsule)

–  It is treated by Nd-YAG-laser posterior capsulotomyQ (Neodymium-Yttrium-Aluminium-Garnet laser) or surgical membranectomy

Retinal photocoagulation includes treatment for diabetic retinopathy, other causes of retinal neovascularization or oedema, retinal breaks, central serous retinochoroidopathy, subretinal neovascular membranes, small retinal tumors, angiomas. Argon green laser is m.c. used for this.

D i.e. Mobile surgery camps

Revised strtegies regarding catarct surgeries under NPCB

• Follow up of operated casesQ
• To shift from eye camp approach to fixed facility surgical approachQ
• To shift from conventional surgery to IOL implantation
• To improve infrastructure i.e. operation theatres, equipments
• To train surgeons in modern techniques
• To strenghthen participation of NGOs
• To target under-served areas

Ans. Within a few weeks of birth

Ans. Central posterior subcapsular lens changes

Ans. Swinging flash light test

Ans. Should be removed

Ans. Progressively improves vision

Ans. Corneal curvature

Ans. 6 weeks

Ans. Preoperative preparation with povidone iodine

Ans. C: Nucleus

This approach is contrasted with intracapsular cataract extraction (ICCE), an older procedure in which the complete lens is removed with its capsule and left the eye aphakic (without a lens).

Ans. C: Nd-YAG

Nd:YAG/ Neodymium-doped yttrium aluminium garnet/ Nd:Y3A15O12

• It is a crystal that is used as a lasing medium for solid-state lasers.
• The dopant, triply ionized neodymium, typically replaces yttrium in the crystal structure of the yttrium aluminium garnet (YAG), since they are of similar size.
• Generally the crystalline host is doped with around 1% neodymium by atomic percent.
• Nd:YAG lasers are optically pumped using a flashtube or laser diodes.
• Nd:YAG lasers typically emit light with a wavelength of 1064 nm, in the infrared.
• However, there are also transitions near 940,1120,1320, and 1440 nm.
• Nd:YAG lasers operate in both pulsed and continuous mode.
• Pulsed Nd:YAG lasers are typically operated in the so called Q-switching mode:
• Nd:YAG absorbs mostly in the bands between 730-760 nm and 790-820 nm.
• At low current densities krypton flashlamps have higher output in those bands than do the more common xenon lamps, which produce more light at around 900 nm.
• The former are therefore more efficient for pumping Nd:YAG lasers

Uses

• Nd:YAG lasers are used in ophthalmology to correct posterior capsular opacification, a condition that may occur after cataract surgery, and for peripheral iridotomy in patients with acute angle-closure glaucoma, where it has superseded surgical iridectomy.
• Frequency-doubled Nd:YAG lasers (wavelength 532 nm) are used for pan-retinal photocoagulation in patients with diabetic retinopathy.
• In oncology, Nd:YAG lasers can be used to remove skin cancers.
• These lasers are also used extensively in the field of cosmetic medicine for laser hair removal and the treatment of minor vascular defects such as spider veins on the face and legs.
• Using hysteroscopy the Nd:YAG laser has been used for removal of uterine septa within the inside of the uterus.
• In podiatry, the Nd:YAG laser is being used to treat onychomycosis, which is fungus infection of the toenail.

Ans. D: Nd:YAG laser

There are numerous ophthalmic applications for Nd:YAG lasers.

• They are most commonly used to treat posterior capsular opacification after cataract surgery
• To create a peripheral iridotomy in patients with narrow angles or angle-closure glaucoma.
• YAG lasers can also be used to cut the anterior capsule for capsular block syndrome and capsular phimosis
• To cut vitreous strands in the anterior chamber.
• In malignant glaucoma, disruption of the anterior hyaloid face is performed with the YAG laser
• In refractory glaucomas, these lasers can be used for cyclophotoablation of the ciliary body.
• They have also been helpful for draining premacular subhyaloid hemorrhages in patients with Valsalva retinopathy.
• Panretinal photocoagulation can be performed with frequency-doubled Nd:YAG lasers.

