Comparative Analysis of Pupillary Constriction in Femto-Second Laser-Assisted Cataract Surgery (FLACS) vs Pre-Operative Intravenous Dexamethasone Injection: A Prospective Randomized Study

Materialand Method:

• Study Type: Prospective, randomized, controlled clinical trial.
• Place of Study: The study will be conducted at NETHRADHAMA super speciality eye hospital.

Durationof study: 12 months to allow for adequate data collection,including preoperative, intraoperative, and postoperative assessments

EQUIPMENTS TO BE USED-

1.     Snellen’svisual acuity charts

2.     Retinoscope(Heine)

3.     NonContact Tonometer (Topcon CT80 USA)

4.     Slitlamp (Topcon)

5.     4-mirrorGonioscope (volk)

6.     Direct& Indirect ophthalmoscope (Heine)

7.    Zeiss IOL master 700.

8.    ZEISS Quatera 700

9.    Lensar Laser System or Ziemer Z8

10.  Carl ZeissCallisto

1. Randomization and Group Assignment:

• Participants will be randomly assigned into two groups:

• Group 1 (Intervention group): FLACS with preoperative IV dexamethasone injection 2ml (4mg/1ml) administered 30 minutes before surgery.

• Group 2 (Control group): FLACS without the administration of IV dexamethasone injection.

 2.Preoperative Assessments:

• Complete Ocular Examination: Including best-corrected visual acuity (BCVA), slit-lamp bio microscopy, tonometry and dilated fundus examination.
• Pupillary Reaction Assessment: Baseline pupillary size and reactivity to light will be recorded under standard illumination conditions (e.g., dim light and bright light) using Zeiss IOL master 700.
• Pentacam: Preoperative corneal topography and pachymetry.
• Biometry: Anterior segment biometry will be assessed to ensure eligibility for FLACS using IOL Master 700.

  3.Intraoperative Procedures:

• All patients will undergo FLACS with implantation of foldable IOL under topical anaesthesia.
• All surgeries will be performed by single experienced surgeon using Lensar laser system or Zeimer Z8 and Zeiss Quatera 700.
• All surgeries will be performed in Nethradhama super speciality hospital, Jayanagar. Banglore, India.

 Routinepreoperative mydriatic treatment consisting of tropicamide 0.8% andphenylephrine 5% eye drops (Itrop plus E/D), four times in the interval of 15minutes 1 hour prior to surgery will be instilled. Group 1 patients will be given2ml (4mg/1ml) intravenous injection of dexamethasone, 30 minutes prior tosurgery. Surgery will be performed under topical anaesthesia, proparacainehydrochloride 0.5% (E/D Paracain). After the eye is painted with 5% povidoneiodine solution and sterile draping, patient is shifted under Lensar lasersystem or Zeimer Z8. The femtosecond laser interface will be docked, and vacuumsuction will be applied. Standard laser parameters will be a 6 mm diameterlaser lens fragmentation in six segments, followed by a 5 mm diametercapsulotomy will be made. A superior main incision of 2.8 mm width and two 1.1mm paracenteses will be made with Femto Second Laser. Photographs will be takenin Lensar laser system/Zeimer Z8 to record the pupillary size before and afterevery steps performed during laser pretreatment.

Patient willbe shifted to Zeiss Quatera 700 without any delay to continue the rest of theprocedure. Photographs of pupil size will be taken with Callisto software (ZeisMeditec AG) at the beginning of procedure. Incisions will be opened with ablunt dissector. Viscoelastic will be injected into the anterior chamber. Thelaser-precut capsulotomy will be removed using Utrata forceps. The lens will behydrodissected from the capsule. The nucleus will be removed usingphacoemulsification. Cortex aspiration, hydro polishing of the posteriorcapsule, and removal of the viscoelastic substance will be performed usingirrigation aspiration system followed by implantation of the foldable intraocularlens in the capsular bag. At the end of surgery, the paracenteses will be hydratedand anterior chamber will be formed. Pupillary size will be measured at thebeginning and in the end of the procedure with Zeiss Callisto software.

 4.Postoperative Assessments:

• Immediate Postoperative Pupillary Assesment: Pupillary size will be assessed immediately postoperatively.
• Inflammation and Intraocular Pressure: Anterior chamber inflammation will be checked in slit lamp (SUN Classification) and IOP measurements with NCT will be taken at follow-up visit of Day1, Day 14 and 3months)
• Visual Acuity: Postoperative UCVA, and BCVA at 2 weeks, and 3 months post-surgery.
• Complications: The presence of complications such as corneal edema, posterior capsular rupture, or other surgical issues will be recorded.

5. OutcomeMeasures:

• Primary Outcome: The degree of pupillary constriction at various intraoperative stages.

• Metric: Pupillary size at different stages (before and after femtosecond laser capsulotomy, during and after phacoemulsification).

• Secondary Outcomes:

• Postoperative Inflammation and IOP: Anterior chamber inflammation and IOP measurements.

• Postoperative Complications: Incidence of complications such as corneal edema, pupillary abnormalities, or posterior capsular rupture.