Institutional Ethics committee approval will be obtained and trial registered with Clinical Trial Registry of India. Patients informed consent will be taken and the procedure explained to them in their own language.

During the proposed pilot phase, a group undergoing FLACS with systematic posterior capsulotomy with the Femtosecond Laser Femto LDV Z8 (Ziemer Ophthalmic Systems AG, Port, Switzerland) will be compared to a control group undergoing FLACS without posterior capsulotomy.

Study design: prospective, pilot, randomized, comparative, hospital-based, single centerinterventional clinical study

Study Population: Patients undergoing cataract surgery (FLACS) with Primary Posterior Capsulotomy with Femto LDV Z8.

Study Setting: Nethradhama Superspeciality Eye Hospital, Bangalore.

Patient selection criteria:Patients will be enrolled into the clinical study and randomized in a ratio of 1:1 in a sequential manner as per the discretion of the Investigator. The patients will also be willing to attend routine follow-up care as described below (1 day up to 6 weeks post-surgery).

Study Duration: Time frame for patient visits and examination are pre-operative, day of surgery, postoperative days 1, 14, and 45 days

Before the surgery, all patients will undergo a complete ophthalmic examination including UVCA BCVA manifest refraction, slit lamp biomicroscopy, noncontact tonometry (Topcon CT-80), and macular OCT(Optovue, Fremont, USA) AS OCT and dilated fundus examination.

Surgical procedure:

Patients will undergo monocular FLACS with the Femto LDV Z8. At random, a patient to be treated will be assigned to the control group or to the group where posterior capsulotomy will be performed using the Femto LDV Z8.

In both groups, the laser will be used to perform anterior capsulotomy and corneal incisions. The surgery algorithm up until to the point at which the IOL is implanted does not differ between the groups. The surgeon will then ensure the corneal incisions are sealing the anterior chamber. Surgeon will place a small amount of viscoelastic between the IOL and the posterior capsule to prevent IOL damage.

For those eyes assigned to the posterior capsulotomy group, the suction ring of the laser will be docked. After suction is achieved, the surgeon checks again that the corneal incision is sealed. After docking the handpiece of the Femto LDV Z8, the surgeon will grade the visibility of the anterior hyaloid on a scale from 0 to 3, where 0 corresponds to no visibility of the anterior hyaloid and 3 corresponds to excellent visibility of the entire Berger Space. The surgeon will then ensure that the cut placement of the posterior capsulotomy is in accordance with the surgical plan. In case satisfying placement of the posterior capsulotomy is not possible, suction will be aborted and the eye will drop out of the study.

After the cut, the surgeon will grade the cut quality of the posterior capsulotomy based on the following criteria:

1.     Tagging or incomplete cuts: The surgeon will grade the cut quality on a scale ranging from 0 to 3, defined the following way:

a.     Value 0 corresponds to a partial cut which is impossible to remove manually

b.     Value 1 corresponds to a circular cut with tags or uncut areas, but it is still possible to remove manually

c.     Value 2 corresponds to a complete cut with filaments.

d.     Value 3 corresponds to a complete circular cut with a free-floating posterior capsulotomy

2.     Capsulotomy Diameter Accuracy:  The surgeon measures the diameter of the posterior capsulotomy. This value will then be compared to the planned value. In case of an elliptic shape, the surgeon will measure both major axes.

3.     Edge Quality: Surgeon will grade smoothness on a scale ranging from 0 to 3, defined the following way:

a.     Grade 0 corresponds to significant irregularities with pronounced jagged or torn edges

b.     Grade 1 corresponds to moderate irregularities with some jagged edges

c.     Grade 2 corresponds to minor irregularities which will not affect the visual outcome

d.     Grade 3 corresponds to a perfectly smooth edge

Finally, the surgeon will use the irrigation/aspiration probe of the phacoemulsifier to remove the posterior capsulotomy if possible.

Method of data collection:

Data will be collected on the demographic profile (age, gender, address, and occupation) and ocular parameters of the patients, as measured by slit lamp examination, 90D lens with slit lamp, and indirect ophthalmoscopy.

Before the surgery, all patients will undergo a complete ophthalmic examination including UVCA BCVA manifest refraction, slit lamp biomicroscopy, noncontact tonometry (Topcon CT-80), and macular OCT(Optovue, Fremont, USA) AS OCT and dilated fundus examination

The following tests will be performed pre-operatively:

1.     Detailed slit lamp and dilated fundus examination

2.     Uncorrected Distance Visual Acuity (UDVA)

3.     Corrected Distance Visual Acuity (CDVA)

4.     Manifest refraction

5.     Non contact tonometry (Topcon CT-80 )

6.     Macular OCT(Optovue, Fremont, USA)

7.     AS OCT

Intra-operative data:

1.     Total Operation time- from first incision to sealing the wound

2.     Effective Phaco Time- time from start of phaco till complete nucleus removal

3.     Amount of OVD injected posterior to IOL – in ml/cc

Post-operatively on day 1, 2 weeks, 6weeks the following tests will be conducted.

1.     Slit lamp examination

2.     Uncorrected distance Visual Acuity(UDVA)

3.     Corrected Distance Visual Acuity (CDVA)

4.     Manifest refraction

5.     Non contact tonometry (Topcon CT-80 )

6.     Macular OCT(Optovue, Fremont, USA)

7.     AS OCT (MS-39)- Evaluate IOL position and tilt

8.     Dilated fundus examination was seen at 6 weeks

9.     Subjective questionnaire