Other applications include the treatment of recurrent corneal erosions and vitreous floaters.

Excimer (Argon fluoride) laser is used in photorefractive keratectomy (PRK), phototherapeutic keratectomy (PTK), LASIK, LASEK

Argon green laser is used in trabeculoplasty, iridoplasty, pupillomydriasis and retinal photocoagulation Diode laser is used in retinal photocoagulation

Ans. is ‘c’ i.e., Posterior capsulectomy

Surgery for congenital or developmental cataract

• Cataract surgery is the treatment of choice for congenital and developmental cataract.
• Extracapsular cataract extraction (extracapsular removal of the cataractous lens) is the surgery of choice.This is done by phacoemulsification.
• Intracapsular cataract extraction (ICCE) in children is contraindicated because of vitreous traction and loss at the wieger capsulohyaloid ligament
• Method for extracapsular cataract extration are :-

1. Posterior capsulectomy and anterior vitrectomy (Procedure of choice). This can be done via limbal or pars plana approach.
2. Lens aspiration
3. Lensectony

• The traditional treatment of needling or discission of congenital cataract are obsolete now.
• After removal of cataractous lens, the resultant aphakia in children is treated by : –

1. If child is < 2 years → Contact lens
2. If child is > 2 years → Intraocular lens implantation

Ans. c. 1 service center for 5,00,000 population

According to Vision 2020, the recommendations for secondary care services including cataract surgery is 1 service center for 5,00,000 population.

• ‘Vision 2020’: The Right to Sight, is a global initiative launched by WHO in 1999 in a broad coalition with a ‘Task Force of International Non-Governmental Organizations (NG0s)’ to combat the gigantic problem of blindness in the world.
• Government of India has adopted ‘Vision 2020: Right to Sight’ under National Programme for Control of Blindness
• There is need to develop 2000 service centres at secondary level. Each with 2 Ophthalmologist and 8 paramedics (Hospital based MLOP), and one eye care manager covering a population of 5 Lacs

Ans. is ‘a’ i.e., Antibiotics 

Perioperative measures toprevent infection

• The most important source of potential infectious organisms is the patient’s own natural conjunctival and skin flora. So, prophylactic antibiotic should adequately cover these organisms. The pre- operative topical antibi­otic should be started 3 days prior to surgery. Preferred antibiotics are fourth generation fluoroquinolones (gatifloxacin, moxifloxacin). Other antibiotics are aminoglycosides, traditional fluoroquinolones (ciprofloxacin, levofloxacin) and gramicidin- neomycin – polymyxin B combination.
• Never the less, complete conjunctival sterility is not usually possible with the use of preoperative antibiotics alone. The topical antiseptic povidone iodine 5% instilled as a single drop 10- 30 minutes before surgery is one of the most effective measure to decrease this bacterial flora.
• Intraoperatively, a large portion of surgeons (66.4%) also use subconjunctival antibiotic. Intracameral antibiotic at the end of surgery showed significant benefit in reducing the rate of bacterial endophthalmitis. 
• Post- operatively topical antibiotics (eye drops) are given along with steroids for 10 -14 days.

Ans. is ‘a’ i.e., ECCE 

Surgery for congenital or developmental cataract

• Cataract surgery is the treatment of choice for congenital and developmental cataract.
• Extracapsular cataract extraction (extracapsular removal of the cataractous lens) is the surgery of choice.This is done by phacoemulsification.
• Intracapsular cataract extraction (ICCE) in children is contraindicated because of vitreous traction and loss at the wieger capsulohyaloid ligament

Method for extracapsular cataract extration are :-

1. Posterior capsulectomy and anterior vitrectomy (Procedure of choice). This can be done via limbal or pars plana approach.
2. Lens aspiration
3. Lensectony

• The traditional treatment of needling or discission of congenital cataract are obsolete now.
• After removal of cataractous lens, the resultant aphakia in children is treated by : –

1. If child is < 2 years → Contact lens
2. If child is > 2 years  →Intraocular lens implantation